<?php

/**

 * Navigation Menu functions

 *

 * @package WordPress

 * @subpackage Nav_Menus

 * @since 3.0.0

 */

/**

 * Returns a navigation menu object.

 *

 * @since 3.0.0

 *

 * @uses get_term

 * @uses get_term_by

 *

 * @param string $menu Menu id, slug or name

 * @return mixed false if $menu param isn't supplied or term does not exist, menu object if successful.

 */

function wp_get_nav_menu_object( $menu ) {

	if ( ! $menu )

		return false;

	$menu_obj = get_term( $menu, 'nav_menu' );

	if ( ! $menu_obj )

		$menu_obj = get_term_by( 'slug', $menu, 'nav_menu' );

	if ( ! $menu_obj )

		$menu_obj = get_term_by( 'name', $menu, 'nav_menu' );

	if ( ! $menu_obj )

		$menu_obj = false;

	return $menu_obj;

}

/**

 * Check if the given ID is a navigation menu.

 *

 * Returns true if it is; false otherwise.

 *

 * @since 3.0.0

 *

 * @param int|string $menu The menu to check (id, slug, or name)

 * @return bool Whether the menu exists.

 */

function is_nav_menu( $menu ) {

	if ( ! $menu )

		return false;

	$menu_obj = wp_get_nav_menu_object( $menu );

	if (

		$menu_obj &&

		! is_wp_error( $menu_obj ) &&

		! empty( $menu_obj->taxonomy ) &&

		'nav_menu' == $menu_obj->taxonomy

	)

		return true;

	return false;

}

/**

 * Register navigation menus for a theme.

 *

 * @since 3.0.0

 *

 * @param array $locations Associative array of menu location identifiers (like a slug) and descriptive text.

 */

function register_nav_menus( $locations = array() ) {

	global $_wp_registered_nav_menus;

	add_theme_support( 'menus' );

	$_wp_registered_nav_menus = array_merge( (array) $_wp_registered_nav_menus, $locations );

}

/**

 * Unregisters a navigation menu for a theme.

 *

 * @param array $location the menu location identifier

 *

 * @return bool True on success, false on failure.

 */

function unregister_nav_menu( $location ) {

	global $_wp_registered_nav_menus;

	if ( is_array( $_wp_registered_nav_menus ) && isset( $_wp_registered_nav_menus[$location] ) ) {

		unset( $_wp_registered_nav_menus[$location] );

		return true;

	}

	return false;

}

/**

 * Register a navigation menu for a theme.

 *

 * @since 3.0.0

 *

 * @param string $location Menu location identifier, like a slug.

 * @param string $description Menu location descriptive text.

 */

function register_nav_menu( $location, $description ) {

	register_nav_menus( array( $location => $description ) );

}

/**

 * Returns an array of all registered navigation menus in a theme

 *

 * @since 3.0.0

 * @return array

 */

function get_registered_nav_menus() {

	global $_wp_registered_nav_menus;

	if ( isset( $_wp_registered_nav_menus ) )

		return $_wp_registered_nav_menus;

	return array();

}

/**

 * Returns an array with the registered navigation menu locations and the menu assigned to it

 *

 * @since 3.0.0

 * @return array

 */

function get_nav_menu_locations() {

	return get_theme_mod( 'nav_menu_locations' );

}

/**

 * Whether a registered nav menu location has a menu assigned to it.

 *

 * @since 3.0.0

 * @param string $location Menu location identifier.

 * @return bool Whether location has a menu.

 */

function has_nav_menu( $location ) {

	$locations = get_nav_menu_locations();

	return ( ! empty( $locations[ $location ] ) );

}

/**

 * Determine whether the given ID is a nav menu item.

 *

 * @since 3.0.0

 *

 * @param int $menu_item_id The ID of the potential nav menu item.

 * @return bool Whether the given ID is that of a nav menu item.

 */

function is_nav_menu_item( $menu_item_id = 0 ) {

	return ( ! is_wp_error( $menu_item_id ) && ( 'nav_menu_item' == get_post_type( $menu_item_id ) ) );

}

/**

 * Create a Navigation Menu.

 *

 * @since 3.0.0

 *

 * @param string $menu_name Menu Name

 * @return mixed Menu object on success|WP_Error on failure

 */

function wp_create_nav_menu( $menu_name ) {

	return wp_update_nav_menu_object( 0, array( 'menu-name' => $menu_name ) );

}

/**

 * Delete a Navigation Menu.

 *

 * @since 3.0.0

 *

 * @param string $menu name|id|slug

 * @return mixed Menu object on success|WP_Error on failure

 */

function wp_delete_nav_menu( $menu ) {

	$menu = wp_get_nav_menu_object( $menu );

	if ( ! $menu )

		return false;

	$menu_objects = get_objects_in_term( $menu->term_id, 'nav_menu' );

	if ( ! empty( $menu_objects ) ) {

		foreach ( $menu_objects as $item ) {

			wp_delete_post( $item );

		}

	}

	$result = wp_delete_term( $menu->term_id, 'nav_menu' );

	if ( $result && !is_wp_error($result) )

		do_action( 'wp_delete_nav_menu', $menu->term_id );

	return $result;

}

/**

 * Save the properties of a menu or create a new menu with those properties.

 *

 * @since 3.0.0

 *

 * @param int $menu_id The ID of the menu or "0" to create a new menu.

 * @param array $menu_data The array of menu data.

 * @return int|error object The menu's ID or WP_Error object.

 */

function wp_update_nav_menu_object( $menu_id = 0, $menu_data = array() ) {

	$menu_id = (int) $menu_id;

	$_menu = wp_get_nav_menu_object( $menu_id );

	$args = array(

		'description' => ( isset( $menu_data['description'] ) ? $menu_data['description']  : '' ),

		'name'        => ( isset( $menu_data['menu-name']   ) ? $menu_data['menu-name']    : '' ),

		'parent'      => ( isset( $menu_data['parent']      ) ? (int) $menu_data['parent'] : 0  ),

		'slug'        => null,

	);

	// double-check that we're not going to have one menu take the name of another

	$_possible_existing = get_term_by( 'name', $menu_data['menu-name'], 'nav_menu' );

	if (

		$_possible_existing &&

		! is_wp_error( $_possible_existing ) &&

		isset( $_possible_existing->term_id ) &&

		$_possible_existing->term_id != $menu_id

	)

		return new WP_Error( 'menu_exists', sprintf( __('The menu name <strong>%s</strong> conflicts with another menu name. Please try another.'), esc_html( $menu_data['menu-name'] ) ) );

	// menu doesn't already exist, so create a new menu

	if ( ! $_menu || is_wp_error( $_menu ) ) {

		$menu_exists = get_term_by( 'name', $menu_data['menu-name'], 'nav_menu' );

		if ( $menu_exists )

			return new WP_Error( 'menu_exists', sprintf( __('The menu name <strong>%s</strong> conflicts with another menu name. Please try another.'), esc_html( $menu_data['menu-name'] ) ) );

		$_menu = wp_insert_term( $menu_data['menu-name'], 'nav_menu', $args );

		if ( is_wp_error( $_menu ) )

			return $_menu;

		do_action( 'wp_create_nav_menu', $_menu['term_id'], $menu_data );

		return (int) $_menu['term_id'];

	}

	if ( ! $_menu || ! isset( $_menu->term_id ) )

		return 0;

	$menu_id = (int) $_menu->term_id;

	$update_response = wp_update_term( $menu_id, 'nav_menu', $args );

	if ( is_wp_error( $update_response ) )

		return $update_response;

	do_action( 'wp_update_nav_menu', $menu_id, $menu_data );

	return $menu_id;

}

/**

 * Save the properties of a menu item or create a new one.

 *

 * @since 3.0.0

 *

 * @param int $menu_id The ID of the menu. Required. If "0", makes the menu item a draft orphan.

 * @param int $menu_item_db_id The ID of the menu item. If "0", creates a new menu item.

 * @param array $menu_item_data The menu item's data.

 * @return int The menu item's database ID or WP_Error object on failure.

 */

function wp_update_nav_menu_item( $menu_id = 0, $menu_item_db_id = 0, $menu_item_data = array() ) {

	$menu_id = (int) $menu_id;

	$menu_item_db_id = (int) $menu_item_db_id;

	// make sure that we don't convert non-nav_menu_item objects into nav_menu_item objects

	if ( ! empty( $menu_item_db_id ) && ! is_nav_menu_item( $menu_item_db_id ) )

		return new WP_Error('update_nav_menu_item_failed', __('The given object ID is not that of a menu item.'));

	$menu = wp_get_nav_menu_object( $menu_id );

	if ( ( ! $menu && 0 !== $menu_id ) || is_wp_error( $menu ) )

		return $menu;

	$defaults = array(

		'menu-item-db-id' => $menu_item_db_id,

		'menu-item-object-id' => 0,

		'menu-item-object' => '',

		'menu-item-parent-id' => 0,

		'menu-item-position' => 0,

		'menu-item-type' => 'custom',

		'menu-item-title' => '',

		'menu-item-url' => '',

		'menu-item-description' => '',

		'menu-item-attr-title' => '',

		'menu-item-target' => '',

		'menu-item-classes' => '',

		'menu-item-xfn' => '',

		'menu-item-status' => '',

	);

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

	if ( 0 == $menu_id ) {

		$args['menu-item-position'] = 1;

	} elseif ( 0 == (int) $args['menu-item-position'] ) {

		$menu_items = 0 == $menu_id ? array() : (array) wp_get_nav_menu_items( $menu_id, array( 'post_status' => 'publish,draft' ) );

		$last_item = array_pop( $menu_items );

		$args['menu-item-position'] = ( $last_item && isset( $last_item->menu_order ) ) ? 1 + $last_item->menu_order : count( $menu_items );

	}

	$original_parent = 0 < $menu_item_db_id ? get_post_field( 'post_parent', $menu_item_db_id ) : 0;

	if ( 'custom' != $args['menu-item-type'] ) {

		/* if non-custom menu item, then:

			* use original object's URL

			* blank default title to sync with original object's

		*/

		$args['menu-item-url'] = '';

		$original_title = '';

		if ( 'taxonomy' == $args['menu-item-type'] ) {

			$original_parent = get_term_field( 'parent', $args['menu-item-object-id'], $args['menu-item-object'], 'raw' );

			$original_title = get_term_field( 'name', $args['menu-item-object-id'], $args['menu-item-object'], 'raw' );

		} elseif ( 'post_type' == $args['menu-item-type'] ) {

			$original_object = get_post( $args['menu-item-object-id'] );

			$original_parent = (int) $original_object->post_parent;

			$original_title = $original_object->post_title;

		}

		if ( empty( $args['menu-item-title'] ) || $args['menu-item-title'] == $original_title ) {

			$args['menu-item-title'] = '';

			// hack to get wp to create a post object when too many properties are empty

			if ( empty( $args['menu-item-description'] ) )

				$args['menu-item-description'] = ' ';

		}

	}

	// Populate the menu item object

	$post = array(

		'menu_order' => $args['menu-item-position'],

		'ping_status' => 0,

		'post_content' => $args['menu-item-description'],

		'post_excerpt' => $args['menu-item-attr-title'],

		'post_parent' => $original_parent,

		'post_title' => $args['menu-item-title'],

		'post_type' => 'nav_menu_item',

	);

	$update = 0 != $menu_item_db_id;

	// Only set the menu term if it isn't set to avoid unnecessary wp_get_object_terms()

	if ( $menu_id && ( ! $update || ! is_object_in_term( $menu_item_db_id, 'nav_menu', (int) $menu->term_id ) ) )

		$post['tax_input'] = array( 'nav_menu' => array( intval( $menu->term_id ) ) );

	// New menu item. Default is draft status

	if ( ! $update ) {

		$post['ID'] = 0;

		$post['post_status'] = 'publish' == $args['menu-item-status'] ? 'publish' : 'draft';

		$menu_item_db_id = wp_insert_post( $post );

		if ( ! $menu_item_db_id	|| is_wp_error( $menu_item_db_id ) )

			return $menu_item_db_id;

	}

	if ( 'custom' == $args['menu-item-type'] ) {

		$args['menu-item-object-id'] = $menu_item_db_id;

		$args['menu-item-object'] = 'custom';

	}

	$menu_item_db_id = (int) $menu_item_db_id;

	update_post_meta( $menu_item_db_id, '_menu_item_type', sanitize_key($args['menu-item-type']) );

	update_post_meta( $menu_item_db_id, '_menu_item_menu_item_parent', strval( (int) $args['menu-item-parent-id'] ) );

	update_post_meta( $menu_item_db_id, '_menu_item_object_id', strval( (int) $args['menu-item-object-id'] ) );

	update_post_meta( $menu_item_db_id, '_menu_item_object', sanitize_key($args['menu-item-object']) );

	update_post_meta( $menu_item_db_id, '_menu_item_target', sanitize_key($args['menu-item-target']) );

	$args['menu-item-classes'] = array_map( 'sanitize_html_class', explode( ' ', $args['menu-item-classes'] ) );

	$args['menu-item-xfn'] = implode( ' ', array_map( 'sanitize_html_class', explode( ' ', $args['menu-item-xfn'] ) ) );

	update_post_meta( $menu_item_db_id, '_menu_item_classes', $args['menu-item-classes'] );

	update_post_meta( $menu_item_db_id, '_menu_item_xfn', $args['menu-item-xfn'] );

	update_post_meta( $menu_item_db_id, '_menu_item_url', esc_url_raw($args['menu-item-url']) );

	if ( 0 == $menu_id )

		update_post_meta( $menu_item_db_id, '_menu_item_orphaned', (string) time() );

	elseif ( get_post_meta( $menu_item_db_id, '_menu_item_orphaned' ) )

		delete_post_meta( $menu_item_db_id, '_menu_item_orphaned' );

	// Update existing menu item. Default is publish status

	if ( $update ) {

		$post['ID'] = $menu_item_db_id;

		$post['post_status'] = 'draft' == $args['menu-item-status'] ? 'draft' : 'publish';

		wp_update_post( $post );

	}

	do_action('wp_update_nav_menu_item', $menu_id, $menu_item_db_id, $args );

	return $menu_item_db_id;

}

/**

 * Returns all navigation menu objects.

 *

 * @since 3.0.0

 *

 * @param array $args Array of arguments passed on to get_terms().

 * @return array menu objects

 */

function wp_get_nav_menus( $args = array() ) {

	$defaults = array( 'hide_empty' => false, 'orderby' => 'none' );

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

	return apply_filters( 'wp_get_nav_menus', get_terms( 'nav_menu',  $args), $args );

}

/**

 * Sort menu items by the desired key.