<?php

/**
 * Class Name: bs4navwalker
 * GitHub URI: https://github.com/dupkey/bs4navwalker
 * Description: A custom WordPress nav walker class for Bootstrap 4 (v4.0.0-alpha.1) nav menus in a custom theme using the WordPress built in menu manager
 * Version: 0.1
 * Author: Dominic Businaro - @dominicbusinaro
 * License: GPL-2.0+
 * License URI: http://www.gnu.org/licenses/gpl-2.0.txt
 */

/* Check if Class Exists. */
if ( ! class_exists( 'Unisco_Walker_Nav_Menu' ) ) {
	class Unisco_Walker_Nav_Menu extends Walker_Nav_Menu {
		/**
		 * Starts the list before the elements are added.
		 *
		 * @see Walker::start_lvl()
		 *
		 * @since 3.0.0
		 *
		 * @param string $output Passed by reference. Used to append additional content.
		 * @param int $depth Depth of menu item. Used for padding.
		 * @param array $args An array of arguments. @see wp_nav_menu()
		 */
		public function start_lvl( &$output, $depth = 0, $args = array() ) {
			$indent = str_repeat( "\t", $depth );
			if( $depth > 0 ) {
				$output .= "\n$indent<ul class=\"dropdown-menu dropdown-submenu\">\n";
			} else {
				$output .= "\n$indent<ul class=\"dropdown-menu\">\n";
			}
		}

		/**
		 * Ends the list of after the elements are added.
		 *
		 * @see Walker::end_lvl()
		 *
		 * @since 3.0.0
		 *
		 * @param string $output Passed by reference. Used to append additional content.
		 * @param int $depth Depth of menu item. Used for padding.
		 * @param array $args An array of arguments. @see wp_nav_menu()
		 */
		public function end_lvl( &$output, $depth = 0, $args = array() ) {
			$indent = str_repeat( "\t", $depth );
			$output .= "$indent</ul>\n";
		}

		/**
		 * Start the element output.
		 *
		 * @see Walker::start_el()
		 *
		 * @since 3.0.0
		 *
		 * @param string $output Passed by reference. Used to append additional content.
		 * @param object $item Menu item data object.
		 * @param int $depth Depth of menu item. Used for padding.
		 * @param array $args An array of arguments. @see wp_nav_menu()
		 * @param int $id Current item ID.
		 */
		public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
			$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

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

			/**
			 * Filter 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 {@see 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 ) );

			// New
			$class_names .= ' nav-item';

			if ( in_array( 'menu-item-has-children', $classes ) ) {
				$class_names .= ' dropdown';
			}

			if ( in_array( 'current-menu-item', $classes ) ) {
				$class_names .= ' active';
			}
			//

			$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

			// print_r($class_names);

			/**
			 * Filter 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 {@see wp_nav_menu()} arguments.
			 * @param int $depth Depth of menu item. Used for padding.
			 */
			$id = apply_filters( 'nav_menu_item_id', 'menu-item-' . $item->ID, $item, $args, $depth );
			$id = $id ? ' id="' . esc_attr( $id ) . '"' : '';

			// New
//			if ( $depth === 0 ) {
				$output .= $indent . '<li' . $id . $class_names . '>';
//			}
			//

			// $output .= $indent . '<li' . $id . $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']  = '';

			// New
			if ( $depth === 0 ) {
				$atts['class'] = 'nav-link';
			}

			if ( $depth > 0 ) {
				$atts['class'] = 'dropdown-item';
			}

			if ( in_array( 'menu-item-has-children', $classes ) ) {
				$atts['class'] .= ' dropdown-toggle';
				$atts['data-toggle'] = 'dropdown';
				$atts['aria-haspopup'] = 'true';
				$atts['aria-expanded'] = 'false';
			}

			if ( in_array( 'current-menu-item', $item->classes ) ) {
				$atts['class'] .= ' active';
			}
			// print_r($item);
			//

			/**
			 * Filter 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 {@see 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 . '"';
				}
			}

			$item_output = $args->before;
			// New
			/*
			if ($depth === 0 && in_array('menu-item-has-children', $classes)) {
				$item_output .= '<a class="nav-link dropdown-toggle"' . $attributes .'data-toggle="dropdown">';
			} elseif ($depth === 0) {
				$item_output .= '<a class="nav-link"' . $attributes .'>';
			} else {
				$item_output .= '<a class="dropdown-item"' . $attributes .'>';
			}
			*/
			//
			$item_output .= '<a' . $attributes . '>';
			/** This filter is documented in wp-includes/post-template.php */
			$item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
			$item_output .= '</a>';
			$item_output .= $args->after;

			/**
			 * Filter 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 {@see wp_nav_menu()} arguments.
			 */
			$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
		}

		/**
		 * Ends the element output, if needed.
		 *
		 * @see Walker::end_el()
		 *
		 * @since 3.0.0
		 *
		 * @param string $output Passed by reference. Used to append additional content.
		 * @param object $item Page data object. Not used.
		 * @param int $depth Depth of page. Not Used.
		 * @param array $args An array of arguments. @see wp_nav_menu()
		 */
		public function end_el( &$output, $item, $depth = 0, $args = array() ) {
			if ( isset( $args->has_children ) && $depth === 0 ) {
				$output .= "</li>\n";
			}
		}
	}
}
