Retrieves the list of bookmarks.

Attempts to retrieve from the cache first based on MD5 hash of arguments. If
that fails, then the query will be built from the arguments and executed. The
results will be stored to the cache.

function get_bookmarks( $args = '' ) {
	global $wpdb;

	$defaults = array(
		'orderby'        => 'name',
		'order'          => 'ASC',
		'limit'          => -1,
		'category'       => '',
		'category_name'  => '',
		'hide_invisible' => 1,
		'show_updated'   => 0,
		'include'        => '',
		'exclude'        => '',
		'search'         => '',
	);

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

	$key   = md5( serialize( $parsed_args ) );
	$cache = wp_cache_get( 'get_bookmarks', 'bookmark' );

	if ( 'rand' !== $parsed_args['orderby'] && $cache ) {
		if ( is_array( $cache ) && isset( $cache[ $key ] ) ) {
			$bookmarks = $cache[ $key ];
			/**
			 * Filters the returned list of bookmarks.
			 *
			 * The first time the hook is evaluated in this file, it returns the cached
			 * bookmarks list. The second evaluation returns a cached bookmarks list if the
			 * link category is passed but does not exist. The third evaluation returns
			 * the full cached results.
			 *
			 * @since 2.1.0
			 *
			 * @see get_bookmarks()
			 *
			 * @param array $bookmarks   List of the cached bookmarks.
			 * @param array $parsed_args An array of bookmark query arguments.
			 */
			return apply_filters( 'get_bookmarks', $bookmarks, $parsed_args );
		}
	}

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

	$inclusions = '';
	if ( ! empty( $parsed_args['include'] ) ) {
		$parsed_args['exclude']       = '';  // Ignore exclude, category, and category_name params if using include.
		$parsed_args['category']      = '';
		$parsed_args['category_name'] = '';

		$inclinks = wp_parse_id_list( $parsed_args['include'] );
		if ( count( $inclinks ) ) {
			foreach ( $inclinks as $inclink ) {
				if ( empty( $inclusions ) ) {
					$inclusions = ' AND ( link_id = ' . $inclink . ' ';
				} else {
					$inclusions .= ' OR link_id = ' . $inclink . ' ';
				}
			}
		}
	}
	if ( ! empty( $inclusions ) ) {
		$inclusions .= ')';
	}

	$exclusions = '';
	if ( ! empty( $parsed_args['exclude'] ) ) {
		$exlinks = wp_parse_id_list( $parsed_args['exclude'] );
		if ( count( $exlinks ) ) {
			foreach ( $exlinks as $exlink ) {
				if ( empty( $exclusions ) ) {
					$exclusions = ' AND ( link_id  ' . $exlink . ' ';
				} else {
					$exclusions .= ' AND link_id  ' . $exlink . ' ';
				}
			}
		}
	}
	if ( ! empty( $exclusions ) ) {
		$exclusions .= ')';
	}

	if ( ! empty( $parsed_args['category_name'] ) ) {
		$parsed_args['category'] = get_term_by( 'name', $parsed_args['category_name'], 'link_category' );
		if ( $parsed_args['category'] ) {
			$parsed_args['category'] = $parsed_args['category']->term_id;
		} else {
			$cache[ $key ] = array();
			wp_cache_set( 'get_bookmarks', $cache, 'bookmark' );
			/** This filter is documented in wp-includes/bookmark.php */
			return apply_filters( 'get_bookmarks', array(), $parsed_args );
		}
	}

	$search = '';
	if ( ! empty( $parsed_args['search'] ) ) {
		$like   = '%' . $wpdb->esc_like( $parsed_args['search'] ) . '%';
		$search = $wpdb->prepare( ' AND ( (link_url LIKE %s) OR (link_name LIKE %s) OR (link_description LIKE %s) ) ', $like, $like, $like );
	}

	$category_query = '';
	$join           = '';
	if ( ! empty( $parsed_args['category'] ) ) {
		$incategories = wp_parse_id_list( $parsed_args['category'] );
		if ( count( $incategories ) ) {
			foreach ( $incategories as $incat ) {
				if ( empty( $category_query ) ) {
					$category_query = ' AND ( tt.term_id = ' . $incat . ' ';
				} else {
					$category_query .= ' OR tt.term_id = ' . $incat . ' ';
				}
			}
		}
	}
	if ( ! empty( $category_query ) ) {
		$category_query .= ") AND taxonomy = 'link_category'";
		$join            = " INNER JOIN $wpdb->term_relationships AS tr ON ($wpdb->links.link_id = tr.object_id) INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_taxonomy_id = tr.term_taxonomy_id";
	}

	if ( $parsed_args['show_updated'] ) {
		$recently_updated_test = ', IF (DATE_ADD(link_updated, INTERVAL 120 MINUTE) >= NOW(), 1,0) as recently_updated ';
	} else {
		$recently_updated_test = '';
	}

	$get_updated = ( $parsed_args['show_updated'] ) ? ', UNIX_TIMESTAMP(link_updated) AS link_updated_f ' : '';

	$orderby = strtolower( $parsed_args['orderby'] );
	$length  = '';
	switch ( $orderby ) {
		case 'length':
			$length = ', CHAR_LENGTH(link_name) AS length';
			break;
		case 'rand':
			$orderby = 'rand()';
			break;
		case 'link_id':
			$orderby = "$wpdb->links.link_id";
			break;
		default:
			$orderparams = array();
			$keys        = array( 'link_id', 'link_name', 'link_url', 'link_visible', 'link_rating', 'link_owner', 'link_updated', 'link_notes', 'link_description' );
			foreach ( explode( ',', $orderby ) as $ordparam ) {
				$ordparam = trim( $ordparam );

				if ( in_array( 'link_' . $ordparam, $keys, true ) ) {
					$orderparams[] = 'link_' . $ordparam;
				} elseif ( in_array( $ordparam, $keys, true ) ) {
					$orderparams[] = $ordparam;
				}
			}
			$orderby = implode( ',', $orderparams );
	}

	if ( empty( $orderby ) ) {
		$orderby = 'link_name';
	}

	$order = strtoupper( $parsed_args['order'] );
	if ( '' !== $order && ! in_array( $order, array( 'ASC', 'DESC' ), true ) ) {
		$order = 'ASC';
	}

	$visible = '';
	if ( $parsed_args['hide_invisible'] ) {
		$visible = "AND link_visible = 'Y'";
	}

	$query  = "SELECT * $length $recently_updated_test $get_updated FROM $wpdb->links $join WHERE 1=1 $visible $category_query";
	$query .= " $exclusions $inclusions $search";
	$query .= " ORDER BY $orderby $order";
	if ( -1 != $parsed_args['limit'] ) {
		$query .= ' LIMIT ' . absint( $parsed_args['limit'] );
	}

	$results = $wpdb->get_results( $query );

	if ( 'rand()' !== $orderby ) {
		$cache[ $key ] = $results;
		wp_cache_set( 'get_bookmarks', $cache, 'bookmark' );
	}

	/** This filter is documented in wp-includes/bookmark.php */
	return apply_filters( 'get_bookmarks', $results, $parsed_args );
}