<?php

/**

 *

 * Functions for retrieving and manipulating metadata of various WordPress object types. Metadata

 * for an object is a represented by a simple key-value pair. Objects may contain multiple

 * metadata entries that share the same key and differ only in their value.

 *

 * @package WordPress

 * @subpackage Meta

 */

/**

 * Add metadata for the specified object.

 *

 * @since 2.9.0

 *

 * @global wpdb $wpdb WordPress database abstraction object.

 *

 */

function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique = false) {

	global $wpdb;

	if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) ) {

		return false;

	}

	$object_id = absint( $object_id );

	if ( ! $object_id ) {

		return false;

	}

	$table = _get_meta_table( $meta_type );

	if ( ! $table ) {

		return false;

	}

	$column = sanitize_key($meta_type . '_id');

	// expected_slashed ($meta_key)

	$meta_key = wp_unslash($meta_key);

	$meta_value = wp_unslash($meta_value);

	/**

	 *

	 * The dynamic portion of the hook, `$meta_type`, refers to the meta

	 * object type (comment, post, or user). Returning a non-null value

	 * will effectively short-circuit the function.

	 *

	 * @since 3.1.0

	 *

	 * @param null|bool $check      Whether to allow adding metadata for the given type.

	 * @param int       $object_id  Object ID.

	 * @param string    $meta_key   Meta key.

	 * @param mixed     $meta_value Meta value. Must be serializable if non-scalar.

	 * @param bool      $unique     Whether the specified meta key should be unique

	 *                              for the object. Optional. Default false.

	 */

	$check = apply_filters( "add_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $unique );

	if ( null !== $check )

		return $check;

	if ( $unique && $wpdb->get_var( $wpdb->prepare(

		"SELECT COUNT(*) FROM $table WHERE meta_key = %s AND $column = %d",

		$meta_key, $object_id ) ) )

		return false;

	$_meta_value = $meta_value;

	$meta_value = maybe_serialize( $meta_value );

	/**

	 * Fires immediately before meta of a specific type is added.

	 *

	 * The dynamic portion of the hook, `$meta_type`, refers to the meta

	 * object type (comment, post, or user).

	 *

	 * @since 3.1.0

	 *

	 * @param int    $object_id  Object ID.

	 * @param string $meta_key   Meta key.

	 * @param mixed  $meta_value Meta value.

	 */

	do_action( "add_{$meta_type}_meta", $object_id, $meta_key, $_meta_value );

	$result = $wpdb->insert( $table, array(

		$column => $object_id,

		'meta_key' => $meta_key,

		'meta_value' => $meta_value

	) );

	if ( ! $result )

		return false;

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

	wp_cache_delete($object_id, $meta_type . '_meta');

	/**

	 * Fires immediately after meta of a specific type is added.

	 *

	 * The dynamic portion of the hook, `$meta_type`, refers to the meta

	 * object type (comment, post, or user).

	 *

	 * @since 2.9.0

	 *

	 * @param int    $mid        The meta ID after successful update.

	 * @param int    $object_id  Object ID.

	 * @param string $meta_key   Meta key.

	 * @param mixed  $meta_value Meta value.

	 */

	do_action( "added_{$meta_type}_meta", $mid, $object_id, $meta_key, $_meta_value );

	return $mid;

}

/**

 * Update metadata for the specified object. If no value already exists for the specified object

 * ID and metadata key, the metadata will be added.

 *

 * @since 2.9.0

 *

 * @global wpdb $wpdb WordPress database abstraction object.

 *

 * @return int|bool Meta ID if the key didn't exist, true on successful update, false on failure.

 */

function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_value = '') {

	global $wpdb;

	if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) ) {

		return false;

	}

	$object_id = absint( $object_id );

	if ( ! $object_id ) {

		return false;

	}

	$table = _get_meta_table( $meta_type );

	if ( ! $table ) {

		return false;

	}

	$column = sanitize_key($meta_type . '_id');

	$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';

	// expected_slashed ($meta_key)

	$meta_key = wp_unslash($meta_key);

	$passed_value = $meta_value;

	$meta_value = wp_unslash($meta_value);

	/**

	 *

	 * The dynamic portion of the hook, `$meta_type`, refers to the meta

	 * object type (comment, post, or user). Returning a non-null value

	 * will effectively short-circuit the function.

	 *

	 * @since 3.1.0

	 *

	 * @param null|bool $check      Whether to allow updating metadata for the given type.

	 * @param int       $object_id  Object ID.

	 * @param string    $meta_key   Meta key.

	 * @param mixed     $meta_value Meta value. Must be serializable if non-scalar.

	 * @param mixed     $prev_value Optional. If specified, only update existing

	 *                              metadata entries with the specified value.

	 *                              Otherwise, update all entries.

	 */

	$check = apply_filters( "update_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $prev_value );

	if ( null !== $check )

		return (bool) $check;

	// Compare existing value to new value if no prev value given and the key exists only once.

	if ( empty($prev_value) ) {

		$old_value = get_metadata($meta_type, $object_id, $meta_key);

		if ( count($old_value) == 1 ) {

			if ( $old_value[0] === $meta_value )

				return false;

		}

	}

	$meta_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $id_column FROM $table WHERE meta_key = %s AND $column = %d", $meta_key, $object_id ) );

	if ( empty( $meta_ids ) ) {

	}

	$_meta_value = $meta_value;

	$meta_value = maybe_serialize( $meta_value );

	$data  = compact( 'meta_value' );

	$where = array( $column => $object_id, 'meta_key' => $meta_key );

	if ( !empty( $prev_value ) ) {

		$prev_value = maybe_serialize($prev_value);

		$where['meta_value'] = $prev_value;

	}

	foreach ( $meta_ids as $meta_id ) {

		/**

		 * Fires immediately before updating metadata of a specific type.

		 *

		 * The dynamic portion of the hook, `$meta_type`, refers to the meta

		 * object type (comment, post, or user).

		 *

		 * @since 2.9.0

		 *

		 * @param int    $meta_id    ID of the metadata entry to update.

		 * @param int    $object_id  Object ID.

		 * @param string $meta_key   Meta key.

		 * @param mixed  $meta_value Meta value.

		 */

		do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );

			/**

			 * Fires immediately before updating a post's metadata.

			 *

			 * @since 2.9.0

			 *

			 * @param int    $meta_id    ID of metadata entry to update.

			 * @param int    $object_id  Object ID.

			 * @param string $meta_key   Meta key.

			 * @param mixed  $meta_value Meta value.

			 */

			do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );

		}

	}

	$result = $wpdb->update( $table, $data, $where );

	if ( ! $result )

		return false;

	wp_cache_delete($object_id, $meta_type . '_meta');

	foreach ( $meta_ids as $meta_id ) {

		/**

		 * Fires immediately after updating metadata of a specific type.

		 *

		 * The dynamic portion of the hook, `$meta_type`, refers to the meta

		 * object type (comment, post, or user).

		 *

		 * @since 2.9.0

		 *

		 * @param int    $meta_id    ID of updated metadata entry.

		 * @param int    $object_id  Object ID.

		 * @param string $meta_key   Meta key.

		 * @param mixed  $meta_value Meta value.

		 */

		do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );

			/**

			 * Fires immediately after updating a post's metadata.

			 *

			 * @since 2.9.0

			 *

			 * @param int    $meta_id    ID of updated metadata entry.

			 * @param int    $object_id  Object ID.

			 * @param string $meta_key   Meta key.

			 * @param mixed  $meta_value Meta value.

			 */

			do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );

		}

	}

	return true;

}

/**

 * Delete metadata for the specified object.

 *

 * @since 2.9.0

 *

 * @global wpdb $wpdb WordPress database abstraction object.

 *

 * @return bool True on successful delete, false on failure.

 */

function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $delete_all = false) {

	global $wpdb;

	if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) && ! $delete_all ) {

		return false;

	}

	$object_id = absint( $object_id );

	if ( ! $object_id && ! $delete_all ) {

		return false;

	}

	$table = _get_meta_table( $meta_type );

	if ( ! $table ) {

		return false;

	}

	$type_column = sanitize_key($meta_type . '_id');

	$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';

	// expected_slashed ($meta_key)

	$meta_key = wp_unslash($meta_key);

	$meta_value = wp_unslash($meta_value);

	/**

	 *

	 * The dynamic portion of the hook, `$meta_type`, refers to the meta

	 * object type (comment, post, or user). Returning a non-null value

	 * will effectively short-circuit the function.

	 *

	 * @since 3.1.0

	 *

	 * @param null|bool $delete     Whether to allow metadata deletion of the given type.

	 * @param int       $object_id  Object ID.

	 * @param string    $meta_key   Meta key.

	 * @param mixed     $meta_value Meta value. Must be serializable if non-scalar.

	 * @param bool      $delete_all Whether to delete the matching metadata entries

	 *                              for all objects, ignoring the specified $object_id.

	 *                              Default false.

	 */

	$check = apply_filters( "delete_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $delete_all );

	if ( null !== $check )

		return (bool) $check;

	$_meta_value = $meta_value;

	$meta_value = maybe_serialize( $meta_value );

	$query = $wpdb->prepare( "SELECT $id_column FROM $table WHERE meta_key = %s", $meta_key );

	if ( !$delete_all )

		$query .= $wpdb->prepare(" AND $type_column = %d", $object_id );

		$query .= $wpdb->prepare(" AND meta_value = %s", $meta_value );

	$meta_ids = $wpdb->get_col( $query );

	if ( !count( $meta_ids ) )

		return false;

	/**

	 * Fires immediately before deleting metadata of a specific type.

	 *

	 * The dynamic portion of the hook, `$meta_type`, refers to the meta

	 * object type (comment, post, or user).

	 *

	 * @since 3.1.0

	 *

	 * @param array  $meta_ids   An array of metadata entry IDs to delete.

	 * @param int    $object_id  Object ID.

	 * @param string $meta_key   Meta key.

	 * @param mixed  $meta_value Meta value.

	 */

	do_action( "delete_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );

	// Old-style action.

	if ( 'post' == $meta_type ) {

		/**

		 * Fires immediately before deleting metadata for a post.

		 *

		 * @since 2.9.0

		 *

		 * @param array $meta_ids An array of post metadata entry IDs to delete.

		 */

		do_action( 'delete_postmeta', $meta_ids );

	}

	$query = "DELETE FROM $table WHERE $id_column IN( " . implode( ',', $meta_ids ) . " )";

	$count = $wpdb->query($query);

	if ( !$count )

		return false;

	if ( $delete_all ) {

		foreach ( (array) $object_ids as $o_id ) {

			wp_cache_delete($o_id, $meta_type . '_meta');

		}

	} else {

		wp_cache_delete($object_id, $meta_type . '_meta');

	}

	/**

	 * Fires immediately after deleting metadata of a specific type.