term, $object_ids );

	/**
	 * Fires after a term in a specific taxonomy is deleted.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the specific
	 * taxonomy the term belonged to.
	 *
	 * Possible hook names include:
	 *
	 *  - `delete_category`
	 *  - `delete_post_tag`
	 *
	 * @since 2.3.0
	 * @since 4.5.0 Introduced the `$object_ids` argument.
	 *
	 * @param int     $term         Term ID.
	 * @param int     $tt_id        Term taxonomy ID.
	 * @param WP_Term $deleted_term Copy of the already-deleted term.
	 * @param array   $object_ids   List of term object IDs.
	 */
	do_action( "delete_{$taxonomy}", $term, $tt_id, $deleted_term, $object_ids );

	return true;
}

/**
 * Deletes one existing category.
 *
 * @since 2.0.0
 *
 * @param int $cat_id Category term ID.
 * @return bool|int|WP_Error Returns true if completes delete action; false if term doesn't exist;
 *                           Zero on attempted deletion of default Category; WP_Error object is
 *                           also a possibility.
 */
function wp_delete_category( $cat_id ) {
	return wp_delete_term( $cat_id, 'category' );
}

/**
 * Retrieves the terms associated with the given object(s), in the supplied taxonomies.
 *
 * @since 2.3.0
 * @since 4.2.0 Added support for 'taxonomy', 'parent', and 'term_taxonomy_id' values of `$orderby`.
 *              Introduced `$parent` argument.
 * @since 4.4.0 Introduced `$meta_query` and `$update_term_meta_cache` arguments. When `$fields` is 'all' or
 *              'all_with_object_id', an array of `WP_Term` objects will be returned.
 * @since 4.7.0 Refactored to use WP_Term_Query, and to support any WP_Term_Query arguments.
 *
 * @param int|int[]       $object_ids The ID(s) of the object(s) to retrieve.
 * @param string|string[] $taxonomies The taxonomy names to retrieve terms from.
 * @param array|string    $args       See WP_Term_Query::__construct() for supported arguments.
 * @return WP_Term[]|int[]|string[]|string|WP_Error Array of terms, a count thereof as a numeric string,
 *                                                  or WP_Error if any of the taxonomies do not exist.
 *                                                  See WP_Term_Query::get_terms() for more information.
 */
function wp_get_object_terms( $object_ids, $taxonomies, $args = array() ) {
	if ( empty( $object_ids ) || empty( $taxonomies ) ) {
		return array();
	}

	if ( ! is_array( $taxonomies ) ) {
		$taxonomies = array( $taxonomies );
	}

	foreach ( $taxonomies as $taxonomy ) {
		if ( ! taxonomy_exists( $taxonomy ) ) {
			return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
		}
	}

	if ( ! is_array( $object_ids ) ) {
		$object_ids = array( $object_ids );
	}
	$object_ids = array_map( 'intval', $object_ids );

	$args = wp_parse_args( $args );

	/**
	 * Filters arguments for retrieving object terms.
	 *
	 * @since 4.9.0
	 *
	 * @param array    $args       An array of arguments for retrieving terms for the given object(s).
	 *                             See {@see wp_get_object_terms()} for details.
	 * @param int[]    $object_ids Array of object IDs.
	 * @param string[] $taxonomies Array of taxonomy names to retrieve terms from.
	 */
	$args = apply_filters( 'wp_get_object_terms_args', $args, $object_ids, $taxonomies );

	/*
	 * When one or more queried taxonomies is registered with an 'args' array,
	 * those params override the `$args` passed to this function.
	 */
	$terms = array();
	if ( count( $taxonomies ) > 1 ) {
		foreach ( $taxonomies as $index => $taxonomy ) {
			$t = get_taxonomy( $taxonomy );
			if ( isset( $t->args ) && is_array( $t->args ) && array_merge( $args, $t->args ) != $args ) {
				unset( $taxonomies[ $index ] );
				$terms = array_merge( $terms, wp_get_object_terms( $object_ids, $taxonomy, array_merge( $args, $t->args ) ) );
			}
		}
	} else {
		$t = get_taxonomy( $taxonomies[0] );
		if ( isset( $t->args ) && is_array( $t->args ) ) {
			$args = array_merge( $args, $t->args );
		}
	}

	$args['taxonomy']   = $taxonomies;
	$args['object_ids'] = $object_ids;

	// Taxonomies registered without an 'args' param are handled here.
	if ( ! empty( $taxonomies ) ) {
		$terms_from_remaining_taxonomies = get_terms( $args );

		// Array keys should be preserved for values of $fields that use term_id for keys.
		if ( ! empty( $args['fields'] ) && 0 === strpos( $args['fields'], 'id=>' ) ) {
			$terms = $terms + $terms_from_remaining_taxonomies;
		} else {
			$terms = array_merge( $terms, $terms_from_remaining_taxonomies );
		}
	}

	/**
	 * Filters the terms for a given object or objects.
	 *
	 * @since 4.2.0
	 *
	 * @param WP_Term[]|int[]|string[]|string $terms      Array of terms or a count thereof as a numeric string.
	 * @param int[]                           $object_ids Array of object IDs for which terms were retrieved.
	 * @param string[]                        $taxonomies Array of taxonomy names from which terms were retrieved.
	 * @param array                           $args       Array of arguments for retrieving terms for the given
	 *                                                    object(s). See wp_get_object_terms() for details.
	 */
	$terms = apply_filters( 'get_object_terms', $terms, $object_ids, $taxonomies, $args );

	$object_ids = implode( ',', $object_ids );
	$taxonomies = "'" . implode( "', '", array_map( 'esc_sql', $taxonomies ) ) . "'";

	/**
	 * Filters the terms for a given object or objects.
	 *
	 * The `$taxonomies` parameter passed to this filter is formatted as a SQL fragment. The
	 * {@see 'get_object_terms'} filter is recommended as an alternative.
	 *
	 * @since 2.8.0
	 *
	 * @param WP_Term[]|int[]|string[]|string $terms      Array of terms or a count thereof as a numeric string.
	 * @param string                          $object_ids Comma separated list of object IDs for which terms were retrieved.
	 * @param string                          $taxonomies SQL fragment of taxonomy names from which terms were retrieved.
	 * @param array                           $args       Array of arguments for retrieving terms for the given
	 *                                                    object(s). See wp_get_object_terms() for details.
	 */
	return apply_filters( 'wp_get_object_terms', $terms, $object_ids, $taxonomies, $args );
}

/**
 * Adds a new term to the database.
 *
 * A non-existent term is inserted in the following sequence:
 * 1. The term is added to the term table, then related to the taxonomy.
 * 2. If everything is correct, several actions are fired.
 * 3. The 'term_id_filter' is evaluated.
 * 4. The term cache is cleaned.
 * 5. Several more actions are fired.
 * 6. An array is returned containing the `term_id` and `term_taxonomy_id`.
 *
 * If the 'slug' argument is not empty, then it is checked to see if the term
 * is invalid. If it is not a valid, existing term, it is added and the term_id
 * is given.
 *
 * If the taxonomy is hierarchical, and the 'parent' argument is not empty,
 * the term is inserted and the term_id will be given.
 *
 * Error handling:
 * If `$taxonomy` does not exist or `$term` is empty,
 * a WP_Error object will be returned.
 *
 * If the term already exists on the same hierarchical level,
 * or the term slug and name are not unique, a WP_Error object will be returned.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 2.3.0
 *
 * @param string       $term     The term name to add.
 * @param string       $taxonomy The taxonomy to which to add the term.
 * @param array|string $args {
 *     Optional. Array or query string of arguments for inserting a term.
 *
 *     @type string $alias_of    Slug of the term to make this term an alias of.
 *                               Default empty string. Accepts a term slug.
 *     @type string $description The term description. Default empty string.
 *     @type int    $parent      The id of the parent term. Default 0.
 *     @type string $slug        The term slug to use. Default empty string.
 * }
 * @return array|WP_Error {
 *     An array of the new term data, WP_Error otherwise.
 *
 *     @type int        $term_id          The new term ID.
 *     @type int|string $term_taxonomy_id The new term taxonomy ID. Can be a numeric string.
 * }
 */
function wp_insert_term( $term, $taxonomy, $args = array() ) {
	global $wpdb;

	if ( ! taxonomy_exists( $taxonomy ) ) {
		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
	}

	/**
	 * Filters a term before it is sanitized and inserted into the database.
	 *
	 * @since 3.0.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param string|WP_Error $term     The term name to add, or a WP_Error object if there's an error.
	 * @param string          $taxonomy Taxonomy slug.
	 * @param array|string    $args     Array or query string of arguments passed to wp_insert_term().
	 */
	$term = apply_filters( 'pre_insert_term', $term, $taxonomy, $args );

	if ( is_wp_error( $term ) ) {
		return $term;
	}

	if ( is_int( $term ) && 0 === $term ) {
		return new WP_Error( 'invalid_term_id', __( 'Invalid term ID.' ) );
	}

	if ( '' === trim( $term ) ) {
		return new WP_Error( 'empty_term_name', __( 'A name is required for this term.' ) );
	}

	$defaults = array(
		'alias_of'    => '',
		'description' => '',
		'parent'      => 0,
		'slug'        => '',
	);
	$args     = wp_parse_args( $args, $defaults );

	if ( (int) $args['parent'] > 0 && ! term_exists( (int) $args['parent'] ) ) {
		return new WP_Error( 'missing_parent', __( 'Parent term does not exist.' ) );
	}

	$args['name']     = $term;
	$args['taxonomy'] = $taxonomy;

	// Coerce null description to strings, to avoid database errors.
	$args['description'] = (string) $args['description'];

	$args = sanitize_term( $args, $taxonomy, 'db' );

	// expected_slashed ($name)
	$name        = wp_unslash( $args['name'] );
	$description = wp_unslash( $args['description'] );
	$parent      = (int) $args['parent'];

	$slug_provided = ! empty( $args['slug'] );
	if ( ! $slug_provided ) {
		$slug = sanitize_title( $name );
	} else {
		$slug = $args['slug'];
	}

	$term_group = 0;
	if ( $args['alias_of'] ) {
		$alias = get_term_by( 'slug', $args['alias_of'], $taxonomy );
		if ( ! empty( $alias->term_group ) ) {
			// The alias we want is already in a group, so let's use that one.
			$term_group = $alias->term_group;
		} elseif ( ! empty( $alias->term_id ) ) {
			/*
			 * The alias is not in a group, so we create a new one
			 * and add the alias to it.
			 */
			$term_group = $wpdb->get_var( "SELECT MAX(term_group) FROM $wpdb->terms" ) + 1;

			wp_update_term(
				$alias->term_id,
				$taxonomy,
				array(
					'term_group' => $term_group,
				)
			);
		}
	}

	/*
	 * Prevent the creation of terms with duplicate names at the same level of a taxonomy hierarchy,
	 * unless a unique slug has been explicitly provided.
	 */
	$name_matches = get_terms(
		array(
			'taxonomy'               => $taxonomy,
			'name'                   => $name,
			'hide_empty'             => false,
			'parent'                 => $args['parent'],
			'update_term_meta_cache' => false,
		)
	);

	/*
	 * The `name` match in `get_terms()` doesn't differentiate accented characters,
	 * so we do a stricter comparison here.
	 */
	$name_match = null;
	if ( $name_matches ) {
		foreach ( $name_matches as $_match ) {
			if ( strtolower( $name ) === strtolower( $_match->name ) ) {
				$name_match = $_match;
				break;
			}
		}
	}

	if ( $name_match ) {
		$slug_match = get_term_by( 'slug', $slug, $taxonomy );
		if ( ! $slug_provided || $name_match->slug === $slug || $slug_match ) {
			if ( is_taxonomy_hierarchical( $taxonomy ) ) {
				$siblings = get_terms(
					array(
						'taxonomy'               => $taxonomy,
						'get'                    => 'all',
						'parent'                 => $parent,
						'update_term_meta_cache' => false,
					)
				);

				$existing_term = null;
				$sibling_names = wp_list_pluck( $siblings, 'name' );
				$sibling_slugs = wp_list_pluck( $siblings, 'slug' );

				if ( ( ! $slug_provided || $name_match->slug === $slug ) && in_array( $name, $sibling_names, true ) ) {
					$existing_term = $name_match;
				} elseif ( $slug_match && in_array( $slug, $sibling_slugs, true ) ) {
					$existing_term = $slug_match;
				}

				if ( $existing_term ) {
					return new WP_Error( 'term_exists', __( 'A term with the name provided already exists with this parent.' ), $existing_term->term_id );
				}
			} else {
				return new WP_Error( 'term_exists', __( 'A term with the name provided already exists in this taxonomy.' ), $name_match->term_id );
			}
		}
	}

	$slug = wp_unique_term_slug( $slug, (object) $args );

	$data = compact( 'name', 'slug', 'term_group' );

	/**
	 * Filters term data before it is inserted into the database.
	 *
	 * @since 4.7.0
	 *
	 * @param array  $data     Term data to be inserted.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_insert_term().
	 */
	$data = apply_filters( 'wp_insert_term_data', $data, $taxonomy, $args );

	if ( false === $wpdb->insert( $wpdb->terms, $data ) ) {
		return new WP_Error( 'db_insert_error', __( 'Could not insert term into the database.' ), $wpdb->last_error );
	}

	$term_id = (int) $wpdb->insert_id;

	// Seems unreachable. However, is used in the case that a term name is provided, which sanitizes to an empty string.
	if ( empty( $slug ) ) {
		$slug = sanitize_title( $slug, $term_id );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edit_terms', $term_id, $taxonomy );
		$wpdb->update( $wpdb->terms, compact( 'slug' ), compact( 'term_id' ) );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edited_terms', $term_id, $taxonomy );
	}

	$tt_id = $wpdb->get_var( $wpdb->prepare( "SELECT tt.term_taxonomy_id FROM $wpdb->term_taxonomy AS tt INNER JOIN $wpdb->terms AS t ON tt.term_id = t.term_id WHERE tt.taxonomy = %s AND t.term_id = %d", $taxonomy, $term_id ) );

	if ( ! empty( $tt_id ) ) {
		return array(
			'term_id'          => $term_id,
			'term_taxonomy_id' => $tt_id,
		);
	}

	if ( false === $wpdb->insert( $wpdb->term_taxonomy, compact( 'term_id', 'taxonomy', 'description', 'parent' ) + array( 'count' => 0 ) ) ) {
		return new WP_Error( 'db_insert_error', __( 'Could not insert term taxonomy into the database.' ), $wpdb->last_error );
	}

	$tt_id = (int) $wpdb->insert_id;

	/*
	 * Sanity check: if we just created a term with the same parent + taxonomy + slug but a higher term_id than
	 * an existing term, then we have unwittingly created a duplicate term. Delete the dupe, and use the term_id
	 * and term_taxonomy_id of the older term instead. Then return out of the function so that the "create" hooks
	 * are not fired.
	 */
	$duplicate_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.term_id, t.slug, tt.term_taxonomy_id, tt.taxonomy FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON ( tt.term_id = t.term_id ) WHERE t.slug = %s AND tt.parent = %d AND tt.taxonomy = %s AND t.term_id < %d AND tt.term_taxonomy_id != %d", $slug, $parent, $taxonomy, $term_id, $tt_id ) );

	/**
	 * Filters the duplicate term check that takes place during term creation.
	 *
	 * Term parent + taxonomy + slug combinations are meant to be unique, and wp_insert_term()
	 * performs a last-minute confirmation of this uniqueness before allowing a new term
	 * to be created. Plugins with different uniqueness requirements may use this filter
	 * to bypass or modify the duplicate-term check.
	 *
	 * @since 5.1.0
	 *
	 * @param object $duplicate_term Duplicate term row from terms table, if found.
	 * @param string $term           Term being inserted.
	 * @param string $taxonomy       Taxonomy name.
	 * @param array  $args           Arguments passed to wp_insert_term().
	 * @param int    $tt_id          term_taxonomy_id for the newly created term.
	 */
	$duplicate_term = apply_filters( 'wp_insert_term_duplicate_term_check', $duplicate_term, $term, $taxonomy, $args, $tt_id );

	if ( $duplicate_term ) {
		$wpdb->delete( $wpdb->terms, array( 'term_id' => $term_id ) );
		$wpdb->delete( $wpdb->term_taxonomy, array( 'term_taxonomy_id' => $tt_id ) );

		$term_id = (int) $duplicate_term->term_id;
		$tt_id   = (int) $duplicate_term->term_taxonomy_id;

		clean_term_cache( $term_id, $taxonomy );
		return array(
			'term_id'          => $term_id,
			'term_taxonomy_id' => $tt_id,
		);
	}

	/**
	 * Fires immediately after a new term is created, before the term cache is cleaned.
	 *
	 * The {@see 'create_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_insert_term().
	 */
	do_action( 'create_term', $term_id, $tt_id, $taxonomy, $args );

	/**
	 * Fires after a new term is created for a specific taxonomy.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers
	 * to the slug of the taxonomy the term was created for.
	 *
	 * Possible hook names include:
	 *
	 *  - `create_category`
	 *  - `create_post_tag`
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param array $args    Arguments passed to wp_insert_term().
	 */
	do_action( "create_{$taxonomy}", $term_id, $tt_id, $args );

	/**
	 * Filters the term ID after a new term is created.
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param array $args    Arguments passed to wp_insert_term().
	 */
	$term_id = apply_filters( 'term_id_filter', $term_id, $tt_id, $args );

	clean_term_cache( $term_id, $taxonomy );

	/**
	 * Fires after a new term is created, and after the term cache has been cleaned.
	 *
	 * The {@see 'created_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_insert_term().
	 */
	do_action( 'created_term', $term_id, $tt_id, $taxonomy, $args );

	/**
	 * Fires after a new term in a specific taxonomy is created, and after the term
	 * cache has been cleaned.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `created_category`
	 *  - `created_post_tag`
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param array $args    Arguments passed to wp_insert_term().
	 */
	do_action( "created_{$taxonomy}", $term_id, $tt_id, $args );

	/**
	 * Fires after a term has been saved, and the term cache has been cleared.
	 *
	 * The {@see 'saved_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 5.5.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param bool   $update   Whether this is an existing term being updated.
	 * @param array  $args     Arguments passed to wp_insert_term().
	 */
	do_action( 'saved_term', $term_id, $tt_id, $taxonomy, false, $args );

	/**
	 * Fires after a term in a specific taxonomy has been saved, and the term
	 * cache has been cleared.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `saved_category`
	 *  - `saved_post_tag`
	 *
	 * @since 5.5.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param bool  $update  Whether this is an existing term being updated.
	 * @param array $args    Arguments passed to wp_insert_term().
	 */
	do_action( "saved_{$taxonomy}", $term_id, $tt_id, false, $args );

	return array(
		'term_id'          => $term_id,
		'term_taxonomy_id' => $tt_id,
	);
}

/**
 * Creates term and taxonomy relationships.
 *
 * Relates an object (post, link, etc.) to a term and taxonomy type. Creates the
 * term and taxonomy relationship if it doesn't already exist. Creates a term if
 * it doesn't exist (using the slug).
 *
 * A relationship means that the term is grouped in or belongs to the taxonomy.
 * A term has no meaning until it is given context by defining which taxonomy it
 * exists under.
 *
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int              $object_id The object to relate to.
 * @param string|int|array $terms     A single term slug, single term ID, or array of either term slugs or IDs.
 *                                    Will replace all existing related terms in this taxonomy. Passing an
 *                                    empty value will remove all related terms.
 * @param string           $taxonomy  The context in which to relate the term to the object.
 * @param bool             $append    Optional. If false will delete difference of terms. Default false.
 * @return array|WP_Error Term taxonomy IDs of the affected terms or WP_Error on failure.
 */
function wp_set_object_terms( $object_id, $terms, $taxonomy, $append = false ) {
	global $wpdb;

	$object_id = (int) $object_id;

	if ( ! taxonomy_exists( $taxonomy ) ) {
		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
	}

	if ( ! is_array( $terms ) ) {
		$terms = array( $terms );
	}

	if ( ! $append ) {
		$old_tt_ids = wp_get_object_terms(
			$object_id,
			$taxonomy,
			array(
				'fields'                 => 'tt_ids',
				'orderby'                => 'none',
				'update_term_meta_cache' => false,
			)
		);
	} else {
		$old_tt_ids = array();
	}

	$tt_ids     = array();
	$term_ids   = array();
	$new_tt_ids = array();

	foreach ( (array) $terms as $term ) {
		if ( '' === trim( $term ) ) {
			continue;
		}

		$term_info = term_exists( $term, $taxonomy );

		if ( ! $term_info ) {
			// Skip if a non-existent term ID is passed.
			if ( is_int( $term ) ) {
				continue;
			}

			$term_info = wp_insert_term( $term, $taxonomy );
		}

		if ( is_wp_error( $term_info ) ) {
			return $term_info;
		}

		$term_ids[] = $term_info['term_id'];
		$tt_id      = $term_info['term_taxonomy_id'];
		$tt_ids[]   = $tt_id;

		if ( $wpdb->get_var( $wpdb->prepare( "SELECT term_taxonomy_id FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id = %d", $object_id, $tt_id ) ) ) {
			continue;
		}

		/**
		 * Fires immediately before an object-term relationship is added.
		 *
		 * @since 2.9.0
		 * @since 4.7.0 Added the `$taxonomy` parameter.
		 *
		 * @param int    $object_id Object ID.
		 * @param int    $tt_id     Term taxonomy ID.
		 * @param string $taxonomy  Taxonomy slug.
		 */
		do_action( 'add_term_relationship', $object_id, $tt_id, $taxonomy );

		$wpdb->insert(
			$wpdb->term_relationships,
			array(
				'object_id'        => $object_id,
				'term_taxonomy_id' => $tt_id,
			)
		);

		/**
		 * Fires immediately after an object-term relationship is added.
		 *
		 * @since 2.9.0
		 * @since 4.7.0 Added the `$taxonomy` parameter.
		 *
		 * @param int    $object_id Object ID.
		 * @param int    $tt_id     Term taxonomy ID.
		 * @param string $taxonomy  Taxonomy slug.
		 */
		do_action( 'added_term_relationship', $object_id, $tt_id, $taxonomy );

		$new_tt_ids[] = $tt_id;
	}

	if ( $new_tt_ids ) {
		wp_update_term_count( $new_tt_ids, $taxonomy );
	}

	if ( ! $append ) {
		$delete_tt_ids = array_diff( $old_tt_ids, $tt_ids );

		if ( $delete_tt_ids ) {
			$in_delete_tt_ids = "'" . implode( "', '", $delete_tt_ids ) . "'";
			$delete_term_ids  = $wpdb->get_col( $wpdb->prepare( "SELECT tt.term_id FROM $wpdb->term_taxonomy AS tt WHERE tt.taxonomy = %s AND tt.term_taxonomy_id IN ($in_delete_tt_ids)", $taxonomy ) );
			$delete_term_ids  = array_map( 'intval', $delete_term_ids );

			$remove = wp_remove_object_terms( $object_id, $delete_term_ids, $taxonomy );
			if ( is_wp_error( $remove ) ) {
				return $remove;
			}
		}
	}

	$t = get_taxonomy( $taxonomy );

	if ( ! $append && isset( $t->sort ) && $t->sort ) {
		$values     = array();
		$term_order = 0;

		$final_tt_ids = wp_get_object_terms(
			$object_id,
			$taxonomy,
			array(
				'fields'                 => 'tt_ids',
				'update_term_meta_cache' => false,
			)
		);

		foreach ( $tt_ids as $tt_id ) {
			if ( in_array( (int) $tt_id, $final_tt_ids, true ) ) {
				$values[] = $wpdb->prepare( '(%d, %d, %d)', $object_id, $tt_id, ++$term_order );
			}
		}

		if ( $values ) {
			if ( false === $wpdb->query( "INSERT INTO $wpdb->term_relationships (object_id, term_taxonomy_id, term_order) VALUES " . implode( ',', $values ) . ' ON DUPLICATE KEY UPDATE term_order = VALUES(term_order)' ) ) {
				return new WP_Error( 'db_insert_error', __( 'Could not insert term relationship into the database.' ), $wpdb->last_error );
			}
		}
	}

	wp_cache_delete( $object_id, $taxonomy . '_relationships' );
	wp_cache_delete( 'last_changed', 'terms' );

	/**
	 * Fires after an object's terms have been set.
	 *
	 * @since 2.8.0
	 *
	 * @param int    $object_id  Object ID.
	 * @param array  $terms      An array of object term IDs or slugs.
	 * @param array  $tt_ids     An array of term taxonomy IDs.
	 * @param string $taxonomy   Taxonomy slug.
	 * @param bool   $append     Whether to append new terms to the old terms.
	 * @param array  $old_tt_ids Old array of term taxonomy IDs.
	 */
	do_action( 'set_object_terms', $object_id, $terms, $tt_ids, $taxonomy, $append, $old_tt_ids );

	return $tt_ids;
}

/**
 * Adds term(s) associated with a given object.
 *
 * @since 3.6.0
 *
 * @param int              $object_id The ID of the object to which the terms will be added.
 * @param string|int|array $terms     The slug(s) or ID(s) of the term(s) to add.
 * @param array|string     $taxonomy  Taxonomy name.
 * @return array|WP_Error Term taxonomy IDs of the affected terms.
 */
function wp_add_object_terms( $object_id, $terms, $taxonomy ) {
	return wp_set_object_terms( $object_id, $terms, $taxonomy, true );
}

/**
 * Removes term(s) associated with a given object.
 *
 * @since 3.6.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int              $object_id The ID of the object from which the terms will be removed.
 * @param string|int|array $terms     The slug(s) or ID(s) of the term(s) to remove.
 * @param string           $taxonomy  Taxonomy name.
 * @return bool|WP_Error True on success, false or WP_Error on failure.
 */
function wp_remove_object_terms( $object_id, $terms, $taxonomy ) {
	global $wpdb;

	$object_id = (int) $object_id;

	if ( ! taxonomy_exists( $taxonomy ) ) {
		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
	}

	if ( ! is_array( $terms ) ) {
		$terms = array( $terms );
	}

	$tt_ids = array();

	foreach ( (array) $terms as $term ) {
		if ( '' === trim( $term ) ) {
			continue;
		}

		$term_info = term_exists( $term, $taxonomy );
		if ( ! $term_info ) {
			// Skip if a non-existent term ID is passed.
			if ( is_int( $term ) ) {
				continue;
			}
		}

		if ( is_wp_error( $term_info ) ) {
			return $term_info;
		}

		$tt_ids[] = $term_info['term_taxonomy_id'];
	}

	if ( $tt_ids ) {
		$in_tt_ids = "'" . implode( "', '", $tt_ids ) . "'";

		/**
		 * Fires immediately before an object-term relationship is deleted.
		 *
		 * @since 2.9.0
		 * @since 4.7.0 Added the `$taxonomy` parameter.
		 *
		 * @param int    $object_id Object ID.
		 * @param array  $tt_ids    An array of term taxonomy IDs.
		 * @param string $taxonomy  Taxonomy slug.
		 */
		do_action( 'delete_term_relationships', $object_id, $tt_ids, $taxonomy );

		$deleted = $wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id IN ($in_tt_ids)", $object_id ) );

		wp_cache_delete( $object_id, $taxonomy . '_relationships' );
		wp_cache_delete( 'last_changed', 'terms' );

		/**
		 * Fires immediately after an object-term relationship is deleted.
		 *
		 * @since 2.9.0
		 * @since 4.7.0 Added the `$taxonomy` parameter.
		 *
		 * @param int    $object_id Object ID.
		 * @param array  $tt_ids    An array of term taxonomy IDs.
		 * @param string $taxonomy  Taxonomy slug.
		 */
		do_action( 'deleted_term_relationships', $object_id, $tt_ids, $taxonomy );

		wp_update_term_count( $tt_ids, $taxonomy );

		return (bool) $deleted;
	}

	return false;
}

/**
 * Makes term slug unique, if it isn't already.
 *
 * The `$slug` has to be unique global to every taxonomy, meaning that one
 * taxonomy term can't have a matching slug with another taxonomy term. Each
 * slug has to be globally unique for every taxonomy.
 *
 * The way this works is that if the taxonomy that the term belongs to is
 * hierarchical and has a parent, it will append that parent to the $slug.
 *
 * If that still doesn't return a unique slug, then it tries to append a number
 * until it finds a number that is truly unique.
 *
 * The only purpose for `$term` is for appending a parent, if one exists.
 *
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string $slug The string that will be tried for a unique slug.
 * @param object $term The term object that the `$slug` will belong to.
 * @return string Will return a true unique slug.
 */
function wp_unique_term_slug( $slug, $term ) {
	global $wpdb;

	$needs_suffix  = true;
	$original_slug = $slug;

	// As of 4.1, duplicate slugs are allowed as long as they're in different taxonomies.
	if ( ! term_exists( $slug ) || get_option( 'db_version' ) >= 30133 && ! get_term_by( 'slug', $slug, $term->taxonomy ) ) {
		$needs_suffix = false;
	}

	/*
	 * If the taxonomy supports hierarchy and the term has a parent, make the slug unique
	 * by incorporating parent slugs.
	 */
	$parent_suffix = '';
	if ( $needs_suffix && is_taxonomy_hierarchical( $term->taxonomy ) && ! empty( $term->parent ) ) {
		$the_parent = $term->parent;
		while ( ! empty( $the_parent ) ) {
			$parent_term = get_term( $the_parent, $term->taxonomy );
			if ( is_wp_error( $parent_term ) || empty( $parent_term ) ) {
				break;
			}
			$parent_suffix .= '-' . $parent_term->slug;
			if ( ! term_exists( $slug . $parent_suffix ) ) {
				break;
			}

			if ( empty( $parent_term->parent ) ) {
				break;
			}
			$the_parent = $parent_term->parent;
		}
	}

	// If we didn't get a unique slug, try appending a number to make it unique.

	/**
	 * Filters whether the proposed unique term slug is bad.
	 *
	 * @since 4.3.0
	 *
	 * @param bool   $needs_suffix Whether the slug needs to be made unique with a suffix.
	 * @param string $slug         The slug.
	 * @param object $term         Term object.
	 */
	if ( apply_filters( 'wp_unique_term_slug_is_bad_slug', $needs_suffix, $slug, $term ) ) {
		if ( $parent_suffix ) {
			$slug .= $parent_suffix;
		}

		if ( ! empty( $term->term_id ) ) {
			$query = $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s AND term_id != %d", $slug, $term->term_id );
		} else {
			$query = $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s", $slug );
		}

		if ( $wpdb->get_var( $query ) ) { // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
			$num = 2;
			do {
				$alt_slug = $slug . "-$num";
				$num++;
				$slug_check = $wpdb->get_var( $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s", $alt_slug ) );
			} while ( $slug_check );
			$slug = $alt_slug;
		}
	}

	/**
	 * Filters the unique term slug.
	 *
	 * @since 4.3.0
	 *
	 * @param string $slug          Unique term slug.
	 * @param object $term          Term object.
	 * @param string $original_slug Slug originally passed to the function for testing.
	 */
	return apply_filters( 'wp_unique_term_slug', $slug, $term, $original_slug );
}

/**
 * Updates term based on arguments provided.
 *
 * The `$args` will indiscriminately override all values with the same field name.
 * Care must be taken to not override important information need to update or
 * update will fail (or perhaps create a new term, neither would be acceptable).
 *
 * Defaults will set 'alias_of', 'description', 'parent', and 'slug' if not
 * defined in `$args` already.
 *
 * 'alias_of' will create a term group, if it doesn't already exist, and
 * update it for the `$term`.
 *
 * If the 'slug' argument in `$args` is missing, then the 'name' will be used.
 * If you set 'slug' and it isn't unique, then a WP_Error is returned.
 * If you don't pass any slug, then a unique one will be created.
 *
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int          $term_id  The ID of the term.
 * @param string       $taxonomy The taxonomy of the term.
 * @param array        $args {
 *     Optional. Array of arguments for updating a term.
 *
 *     @type string $alias_of    Slug of the term to make this term an alias of.
 *                               Default empty string. Accepts a term slug.
 *     @type string $description The term description. Default empty string.
 *     @type int    $parent      The id of the parent term. Default 0.
 *     @type string $slug        The term slug to use. Default empty string.
 * }
 * @return array|WP_Error An array containing the `term_id` and `term_taxonomy_id`,
 *                        WP_Error otherwise.
 */
function wp_update_term( $term_id, $taxonomy, $args = array() ) {
	global $wpdb;

	if ( ! taxonomy_exists( $taxonomy ) ) {
		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
	}

	$term_id = (int) $term_id;

	// First, get all of the original args.
	$term = get_term( $term_id, $taxonomy );

	if ( is_wp_error( $term ) ) {
		return $term;
	}

	if ( ! $term ) {
		return new WP_Error( 'invalid_term', __( 'Empty Term.' ) );
	}

	$term = (array) $term->data;

	// Escape data pulled from DB.
	$term = wp_slash( $term );

	// Merge old and new args with new args overwriting old ones.
	$args = array_merge( $term, $args );

	$defaults    = array(
		'alias_of'    => '',
		'description' => '',
		'parent'      => 0,
		'slug'        => '',
	);
	$args        = wp_parse_args( $args, $defaults );
	$args        = sanitize_term( $args, $taxonomy, 'db' );
	$parsed_args = $args;

	// expected_slashed ($name)
	$name        = wp_unslash( $args['name'] );
	$description = wp_unslash( $args['description'] );

	$parsed_args['name']        = $name;
	$parsed_args['description'] = $description;

	if ( '' === trim( $name ) ) {
		return new WP_Error( 'empty_term_name', __( 'A name is required for this term.' ) );
	}

	if ( (int) $parsed_args['parent'] > 0 && ! term_exists( (int) $parsed_args['parent'] ) ) {
		return new WP_Error( 'missing_parent', __( 'Parent term does not exist.' ) );
	}

	$empty_slug = false;
	if ( empty( $args['slug'] ) ) {
		$empty_slug = true;
		$slug       = sanitize_title( $name );
	} else {
		$slug = $args['slug'];
	}

	$parsed_args['slug'] = $slug;

	$term_group = isset( $parsed_args['term_group'] ) ? $parsed_args['term_group'] : 0;
	if ( $args['alias_of'] ) {
		$alias = get_term_by( 'slug', $args['alias_of'], $taxonomy );
		if ( ! empty( $alias->term_group ) ) {
			// The alias we want is already in a group, so let's use that one.
			$term_group = $alias->term_group;
		} elseif ( ! empty( $alias->term_id ) ) {
			/*
			 * The alias is not in a group, so we create a new one
			 * and add the alias to it.
			 */
			$term_group = $wpdb->get_var( "SELECT MAX(term_group) FROM $wpdb->terms" ) + 1;

			wp_update_term(
				$alias->term_id,
				$taxonomy,
				array(
					'term_group' => $term_group,
				)
			);
		}

		$parsed_args['term_group'] = $term_group;
	}

	/**
	 * Filters the term parent.
	 *
	 * Hook to this filter to see if it will cause a hierarchy loop.
	 *
	 * @since 3.1.0
	 *
	 * @param int    $parent_term ID of the parent term.
	 * @param int    $term_id     Term ID.
	 * @param string $taxonomy    Taxonomy slug.
	 * @param array  $parsed_args An array of potentially altered update arguments for the given term.
	 * @param array  $args        Arguments passed to wp_update_term().
	 */
	$parent = (int) apply_filters( 'wp_update_term_parent', $args['parent'], $term_id, $taxonomy, $parsed_args, $args );

	// Check for duplicate slug.
	$duplicate = get_term_by( 'slug', $slug, $taxonomy );
	if ( $duplicate && $duplicate->term_id !== $term_id ) {
		// If an empty slug was passed or the parent changed, reset the slug to something unique.
		// Otherwise, bail.
		if ( $empty_slug || ( $parent !== (int) $term['parent'] ) ) {
			$slug = wp_unique_term_slug( $slug, (object) $args );
		} else {
			/* translators: %s: Taxonomy term slug. */
			return new WP_Error( 'duplicate_term_slug', sprintf( __( 'The slug &#8220;%s&#8221; is already in use by another term.' ), $slug ) );
		}
	}

	$tt_id = (int) $wpdb->get_var( $wpdb->prepare( "SELECT tt.term_taxonomy_id FROM $wpdb->term_taxonomy AS tt INNER JOIN $wpdb->terms AS t ON tt.term_id = t.term_id WHERE tt.taxonomy = %s AND t.term_id = %d", $taxonomy, $term_id ) );

	// Check whether this is a shared term that needs splitting.
	$_term_id = _split_shared_term( $term_id, $tt_id );
	if ( ! is_wp_error( $_term_id ) ) {
		$term_id = $_term_id;
	}

	/**
	 * Fires immediately before the given terms are edited.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edit_terms', $term_id, $taxonomy, $args );

	$data = compact( 'name', 'slug', 'term_group' );

	/**
	 * Filters term data before it is updated in the database.
	 *
	 * @since 4.7.0
	 *
	 * @param array  $data     Term data to be updated.
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	$data = apply_filters( 'wp_update_term_data', $data, $term_id, $taxonomy, $args );

	$wpdb->update( $wpdb->terms, $data, compact( 'term_id' ) );

	if ( empty( $slug ) ) {
		$slug = sanitize_title( $name, $term_id );
		$wpdb->update( $wpdb->terms, compact( 'slug' ), compact( 'term_id' ) );
	}

	/**
	 * Fires immediately after a term is updated in the database, but before its
	 * term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edited_terms', $term_id, $taxonomy, $args );

	/**
	 * Fires immediate before a term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edit_term_taxonomy', $tt_id, $taxonomy, $args );

	$wpdb->update( $wpdb->term_taxonomy, compact( 'term_id', 'taxonomy', 'description', 'parent' ), array( 'term_taxonomy_id' => $tt_id ) );

	/**
	 * Fires immediately after a term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edited_term_taxonomy', $tt_id, $taxonomy, $args );

	/**
	 * Fires after a term has been updated, but before the term cache has been cleaned.
	 *
	 * The {@see 'edit_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edit_term', $term_id, $tt_id, $taxonomy, $args );

	/**
	 * Fires after a term in a specific taxonomy has been updated, but before the term
	 * cache has been cleaned.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `edit_category`
	 *  - `edit_post_tag`
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param array $args    Arguments passed to wp_update_term().
	 */
	do_action( "edit_{$taxonomy}", $term_id, $tt_id, $args );

	/** This filter is documented in wp-includes/taxonomy.php */
	$term_id = apply_filters( 'term_id_filter', $term_id, $tt_id );

	clean_term_cache( $term_id, $taxonomy );

	/**
	 * Fires after a term has been updated, and the term cache has been cleaned.
	 *
	 * The {@see 'edited_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	do_action( 'edited_term', $term_id, $tt_id, $taxonomy, $args );

	/**
	 * Fires after a term for a specific taxonomy has been updated, and the term
	 * cache has been cleaned.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `edited_category`
	 *  - `edited_post_tag`
	 *
	 * @since 2.3.0
	 * @since 6.1.0 The `$args` parameter was added.
	 *
	 * @param int   $term_id Term ID.
	 * @param int   $tt_id   Term taxonomy ID.
	 * @param array $args    Arguments passed to wp_update_term().
	 */
	do_action( "edited_{$taxonomy}", $term_id, $tt_id, $args );

	/** This action is documented in wp-includes/taxonomy.php */
	do_action( 'saved_term', $term_id, $tt_id, $taxonomy, true, $args );

	/** This action is documented in wp-includes/taxonomy.php */
	do_action( "saved_{$taxonomy}", $term_id, $tt_id, true, $args );

	return array(
		'term_id'          => $term_id,
		'term_taxonomy_id' => $tt_id,
	);
}

/**
 * Enables or disables term counting.
 *
 * @since 2.5.0
 *
 * @param bool $defer Optional. Enable if true, disable if false.
 * @return bool Whether term counting is enabled or disabled.
 */
function wp_defer_term_counting( $defer = null ) {
	static $_defer = false;

	if ( is_bool( $defer ) ) {
		$_defer = $defer;
		// Flush any deferred counts.
		if ( ! $defer ) {
			wp_update_term_count( null, null, true );
		}
	}

	return $_defer;
}

/**
 * Updates the amount of terms in taxonomy.
 *
 * If there is a taxonomy callback applied, then it will be called for updating
 * the count.
 *
 * The default action is to count what the amount of terms have the relationship
 * of term ID. Once that is done, then update the database.
 *
 * @since 2.3.0
 *
 * @param int|array $terms       The term_taxonomy_id of the terms.
 * @param string    $taxonomy    The context of the term.
 * @param bool      $do_deferred Whether to flush the deferred term counts too. Default false.
 * @return bool If no terms will return false, and if successful will return true.
 */
function wp_update_term_count( $terms, $taxonomy, $do_deferred = false ) {
	static $_deferred = array();

	if ( $do_deferred ) {
		foreach ( (array) array_keys( $_deferred ) as $tax ) {
			wp_update_term_count_now( $_deferred[ $tax ], $tax );
			unset( $_deferred[ $tax ] );
		}
	}

	if ( empty( $terms ) ) {
		return false;
	}

	if ( ! is_array( $terms ) ) {
		$terms = array( $terms );
	}

	if ( wp_defer_term_counting() ) {
		if ( ! isset( $_deferred[ $taxonomy ] ) ) {
			$_deferred[ $taxonomy ] = array();
		}
		$_deferred[ $taxonomy ] = array_unique( array_merge( $_deferred[ $taxonomy ], $terms ) );
		return true;
	}

	return wp_update_term_count_now( $terms, $taxonomy );
}

/**
 * Performs term count update immediately.
 *
 * @since 2.5.0
 *
 * @param array  $terms    The term_taxonomy_id of terms to update.
 * @param string $taxonomy The context of the term.
 * @return true Always true when complete.
 */
function wp_update_term_count_now( $terms, $taxonomy ) {
	$terms = array_map( 'intval', $terms );

	$taxonomy = get_taxonomy( $taxonomy );
	if ( ! empty( $taxonomy->update_count_callback ) ) {
		call_user_func( $taxonomy->update_count_callback, $terms, $taxonomy );
	} else {
		$object_types = (array) $taxonomy->object_type;
		foreach ( $object_types as &$object_type ) {
			if ( 0 === strpos( $object_type, 'attachment:' ) ) {
				list( $object_type ) = explode( ':', $object_type );
			}
		}

		if ( array_filter( $object_types, 'post_type_exists' ) == $object_types ) {
			// Only post types are attached to this taxonomy.
			_update_post_term_count( $terms, $taxonomy );
		} else {
			// Default count updater.
			_update_generic_term_count( $terms, $taxonomy );
		}
	}

	clean_term_cache( $terms, '', false );

	return true;
}

//
// Cache.
//

/**
 * Removes the taxonomy relationship to terms from the cache.
 *
 * Will remove the entire taxonomy relationship containing term `$object_id`. The
 * term IDs have to exist within the taxonomy `$object_type` for the deletion to
 * take place.
 *
 * @since 2.3.0
 *
 * @global bool $_wp_suspend_cache_invalidation
 *
 * @see get_object_taxonomies() for more on $object_type.
 *
 * @param int|array    $object_ids  Single or list of term object ID(s).
 * @param array|string $object_type The taxonomy object type.
 */
function clean_object_term_cache( $object_ids, $object_type ) {
	global $_wp_suspend_cache_invalidation;

	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
		return;
	}

	if ( ! is_array( $object_ids ) ) {
		$object_ids = array( $object_ids );
	}

	$taxonomies = get_object_taxonomies( $object_type );

	foreach ( $taxonomies as $taxonomy ) {
		wp_cache_delete_multiple( $object_ids, "{$taxonomy}_relationships" );
	}

	wp_cache_delete( 'last_changed', 'terms' );

	/**
	 * Fires after the object term cache has been cleaned.
	 *
	 * @since 2.5.0
	 *
	 * @param array  $object_ids An array of object IDs.
	 * @param string $object_type Object type.
	 */
	do_action( 'clean_object_term_cache', $object_ids, $object_type );
}

/**
 * Removes all of the term IDs from the cache.
 *
 * @since 2.3.0
 *
 * @global wpdb $wpdb                           WordPress database abstraction object.
 * @global bool $_wp_suspend_cache_invalidation
 *
 * @param int|int[] $ids            Single or array of term IDs.
 * @param string    $taxonomy       Optional. Taxonomy slug. Can be empty, in which case the taxonomies of the passed
 *                                  term IDs will be used. Default empty.
 * @param bool      $clean_taxonomy Optional. Whether to clean taxonomy wide caches (true), or just individual
 *                                  term object caches (false). Default true.
 */
function clean_term_cache( $ids, $taxonomy = '', $clean_taxonomy = true ) {
	global $wpdb, $_wp_suspend_cache_invalidation;

	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
		return;
	}

	if ( ! is_array( $ids ) ) {
		$ids = array( $ids );
	}

	$taxonomies = array();
	// If no taxonomy, assume tt_ids.
	if ( empty( $taxonomy ) ) {
		$tt_ids = array_map( 'intval', $ids );
		$tt_ids = implode( ', ', $tt_ids );
		$terms  = $wpdb->get_results( "SELECT term_id, taxonomy FROM $wpdb->term_taxonomy WHERE term_taxonomy_id IN ($tt_ids)" );
		$ids    = array();

		foreach ( (array) $terms as $term ) {
			$taxonomies[] = $term->taxonomy;
			$ids[]        = $term->term_id;
		}
		wp_cache_delete_multiple( $ids, 'terms' );
		$taxonomies = array_unique( $taxonomies );
	} else {
		wp_cache_delete_multiple( $ids, 'terms' );
		$taxonomies = array( $taxonomy );
	}

	foreach ( $taxonomies as $taxonomy ) {
		if ( $clean_taxonomy ) {
			clean_taxonomy_cache( $taxonomy );
		}

		/**
		 * Fires once after each taxonomy's term cache has been cleaned.
		 *
		 * @since 2.5.0
		 * @since 4.5.0 Added the `$clean_taxonomy` parameter.
		 *
		 * @param array  $ids            An array of term IDs.
		 * @param string $taxonomy       Taxonomy slug.
		 * @param bool   $clean_taxonomy Whether or not to clean taxonomy-wide caches
		 */
		do_action( 'clean_term_cache', $ids, $taxonomy, $clean_taxonomy );
	}

	wp_cache_set( 'last_changed', microtime(), 'terms' );
}

/**
 * Cleans the caches for a taxonomy.
 *
 * @since 4.9.0
 *
 * @param string $taxonomy Taxonomy slug.
 */
function clean_taxonomy_cache( $taxonomy ) {
	wp_cache_delete( 'all_ids', $taxonomy );
	wp_cache_delete( 'get', $taxonomy );
	wp_cache_delete( 'last_changed', 'terms' );

	// Regenerate cached hierarchy.
	delete_option( "{$taxonomy}_children" );
	_get_term_hierarchy( $taxonomy );

	/**
	 * Fires after a taxonomy's caches have been cleaned.
	 *
	 * @since 4.9.0
	 *
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'clean_taxonomy_cache', $taxonomy );
}

/**
 * Retrieves the cached term objects for the given object ID.
 *
 * Upstream functions (like get_the_terms() and is_object_in_term()) are
 * responsible for populating the object-term relationship cache. The current
 * function only fetches relationship data that is already in the cache.
 *
 * @since 2.3.0
 * @since 4.7.0 Returns a `WP_Error` object if there's an error with
 *              any of the matched terms.
 *
 * @param int    $id       Term object ID, for example a post, comment, or user ID.
 * @param string $taxonomy Taxonomy name.
 * @return bool|WP_Term[]|WP_Error Array of `WP_Term` objects, if cached.
 *                                 False if cache is empty for `$taxonomy` and `$id`.
 *                                 WP_Error if get_term() returns an error object for any term.
 */
function get_object_term_cache( $id, $taxonomy ) {
	$_term_ids = wp_cache_get( $id, "{$taxonomy}_relationships" );

	// We leave the priming of relationship caches to upstream functions.
	if ( false === $_term_ids ) {
		return false;
	}

	// Backward compatibility for if a plugin is putting objects into the cache, rather than IDs.
	$term_ids = array();
	foreach ( $_term_ids as $term_id ) {
		if ( is_numeric( $term_id ) ) {
			$term_ids[] = (int) $term_id;
		} elseif ( isset( $term_id->term_id ) ) {
			$term_ids[] = (int) $term_id->term_id;
		}
	}

	// Fill the term objects.
	_prime_term_caches( $term_ids );

	$terms = array();
	foreach ( $term_ids as $term_id ) {
		$term = get_term( $term_id, $taxonomy );
		if ( is_wp_error( $term ) ) {
			return $term;
		}

		$terms[] = $term;
	}

	return $terms;
}

/**
 * Updates the cache for the given term object ID(s).
 *
 * Note: Due to performance concerns, great care should be taken to only update
 * term caches when necessary. Processing time can increase exponentially depending
 * on both the number of passed term IDs and the number of taxonomies those terms
 * belong to.
 *
 * Caches will only be updated for terms not already cached.
 *
 * @since 2.3.0
 *
 * @param string|int[]    $object_ids  Comma-separated list or array of term object IDs.
 * @param string|string[] $object_type The taxonomy object type or array of the same.
 * @return void|false Void on success or if the `$object_ids` parameter is empty,
 *                    false if all of the terms in `$object_ids` are already cached.
 */
function update_object_term_cache( $object_ids, $object_type ) {
	if ( empty( $object_ids ) ) {
		return;
	}

	if ( ! is_array( $object_ids ) ) {
		$object_ids = explode( ',', $object_ids );
	}

	$object_ids     = array_map( 'intval', $object_ids );
	$non_cached_ids = array();

	$taxonomies = get_object_taxonomies( $object_type );

	foreach ( $taxonomies as $taxonomy ) {
		$cache_values = wp_cache_get_multiple( (array) $object_ids, "{$taxonomy}_relationships" );

		foreach ( $cache_values as $id => $value ) {
			if ( false === $value ) {
				$non_cached_ids[] = $id;
			}
		}
	}

	if ( empty( $non_cached_ids ) ) {
		return false;
	}

	$non_cached_ids = array_unique( $non_cached_ids );

	$terms = wp_get_object_terms(
		$non_cached_ids,
		$taxonomies,
		array(
			'fields'                 => 'all_with_object_id',
			'orderby'                => 'name',
			'update_term_meta_cache' => false,
		)
	);

	$object_terms = array();
	foreach ( (array) $terms as $term ) {
		$object_terms[ $term->object_id ][ $term->taxonomy ][] = $term->term_id;
	}

	foreach ( $non_cached_ids as $id ) {
		foreach ( $taxonomies as $taxonomy ) {
			if ( ! isset( $object_terms[ $id ][ $taxonomy ] ) ) {
				if ( ! isset( $object_terms[ $id ] ) ) {
					$object_terms[ $id ] = array();
				}
				$object_terms[ $id ][ $taxonomy ] = array();
			}
		}
	}

	$cache_values = array();
	foreach ( $object_terms as $id => $value ) {
		foreach ( $value as $taxonomy => $terms ) {
			$cache_values[ $taxonomy ][ $id ] = $terms;
		}
	}
	foreach ( $cache_values as $taxonomy => $data ) {
		wp_cache_add_multiple( $data, "{$taxonomy}_relationships" );
	}
}

/**
 * Updates terms in cache.
 *
 * @since 2.3.0
 *
 * @param WP_Term[] $terms    Array of term objects to change.
 * @param string    $taxonomy Not used.
 */
function update_term_cache( $terms, $taxonomy = '' ) {
	$data = array();
	foreach ( (array) $terms as $term ) {
		// Create a copy in case the array was passed by reference.
		$_term = clone $term;

		// Object ID should not be cached.
		unset( $_term->object_id );

		$data[ $term->term_id ] = $_term;
	}
	wp_cache_add_multiple( $data, 'terms' );
}

//
// Private.
//

/**
 * Retrieves children of taxonomy as term IDs.
 *
 * @access private
 * @since 2.3.0
 *
 * @param string $taxonomy Taxonomy name.
 * @return array Empty if $taxonomy isn't hierarchical or returns children as term IDs.
 */
function _get_term_hierarchy( $taxonomy ) {
	if ( ! is_taxonomy_hierarchical( $taxonomy ) ) {
		return array();
	}
	$children = get_option( "{$taxonomy}_children" );

	if ( is_array( $children ) ) {
		return $children;
	}
	$children = array();
	$terms    = get_terms(
		array(
			'taxonomy'               => $taxonomy,
			'get'                    => 'all',
			'orderby'                => 'id',
			'fields'                 => 'id=>parent',
			'update_term_meta_cache' => false,
		)
	);
	foreach ( $terms as $term_id => $parent ) {
		if ( $parent > 0 ) {
			$children[ $parent ][] = $term_id;
		}
	}
	update_option( "{$taxonomy}_children", $children );

	return $children;
}

/**
 * Gets the subset of $terms that are descendants of $term_id.
 *
 * If `$terms` is an array of objects, then _get_term_children() returns an array of objects.
 * If `$terms` is an array of IDs, then _get_term_children() returns an array of IDs.
 *
 * @access private
 * @since 2.3.0
 *
 * @param int    $term_id   The ancestor term: all returned terms should be descendants of `$term_id`.
 * @param array  $terms     The set of terms - either an array of term objects or term IDs - from which those that
 *                          are descendants of $term_id will be chosen.
 * @param string $taxonomy  The taxonomy which determines the hierarchy of the terms.
 * @param array  $ancestors Optional. Term ancestors that have already been identified. Passed by reference, to keep
 *                          track of found terms when recursing the hierarchy. The array of located ancestors is used
 *                          to prevent infinite recursion loops. For performance, `term_ids` are used as array keys,
 *                          with 1 as value. Default empty array.
 * @return array|WP_Error The subset of $terms that are descendants of $term_id.
 */
function _get_term_children( $term_id, $terms, $taxonomy, &$ancestors = array() ) {
	$empty_array = array();
	if ( empty( $terms ) ) {
		return $empty_array;
	}

	$term_id      = (int) $term_id;
	$term_list    = array();
	$has_children = _get_term_hierarchy( $taxonomy );

	if ( $term_id && ! isset( $has_children[ $term_id ] ) ) {
		return $empty_array;
	}

	// Include the term itself in the ancestors array, so we can properly detect when a loop has occurred.
	if ( empty( $ancestors ) ) {
		$ancestors[ $term_id ] = 1;
	}

	foreach ( (array) $terms as $term ) {
		$use_id = false;
		if ( ! is_object( $term ) ) {
			$term = get_term( $term, $taxonomy );
			if ( is_wp_error( $term ) ) {
				return $term;
			}
			$use_id = true;
		}

		// Don't recurse if we've already identified the term as a child - this indicates a loop.
		if ( isset( $ancestors[ $term->term_id ] ) ) {
			continue;
		}

		if ( (int) $term->parent === $term_id ) {
			if ( $use_id ) {
				$term_list[] = $term->term_id;
			} else {
				$term_list[] = $term;
			}

			if ( ! isset( $has_children[ $term->term_id ] ) ) {
				continue;
			}

			$ancestors[ $term->term_id ] = 1;

			$children = _get_term_children( $term->term_id, $terms, $taxonomy, $ancestors );
			if ( $children ) {
				$term_list = array_merge( $term_list, $children );
			}
		}
	}

	return $term_list;
}

/**
 * Adds count of children to parent count.
 *
 * Recalculates term counts by including items from child terms. Assumes all
 * relevant children are already in the $terms argument.
 *
 * @access private
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param object[]|WP_Term[] $terms    List of term objects (passed by reference).
 * @param string             $taxonomy Term context.
 */
function _pad_term_counts( &$terms, $taxonomy ) {
	global $wpdb;

	// This function only works for hierarchical taxonomies like post categories.
	if ( ! is_taxonomy_hierarchical( $taxonomy ) ) {
		return;
	}

	$term_hier = _get_term_hierarchy( $taxonomy );

	if ( empty( $term_hier ) ) {
		return;
	}

	$term_items  = array();
	$terms_by_id = array();
	$term_ids    = array();

	foreach ( (array) $terms as $key => $term ) {
		$terms_by_id[ $term->term_id ]       = & $terms[ $key ];
		$term_ids[ $term->term_taxonomy_id ] = $term->term_id;
	}

	// Get the object and term IDs and stick them in a lookup table.
	$tax_obj      = get_taxonomy( $taxonomy );
	$object_types = esc_sql( $tax_obj->object_type );
	$results      = $wpdb->get_results( "SELECT object_id, term_taxonomy_id FROM $wpdb->term_relationships INNER JOIN $wpdb->posts ON object_id = ID WHERE term_taxonomy_id IN (" . implode( ',', array_keys( $term_ids ) ) . ") AND post_type IN ('" . implode( "', '", $object_types ) . "') AND post_status = 'publish'" );

	foreach ( $results as $row ) {
		$id = $term_ids[ $row->term_taxonomy_id ];

		$term_items[ $id ][ $row->object_id ] = isset( $term_items[ $id ][ $row->object_id ] ) ? ++$term_items[ $id ][ $row->object_id ] : 1;
	}

	// Touch every ancestor's lookup row for each post in each term.
	foreach ( $term_ids as $term_id ) {
		$child     = $term_id;
		$ancestors = array();
		while ( ! empty( $terms_by_id[ $child ] ) && $parent = $terms_by_id[ $child ]->parent ) {
			$ancestors[] = $child;

			if ( ! empty( $term_items[ $term_id ] ) ) {
				foreach ( $term_items[ $term_id ] as $item_id => $touches ) {
					$term_items[ $parent ][ $item_id ] = isset( $term_items[ $parent ][ $item_id ] ) ? ++$term_items[ $parent ][ $item_id ] : 1;
				}
			}

			$child = $parent;

			if ( in_array( $parent, $ancestors, true ) ) {
				break;
			}
		}
	}

	// Transfer the touched cells.
	foreach ( (array) $term_items as $id => $items ) {
		if ( isset( $terms_by_id[ $id ] ) ) {
			$terms_by_id[ $id ]->count = count( $items );
		}
	}
}

/**
 * Adds any terms from the given IDs to the cache that do not already exist in cache.
 *
 * @since 4.6.0
 * @since 6.1.0 This function is no longer marked as "private".
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $term_ids          Array of term IDs.
 * @param bool  $update_meta_cache Optional. Whether to update the meta cache. Default true.
 */
function _prime_term_caches( $term_ids, $update_meta_cache = true ) {
	global $wpdb;

	$non_cached_ids = _get_non_cached_ids( $term_ids, 'terms' );
	if ( ! empty( $non_cached_ids ) ) {
		$fresh_terms = $wpdb->get_results( sprintf( "SELECT t.*, tt.* FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id WHERE t.term_id IN (%s)", implode( ',', array_map( 'intval', $non_cached_ids ) ) ) );

		update_term_cache( $fresh_terms );

		if ( $update_meta_cache ) {
			update_termmeta_cache( $non_cached_ids );
		}
	}
}

//
// Default callbacks.
//

/**
 * Updates term count based on object types of the current taxonomy.
 *
 * Private function for the default callback for post_tag and category
 * taxonomies.
 *
 * @access private
 * @since 2.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int[]       $terms    List of term taxonomy IDs.
 * @param WP_Taxonomy $taxonomy Current taxonomy object of terms.
 */
function _update_post_term_count( $terms, $taxonomy ) {
	global $wpdb;

	$object_types = (array) $taxonomy->object_type;

	foreach ( $object_types as &$object_type ) {
		list( $object_type ) = explode( ':', $object_type );
	}

	$object_types = array_unique( $object_types );

	$check_attachments = array_search( 'attachment', $object_types, true );
	if ( false !== $check_attachments ) {
		unset( $object_types[ $check_attachments ] );
		$check_attachments = true;
	}

	if ( $object_types ) {
		$object_types = esc_sql( array_filter( $object_types, 'post_type_exists' ) );
	}

	$post_statuses = array( 'publish' );

	/**
	 * Filters the post statuses for updating the term count.
	 *
	 * @since 5.7.0
	 *
	 * @param string[]    $post_statuses List of post statuses to include in the count. Default is 'publish'.
	 * @param WP_Taxonomy $taxonomy      Current taxonomy object.
	 */
	$post_statuses = esc_sql( apply_filters( 'update_post_term_count_statuses', $post_statuses, $taxonomy ) );

	foreach ( (array) $terms as $term ) {
		$count = 0;

		// Attachments can be 'inherit' status, we need to base count off the parent's status if so.
		if ( $check_attachments ) {
			// phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.QuotedDynamicPlaceholderGeneration
			$count += (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships, $wpdb->posts p1 WHERE p1.ID = $wpdb->term_relationships.object_id AND ( post_status IN ('" . implode( "', '", $post_statuses ) . "') OR ( post_status = 'inherit' AND post_parent > 0 AND ( SELECT post_status FROM $wpdb->posts WHERE ID = p1.post_parent ) IN ('" . implode( "', '", $post_statuses ) . "') ) ) AND post_type = 'attachment' AND term_taxonomy_id = %d", $term ) );
		}

		if ( $object_types ) {
			// phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.QuotedDynamicPlaceholderGeneration
			$count += (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships, $wpdb->posts WHERE $wpdb->posts.ID = $wpdb->term_relationships.object_id AND post_status IN ('" . implode( "', '", $post_statuses ) . "') AND post_type IN ('" . implode( "', '", $object_types ) . "') AND term_taxonomy_id = %d", $term ) );
		}

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edit_term_taxonomy', $term, $taxonomy->name );
		$wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term ) );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edited_term_taxonomy', $term, $taxonomy->name );
	}
}

/**
 * Updates term count based on number of objects.
 *
 * Default callback for the 'link_category' taxonomy.
 *
 * @since 3.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int[]       $terms    List of term taxonomy IDs.
 * @param WP_Taxonomy $taxonomy Current taxonomy object of terms.
 */
function _update_generic_term_count( $terms, $taxonomy ) {
	global $wpdb;

	foreach ( (array) $terms as $term ) {
		$count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships WHERE term_taxonomy_id = %d", $term ) );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edit_term_taxonomy', $term, $taxonomy->name );
		$wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term ) );

		/** This action is documented in wp-includes/taxonomy.php */
		do_action( 'edited_term_taxonomy', $term, $taxonomy->name );
	}
}

/**
 * Creates a new term for a term_taxonomy item that currently shares its term
 * with another term_taxonomy.
 *
 * @ignore
 * @since 4.2.0
 * @since 4.3.0 Introduced `$record` parameter. Also, `$term_id` and
 *              `$term_taxonomy_id` can now accept objects.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int|object $term_id          ID of the shared term, or the shared term object.
 * @param int|object $term_taxonomy_id ID of the term_taxonomy item to receive a new term, or the term_taxonomy object
 *                                     (corresponding to a row from the term_taxonomy table).
 * @param bool       $record           Whether to record data about the split term in the options table. The recording
 *                                     process has the potential to be resource-intensive, so during batch operations
 *                                     it can be beneficial to skip inline recording and do it just once, after the
 *                                     batch is processed. Only set this to `false` if you know what you are doing.
 *                                     Default: true.
 * @return int|WP_Error When the current term does not need to be split (or cannot be split on the current
 *                      database schema), `$term_id` is returned. When the term is successfully split, the
 *                      new term_id is returned. A WP_Error is returned for miscellaneous errors.
 */
function _split_shared_term( $term_id, $term_taxonomy_id, $record = true ) {
	global $wpdb;

	if ( is_object( $term_id ) ) {
		$shared_term = $term_id;
		$term_id     = (int) $shared_term->term_id;
	}

	if ( is_object( $term_taxonomy_id ) ) {
		$term_taxonomy    = $term_taxonomy_id;
		$term_taxonomy_id = (int) $term_taxonomy->term_taxonomy_id;
	}

	// If there are no shared term_taxonomy rows, there's nothing to do here.
	$shared_tt_count = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_taxonomy tt WHERE tt.term_id = %d AND tt.term_taxonomy_id != %d", $term_id, $term_taxonomy_id ) );

	if ( ! $shared_tt_count ) {
		return $term_id;
	}

	/*
	 * Verify that the term_taxonomy_id passed to the function is actually associated with the term_id.
	 * If there's a mismatch, it may mean that the term is already split. Return the actual term_id from the db.
	 */
	$check_term_id = (int) $wpdb->get_var( $wpdb->prepare( "SELECT term_id FROM $wpdb->term_taxonomy WHERE term_taxonomy_id = %d", $term_taxonomy_id ) );
	if ( $check_term_id !== $term_id ) {
		return $check_term_id;
	}

	// Pull up data about the currently shared slug, which we'll use to populate the new one.
	if ( empty( $shared_term ) ) {
		$shared_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.* FROM $wpdb->terms t WHERE t.term_id = %d", $term_id ) );
	}

	$new_term_data = array(
		'name'       => $shared_term->name,
		'slug'       => $shared_term->slug,
		'term_group' => $shared_term->term_group,
	);

	if ( false === $wpdb->insert( $wpdb->terms, $new_term_data ) ) {
		return new WP_Error( 'db_insert_error', __( 'Could not split shared term.' ), $wpdb->last_error );
	}

	$new_term_id = (int) $wpdb->insert_id;

	// Update the existing term_taxonomy to point to the newly created term.
	$wpdb->update(
		$wpdb->term_taxonomy,
		array( 'term_id' => $new_term_id ),
		array( 'term_taxonomy_id' => $term_taxonomy_id )
	);

	// Reassign child terms to the new parent.
	if ( empty( $term_taxonomy ) ) {
		$term_taxonomy = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->term_taxonomy WHERE term_taxonomy_id = %d", $term_taxonomy_id ) );
	}

	$children_tt_ids = $wpdb->get_col( $wpdb->prepare( "SELECT term_taxonomy_id FROM $wpdb->term_taxonomy WHERE parent = %d AND taxonomy = %s", $term_id, $term_taxonomy->taxonomy ) );
	if ( ! empty( $children_tt_ids ) ) {
		foreach ( $children_tt_ids as $child_tt_id ) {
			$wpdb->update(
				$wpdb->term_taxonomy,
				array( 'parent' => $new_term_id ),
				array( 'term_taxonomy_id' => $child_tt_id )
			);
			clean_term_cache( (int) $child_tt_id, '', false );
		}
	} else {
		// If the term has no children, we must force its taxonomy cache to be rebuilt separately.
		clean_term_cache( $new_term_id, $term_taxonomy->taxonomy, false );
	}

	clean_term_cache( $term_id, $term_taxonomy->taxonomy, false );

	/*
	 * Taxonomy cache clearing is delayed to avoid race conditions that may occur when
	 * regenerating the taxonomy's hierarchy tree.
	 */
	$taxonomies_to_clean = array( $term_taxonomy->taxonomy );

	// Clean the cache for term taxonomies formerly shared with the current term.
	$shared_term_taxonomies = $wpdb->get_col( $wpdb->prepare( "SELECT taxonomy FROM $wpdb->term_taxonomy WHERE term_id = %d", $term_id ) );
	$taxonomies_to_clean    = array_merge( $taxonomies_to_clean, $shared_term_taxonomies );

	foreach ( $taxonomies_to_clean as $taxonomy_to_clean ) {
		clean_taxonomy_cache( $taxonomy_to_clean );
	}

	// Keep a record of term_ids that have been split, keyed by old term_id. See wp_get_split_term().
	if ( $record ) {
		$split_term_data = get_option( '_split_terms', array() );
		if ( ! isset( $split_term_data[ $term_id ] ) ) {
			$split_term_data[ $term_id ] = array();
		}

		$split_term_data[ $term_id ][ $term_taxonomy->taxonomy ] = $new_term_id;
		update_option( '_split_terms', $split_term_data );
	}

	// If we've just split the final shared term, set the "finished" flag.
	$shared_terms_exist = $wpdb->get_results(
		"SELECT tt.term_id, t.*, count(*) as term_tt_count FROM {$wpdb->term_taxonomy} tt
		 LEFT JOIN {$wpdb->terms} t ON t.term_id = tt.term_id
		 GROUP BY t.term_id
		 HAVING term_tt_count > 1
		 LIMIT 1"
	);
	if ( ! $shared_terms_exist ) {
		update_option( 'finished_splitting_shared_terms', true );
	}

	/**
	 * Fires after a previously shared taxonomy term is split into two separate terms.
	 *
	 * @since 4.2.0
	 *
	 * @param int    $term_id          ID of the formerly shared term.
	 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
	 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
	 * @param string $taxonomy         Taxonomy for the split term.
	 */
	do_action( 'split_shared_term', $term_id, $new_term_id, $term_taxonomy_id, $term_taxonomy->taxonomy );

	return $new_term_id;
}

/**
 * Splits a batch of shared taxonomy terms.
 *
 * @since 4.3.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 */
function _wp_batch_split_terms() {
	global $wpdb;

	$lock_name = 'term_split.lock';

	// Try to lock.
	$lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'no') /* LOCK */", $lock_name, time() ) );

	if ( ! $lock_result ) {
		$lock_result = get_option( $lock_name );

		// Bail if we were unable to create a lock, or if the existing lock is still valid.
		if ( ! $lock_result || ( $lock_result > ( time() - HOUR_IN_SECONDS ) ) ) {
			wp_schedule_single_event( time() + ( 5 * MINUTE_IN_SECONDS ), 'wp_split_shared_term_batch' );
			return;
		}
	}

	// Update the lock, as by this point we've definitely got a lock, just need to fire the actions.
	update_option( $lock_name, time() );

	// Get a list of shared terms (those with more than one associated row in term_taxonomy).
	$shared_terms = $wpdb->get_results(
		"SELECT tt.term_id, t.*, count(*) as term_tt_count FROM {$wpdb->term_taxonomy} tt
		 LEFT JOIN {$wpdb->terms} t ON t.term_id = tt.term_id
		 GROUP BY t.term_id
		 HAVING term_tt_count > 1
		 LIMIT 10"
	);

	// No more terms, we're done here.
	if ( ! $shared_terms ) {
		update_option( 'finished_splitting_shared_terms', true );
		delete_option( $lock_name );
		return;
	}

	// Shared terms found? We'll need to run this script again.
	wp_schedule_single_event( time() + ( 2 * MINUTE_IN_SECONDS ), 'wp_split_shared_term_batch' );

	// Rekey shared term array for faster lookups.
	$_shared_terms = array();
	foreach ( $shared_terms as $shared_term ) {
		$term_id                   = (int) $shared_term->term_id;
		$_shared_terms[ $term_id ] = $shared_term;
	}
	$shared_terms = $_shared_terms;

	// Get term taxonomy data for all shared terms.
	$shared_term_ids = implode( ',', array_keys( $shared_terms ) );
	$shared_tts      = $wpdb->get_results( "SELECT * FROM {$wpdb->term_taxonomy} WHERE `term_id` IN ({$shared_term_ids})" );

	// Split term data recording is slow, so we do it just once, outside the loop.
	$split_term_data    = get_option( '_split_terms', array() );
	$skipped_first_term = array();
	$taxonomies         = array();
	foreach ( $shared_tts as $shared_tt ) {
		$term_id = (int) $shared_tt->term_id;

		// Don't split the first tt belonging to a given term_id.
		if ( ! isset( $skipped_first_term[ $term_id ] ) ) {
			$skipped_first_term[ $term_id ] = 1;
			continue;
		}

		if ( ! isset( $split_term_data[ $term_id ] ) ) {
			$split_term_data[ $term_id ] = array();
		}

		// Keep track of taxonomies whose hierarchies need flushing.
		if ( ! isset( $taxonomies[ $shared_tt->taxonomy ] ) ) {
			$taxonomies[ $shared_tt->taxonomy ] = 1;
		}

		// Split the term.
		$split_term_data[ $term_id ][ $shared_tt->taxonomy ] = _split_shared_term( $shared_terms[ $term_id ], $shared_tt, false );
	}

	// Rebuild the cached hierarchy for each affected taxonomy.
	foreach ( array_keys( $taxonomies ) as $tax ) {
		delete_option( "{$tax}_children" );
		_get_term_hierarchy( $tax );
	}

	update_option( '_split_terms', $split_term_data );

	delete_option( $lock_name );
}

/**
 * In order to avoid the _wp_batch_split_terms() job being accidentally removed,
 * checks that it's still scheduled while we haven't finished splitting terms.
 *
 * @ignore
 * @since 4.3.0
 */
function _wp_check_for_scheduled_split_terms() {
	if ( ! get_option( 'finished_splitting_shared_terms' ) && ! wp_next_scheduled( 'wp_split_shared_term_batch' ) ) {
		wp_schedule_single_event( time() + MINUTE_IN_SECONDS, 'wp_split_shared_term_batch' );
	}
}

/**
 * Checks default categories when a term gets split to see if any of them need to be updated.
 *
 * @ignore
 * @since 4.2.0
 *
 * @param int    $term_id          ID of the formerly shared term.
 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
 * @param string $taxonomy         Taxonomy for the split term.
 */
function _wp_check_split_default_terms( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
	if ( 'category' !== $taxonomy ) {
		return;
	}

	foreach ( array( 'default_category', 'default_link_category', 'default_email_category' ) as $option ) {
		if ( (int) get_option( $option, -1 ) === $term_id ) {
			update_option( $option, $new_term_id );
		}
	}
}

/**
 * Checks menu items when a term gets split to see if any of them need to be updated.
 *
 * @ignore
 * @since 4.2.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int    $term_id          ID of the formerly shared term.
 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
 * @param string $taxonomy         Taxonomy for the split term.
 */
function _wp_check_split_terms_in_menus( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
	global $wpdb;
	$post_ids = $wpdb->get_col(
		$wpdb->prepare(
			"SELECT m1.post_id
		FROM {$wpdb->postmeta} AS m1
			INNER JOIN {$wpdb->postmeta} AS m2 ON ( m2.post_id = m1.post_id )
			INNER JOIN {$wpdb->postmeta} AS m3 ON ( m3.post_id = m1.post_id )
		WHERE ( m1.meta_key = '_menu_item_type' AND m1.meta_value = 'taxonomy' )
			AND ( m2.meta_key = '_menu_item_object' AND m2.meta_value = %s )
			AND ( m3.meta_key = '_menu_item_object_id' AND m3.meta_value = %d )",
			$taxonomy,
			$term_id
		)
	);

	if ( $post_ids ) {
		foreach ( $post_ids as $post_id ) {
			update_post_meta( $post_id, '_menu_item_object_id', $new_term_id, $term_id );
		}
	}
}

/**
 * If the term being split is a nav_menu, changes associations.
 *
 * @ignore
 * @since 4.3.0
 *
 * @param int    $term_id          ID of the formerly shared term.
 * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
 * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
 * @param string $taxonomy         Taxonomy for the split term.
 */
function _wp_check_split_nav_menu_terms( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
	if ( 'nav_menu' !== $taxonomy ) {
		return;
	}

	// Update menu locations.
	$locations = get_nav_menu_locations();
	foreach ( $locations as $location => $menu_id ) {
		if ( $term_id === $menu_id ) {
			$locations[ $location ] = $new_term_id;
		}
	}
	set_theme_mod( 'nav_menu_locations', $locations );
}

/**
 * Gets data about terms that previously shared a single term_id, but have since been split.
 *
 * @since 4.2.0
 *
 * @param int $old_term_id Term ID. This is the old, pre-split term ID.
 * @return array Array of new term IDs, keyed by taxonomy.
 */
function wp_get_split_terms( $old_term_id ) {
	$split_terms = get_option( '_split_terms', array() );

	$terms = array();
	if ( isset( $split_terms[ $old_term_id ] ) ) {
		$terms = $split_terms[ $old_term_id ];
	}

	return $terms;
}

/**
 * Gets the new term ID corresponding to a previously split term.
 *
 * @since 4.2.0
 *
 * @param int    $old_term_id Term ID. This is the old, pre-split term ID.
 * @param string $taxonomy    Taxonomy that the term belongs to.
 * @return int|false If a previously split term is found corresponding to the old term_id and taxonomy,
 *                   the new term_id will be returned. If no previously split term is found matching
 *                   the parameters, returns false.
 */
function wp_get_split_term( $old_term_id, $taxonomy ) {
	$split_terms = wp_get_split_terms( $old_term_id );

	$term_id = false;
	if ( isset( $split_terms[ $taxonomy ] ) ) {
		$term_id = (int) $split_terms[ $taxonomy ];
	}

	return $term_id;
}

/**
 * Determines whether a term is shared between multiple taxonomies.
 *
 * Shared taxonomy terms began to be split in 4.3, but failed cron tasks or
 * other delays in upgrade routines may cause shared terms to remain.
 *
 * @since 4.4.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int $term_id Term ID.
 * @return bool Returns false if a term is not shared between multiple taxonomies or
 *              if splitting shared taxonomy terms is finished.
 */
function wp_term_is_shared( $term_id ) {
	global $wpdb;

	if ( get_option( 'finished_splitting_shared_terms' ) ) {
		return false;
	}

	$tt_count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_taxonomy WHERE term_id = %d", $term_id ) );

	return $tt_count > 1;
}

/**
 * Generates a permalink for a taxonomy term archive.
 *
 * @since 2.5.0
 *
 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 *
 * @param WP_Term|int|string $term     The term object, ID, or slug whose link will be retrieved.
 * @param string             $taxonomy Optional. Taxonomy. Default empty.
 * @return string|WP_Error URL of the taxonomy term archive on success, WP_Error if term does not exist.
 */
function get_term_link( $term, $taxonomy = '' ) {
	global $wp_rewrite;

	if ( ! is_object( $term ) ) {
		if ( is_int( $term ) ) {
			$term = get_term( $term, $taxonomy );
		} else {
			$term = get_term_by( 'slug', $term, $taxonomy );
		}
	}

	if ( ! is_object( $term ) ) {
		$term = new WP_Error( 'invalid_term', __( 'Empty Term.' ) );
	}

	if ( is_wp_error( $term ) ) {
		return $term;
	}

	$taxonomy = $term->taxonomy;

	$termlink = $wp_rewrite->get_extra_permastruct( $taxonomy );

	/**
	 * Filters the permalink structure for a term before token replacement occurs.
	 *
	 * @since 4.9.0
	 *
	 * @param string  $termlink The permalink structure for the term's taxonomy.
	 * @param WP_Term $term     The term object.
	 */
	$termlink = apply_filters( 'pre_term_link', $termlink, $term );

	$slug = $term->slug;
	$t    = get_taxonomy( $taxonomy );

	if ( empty( $termlink ) ) {
		if ( 'category' === $taxonomy ) {
			$termlink = '?cat=' . $term->term_id;
		} elseif ( $t->query_var ) {
			$termlink = "?$t->query_var=$slug";
		} else {
			$termlink = "?taxonomy=$taxonomy&term=$slug";
		}
		$termlink = home_url( $termlink );
	} else {
		if ( ! empty( $t->rewrite['hierarchical'] ) ) {
			$hierarchical_slugs = array();
			$ancestors          = get_ancestors( $term->term_id, $taxonomy, 'taxonomy' );
			foreach ( (array) $ancestors as $ancestor ) {
				$ancestor_term        = get_term( $ancestor, $taxonomy );
				$hierarchical_slugs[] = $ancestor_term->slug;
			}
			$hierarchical_slugs   = array_reverse( $hierarchical_slugs );
			$hierarchical_slugs[] = $slug;
			$termlink             = str_replace( "%$taxonomy%", implode( '/', $hierarchical_slugs ), $termlink );
		} else {
			$termlink = str_replace( "%$taxonomy%", $slug, $termlink );
		}
		$termlink = home_url( user_trailingslashit( $termlink, 'category' ) );
	}

	// Back compat filters.
	if ( 'post_tag' === $taxonomy ) {

		/**
		 * Filters the tag link.
		 *
		 * @since 2.3.0
		 * @since 2.5.0 Deprecated in favor of {@see 'term_link'} filter.
		 * @since 5.4.1 Restored (un-deprecated).
		 *
		 * @param string $termlink Tag link URL.
		 * @param int    $term_id  Term ID.
		 */
		$termlink = apply_filters( 'tag_link', $termlink, $term->term_id );
	} elseif ( 'category' === $taxonomy ) {

		/**
		 * Filters the category link.
		 *
		 * @since 1.5.0
		 * @since 2.5.0 Deprecated in favor of {@see 'term_link'} filter.
		 * @since 5.4.1 Restored (un-deprecated).
		 *
		 * @param string $termlink Category link URL.
		 * @param int    $term_id  Term ID.
		 */
		$termlink = apply_filters( 'category_link', $termlink, $term->term_id );
	}

	/**
	 * Filters the term link.
	 *
	 * @since 2.5.0
	 *
	 * @param string  $termlink Term link URL.
	 * @param WP_Term $term     Term object.
	 * @param string  $taxonomy Taxonomy slug.
	 */
	return apply_filters( 'term_link', $termlink, $term, $taxonomy );
}

/**
 * Displays the taxonomies of a post with available options.
 *
 * This function can be used within the loop to display the taxonomies for a
 * post without specifying the Post ID. You can also use it outside the Loop to
 * display the taxonomies for a specific post.
 *
 * @since 2.5.0
 *
 * @param array $args {
 *     Arguments about which post to use and how to format the output. Shares all of the arguments
 *     supported by get_the_taxonomies(), in addition to the following.
 *
 *     @type int|WP_Post $post   Post ID or object to get taxonomies of. Default current post.
 *     @type string      $before Displays before the taxonomies. Default empty string.
 *     @type string      $sep    Separates each taxonomy. Default is a space.
 *     @type string      $after  Displays after the taxonomies. Default empty string.
 * }
 */
function the_taxonomies( $args = array() ) {
	$defaults = array(
		'post'   => 0,
		'before' => '',
		'sep'    => ' ',
		'after'  => '',
	);

	$parsed_args = wp_parse_args( $args, $defaults );

	echo $parsed_args['before'] . implode( $parsed_args['sep'], get_the_taxonomies( $parsed_args['post'], $parsed_args ) ) . $parsed_args['after'];
}

/**
 * Retrieves all taxonomies associated with a post.
 *
 * This function can be used within the loop. It will also return an array of
 * the taxonomies with links to the taxonomy and name.
 *
 * @since 2.5.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @param array       $args {
 *           Optional. Arguments about how to format the list of taxonomies. Default empty array.
 *
 *     @type string $template      Template for displaying a taxonomy label and list of terms.
 *                                 Default is "Label: Terms."
 *     @type string $term_template Template for displaying a single term in the list. Default is the term name
 *                                 linked to its archive.
 * }
 * @return string[] List of taxonomies.
 */
function get_the_taxonomies( $post = 0, $args = array() ) {
	$post = get_post( $post );

	$args = wp_parse_args(
		$args,
		array(
			/* translators: %s: Taxonomy label, %l: List of terms formatted as per $term_template. */
			'template'      => __( '%s: %l.' ),
			'term_template' => '<a href="%1$s">%2$s</a>',
		)
	);

	$taxonomies = array();

	if ( ! $post ) {
		return $taxonomies;
	}

	foreach ( get_object_taxonomies( $post ) as $taxonomy ) {
		$t = (array) get_taxonomy( $taxonomy );
		if ( empty( $t['label'] ) ) {
			$t['label'] = $taxonomy;
		}
		if ( empty( $t['args'] ) ) {
			$t['args'] = array();
		}
		if ( empty( $t['template'] ) ) {
			$t['template'] = $args['template'];
		}
		if ( empty( $t['term_template'] ) ) {
			$t['term_template'] = $args['term_template'];
		}

		$terms = get_object_term_cache( $post->ID, $taxonomy );
		if ( false === $terms ) {
			$terms = wp_get_object_terms( $post->ID, $taxonomy, $t['args'] );
		}
		$links = array();

		foreach ( $terms as $term ) {
			$links[] = wp_sprintf( $t['term_template'], esc_attr( get_term_link( $term ) ), $term->name );
		}
		if ( $links ) {
			$taxonomies[ $taxonomy ] = wp_sprintf( $t['template'], $t['label'], $links, $terms );
		}
	}
	return $taxonomies;
}

/**
 * Retrieves all taxonomy names for the given post.
 *
 * @since 2.5.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return string[] An array of all taxonomy names for the given post.
 */
function get_post_taxonomies( $post = 0 ) {
	$post = get_post( $post );

	return get_object_taxonomies( $post );
}

/**
 * Determines if the given object is associated with any of the given terms.
 *
 * The given terms are checked against the object's terms' term_ids, names and slugs.
 * Terms given as integers will only be checked against the object's terms' term_ids.
 * If no terms are given, determines if object is associated with any terms in the given taxonomy.
 *
 * @since 2.7.0
 *
 * @param int                       $object_id ID of the object (post ID, link ID, ...).
 * @param string                    $taxonomy  Single taxonomy name.
 * @param int|string|int[]|string[] $terms     Optional. Term ID, name, slug, or array of such
 *                                             to check against. Default null.
 * @return bool|WP_Error WP_Error on input error.
 */
function is_object_in_term( $object_id, $taxonomy, $terms = null ) {
	$object_id = (int) $object_id;
	if ( ! $object_id ) {
		return new WP_Error( 'invalid_object', __( 'Invalid object ID.' ) );
	}

	$object_terms = get_object_term_cache( $object_id, $taxonomy );
	if ( false === $object_terms ) {
		$object_terms = wp_get_object_terms( $object_id, $taxonomy, array( 'update_term_meta_cache' => false ) );
		if ( is_wp_error( $object_terms ) ) {
			return $object_terms;
		}

		wp_cache_set( $object_id, wp_list_pluck( $object_terms, 'term_id' ), "{$taxonomy}_relationships" );
	}

	if ( is_wp_error( $object_terms ) ) {
		return $object_terms;
	}
	if ( empty( $object_terms ) ) {
		return false;
	}
	if ( empty( $terms ) ) {
		return ( ! empty( $object_terms ) );
	}

	$terms = (array) $terms;

	$ints = array_filter( $terms, 'is_int' );
	if ( $ints ) {
		$strs = array_diff( $terms, $ints );
	} else {
		$strs =& $terms;
	}

	foreach ( $object_terms as $object_term ) {
		// If term is an int, check against term_ids only.
		if ( $ints && in_array( $object_term->term_id, $ints, true ) ) {
			return true;
		}

		if ( $strs ) {
			// Only check numeric strings against term_id, to avoid false matches due to type juggling.
			$numeric_strs = array_map( 'intval', array_filter( $strs, 'is_numeric' ) );
			if ( in_array( $object_term->term_id, $numeric_strs, true ) ) {
				return true;
			}

			if ( in_array( $object_term->name, $strs, true ) ) {
				return true;
			}
			if ( in_array( $object_term->slug, $strs, true ) ) {
				return true;
			}
		}
	}

	return false;
}

/**
 * Determines if the given object type is associated with the given taxonomy.
 *
 * @since 3.0.0
 *
 * @param string $object_type Object type string.
 * @param string $taxonomy    Single taxonomy name.
 * @return bool True if object is associated with the taxonomy, otherwise false.
 */
function is_object_in_taxonomy( $object_type, $taxonomy ) {
	$taxonomies = get_object_taxonomies( $object_type );
	if ( empty( $taxonomies ) ) {
		return false;
	}
	return in_array( $taxonomy, $taxonomies, true );
}

/**
 * Gets an array of ancestor IDs for a given object.
 *
 * @since 3.1.0
 * @since 4.1.0 Introduced the `$resource_type` argument.
 *
 * @param int    $object_id     Optional. The ID of the object. Default 0.
 * @param string $object_type   Optional. The type of object for which we'll be retrieving
 *                              ancestors. Accepts a post type or a taxonomy name. Default empty.
 * @param string $resource_type Optional. Type of resource $object_type is. Accepts 'post_type'
 *                              or 'taxonomy'. Default empty.
 * @return int[] An array of IDs of ancestors from lowest to highest in the hierarchy.
 */
function get_ancestors( $object_id = 0, $object_type = '', $resource_type = '' ) {
	$object_id = (int) $object_id;

	$ancestors = array();

	if ( empty( $object_id ) ) {

		/** This filter is documented in wp-includes/taxonomy.php */
		return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
	}

	if ( ! $resource_type ) {
		if ( is_taxonomy_hierarchical( $object_type ) ) {
			$resource_type = 'taxonomy';
		} elseif ( post_type_exists( $object_type ) ) {
			$resource_type = 'post_type';
		}
	}

	if ( 'taxonomy' === $resource_type ) {
		$term = get_term( $object_id, $object_type );
		while ( ! is_wp_error( $term ) && ! empty( $term->parent ) && ! in_array( $term->parent, $ancestors, true ) ) {
			$ancestors[] = (int) $term->parent;
			$term        = get_term( $term->parent, $object_type );
		}
	} elseif ( 'post_type' === $resource_type ) {
		$ancestors = get_post_ancestors( $object_id );
	}

	/**
	 * Filters a given object's ancestors.
	 *
	 * @since 3.1.0
	 * @since 4.1.1 Introduced the `$resource_type` parameter.
	 *
	 * @param int[]  $ancestors     An array of IDs of object ancestors.
	 * @param int    $object_id     Object ID.
	 * @param string $object_type   Type of object.
	 * @param string $resource_type Type of resource $object_type is.
	 */
	return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
}

/**
 * Returns the term's parent's term ID.
 *
 * @since 3.1.0
 *
 * @param int    $term_id  Term ID.
 * @param string $taxonomy Taxonomy name.
 * @return int|false Parent term ID on success, false on failure.
 */
function wp_get_term_taxonomy_parent_id( $term_id, $taxonomy ) {
	$term = get_term( $term_id, $taxonomy );
	if ( ! $term || is_wp_error( $term ) ) {
		return false;
	}
	return (int) $term->parent;
}

/**
 * Checks the given subset of the term hierarchy for hierarchy loops.
 * Prevents loops from forming and breaks those that it finds.
 *
 * Attached to the {@see 'wp_update_term_parent'} filter.
 *
 * @since 3.1.0
 *
 * @param int    $parent_term `term_id` of the parent for the term we're checking.
 * @param int    $term_id     The term we're checking.
 * @param string $taxonomy    The taxonomy of the term we're checking.
 * @return int The new parent for the term.
 */
function wp_check_term_hierarchy_for_loops( $parent_term, $term_id, $taxonomy ) {
	// Nothing fancy here - bail.
	if ( ! $parent_term ) {
		return 0;
	}

	// Can't be its own parent.
	if ( $parent_term === $term_id ) {
		return 0;
	}

	// Now look for larger loops.
	$loop = wp_find_hierarchy_loop( 'wp_get_term_taxonomy_parent_id', $term_id, $parent_term, array( $taxonomy ) );
	if ( ! $loop ) {
		return $parent_term; // No loop.
	}

	// Setting $parent_term to the given value causes a loop.
	if ( isset( $loop[ $term_id ] ) ) {
		return 0;
	}

	// There's a loop, but it doesn't contain $term_id. Break the loop.
	foreach ( array_keys( $loop ) as $loop_member ) {
		wp_update_term( $loop_member, $taxonomy, array( 'parent' => 0 ) );
	}

	return $parent_term;
}

/**
 * Determines whether a taxonomy is considered "viewable".
 *
 * @since 5.1.0
 *
 * @param string|WP_Taxonomy $taxonomy Taxonomy name or object.
 * @return bool Whether the taxonomy should be considered viewable.
 */
function is_taxonomy_viewable( $taxonomy ) {
	if ( is_scalar( $taxonomy ) ) {
		$taxonomy = get_taxonomy( $taxonomy );
		if ( ! $taxonomy ) {
			return false;
		}
	}

	return $taxonomy->publicly_queryable;
}

/**
 * Determines whether a term is publicly viewable.
 *
 * A term is considered publicly viewable if its taxonomy is viewable.
 *
 * @since 6.1.0
 *
 * @param int|WP_Term $term Term ID or term object.
 * @return bool Whether the term is publicly viewable.
 */
function is_term_publicly_viewable( $term ) {
	$term = get_term( $term );

	if ( ! $term ) {
		return false;
	}

	return is_taxonomy_viewable( $term->taxonomy );
}

/**
 * Sets the last changed time for the 'terms' cache group.
 *
 * @since 5.0.0
 */
function wp_cache_set_terms_last_changed() {
	wp_cache_set( 'last_changed', microtime(), 'terms' );
}

/**
 * Aborts calls to term meta if it is not supported.
 *
 * @since 5.0.0
 *
 * @param mixed $check Skip-value for whether to proceed term meta function execution.
 * @return mixed Original value of $check, or false if term meta is not supported.
 */
function wp_check_term_meta_support_prefilter( $check ) {
	if ( get_option( 'db_version' ) < 34370 ) {
		return false;
	}

	return $check;
}
tatus of authenticating with an application password.
 *
 * @since 5.6.0
 * @since 5.7.0 Added the `$app_password` parameter.
 *
 * @global WP_User|WP_Error|null $wp_rest_application_password_status
 * @global string|null $wp_rest_application_password_uuid
 *
 * @param WP_Error $user_or_error The authenticated user or error instance.
 * @param array    $app_password  The Application Password used to authenticate.
 */
function rest_application_password_collect_status( $user_or_error, $app_password = array() ) {
	global $wp_rest_application_password_status, $wp_rest_application_password_uuid;

	$wp_rest_application_password_status = $user_or_error;

	if ( empty( $app_password['uuid'] ) ) {
		$wp_rest_application_password_uuid = null;
	} else {
		$wp_rest_application_password_uuid = $app_password['uuid'];
	}
}

/**
 * Gets the Application Password used for authenticating the request.
 *
 * @since 5.7.0
 *
 * @global string|null $wp_rest_application_password_uuid
 *
 * @return string|null The Application Password UUID, or null if Application Passwords was not used.
 */
function rest_get_authenticated_app_password() {
	global $wp_rest_application_password_uuid;

	return $wp_rest_application_password_uuid;
}

/**
 * Checks for errors when using application password-based authentication.
 *
 * @since 5.6.0
 *
 * @global WP_User|WP_Error|null $wp_rest_application_password_status
 *
 * @param WP_Error|null|true $result Error from another authentication handler,
 *                                   null if we should handle it, or another value if not.
 * @return WP_Error|null|true WP_Error if the application password is invalid, the $result, otherwise true.
 */
function rest_application_password_check_errors( $result ) {
	global $wp_rest_application_password_status;

	if ( ! empty( $result ) ) {
		return $result;
	}

	if ( is_wp_error( $wp_rest_application_password_status ) ) {
		$data = $wp_rest_application_password_status->get_error_data();

		if ( ! isset( $data['status'] ) ) {
			$data['status'] = 401;
		}

		$wp_rest_application_password_status->add_data( $data );

		return $wp_rest_application_password_status;
	}

	if ( $wp_rest_application_password_status instanceof WP_User ) {
		return true;
	}

	return $result;
}

/**
 * Adds Application Passwords info to the REST API index.
 *
 * @since 5.6.0
 *
 * @param WP_REST_Response $response The index response object.
 * @return WP_REST_Response
 */
function rest_add_application_passwords_to_index( $response ) {
	if ( ! wp_is_application_passwords_available() ) {
		return $response;
	}

	$response->data['authentication']['application-passwords'] = array(
		'endpoints' => array(
			'authorization' => admin_url( 'authorize-application.php' ),
		),
	);

	return $response;
}

/**
 * Retrieves the avatar urls in various sizes.
 *
 * @since 4.7.0
 *
 * @see get_avatar_url()
 *
 * @param mixed $id_or_email The Gravatar to retrieve a URL for. Accepts a user_id, gravatar md5 hash,
 *                           user email, WP_User object, WP_Post object, or WP_Comment object.
 * @return (string|false)[] Avatar URLs keyed by size. Each value can be a URL string or boolean false.
 */
function rest_get_avatar_urls( $id_or_email ) {
	$avatar_sizes = rest_get_avatar_sizes();

	$urls = array();
	foreach ( $avatar_sizes as $size ) {
		$urls[ $size ] = get_avatar_url( $id_or_email, array( 'size' => $size ) );
	}

	return $urls;
}

/**
 * Retrieves the pixel sizes for avatars.
 *
 * @since 4.7.0
 *
 * @return int[] List of pixel sizes for avatars. Default `[ 24, 48, 96 ]`.
 */
function rest_get_avatar_sizes() {
	/**
	 * Filters the REST avatar sizes.
	 *
	 * Use this filter to adjust the array of sizes returned by the
	 * `rest_get_avatar_sizes` function.
	 *
	 * @since 4.4.0
	 *
	 * @param int[] $sizes An array of int values that are the pixel sizes for avatars.
	 *                     Default `[ 24, 48, 96 ]`.
	 */
	return apply_filters( 'rest_avatar_sizes', array( 24, 48, 96 ) );
}

/**
 * Parses an RFC3339 time into a Unix timestamp.
 *
 * @since 4.4.0
 *
 * @param string $date      RFC3339 timestamp.
 * @param bool   $force_utc Optional. Whether to force UTC timezone instead of using
 *                          the timestamp's timezone. Default false.
 * @return int Unix timestamp.
 */
function rest_parse_date( $date, $force_utc = false ) {
	if ( $force_utc ) {
		$date = preg_replace( '/[+-]\d+:?\d+$/', '+00:00', $date );
	}

	$regex = '#^\d{4}-\d{2}-\d{2}[Tt ]\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}(?::\d{2})?)?$#';

	if ( ! preg_match( $regex, $date, $matches ) ) {
		return false;
	}

	return strtotime( $date );
}

/**
 * Parses a 3 or 6 digit hex color (with #).
 *
 * @since 5.4.0
 *
 * @param string $color 3 or 6 digit hex color (with #).
 * @return string|false
 */
function rest_parse_hex_color( $color ) {
	$regex = '|^#([A-Fa-f0-9]{3}){1,2}$|';
	if ( ! preg_match( $regex, $color, $matches ) ) {
		return false;
	}

	return $color;
}

/**
 * Parses a date into both its local and UTC equivalent, in MySQL datetime format.
 *
 * @since 4.4.0
 *
 * @see rest_parse_date()
 *
 * @param string $date   RFC3339 timestamp.
 * @param bool   $is_utc Whether the provided date should be interpreted as UTC. Default false.
 * @return array|null {
 *     Local and UTC datetime strings, in MySQL datetime format (Y-m-d H:i:s),
 *     null on failure.
 *
 *     @type string $0 Local datetime string.
 *     @type string $1 UTC datetime string.
 * }
 */
function rest_get_date_with_gmt( $date, $is_utc = false ) {
	/*
	 * Whether or not the original date actually has a timezone string
	 * changes the way we need to do timezone conversion.
	 * Store this info before parsing the date, and use it later.
	 */
	$has_timezone = preg_match( '#(Z|[+-]\d{2}(:\d{2})?)$#', $date );

	$date = rest_parse_date( $date );

	if ( empty( $date ) ) {
		return null;
	}

	/*
	 * At this point $date could either be a local date (if we were passed
	 * a *local* date without a timezone offset) or a UTC date (otherwise).
	 * Timezone conversion needs to be handled differently between these two cases.
	 */
	if ( ! $is_utc && ! $has_timezone ) {
		$local = gmdate( 'Y-m-d H:i:s', $date );
		$utc   = get_gmt_from_date( $local );
	} else {
		$utc   = gmdate( 'Y-m-d H:i:s', $date );
		$local = get_date_from_gmt( $utc );
	}

	return array( $local, $utc );
}

/**
 * Returns a contextual HTTP error code for authorization failure.
 *
 * @since 4.7.0
 *
 * @return int 401 if the user is not logged in, 403 if the user is logged in.
 */
function rest_authorization_required_code() {
	return is_user_logged_in() ? 403 : 401;
}

/**
 * Validate a request argument based on details registered to the route.
 *
 * @since 4.7.0
 *
 * @param mixed           $value
 * @param WP_REST_Request $request
 * @param string          $param
 * @return true|WP_Error
 */
function rest_validate_request_arg( $value, $request, $param ) {
	$attributes = $request->get_attributes();
	if ( ! isset( $attributes['args'][ $param ] ) || ! is_array( $attributes['args'][ $param ] ) ) {
		return true;
	}
	$args = $attributes['args'][ $param ];

	return rest_validate_value_from_schema( $value, $args, $param );
}

/**
 * Sanitize a request argument based on details registered to the route.
 *
 * @since 4.7.0
 *
 * @param mixed           $value
 * @param WP_REST_Request $request
 * @param string          $param
 * @return mixed
 */
function rest_sanitize_request_arg( $value, $request, $param ) {
	$attributes = $request->get_attributes();
	if ( ! isset( $attributes['args'][ $param ] ) || ! is_array( $attributes['args'][ $param ] ) ) {
		return $value;
	}
	$args = $attributes['args'][ $param ];

	return rest_sanitize_value_from_schema( $value, $args, $param );
}

/**
 * Parse a request argument based on details registered to the route.
 *
 * Runs a validation check and sanitizes the value, primarily to be used via
 * the `sanitize_callback` arguments in the endpoint args registration.
 *
 * @since 4.7.0
 *
 * @param mixed           $value
 * @param WP_REST_Request $request
 * @param string          $param
 * @return mixed
 */
function rest_parse_request_arg( $value, $request, $param ) {
	$is_valid = rest_validate_request_arg( $value, $request, $param );

	if ( is_wp_error( $is_valid ) ) {
		return $is_valid;
	}

	$value = rest_sanitize_request_arg( $value, $request, $param );

	return $value;
}

/**
 * Determines if an IP address is valid.
 *
 * Handles both IPv4 and IPv6 addresses.
 *
 * @since 4.7.0
 *
 * @param string $ip IP address.
 * @return string|false The valid IP address, otherwise false.
 */
function rest_is_ip_address( $ip ) {
	$ipv4_pattern = '/^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/';

	if ( ! preg_match( $ipv4_pattern, $ip ) && ! WpOrg\Requests\Ipv6::check_ipv6( $ip ) ) {
		return false;
	}

	return $ip;
}

/**
 * Changes a boolean-like value into the proper boolean value.
 *
 * @since 4.7.0
 *
 * @param bool|string|int $value The value being evaluated.
 * @return bool Returns the proper associated boolean value.
 */
function rest_sanitize_boolean( $value ) {
	// String values are translated to `true`; make sure 'false' is false.
	if ( is_string( $value ) ) {
		$value = strtolower( $value );
		if ( in_array( $value, array( 'false', '0' ), true ) ) {
			$value = false;
		}
	}

	// Everything else will map nicely to boolean.
	return (bool) $value;
}

/**
 * Determines if a given value is boolean-like.
 *
 * @since 4.7.0
 *
 * @param bool|string $maybe_bool The value being evaluated.
 * @return bool True if a boolean, otherwise false.
 */
function rest_is_boolean( $maybe_bool ) {
	if ( is_bool( $maybe_bool ) ) {
		return true;
	}

	if ( is_string( $maybe_bool ) ) {
		$maybe_bool = strtolower( $maybe_bool );

		$valid_boolean_values = array(
			'false',
			'true',
			'0',
			'1',
		);

		return in_array( $maybe_bool, $valid_boolean_values, true );
	}

	if ( is_int( $maybe_bool ) ) {
		return in_array( $maybe_bool, array( 0, 1 ), true );
	}

	return false;
}

/**
 * Determines if a given value is integer-like.
 *
 * @since 5.5.0
 *
 * @param mixed $maybe_integer The value being evaluated.
 * @return bool True if an integer, otherwise false.
 */
function rest_is_integer( $maybe_integer ) {
	return is_numeric( $maybe_integer ) && round( (float) $maybe_integer ) === (float) $maybe_integer;
}

/**
 * Determines if a given value is array-like.
 *
 * @since 5.5.0
 *
 * @param mixed $maybe_array The value being evaluated.
 * @return bool
 */
function rest_is_array( $maybe_array ) {
	if ( is_scalar( $maybe_array ) ) {
		$maybe_array = wp_parse_list( $maybe_array );
	}

	return wp_is_numeric_array( $maybe_array );
}

/**
 * Converts an array-like value to an array.
 *
 * @since 5.5.0
 *
 * @param mixed $maybe_array The value being evaluated.
 * @return array Returns the array extracted from the value.
 */
function rest_sanitize_array( $maybe_array ) {
	if ( is_scalar( $maybe_array ) ) {
		return wp_parse_list( $maybe_array );
	}

	if ( ! is_array( $maybe_array ) ) {
		return array();
	}

	// Normalize to numeric array so nothing unexpected is in the keys.
	return array_values( $maybe_array );
}

/**
 * Determines if a given value is object-like.
 *
 * @since 5.5.0
 *
 * @param mixed $maybe_object The value being evaluated.
 * @return bool True if object like, otherwise false.
 */
function rest_is_object( $maybe_object ) {
	if ( '' === $maybe_object ) {
		return true;
	}

	if ( $maybe_object instanceof stdClass ) {
		return true;
	}

	if ( $maybe_object instanceof JsonSerializable ) {
		$maybe_object = $maybe_object->jsonSerialize();
	}

	return is_array( $maybe_object );
}

/**
 * Converts an object-like value to an array.
 *
 * @since 5.5.0
 *
 * @param mixed $maybe_object The value being evaluated.
 * @return array Returns the object extracted from the value as an associative array.
 */
function rest_sanitize_object( $maybe_object ) {
	if ( '' === $maybe_object ) {
		return array();
	}

	if ( $maybe_object instanceof stdClass ) {
		return (array) $maybe_object;
	}

	if ( $maybe_object instanceof JsonSerializable ) {
		$maybe_object = $maybe_object->jsonSerialize();
	}

	if ( ! is_array( $maybe_object ) ) {
		return array();
	}

	return $maybe_object;
}

/**
 * Gets the best type for a value.
 *
 * @since 5.5.0
 *
 * @param mixed    $value The value to check.
 * @param string[] $types The list of possible types.
 * @return string The best matching type, an empty string if no types match.
 */
function rest_get_best_type_for_value( $value, $types ) {
	static $checks = array(
		'array'   => 'rest_is_array',
		'object'  => 'rest_is_object',
		'integer' => 'rest_is_integer',
		'number'  => 'is_numeric',
		'boolean' => 'rest_is_boolean',
		'string'  => 'is_string',
		'null'    => 'is_null',
	);

	// Both arrays and objects allow empty strings to be converted to their types.
	// But the best answer for this type is a string.
	if ( '' === $value && in_array( 'string', $types, true ) ) {
		return 'string';
	}

	foreach ( $types as $type ) {
		if ( isset( $checks[ $type ] ) && $checks[ $type ]( $value ) ) {
			return $type;
		}
	}

	return '';
}

/**
 * Handles getting the best type for a multi-type schema.
 *
 * This is a wrapper for {@see rest_get_best_type_for_value()} that handles
 * backward compatibility for schemas that use invalid types.
 *
 * @since 5.5.0
 *
 * @param mixed  $value The value to check.
 * @param array  $args  The schema array to use.
 * @param string $param The parameter name, used in error messages.
 * @return string
 */
function rest_handle_multi_type_schema( $value, $args, $param = '' ) {
	$allowed_types = array( 'array', 'object', 'string', 'number', 'integer', 'boolean', 'null' );
	$invalid_types = array_diff( $args['type'], $allowed_types );

	if ( $invalid_types ) {
		_doing_it_wrong(
			__FUNCTION__,
			/* translators: 1: Parameter, 2: List of allowed types. */
			wp_sprintf( __( 'The "type" schema keyword for %1$s can only contain the built-in types: %2$l.' ), $param, $allowed_types ),
			'5.5.0'
		);
	}

	$best_type = rest_get_best_type_for_value( $value, $args['type'] );

	if ( ! $best_type ) {
		if ( ! $invalid_types ) {
			return '';
		}

		// Backward compatibility for previous behavior which allowed the value if there was an invalid type used.
		$best_type = reset( $invalid_types );
	}

	return $best_type;
}

/**
 * Checks if an array is made up of unique items.
 *
 * @since 5.5.0
 *
 * @param array $input_array The array to check.
 * @return bool True if the array contains unique items, false otherwise.
 */
function rest_validate_array_contains_unique_items( $input_array ) {
	$seen = array();

	foreach ( $input_array as $item ) {
		$stabilized = rest_stabilize_value( $item );
		$key        = serialize( $stabilized );

		if ( ! isset( $seen[ $key ] ) ) {
			$seen[ $key ] = true;

			continue;
		}

		return false;
	}

	return true;
}

/**
 * Stabilizes a value following JSON Schema semantics.
 *
 * For lists, order is preserved. For objects, properties are reordered alphabetically.
 *
 * @since 5.5.0
 *
 * @param mixed $value The value to stabilize. Must already be sanitized. Objects should have been converted to arrays.
 * @return mixed The stabilized value.
 */
function rest_stabilize_value( $value ) {
	if ( is_scalar( $value ) || is_null( $value ) ) {
		return $value;
	}

	if ( is_object( $value ) ) {
		_doing_it_wrong( __FUNCTION__, __( 'Cannot stabilize objects. Convert the object to an array first.' ), '5.5.0' );

		return $value;
	}

	ksort( $value );

	foreach ( $value as $k => $v ) {
		$value[ $k ] = rest_stabilize_value( $v );
	}

	return $value;
}

/**
 * Validates if the JSON Schema pattern matches a value.
 *
 * @since 5.6.0
 *
 * @param string $pattern The pattern to match against.
 * @param string $value   The value to check.
 * @return bool           True if the pattern matches the given value, false otherwise.
 */
function rest_validate_json_schema_pattern( $pattern, $value ) {
	$escaped_pattern = str_replace( '#', '\\#', $pattern );

	return 1 === preg_match( '#' . $escaped_pattern . '#u', $value );
}

/**
 * Finds the schema for a property using the patternProperties keyword.
 *
 * @since 5.6.0
 *
 * @param string $property The property name to check.
 * @param array  $args     The schema array to use.
 * @return array|null      The schema of matching pattern property, or null if no patterns match.
 */
function rest_find_matching_pattern_property_schema( $property, $args ) {
	if ( isset( $args['patternProperties'] ) ) {
		foreach ( $args['patternProperties'] as $pattern => $child_schema ) {
			if ( rest_validate_json_schema_pattern( $pattern, $property ) ) {
				return $child_schema;
			}
		}
	}

	return null;
}

/**
 * Formats a combining operation error into a WP_Error object.
 *
 * @since 5.6.0
 *
 * @param string $param The parameter name.
 * @param array $error  The error details.
 * @return WP_Error
 */
function rest_format_combining_operation_error( $param, $error ) {
	$position = $error['index'];
	$reason   = $error['error_object']->get_error_message();

	if ( isset( $error['schema']['title'] ) ) {
		$title = $error['schema']['title'];

		return new WP_Error(
			'rest_no_matching_schema',
			/* translators: 1: Parameter, 2: Schema title, 3: Reason. */
			sprintf( __( '%1$s is not a valid %2$s. Reason: %3$s' ), $param, $title, $reason ),
			array( 'position' => $position )
		);
	}

	return new WP_Error(
		'rest_no_matching_schema',
		/* translators: 1: Parameter, 2: Reason. */
		sprintf( __( '%1$s does not match the expected format. Reason: %2$s' ), $param, $reason ),
		array( 'position' => $position )
	);
}

/**
 * Gets the error of combining operation.
 *
 * @since 5.6.0
 *
 * @param array  $value  The value to validate.
 * @param string $param  The parameter name, used in error messages.
 * @param array  $errors The errors array, to search for possible error.
 * @return WP_Error      The combining operation error.
 */
function rest_get_combining_operation_error( $value, $param, $errors ) {
	// If there is only one error, simply return it.
	if ( 1 === count( $errors ) ) {
		return rest_format_combining_operation_error( $param, $errors[0] );
	}

	// Filter out all errors related to type validation.
	$filtered_errors = array();
	foreach ( $errors as $error ) {
		$error_code = $error['error_object']->get_error_code();
		$error_data = $error['error_object']->get_error_data();

		if ( 'rest_invalid_type' !== $error_code || ( isset( $error_data['param'] ) && $param !== $error_data['param'] ) ) {
			$filtered_errors[] = $error;
		}
	}

	// If there is only one error left, simply return it.
	if ( 1 === count( $filtered_errors ) ) {
		return rest_format_combining_operation_error( $param, $filtered_errors[0] );
	}

	// If there are only errors related to object validation, try choosing the most appropriate one.
	if ( count( $filtered_errors ) > 1 && 'object' === $filtered_errors[0]['schema']['type'] ) {
		$result = null;
		$number = 0;

		foreach ( $filtered_errors as $error ) {
			if ( isset( $error['schema']['properties'] ) ) {
				$n = count( array_intersect_key( $error['schema']['properties'], $value ) );
				if ( $n > $number ) {
					$result = $error;
					$number = $n;
				}
			}
		}

		if ( null !== $result ) {
			return rest_format_combining_operation_error( $param, $result );
		}
	}

	// If each schema has a title, include those titles in the error message.
	$schema_titles = array();
	foreach ( $errors as $error ) {
		if ( isset( $error['schema']['title'] ) ) {
			$schema_titles[] = $error['schema']['title'];
		}
	}

	if ( count( $schema_titles ) === count( $errors ) ) {
		/* translators: 1: Parameter, 2: Schema titles. */
		return new WP_Error( 'rest_no_matching_schema', wp_sprintf( __( '%1$s is not a valid %2$l.' ), $param, $schema_titles ) );
	}

	/* translators: %s: Parameter. */
	return new WP_Error( 'rest_no_matching_schema', sprintf( __( '%s does not match any of the expected formats.' ), $param ) );
}

/**
 * Finds the matching schema among the "anyOf" schemas.
 *
 * @since 5.6.0
 *
 * @param mixed  $value   The value to validate.
 * @param array  $args    The schema array to use.
 * @param string $param   The parameter name, used in error messages.
 * @return array|WP_Error The matching schema or WP_Error instance if all schemas do not match.
 */
function rest_find_any_matching_schema( $value, $args, $param ) {
	$errors = array();

	foreach ( $args['anyOf'] as $index => $schema ) {
		if ( ! isset( $schema['type'] ) && isset( $args['type'] ) ) {
			$schema['type'] = $args['type'];
		}

		$is_valid = rest_validate_value_from_schema( $value, $schema, $param );
		if ( ! is_wp_error( $is_valid ) ) {
			return $schema;
		}

		$errors[] = array(
			'error_object' => $is_valid,
			'schema'       => $schema,
			'index'        => $index,
		);
	}

	return rest_get_combining_operation_error( $value, $param, $errors );
}

/**
 * Finds the matching schema among the "oneOf" schemas.
 *
 * @since 5.6.0
 *
 * @param mixed  $value                  The value to validate.
 * @param array  $args                   The schema array to use.
 * @param string $param                  The parameter name, used in error messages.
 * @param bool   $stop_after_first_match Optional. Whether the process should stop after the first successful match.
 * @return array|WP_Error                The matching schema or WP_Error instance if the number of matching schemas is not equal to one.
 */
function rest_find_one_matching_schema( $value, $args, $param, $stop_after_first_match = false ) {
	$matching_schemas = array();
	$errors           = array();

	foreach ( $args['oneOf'] as $index => $schema ) {
		if ( ! isset( $schema['type'] ) && isset( $args['type'] ) ) {
			$schema['type'] = $args['type'];
		}

		$is_valid = rest_validate_value_from_schema( $value, $schema, $param );
		if ( ! is_wp_error( $is_valid ) ) {
			if ( $stop_after_first_match ) {
				return $schema;
			}

			$matching_schemas[] = array(
				'schema_object' => $schema,
				'index'         => $index,
			);
		} else {
			$errors[] = array(
				'error_object' => $is_valid,
				'schema'       => $schema,
				'index'        => $index,
			);
		}
	}

	if ( ! $matching_schemas ) {
		return rest_get_combining_operation_error( $value, $param, $errors );
	}

	if ( count( $matching_schemas ) > 1 ) {
		$schema_positions = array();
		$schema_titles    = array();

		foreach ( $matching_schemas as $schema ) {
			$schema_positions[] = $schema['index'];

			if ( isset( $schema['schema_object']['title'] ) ) {
				$schema_titles[] = $schema['schema_object']['title'];
			}
		}

		// If each schema has a title, include those titles in the error message.
		if ( count( $schema_titles ) === count( $matching_schemas ) ) {
			return new WP_Error(
				'rest_one_of_multiple_matches',
				/* translators: 1: Parameter, 2: Schema titles. */
				wp_sprintf( __( '%1$s matches %2$l, but should match only one.' ), $param, $schema_titles ),
				array( 'positions' => $schema_positions )
			);
		}

		return new WP_Error(
			'rest_one_of_multiple_matches',
			/* translators: %s: Parameter. */
			sprintf( __( '%s matches more than one of the expected formats.' ), $param ),
			array( 'positions' => $schema_positions )
		);
	}

	return $matching_schemas[0]['schema_object'];
}

/**
 * Checks the equality of two values, following JSON Schema semantics.
 *
 * Property order is ignored for objects.
 *
 * Values must have been previously sanitized/coerced to their native types.
 *
 * @since 5.7.0
 *
 * @param mixed $value1 The first value to check.
 * @param mixed $value2 The second value to check.
 * @return bool True if the values are equal or false otherwise.
 */
function rest_are_values_equal( $value1, $value2 ) {
	if ( is_array( $value1 ) && is_array( $value2 ) ) {
		if ( count( $value1 ) !== count( $value2 ) ) {
			return false;
		}

		foreach ( $value1 as $index => $value ) {
			if ( ! array_key_exists( $index, $value2 ) || ! rest_are_values_equal( $value, $value2[ $index ] ) ) {
				return false;
			}
		}

		return true;
	}

	if ( is_int( $value1 ) && is_float( $value2 )
		|| is_float( $value1 ) && is_int( $value2 )
	) {
		return (float) $value1 === (float) $value2;
	}

	return $value1 === $value2;
}

/**
 * Validates that the given value is a member of the JSON Schema "enum".
 *
 * @since 5.7.0
 *
 * @param mixed  $value  The value to validate.
 * @param array  $args   The schema array to use.
 * @param string $param  The parameter name, used in error messages.
 * @return true|WP_Error True if the "enum" contains the value or a WP_Error instance otherwise.
 */
function rest_validate_enum( $value, $args, $param ) {
	$sanitized_value = rest_sanitize_value_from_schema( $value, $args, $param );
	if ( is_wp_error( $sanitized_value ) ) {
		return $sanitized_value;
	}

	foreach ( $args['enum'] as $enum_value ) {
		if ( rest_are_values_equal( $sanitized_value, $enum_value ) ) {
			return true;
		}
	}

	$encoded_enum_values = array();
	foreach ( $args['enum'] as $enum_value ) {
		$encoded_enum_values[] = is_scalar( $enum_value ) ? $enum_value : wp_json_encode( $enum_value );
	}

	if ( count( $encoded_enum_values ) === 1 ) {
		/* translators: 1: Parameter, 2: Valid values. */
		return new WP_Error( 'rest_not_in_enum', wp_sprintf( __( '%1$s is not %2$s.' ), $param, $encoded_enum_values[0] ) );
	}

	/* translators: 1: Parameter, 2: List of valid values. */
	return new WP_Error( 'rest_not_in_enum', wp_sprintf( __( '%1$s is not one of %2$l.' ), $param, $encoded_enum_values ) );
}

/**
 * Get all valid JSON schema properties.
 *
 * @since 5.6.0
 *
 * @return string[] All valid JSON schema properties.
 */
function rest_get_allowed_schema_keywords() {
	return array(
		'title',
		'description',
		'default',
		'type',
		'format',
		'enum',
		'items',
		'properties',
		'additionalProperties',
		'patternProperties',
		'minProperties',
		'maxProperties',
		'minimum',
		'maximum',
		'exclusiveMinimum',
		'exclusiveMaximum',
		'multipleOf',
		'minLength',
		'maxLength',
		'pattern',
		'minItems',
		'maxItems',
		'uniqueItems',
		'anyOf',
		'oneOf',
	);
}

/**
 * Validate a value based on a schema.
 *
 * @since 4.7.0
 * @since 4.9.0 Support the "object" type.
 * @since 5.2.0 Support validating "additionalProperties" against a schema.
 * @since 5.3.0 Support multiple types.
 * @since 5.4.0 Convert an empty string to an empty object.
 * @since 5.5.0 Add the "uuid" and "hex-color" formats.
 *              Support the "minLength", "maxLength" and "pattern" keywords for strings.
 *              Support the "minItems", "maxItems" and "uniqueItems" keywords for arrays.
 *              Validate required properties.
 * @since 5.6.0 Support the "minProperties" and "maxProperties" keywords for objects.
 *              Support the "multipleOf" keyword for numbers and integers.
 *              Support the "patternProperties" keyword for objects.
 *              Support the "anyOf" and "oneOf" keywords.
 *
 * @param mixed  $value The value to validate.
 * @param array  $args  Schema array to use for validation.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_value_from_schema( $value, $args, $param = '' ) {
	if ( isset( $args['anyOf'] ) ) {
		$matching_schema = rest_find_any_matching_schema( $value, $args, $param );
		if ( is_wp_error( $matching_schema ) ) {
			return $matching_schema;
		}

		if ( ! isset( $args['type'] ) && isset( $matching_schema['type'] ) ) {
			$args['type'] = $matching_schema['type'];
		}
	}

	if ( isset( $args['oneOf'] ) ) {
		$matching_schema = rest_find_one_matching_schema( $value, $args, $param );
		if ( is_wp_error( $matching_schema ) ) {
			return $matching_schema;
		}

		if ( ! isset( $args['type'] ) && isset( $matching_schema['type'] ) ) {
			$args['type'] = $matching_schema['type'];
		}
	}

	$allowed_types = array( 'array', 'object', 'string', 'number', 'integer', 'boolean', 'null' );

	if ( ! isset( $args['type'] ) ) {
		/* translators: %s: Parameter. */
		_doing_it_wrong( __FUNCTION__, sprintf( __( 'The "type" schema keyword for %s is required.' ), $param ), '5.5.0' );
	}

	if ( is_array( $args['type'] ) ) {
		$best_type = rest_handle_multi_type_schema( $value, $args, $param );

		if ( ! $best_type ) {
			return new WP_Error(
				'rest_invalid_type',
				/* translators: 1: Parameter, 2: List of types. */
				sprintf( __( '%1$s is not of type %2$s.' ), $param, implode( ',', $args['type'] ) ),
				array( 'param' => $param )
			);
		}

		$args['type'] = $best_type;
	}

	if ( ! in_array( $args['type'], $allowed_types, true ) ) {
		_doing_it_wrong(
			__FUNCTION__,
			/* translators: 1: Parameter, 2: The list of allowed types. */
			wp_sprintf( __( 'The "type" schema keyword for %1$s can only be one of the built-in types: %2$l.' ), $param, $allowed_types ),
			'5.5.0'
		);
	}

	switch ( $args['type'] ) {
		case 'null':
			$is_valid = rest_validate_null_value_from_schema( $value, $param );
			break;
		case 'boolean':
			$is_valid = rest_validate_boolean_value_from_schema( $value, $param );
			break;
		case 'object':
			$is_valid = rest_validate_object_value_from_schema( $value, $args, $param );
			break;
		case 'array':
			$is_valid = rest_validate_array_value_from_schema( $value, $args, $param );
			break;
		case 'number':
			$is_valid = rest_validate_number_value_from_schema( $value, $args, $param );
			break;
		case 'string':
			$is_valid = rest_validate_string_value_from_schema( $value, $args, $param );
			break;
		case 'integer':
			$is_valid = rest_validate_integer_value_from_schema( $value, $args, $param );
			break;
		default:
			$is_valid = true;
			break;
	}

	if ( is_wp_error( $is_valid ) ) {
		return $is_valid;
	}

	if ( ! empty( $args['enum'] ) ) {
		$enum_contains_value = rest_validate_enum( $value, $args, $param );
		if ( is_wp_error( $enum_contains_value ) ) {
			return $enum_contains_value;
		}
	}

	// The "format" keyword should only be applied to strings. However, for backward compatibility,
	// we allow the "format" keyword if the type keyword was not specified, or was set to an invalid value.
	if ( isset( $args['format'] )
		&& ( ! isset( $args['type'] ) || 'string' === $args['type'] || ! in_array( $args['type'], $allowed_types, true ) )
	) {
		switch ( $args['format'] ) {
			case 'hex-color':
				if ( ! rest_parse_hex_color( $value ) ) {
					return new WP_Error( 'rest_invalid_hex_color', __( 'Invalid hex color.' ) );
				}
				break;

			case 'date-time':
				if ( ! rest_parse_date( $value ) ) {
					return new WP_Error( 'rest_invalid_date', __( 'Invalid date.' ) );
				}
				break;

			case 'email':
				if ( ! is_email( $value ) ) {
					return new WP_Error( 'rest_invalid_email', __( 'Invalid email address.' ) );
				}
				break;
			case 'ip':
				if ( ! rest_is_ip_address( $value ) ) {
					/* translators: %s: IP address. */
					return new WP_Error( 'rest_invalid_ip', sprintf( __( '%s is not a valid IP address.' ), $param ) );
				}
				break;
			case 'uuid':
				if ( ! wp_is_uuid( $value ) ) {
					/* translators: %s: The name of a JSON field expecting a valid UUID. */
					return new WP_Error( 'rest_invalid_uuid', sprintf( __( '%s is not a valid UUID.' ), $param ) );
				}
				break;
		}
	}

	return true;
}

/**
 * Validates a null value based on a schema.
 *
 * @since 5.7.0
 *
 * @param mixed  $value The value to validate.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_null_value_from_schema( $value, $param ) {
	if ( null !== $value ) {
		return new WP_Error(
			'rest_invalid_type',
			/* translators: 1: Parameter, 2: Type name. */
			sprintf( __( '%1$s is not of type %2$s.' ), $param, 'null' ),
			array( 'param' => $param )
		);
	}

	return true;
}

/**
 * Validates a boolean value based on a schema.
 *
 * @since 5.7.0
 *
 * @param mixed  $value The value to validate.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_boolean_value_from_schema( $value, $param ) {
	if ( ! rest_is_boolean( $value ) ) {
		return new WP_Error(
			'rest_invalid_type',
			/* translators: 1: Parameter, 2: Type name. */
			sprintf( __( '%1$s is not of type %2$s.' ), $param, 'boolean' ),
			array( 'param' => $param )
		);
	}

	return true;
}

/**
 * Validates an object value based on a schema.
 *
 * @since 5.7.0
 *
 * @param mixed  $value The value to validate.
 * @param array  $args  Schema array to use for validation.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_object_value_from_schema( $value, $args, $param ) {
	if ( ! rest_is_object( $value ) ) {
		return new WP_Error(
			'rest_invalid_type',
			/* translators: 1: Parameter, 2: Type name. */
			sprintf( __( '%1$s is not of type %2$s.' ), $param, 'object' ),
			array( 'param' => $param )
		);
	}

	$value = rest_sanitize_object( $value );

	if ( isset( $args['required'] ) && is_array( $args['required'] ) ) { // schema version 4
		foreach ( $args['required'] as $name ) {
			if ( ! array_key_exists( $name, $value ) ) {
				return new WP_Error(
					'rest_property_required',
					/* translators: 1: Property of an object, 2: Parameter. */
					sprintf( __( '%1$s is a required property of %2$s.' ), $name, $param )
				);
			}
		}
	} elseif ( isset( $args['properties'] ) ) { // schema version 3
		foreach ( $args['properties'] as $name => $property ) {
			if ( isset( $property['required'] ) && true === $property['required'] && ! array_key_exists( $name, $value ) ) {
				return new WP_Error(
					'rest_property_required',
					/* translators: 1: Property of an object, 2: Parameter. */
					sprintf( __( '%1$s is a required property of %2$s.' ), $name, $param )
				);
			}
		}
	}

	foreach ( $value as $property => $v ) {
		if ( isset( $args['properties'][ $property ] ) ) {
			$is_valid = rest_validate_value_from_schema( $v, $args['properties'][ $property ], $param . '[' . $property . ']' );
			if ( is_wp_error( $is_valid ) ) {
				return $is_valid;
			}
			continue;
		}

		$pattern_property_schema = rest_find_matching_pattern_property_schema( $property, $args );
		if ( null !== $pattern_property_schema ) {
			$is_valid = rest_validate_value_from_schema( $v, $pattern_property_schema, $param . '[' . $property . ']' );
			if ( is_wp_error( $is_valid ) ) {
				return $is_valid;
			}
			continue;
		}

		if ( isset( $args['additionalProperties'] ) ) {
			if ( false === $args['additionalProperties'] ) {
				return new WP_Error(
					'rest_additional_properties_forbidden',
					/* translators: %s: Property of an object. */
					sprintf( __( '%1$s is not a valid property of Object.' ), $property )
				);
			}

			if ( is_array( $args['additionalProperties'] ) ) {
				$is_valid = rest_validate_value_from_schema( $v, $args['additionalProperties'], $param . '[' . $property . ']' );
				if ( is_wp_error( $is_valid ) ) {
					return $is_valid;
				}
			}
		}
	}

	if ( isset( $args['minProperties'] ) && count( $value ) < $args['minProperties'] ) {
		return new WP_Error(
			'rest_too_few_properties',
			sprintf(
				/* translators: 1: Parameter, 2: Number. */
				_n(
					'%1$s must contain at least %2$s property.',
					'%1$s must contain at least %2$s properties.',
					$args['minProperties']
				),
				$param,
				number_format_i18n( $args['minProperties'] )
			)
		);
	}

	if ( isset( $args['maxProperties'] ) && count( $value ) > $args['maxProperties'] ) {
		return new WP_Error(
			'rest_too_many_properties',
			sprintf(
				/* translators: 1: Parameter, 2: Number. */
				_n(
					'%1$s must contain at most %2$s property.',
					'%1$s must contain at most %2$s properties.',
					$args['maxProperties']
				),
				$param,
				number_format_i18n( $args['maxProperties'] )
			)
		);
	}

	return true;
}

/**
 * Validates an array value based on a schema.
 *
 * @since 5.7.0
 *
 * @param mixed  $value The value to validate.
 * @param array  $args  Schema array to use for validation.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_array_value_from_schema( $value, $args, $param ) {
	if ( ! rest_is_array( $value ) ) {
		return new WP_Error(
			'rest_invalid_type',
			/* translators: 1: Parameter, 2: Type name. */
			sprintf( __( '%1$s is not of type %2$s.' ), $param, 'array' ),
			array( 'param' => $param )
		);
	}

	$value = rest_sanitize_array( $value );

	if ( isset( $args['items'] ) ) {
		foreach ( $value as $index => $v ) {
			$is_valid = rest_validate_value_from_schema( $v, $args['items'], $param . '[' . $index . ']' );
			if ( is_wp_error( $is_valid ) ) {
				return $is_valid;
			}
		}
	}

	if ( isset( $args['minItems'] ) && count( $value ) < $args['minItems'] ) {
		return new WP_Error(
			'rest_too_few_items',
			sprintf(
				/* translators: 1: Parameter, 2: Number. */
				_n(
					'%1$s must contain at least %2$s item.',
					'%1$s must contain at least %2$s items.',
					$args['minItems']
				),
				$param,
				number_format_i18n( $args['minItems'] )
			)
		);
	}

	if ( isset( $args['maxItems'] ) && count( $value ) > $args['maxItems'] ) {
		return new WP_Error(
			'rest_too_many_items',
			sprintf(
				/* translators: 1: Parameter, 2: Number. */
				_n(
					'%1$s must contain at most %2$s item.',
					'%1$s must contain at most %2$s items.',
					$args['maxItems']
				),
				$param,
				number_format_i18n( $args['maxItems'] )
			)
		);
	}

	if ( ! empty( $args['uniqueItems'] ) && ! rest_validate_array_contains_unique_items( $value ) ) {
		/* translators: %s: Parameter. */
		return new WP_Error( 'rest_duplicate_items', sprintf( __( '%s has duplicate items.' ), $param ) );
	}

	return true;
}

/**
 * Validates a number value based on a schema.
 *
 * @since 5.7.0
 *
 * @param mixed  $value The value to validate.
 * @param array  $args  Schema array to use for validation.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_number_value_from_schema( $value, $args, $param ) {
	if ( ! is_numeric( $value ) ) {
		return new WP_Error(
			'rest_invalid_type',
			/* translators: 1: Parameter, 2: Type name. */
			sprintf( __( '%1$s is not of type %2$s.' ), $param, $args['type'] ),
			array( 'param' => $param )
		);
	}

	if ( isset( $args['multipleOf'] ) && fmod( $value, $args['multipleOf'] ) !== 0.0 ) {
		return new WP_Error(
			'rest_invalid_multiple',
			/* translators: 1: Parameter, 2: Multiplier. */
			sprintf( __( '%1$s must be a multiple of %2$s.' ), $param, $args['multipleOf'] )
		);
	}

	if ( isset( $args['minimum'] ) && ! isset( $args['maximum'] ) ) {
		if ( ! empty( $args['exclusiveMinimum'] ) && $value <= $args['minimum'] ) {
			return new WP_Error(
				'rest_out_of_bounds',
				/* translators: 1: Parameter, 2: Minimum number. */
				sprintf( __( '%1$s must be greater than %2$d' ), $param, $args['minimum'] )
			);
		}

		if ( empty( $args['exclusiveMinimum'] ) && $value < $args['minimum'] ) {
			return new WP_Error(
				'rest_out_of_bounds',
				/* translators: 1: Parameter, 2: Minimum number. */
				sprintf( __( '%1$s must be greater than or equal to %2$d' ), $param, $args['minimum'] )
			);
		}
	}

	if ( isset( $args['maximum'] ) && ! isset( $args['minimum'] ) ) {
		if ( ! empty( $args['exclusiveMaximum'] ) && $value >= $args['maximum'] ) {
			return new WP_Error(
				'rest_out_of_bounds',
				/* translators: 1: Parameter, 2: Maximum number. */
				sprintf( __( '%1$s must be less than %2$d' ), $param, $args['maximum'] )
			);
		}

		if ( empty( $args['exclusiveMaximum'] ) && $value > $args['maximum'] ) {
			return new WP_Error(
				'rest_out_of_bounds',
				/* translators: 1: Parameter, 2: Maximum number. */
				sprintf( __( '%1$s must be less than or equal to %2$d' ), $param, $args['maximum'] )
			);
		}
	}

	if ( isset( $args['minimum'], $args['maximum'] ) ) {
		if ( ! empty( $args['exclusiveMinimum'] ) && ! empty( $args['exclusiveMaximum'] ) ) {
			if ( $value >= $args['maximum'] || $value <= $args['minimum'] ) {
				return new WP_Error(
					'rest_out_of_bounds',
					sprintf(
						/* translators: 1: Parameter, 2: Minimum number, 3: Maximum number. */
						__( '%1$s must be between %2$d (exclusive) and %3$d (exclusive)' ),
						$param,
						$args['minimum'],
						$args['maximum']
					)
				);
			}
		}

		if ( ! empty( $args['exclusiveMinimum'] ) && empty( $args['exclusiveMaximum'] ) ) {
			if ( $value > $args['maximum'] || $value <= $args['minimum'] ) {
				return new WP_Error(
					'rest_out_of_bounds',
					sprintf(
						/* translators: 1: Parameter, 2: Minimum number, 3: Maximum number. */
						__( '%1$s must be between %2$d (exclusive) and %3$d (inclusive)' ),
						$param,
						$args['minimum'],
						$args['maximum']
					)
				);
			}
		}

		if ( ! empty( $args['exclusiveMaximum'] ) && empty( $args['exclusiveMinimum'] ) ) {
			if ( $value >= $args['maximum'] || $value < $args['minimum'] ) {
				return new WP_Error(
					'rest_out_of_bounds',
					sprintf(
						/* translators: 1: Parameter, 2: Minimum number, 3: Maximum number. */
						__( '%1$s must be between %2$d (inclusive) and %3$d (exclusive)' ),
						$param,
						$args['minimum'],
						$args['maximum']
					)
				);
			}
		}

		if ( empty( $args['exclusiveMinimum'] ) && empty( $args['exclusiveMaximum'] ) ) {
			if ( $value > $args['maximum'] || $value < $args['minimum'] ) {
				return new WP_Error(
					'rest_out_of_bounds',
					sprintf(
						/* translators: 1: Parameter, 2: Minimum number, 3: Maximum number. */
						__( '%1$s must be between %2$d (inclusive) and %3$d (inclusive)' ),
						$param,
						$args['minimum'],
						$args['maximum']
					)
				);
			}
		}
	}

	return true;
}

/**
 * Validates a string value based on a schema.
 *
 * @since 5.7.0
 *
 * @param mixed  $value The value to validate.
 * @param array  $args  Schema array to use for validation.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_string_value_from_schema( $value, $args, $param ) {
	if ( ! is_string( $value ) ) {
		return new WP_Error(
			'rest_invalid_type',
			/* translators: 1: Parameter, 2: Type name. */
			sprintf( __( '%1$s is not of type %2$s.' ), $param, 'string' ),
			array( 'param' => $param )
		);
	}

	if ( isset( $args['minLength'] ) && mb_strlen( $value ) < $args['minLength'] ) {
		return new WP_Error(
			'rest_too_short',
			sprintf(
				/* translators: 1: Parameter, 2: Number of characters. */
				_n(
					'%1$s must be at least %2$s character long.',
					'%1$s must be at least %2$s characters long.',
					$args['minLength']
				),
				$param,
				number_format_i18n( $args['minLength'] )
			)
		);
	}

	if ( isset( $args['maxLength'] ) && mb_strlen( $value ) > $args['maxLength'] ) {
		return new WP_Error(
			'rest_too_long',
			sprintf(
				/* translators: 1: Parameter, 2: Number of characters. */
				_n(
					'%1$s must be at most %2$s character long.',
					'%1$s must be at most %2$s characters long.',
					$args['maxLength']
				),
				$param,
				number_format_i18n( $args['maxLength'] )
			)
		);
	}

	if ( isset( $args['pattern'] ) && ! rest_validate_json_schema_pattern( $args['pattern'], $value ) ) {
		return new WP_Error(
			'rest_invalid_pattern',
			/* translators: 1: Parameter, 2: Pattern. */
			sprintf( __( '%1$s does not match pattern %2$s.' ), $param, $args['pattern'] )
		);
	}

	return true;
}

/**
 * Validates an integer value based on a schema.
 *
 * @since 5.7.0
 *
 * @param mixed  $value The value to validate.
 * @param array  $args  Schema array to use for validation.
 * @param string $param The parameter name, used in error messages.
 * @return true|WP_Error
 */
function rest_validate_integer_value_from_schema( $value, $args, $param ) {
	$is_valid_number = rest_validate_number_value_from_schema( $value, $args, $param );
	if ( is_wp_error( $is_valid_number ) ) {
		return $is_valid_number;
	}

	if ( ! rest_is_integer( $value ) ) {
		return new WP_Error(
			'rest_invalid_type',
			/* translators: 1: Parameter, 2: Type name. */
			sprintf( __( '%1$s is not of type %2$s.' ), $param, 'integer' ),
			array( 'param' => $param )
		);
	}

	return true;
}

/**
 * Sanitize a value based on a schema.
 *
 * @since 4.7.0
 * @since 5.5.0 Added the `$param` parameter.
 * @since 5.6.0 Support the "anyOf" and "oneOf" keywords.
 * @since 5.9.0 Added `text-field` and `textarea-field` formats.
 *
 * @param mixed  $value The value to sanitize.
 * @param array  $args  Schema array to use for sanitization.
 * @param string $param The parameter name, used in error messages.
 * @return mixed|WP_Error The sanitized value or a WP_Error instance if the value cannot be safely sanitized.
 */
function rest_sanitize_value_from_schema( $value, $args, $param = '' ) {
	if ( isset( $args['anyOf'] ) ) {
		$matching_schema = rest_find_any_matching_schema( $value, $args, $param );
		if ( is_wp_error( $matching_schema ) ) {
			return $matching_schema;
		}

		if ( ! isset( $args['type'] ) ) {
			$args['type'] = $matching_schema['type'];
		}

		$value = rest_sanitize_value_from_schema( $value, $matching_schema, $param );
	}

	if ( isset( $args['oneOf'] ) ) {
		$matching_schema = rest_find_one_matching_schema( $value, $args, $param );
		if ( is_wp_error( $matching_schema ) ) {
			return $matching_schema;
		}

		if ( ! isset( $args['type'] ) ) {
			$args['type'] = $matching_schema['type'];
		}

		$value = rest_sanitize_value_from_schema( $value, $matching_schema, $param );
	}

	$allowed_types = array( 'array', 'object', 'string', 'number', 'integer', 'boolean', 'null' );

	if ( ! isset( $args['type'] ) ) {
		/* translators: %s: Parameter. */
		_doing_it_wrong( __FUNCTION__, sprintf( __( 'The "type" schema keyword for %s is required.' ), $param ), '5.5.0' );
	}

	if ( is_array( $args['type'] ) ) {
		$best_type = rest_handle_multi_type_schema( $value, $args, $param );

		if ( ! $best_type ) {
			return null;
		}

		$args['type'] = $best_type;
	}

	if ( ! in_array( $args['type'], $allowed_types, true ) ) {
		_doing_it_wrong(
			__FUNCTION__,
			/* translators: 1: Parameter, 2: The list of allowed types. */
			wp_sprintf( __( 'The "type" schema keyword for %1$s can only be one of the built-in types: %2$l.' ), $param, $allowed_types ),
			'5.5.0'
		);
	}

	if ( 'array' === $args['type'] ) {
		$value = rest_sanitize_array( $value );

		if ( ! empty( $args['items'] ) ) {
			foreach ( $value as $index => $v ) {
				$value[ $index ] = rest_sanitize_value_from_schema( $v, $args['items'], $param . '[' . $index . ']' );
			}
		}

		if ( ! empty( $args['uniqueItems'] ) && ! rest_validate_array_contains_unique_items( $value ) ) {
			/* translators: %s: Parameter. */
			return new WP_Error( 'rest_duplicate_items', sprintf( __( '%s has duplicate items.' ), $param ) );
		}

		return $value;
	}

	if ( 'object' === $args['type'] ) {
		$value = rest_sanitize_object( $value );

		foreach ( $value as $property => $v ) {
			if ( isset( $args['properties'][ $property ] ) ) {
				$value[ $property ] = rest_sanitize_value_from_schema( $v, $args['properties'][ $property ], $param . '[' . $property . ']' );
				continue;
			}

			$pattern_property_schema = rest_find_matching_pattern_property_schema( $property, $args );
			if ( null !== $pattern_property_schema ) {
				$value[ $property ] = rest_sanitize_value_from_schema( $v, $pattern_property_schema, $param . '[' . $property . ']' );
				continue;
			}

			if ( isset( $args['additionalProperties'] ) ) {
				if ( false === $args['additionalProperties'] ) {
					unset( $value[ $property ] );
				} elseif ( is_array( $args['additionalProperties'] ) ) {
					$value[ $property ] = rest_sanitize_value_from_schema( $v, $args['additionalProperties'], $param . '[' . $property . ']' );
				}
			}
		}

		return $value;
	}

	if ( 'null' === $args['type'] ) {
		return null;
	}

	if ( 'integer' === $args['type'] ) {
		return (int) $value;
	}

	if ( 'number' === $args['type'] ) {
		return (float) $value;
	}

	if ( 'boolean' === $args['type'] ) {
		return rest_sanitize_boolean( $value );
	}

	// This behavior matches rest_validate_value_from_schema().
	if ( isset( $args['format'] )
		&& ( ! isset( $args['type'] ) || 'string' === $args['type'] || ! in_array( $args['type'], $allowed_types, true ) )
	) {
		switch ( $args['format'] ) {
			case 'hex-color':
				return (string) sanitize_hex_color( $value );

			case 'date-time':
				return sanitize_text_field( $value );

			case 'email':
				// sanitize_email() validates, which would be unexpected.
				return sanitize_text_field( $value );

			case 'uri':
				return sanitize_url( $value );

			case 'ip':
				return sanitize_text_field( $value );

			case 'uuid':
				return sanitize_text_field( $value );

			case 'text-field':
				return sanitize_text_field( $value );

			case 'textarea-field':
				return sanitize_textarea_field( $value );
		}
	}

	if ( 'string' === $args['type'] ) {
		return (string) $value;
	}

	return $value;
}

/**
 * Append result of internal request to REST API for purpose of preloading data to be attached to a page.
 * Expected to be called in the context of `array_reduce`.
 *
 * @since 5.0.0
 *
 * @param array  $memo Reduce accumulator.
 * @param string $path REST API path to preload.
 * @return array Modified reduce accumulator.
 */
function rest_preload_api_request( $memo, $path ) {
	// array_reduce() doesn't support passing an array in PHP 5.2,
	// so we need to make sure we start with one.
	if ( ! is_array( $memo ) ) {
		$memo = array();
	}

	if ( empty( $path ) ) {
		return $memo;
	}

	$method = 'GET';
	if ( is_array( $path ) && 2 === count( $path ) ) {
		$method = end( $path );
		$path   = reset( $path );

		if ( ! in_array( $method, array( 'GET', 'OPTIONS' ), true ) ) {
			$method = 'GET';
		}
	}

	$path = untrailingslashit( $path );
	if ( empty( $path ) ) {
		$path = '/';
	}

	$path_parts = parse_url( $path );
	if ( false === $path_parts ) {
		return $memo;
	}

	$request = new WP_REST_Request( $method, $path_parts['path'] );
	if ( ! empty( $path_parts['query'] ) ) {
		parse_str( $path_parts['query'], $query_params );
		$request->set_query_params( $query_params );
	}

	$response = rest_do_request( $request );
	if ( 200 === $response->status ) {
		$server = rest_get_server();
		/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
		$response = apply_filters( 'rest_post_dispatch', rest_ensure_response( $response ), $server, $request );
		$embed    = $request->has_param( '_embed' ) ? rest_parse_embed_param( $request['_embed'] ) : false;
		$data     = (array) $server->response_to_data( $response, $embed );

		if ( 'OPTIONS' === $method ) {
			$memo[ $method ][ $path ] = array(
				'body'    => $data,
				'headers' => $response->headers,
			);
		} else {
			$memo[ $path ] = array(
				'body'    => $data,
				'headers' => $response->headers,
			);
		}
	}

	return $memo;
}

/**
 * Parses the "_embed" parameter into the list of resources to embed.
 *
 * @since 5.4.0
 *
 * @param string|array $embed Raw "_embed" parameter value.
 * @return true|string[] Either true to embed all embeds, or a list of relations to embed.
 */
function rest_parse_embed_param( $embed ) {
	if ( ! $embed || 'true' === $embed || '1' === $embed ) {
		return true;
	}

	$rels = wp_parse_list( $embed );

	if ( ! $rels ) {
		return true;
	}

	return $rels;
}

/**
 * Filters the response to remove any fields not available in the given context.
 *
 * @since 5.5.0
 * @since 5.6.0 Support the "patternProperties" keyword for objects.
 *              Support the "anyOf" and "oneOf" keywords.
 *
 * @param array|object $response_data The response data to modify.
 * @param array        $schema        The schema for the endpoint used to filter the response.
 * @param string       $context       The requested context.
 * @return array|object The filtered response data.
 */
function rest_filter_response_by_context( $response_data, $schema, $context ) {
	if ( isset( $schema['anyOf'] ) ) {
		$matching_schema = rest_find_any_matching_schema( $response_data, $schema, '' );
		if ( ! is_wp_error( $matching_schema ) ) {
			if ( ! isset( $schema['type'] ) ) {
				$schema['type'] = $matching_schema['type'];
			}

			$response_data = rest_filter_response_by_context( $response_data, $matching_schema, $context );
		}
	}

	if ( isset( $schema['oneOf'] ) ) {
		$matching_schema = rest_find_one_matching_schema( $response_data, $schema, '', true );
		if ( ! is_wp_error( $matching_schema ) ) {
			if ( ! isset( $schema['type'] ) ) {
				$schema['type'] = $matching_schema['type'];
			}

			$response_data = rest_filter_response_by_context( $response_data, $matching_schema, $context );
		}
	}

	if ( ! is_array( $response_data ) && ! is_object( $response_data ) ) {
		return $response_data;
	}

	if ( isset( $schema['type'] ) ) {
		$type = $schema['type'];
	} elseif ( isset( $schema['properties'] ) ) {
		$type = 'object'; // Back compat if a developer accidentally omitted the type.
	} else {
		return $response_data;
	}

	$is_array_type  = 'array' === $type || ( is_array( $type ) && in_array( 'array', $type, true ) );
	$is_object_type = 'object' === $type || ( is_array( $type ) && in_array( 'object', $type, true ) );

	if ( $is_array_type && $is_object_type ) {
		if ( rest_is_array( $response_data ) ) {
			$is_object_type = false;
		} else {
			$is_array_type = false;
		}
	}

	$has_additional_properties = $is_object_type && isset( $schema['additionalProperties'] ) && is_array( $schema['additionalProperties'] );

	foreach ( $response_data as $key => $value ) {
		$check = array();

		if ( $is_array_type ) {
			$check = isset( $schema['items'] ) ? $schema['items'] : array();
		} elseif ( $is_object_type ) {
			if ( isset( $schema['properties'][ $key ] ) ) {
				$check = $schema['properties'][ $key ];
			} else {
				$pattern_property_schema = rest_find_matching_pattern_property_schema( $key, $schema );
				if ( null !== $pattern_property_schema ) {
					$check = $pattern_property_schema;
				} elseif ( $has_additional_properties ) {
					$check = $schema['additionalProperties'];
				}
			}
		}

		if ( ! isset( $check['context'] ) ) {
			continue;
		}

		if ( ! in_array( $context, $check['context'], true ) ) {
			if ( $is_array_type ) {
				// All array items share schema, so there's no need to check each one.
				$response_data = array();
				break;
			}

			if ( is_object( $response_data ) ) {
				unset( $response_data->$key );
			} else {
				unset( $response_data[ $key ] );
			}
		} elseif ( is_array( $value ) || is_object( $value ) ) {
			$new_value = rest_filter_response_by_context( $value, $check, $context );

			if ( is_object( $response_data ) ) {
				$response_data->$key = $new_value;
			} else {
				$response_data[ $key ] = $new_value;
			}
		}
	}

	return $response_data;
}

/**
 * Sets the "additionalProperties" to false by default for all object definitions in the schema.
 *
 * @since 5.5.0
 * @since 5.6.0 Support the "patternProperties" keyword.
 *
 * @param array $schema The schema to modify.
 * @return array The modified schema.
 */
function rest_default_additional_properties_to_false( $schema ) {
	$type = (array) $schema['type'];

	if ( in_array( 'object', $type, true ) ) {
		if ( isset( $schema['properties'] ) ) {
			foreach ( $schema['properties'] as $key => $child_schema ) {
				$schema['properties'][ $key ] = rest_default_additional_properties_to_false( $child_schema );
			}
		}

		if ( isset( $schema['patternProperties'] ) ) {
			foreach ( $schema['patternProperties'] as $key => $child_schema ) {
				$schema['patternProperties'][ $key ] = rest_default_additional_properties_to_false( $child_schema );
			}
		}

		if ( ! isset( $schema['additionalProperties'] ) ) {
			$schema['additionalProperties'] = false;
		}
	}

	if ( in_array( 'array', $type, true ) ) {
		if ( isset( $schema['items'] ) ) {
			$schema['items'] = rest_default_additional_properties_to_false( $schema['items'] );
		}
	}

	return $schema;
}

/**
 * Gets the REST API route for a post.
 *
 * @since 5.5.0
 *
 * @param int|WP_Post $post Post ID or post object.
 * @return string The route path with a leading slash for the given post,
 *                or an empty string if there is not a route.
 */
function rest_get_route_for_post( $post ) {
	$post = get_post( $post );

	if ( ! $post instanceof WP_Post ) {
		return '';
	}

	$post_type_route = rest_get_route_for_post_type_items( $post->post_type );
	if ( ! $post_type_route ) {
		return '';
	}

	$route = sprintf( '%s/%d', $post_type_route, $post->ID );

	/**
	 * Filters the REST API route for a post.
	 *
	 * @since 5.5.0
	 *
	 * @param string  $route The route path.
	 * @param WP_Post $post  The post object.
	 */
	return apply_filters( 'rest_route_for_post', $route, $post );
}

/**
 * Gets the REST API route for a post type.
 *
 * @since 5.9.0
 *
 * @param string $post_type The name of a registered post type.
 * @return string The route path with a leading slash for the given post type,
 *                or an empty string if there is not a route.
 */
function rest_get_route_for_post_type_items( $post_type ) {
	$post_type = get_post_type_object( $post_type );
	if ( ! $post_type ) {
		return '';
	}

	if ( ! $post_type->show_in_rest ) {
		return '';
	}

	$namespace = ! empty( $post_type->rest_namespace ) ? $post_type->rest_namespace : 'wp/v2';
	$rest_base = ! empty( $post_type->rest_base ) ? $post_type->rest_base : $post_type->name;
	$route     = sprintf( '/%s/%s', $namespace, $rest_base );

	/**
	 * Filters the REST API route for a post type.
	 *
	 * @since 5.9.0
	 *
	 * @param string       $route      The route path.
	 * @param WP_Post_Type $post_type  The post type object.
	 */
	return apply_filters( 'rest_route_for_post_type_items', $route, $post_type );
}

/**
 * Gets the REST API route for a term.
 *
 * @since 5.5.0
 *
 * @param int|WP_Term $term Term ID or term object.
 * @return string The route path with a leading slash for the given term,
 *                or an empty string if there is not a route.
 */
function rest_get_route_for_term( $term ) {
	$term = get_term( $term );

	if ( ! $term instanceof WP_Term ) {
		return '';
	}

	$taxonomy_route = rest_get_route_for_taxonomy_items( $term->taxonomy );
	if ( ! $taxonomy_route ) {
		return '';
	}

	$route = sprintf( '%s/%d', $taxonomy_route, $term->term_id );

	/**
	 * Filters the REST API route for a term.
	 *
	 * @since 5.5.0
	 *
	 * @param string  $route The route path.
	 * @param WP_Term $term  The term object.
	 */
	return apply_filters( 'rest_route_for_term', $route, $term );
}

/**
 * Gets the REST API route for a taxonomy.
 *
 * @since 5.9.0
 *
 * @param string $taxonomy Name of taxonomy.
 * @return string The route path with a leading slash for the given taxonomy.
 */
function rest_get_route_for_taxonomy_items( $taxonomy ) {
	$taxonomy = get_taxonomy( $taxonomy );
	if ( ! $taxonomy ) {
		return '';
	}

	if ( ! $taxonomy->show_in_rest ) {
		return '';
	}

	$namespace = ! empty( $taxonomy->rest_namespace ) ? $taxonomy->rest_namespace : 'wp/v2';
	$rest_base = ! empty( $taxonomy->rest_base ) ? $taxonomy->rest_base : $taxonomy->name;
	$route     = sprintf( '/%s/%s', $namespace, $rest_base );

	/**
	 * Filters the REST API route for a taxonomy.
	 *
	 * @since 5.9.0
	 *
	 * @param string      $route    The route path.
	 * @param WP_Taxonomy $taxonomy The taxonomy object.
	 */
	return apply_filters( 'rest_route_for_taxonomy_items', $route, $taxonomy );
}

/**
 * Gets the REST route for the currently queried object.
 *
 * @since 5.5.0
 *
 * @return string The REST route of the resource, or an empty string if no resource identified.
 */
function rest_get_queried_resource_route() {
	if ( is_singular() ) {
		$route = rest_get_route_for_post( get_queried_object() );
	} elseif ( is_category() || is_tag() || is_tax() ) {
		$route = rest_get_route_for_term( get_queried_object() );
	} elseif ( is_author() ) {
		$route = '/wp/v2/users/' . get_queried_object_id();
	} else {
		$route = '';
	}

	/**
	 * Filters the REST route for the currently queried object.
	 *
	 * @since 5.5.0
	 *
	 * @param string $link The route with a leading slash, or an empty string.
	 */
	return apply_filters( 'rest_queried_resource_route', $route );
}

/**
 * Retrieves an array of endpoint arguments from the item schema and endpoint method.
 *
 * @since 5.6.0
 *
 * @param array  $schema The full JSON schema for the endpoint.
 * @param string $method Optional. HTTP method of the endpoint. The arguments for `CREATABLE` endpoints are
 *                       checked for required values and may fall-back to a given default, this is not done
 *                       on `EDITABLE` endpoints. Default WP_REST_Server::CREATABLE.
 * @return array The endpoint arguments.
 */
function rest_get_endpoint_args_for_schema( $schema, $method = WP_REST_Server::CREATABLE ) {

	$schema_properties       = ! empty( $schema['properties'] ) ? $schema['properties'] : array();
	$endpoint_args           = array();
	$valid_schema_properties = rest_get_allowed_schema_keywords();
	$valid_schema_properties = array_diff( $valid_schema_properties, array( 'default', 'required' ) );

	foreach ( $schema_properties as $field_id => $params ) {

		// Arguments specified as `readonly` are not allowed to be set.
		if ( ! empty( $params['readonly'] ) ) {
			continue;
		}

		$endpoint_args[ $field_id ] = array(
			'validate_callback' => 'rest_validate_request_arg',
			'sanitize_callback' => 'rest_sanitize_request_arg',
		);

		if ( WP_REST_Server::CREATABLE === $method && isset( $params['default'] ) ) {
			$endpoint_args[ $field_id ]['default'] = $params['default'];
		}

		if ( WP_REST_Server::CREATABLE === $method && ! empty( $params['required'] ) ) {
			$endpoint_args[ $field_id ]['required'] = true;
		}

		foreach ( $valid_schema_properties as $schema_prop ) {
			if ( isset( $params[ $schema_prop ] ) ) {
				$endpoint_args[ $field_id ][ $schema_prop ] = $params[ $schema_prop ];
			}
		}

		// Merge in any options provided by the schema property.
		if ( isset( $params['arg_options'] ) ) {

			// Only use required / default from arg_options on CREATABLE endpoints.
			if ( WP_REST_Server::CREATABLE !== $method ) {
				$params['arg_options'] = array_diff_key(
					$params['arg_options'],
					array(
						'required' => '',
						'default'  => '',
					)
				);
			}

			$endpoint_args[ $field_id ] = array_merge( $endpoint_args[ $field_id ], $params['arg_options'] );
		}
	}

	return $endpoint_args;
}


/**
 * Converts an error to a response object.
 *
 * This iterates over all error codes and messages to change it into a flat
 * array. This enables simpler client behavior, as it is represented as a
 * list in JSON rather than an object/map.
 *
 * @since 5.7.0
 *
 * @param WP_Error $error WP_Error instance.
 *
 * @return WP_REST_Response List of associative arrays with code and message keys.
 */
function rest_convert_error_to_response( $error ) {
	$status = array_reduce(
		$error->get_all_error_data(),
		static function ( $status, $error_data ) {
			return is_array( $error_data ) && isset( $error_data['status'] ) ? $error_data['status'] : $status;
		},
		500
	);

	$errors = array();

	foreach ( (array) $error->errors as $code => $messages ) {
		$all_data  = $error->get_all_error_data( $code );
		$last_data = array_pop( $all_data );

		foreach ( (array) $messages as $message ) {
			$formatted = array(
				'code'    => $code,
				'message' => $message,
				'data'    => $last_data,
			);

			if ( $all_data ) {
				$formatted['additional_data'] = $all_data;
			}

			$errors[] = $formatted;
		}
	}

	$data = $errors[0];
	if ( count( $errors ) > 1 ) {
		// Remove the primary error.
		array_shift( $errors );
		$data['additional_errors'] = $errors;
	}

	return new WP_REST_Response( $data, $status );
}