<?php
/**
 * @copyright	Copyright (C) 2016. All rights reserved.
 * @license		GNU General Public License version 2 or later; see LICENSE.txt
 * @author		Plugins CK - C�dric KEIFLIN - http://www.wp-pluginsck.com
 */

defined('ABSPATH') or die;

class Accordeonmenuck_Walker_Nav_Menu extends Walker_Nav_Menu {

	/**
	 * Display array of elements hierarchically.
	 *
	 * Does not assume any existing order of elements.
	 *
	 * $max_depth = -1 means flatly display every element.
	 * $max_depth = 0 means display all levels.
	 * $max_depth > 0 specifies the number of display levels.
	 *
	 * @since 2.1.0
	 *
	 * @param array $elements  An array of elements.
	 * @param int   $max_depth The maximum hierarchical depth.
	 * @return string The hierarchical item output.
	 */
	public function walk( $elements, $max_depth ) {
		$args = array_slice(func_get_args(), 2);
		$args = $args[0];
		$output = '';

		//invalid parameter or nothing to walk
		if ( $max_depth < -1 || empty( $elements ) ) {
			return $output;
		}

		$parent_field = $this->db_fields['parent'];

		// flat display
		if ( -1 == $max_depth ) {
			$empty_array = array();
			foreach ( $elements as $e )
				$this->display_element( $e, $empty_array, 1, 0, $args, $output );
			return $output;
		}

		/*
		 * Need to display in hierarchical order.
		 * Separate elements into two buckets: top level and children elements.
		 * Children_elements is two dimensional array, eg.
		 * Children_elements[10][] contains all sub-elements whose parent is 10.
		 */
		$top_level_elements = array();
		$children_elements  = array();
		foreach ( $elements as $e) {
			if ( empty( $e->$parent_field ) )
				$top_level_elements[] = $e;
			else
				$children_elements[ $e->$parent_field ][] = $e;
		}

		/*
		 * When none of the elements is top level.
		 * Assume the first one must be root of the sub elements.
		 */
		if ( empty($top_level_elements) ) {

			$first = array_slice( $elements, 0, 1 );
			$root = $first[0];

			$top_level_elements = array();
			$children_elements  = array();
			foreach ( $elements as $e) {
				if ( $root->$parent_field == $e->$parent_field )
					$top_level_elements[] = $e;
				else
					$children_elements[ $e->$parent_field ][] = $e;
			}
		}

		foreach ( $top_level_elements as $e )
			$this->display_element( $e, $children_elements, $max_depth, 0, $args, $output );

		/*
		 * If we are displaying all levels, and remaining children_elements is not empty,
		 * then we got orphans, which should be displayed regardless.
		 */
		if ( ( $max_depth == 0 ) && count( $children_elements ) > 0 ) {
			$empty_array = array();
			foreach ( $children_elements as $orphans )
				foreach ( $orphans as $op )
					$this->display_element( $op, $empty_array, 1, 0, $args, $output );
		 }

		return $output;
	}
	
	/**
	 * Traverse elements to create list from elements.
	 *
	 * Display one element if the element doesn't have any children otherwise,
	 * display the element and its children. Will only traverse up to the max
	 * depth and no ignore elements under that depth. It is possible to set the
	 * max depth to include all depths, see walk() method.
	 *
	 * This method should not be called directly, use the walk() method instead.
	 *
	 * @since 2.5.0
	 *
	 * @param object $element           Data object.
	 * @param array  $children_elements List of elements to continue traversing.
	 * @param int    $max_depth         Max depth to traverse.
	 * @param int    $depth             Depth of current element.
	 * @param array  $args              An array of arguments.
	 * @param string $output            Passed by reference. Used to append additional content.
	 */
	public function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
		if ( ! $element ) {
			return;
		}

		$id_field = $this->db_fields['id'];
		$id       = $element->$id_field;

		
		//display this element
		$this->has_children = ! empty( $children_elements[ $id ] );
		if ( isset( $args ) && is_array( $args ) ) {
			$args['has_children'] = $this->has_children; // Back-compat.
		}

		$item = $element;
//		$cb_args = array_merge( array(&$output, $element, $depth), $args);

		// call_user_func_array(array($this, 'start_el'), $cb_args);
		// $item->classes[] = 'accordeonck' . $depth;
		$item->classes[] = 'accordeonck';
		if (in_array('menu-item-has-children', $item->classes) && ($max_depth == 0 || $max_depth > $depth+1) ) $item->classes[] = 'parent';
		// parent::start_el( $output, $item, $depth, $args, $id );

		$indent = ( $depth ) ? str_repeat( "\t", ($depth-1) ) : '';

		$classes = empty( $item->classes ) ? array() : (array) $item->classes;
		$classes[] = 'menu-item-' . $item->ID;
		$classes[] = 'level' . ($depth+1);

		$toggler = '';
		$spanclass = '';
		if (isset( $children_elements[$id]) && ($max_depth == 0 || $max_depth > $depth+1)) {
			$classes[] = 'parent';
			$toggler = '<span class="toggler_icon"></span>';
			$spanclass = 'toggler toggler_'.$depth;
		}
		/**
		 * Filters the arguments for a single nav menu item.
		 *
		 * @since 4.4.0
		 *
		 * @param array  $args  An array of arguments.
		 * @param object $item  Menu item data object.
		 * @param int    $depth Depth of menu item. Used for padding.
		 */
		$args = apply_filters( 'nav_menu_item_args', $args, $item, $depth );

		/**
		 * Filters the CSS class(es) applied to a menu item's list item element.
		 *
		 * @since 3.0.0
		 * @since 4.1.0 The `$depth` parameter was added.
		 *
		 * @param array  $classes The CSS classes that are applied to the menu item's `<li>` element.
		 * @param object $item    The current menu item.
		 * @param array  $args    An array of wp_nav_menu() arguments.
		 * @param int    $depth   Depth of menu item. Used for padding.
		 */
		$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth ) );
		$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

		/**
		 * Filters the ID applied to a menu item's list item element.
		 *
		 * @since 3.0.1
		 * @since 4.1.0 The `$depth` parameter was added.
		 *
		 * @param string $menu_id The ID that is applied to the menu item's `<li>` element.
		 * @param object $item    The current menu item.
		 * @param array  $args    An array of wp_nav_menu() arguments.
		 * @param int    $depth   Depth of menu item. Used for padding.
		 */
		$itemid = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args, $depth );
		$itemid = $itemid ? ' id="' . esc_attr( $itemid ) . '"' : '';

		$output .= $indent . '<li' . $itemid . $class_names .'>';

		$atts = array();
		$atts['title']  = ! empty( $item->attr_title ) ? $item->attr_title : '';
		$atts['target'] = ! empty( $item->target )     ? $item->target     : '';
		$atts['rel']    = ! empty( $item->xfn )        ? $item->xfn        : '';
		$atts['href']   = ! empty( $item->url )        ? $item->url        : '';
		$atts['class']   = ! empty( $item->class )        ? $item->class . ' accordeonck' : 'accordeonck';

		/**
		 * Filters the HTML attributes applied to a menu item's anchor element.
		 *
		 * @since 3.6.0
		 * @since 4.1.0 The `$depth` parameter was added.
		 *
		 * @param array $atts {
		 *     The HTML attributes applied to the menu item's `<a>` element, empty strings are ignored.
		 *
		 *     @type string $title  Title attribute.
		 *     @type string $target Target attribute.
		 *     @type string $rel    The rel attribute.
		 *     @type string $href   The href attribute.
		 * }
		 * @param object $item  The current menu item.
		 * @param array  $args  An array of wp_nav_menu() arguments.
		 * @param int    $depth Depth of menu item. Used for padding.
		 */
		$atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args, $depth );

		$attributes = '';
		foreach ( $atts as $attr => $value ) {
			if ( ! empty( $value ) ) {
				$value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
				$attributes .= ' ' . $attr . '="' . $value . '"';
			}
		}

		/** This filter is documented in wp-includes/post-template.php */
		$title = apply_filters( 'the_title', $item->title, $item->ID );

		/**
		 * Filters a menu item's title.
		 *
		 * @since 4.4.0
		 *
		 * @param string $title The menu item's title.
		 * @param object $item  The current menu item.
		 * @param array  $args  An array of wp_nav_menu() arguments.
		 * @param int    $depth Depth of menu item. Used for padding.
		 */
		$title = apply_filters( 'nav_menu_item_title', $title, $item, $args, $depth );
		$item_output = '<span class="accordeonck_outer ' . $spanclass . '">' . $toggler . $args->before;
		$item_output .= '<a'. $attributes .'>';
		$item_output .= $args->link_before . $title . $args->link_after;
		if ( $args->description && $item->description )
			$item_output .= '<span class="accordeonck_desc">' . esc_html($item->description) . '</span>';
		$item_output .= '</a>';
		$item_output .= $args->after . '</span>';

		/**
		 * Filters a menu item's starting output.
		 *
		 * The menu item's starting output only includes `$args->before`, the opening `<a>`,
		 * the menu item's title, the closing `</a>`, and `$args->after`. Currently, there is
		 * no filter for modifying the opening and closing `<li>` for a menu item.
		 *
		 * @since 3.0.0
		 *
		 * @param string $item_output The menu item's starting HTML output.
		 * @param object $item        Menu item data object.
		 * @param int    $depth       Depth of menu item. Used for padding.
		 * @param array  $args        An array of wp_nav_menu() arguments.
		 */
		$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );

		// descend only when the depth is right and there are childrens for this element
		if ( ($max_depth == 0 || $max_depth > $depth+1 ) && isset( $children_elements[$id]) ) {

			foreach ( $children_elements[ $id ] as $child ){

				if ( !isset($newlevel) ) {
					$newlevel = true;
					//start the child delimiter
//					$cb_args = array_merge( array(&$output, $depth), $args);
					// call_user_func_array(array($this, 'start_lvl'), $cb_args);
					$indent = str_repeat("\t", $depth);
					// var_dump($element->current_item_parent);
					$ulstyles = ( (!$element->current_item_parent)
						// || ($item->isactive && $params->get('activeeffect'))
						) ? 'display:none;' : '';
					$output .= "\n$indent<ul class=\"content_$depth\" style=\"$ulstyles\">\n";
				}
				$this->display_element( $child, $children_elements, $max_depth, $depth + 1, $args, $output );
			}
			unset( $children_elements[ $id ] );
		}

		if ( isset($newlevel) && $newlevel ){
			//end the child delimiter
//			$cb_args = array_merge( array(&$output, $depth), $args);
			// call_user_func_array(array($this, 'end_lvl'), $cb_args);
			$indent = str_repeat("\t", $depth);
			$output .= "$indent</ul>\n";
		}

		//end this element
//		$cb_args = array_merge( array(&$output, $element, $depth), $args);
		// call_user_func_array(array($this, 'end_el'), $cb_args);
		$output .= "</li>\n";
	}
}