<?php
/**
 * WP Bootstrap Navwalker
 *
 * @package WP-Bootstrap-Navwalker
 */

/*
 * Class Name: WP_Bootstrap_Navwalker
 * Plugin Name: WP Bootstrap Navwalker
 * Plugin URI:  https://github.com/wp-bootstrap/wp-bootstrap-navwalker
 * Description: A custom WordPress nav walker class to implement the Bootstrap 3 navigation style in a custom theme using the WordPress built in menu manager.
 * Author: Edward McIntyre - @twittem, WP Bootstrap
 * Version: 2.0.5
 * Author URI: https://github.com/wp-bootstrap
 * GitHub Plugin URI: https://github.com/wp-bootstrap/wp-bootstrap-navwalker
 * GitHub Branch: master
 * License: GPL-3.0+
 * License URI: http://www.gnu.org/licenses/gpl-3.0.txt
*/

/* Check if Class Exists. */
if ( ! class_exists( 'WP_Bootstrap_Navwalker' ) ) {
	/**
	 * WP_Bootstrap_Navwalker class.
	 *
	 * @extends Walker_Nav_Menu
	 */
	class WP_Bootstrap_Navwalker extends Walker_Nav_Menu {

		/**
		 * Start Level.
		 *
		 * @see Walker::start_lvl()
		 * @since 3.0.0
		 *
		 * @access public
		 * @param mixed $output Passed by reference. Used to append additional content.
		 * @param int   $depth (default: 0) Depth of page. Used for padding.
		 * @param array $args (default: array()) Arguments.
		 * @return void
		 */
		public function start_lvl( &$output, $depth = 0, $args = array() ) {
			$indent = str_repeat( "\t", $depth );
			$output .= "\n$indent<ul role=\"menu\" class=\" dropdown-menu\" >\n";
		}

		/**
		 * Start El.
		 *
		 * @see Walker::start_el()
		 * @since 3.0.0
		 *
		 * @access public
		 * @param mixed $output Passed by reference. Used to append additional content.
		 * @param mixed $item Menu item data object.
		 * @param int   $depth (default: 0) Depth of menu item. Used for padding.
		 * @param array $args (default: array()) Arguments.
		 * @param int   $id (default: 0) Menu item ID.
		 * @return void
		 */
		public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
			$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

			/**
			* Dividers, Headers or Disabled
			* =============================
			* Determine whether the item is a Divider, Header, Disabled or regular
			* menu item. To prevent errors we use the strcasecmp() function to so a
			* comparison that is not case sensitive. The strcasecmp() function returns
			* a 0 if the strings are equal.
		 	*/
			if ( 0 === strcasecmp( $item->attr_title, 'divider' ) && 1 === $depth ) {
				$output .= $indent . '<li role="presentation" class="divider">';
			} elseif ( 0 === strcasecmp( $item->title, 'divider' ) && 1 === $depth ) {
				$output .= $indent . '<li role="presentation" class="divider">';
			} elseif ( 0 === strcasecmp( $item->attr_title, 'dropdown-header' ) && 1 === $depth ) {
				$output .= $indent . '<li role="presentation" class="dropdown-header">' . esc_attr( $item->title );
			} elseif ( 0 === strcasecmp( $item->attr_title, 'disabled' ) ) {
				$output .= $indent . '<li role="presentation" class="disabled"><a href="#">' . esc_attr( $item->title ) . '</a>';
			} else {
				$class_names = $value = '';
				$classes = empty( $item->classes ) ? array() : (array) $item->classes;
				$classes[] = 'menu-item-' . $item->ID;
				$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
				if ( $args->has_children ) {
					$class_names .= ' dropdown'; }
				if ( in_array( 'current-menu-item', $classes, true ) ) {
					$class_names .= ' active'; }
				$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
				$id = apply_filters( 'nav_menu_item_id', 'menu-item-' . $item->ID, $item, $args );
				$id = $id ? ' id="' . esc_attr( $id ) . '"' : '';
				$output .= $indent . '<li itemscope="itemscope" itemtype="https://www.schema.org/SiteNavigationElement"' . $id . $value . $class_names . '>';
				$atts = array();

				if ( empty( $item->attr_title ) ) {
		  			$atts['title']  = ! empty( $item->title )   ? strip_tags( $item->title ) : '';
				} else {
		  			$atts['title'] = $item->attr_title;
				}

				$atts['target'] = ! empty( $item->target )	? $item->target	: '';
				$atts['rel']    = ! empty( $item->xfn )		? $item->xfn	: '';
				// If item has_children add atts to a.
				if ( $args->has_children && 0 === $depth ) {
					$atts['href']   		= '#';
					$atts['data-toggle']	= 'dropdown';
					$atts['class']			= 'dropdown-toggle';
					$atts['aria-haspopup']	= 'true';
				} else {
					$atts['href'] = ! empty( $item->url ) ? $item->url : '';
				}
				$atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );
				$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;

				/*
				 * Glyphicons/Font-Awesome
				 * ===========
				 * Since the the menu item is NOT a Divider or Header we check the see
				 * if there is a value in the attr_title property. If the attr_title
				 * property is NOT null we apply it as the class name for the glyphicon.
				 */
				if ( ! empty( $item->attr_title ) ) :
								$pos = strpos( esc_attr( $item->attr_title ), 'glyphicon' );
					if ( false !== $pos ) :
						$item_output .= '<a' . $attributes . '><span class="glyphicon ' . esc_attr( $item->attr_title ) . '" aria-hidden="true"></span>&nbsp;';
								else :
									$item_output .= '<a' . $attributes . '><i class="fa ' . esc_attr( $item->attr_title ) . '" aria-hidden="true"></i>&nbsp;';
											endif;
				else :
					$item_output .= '<a' . $attributes . '>';
				endif;
				$item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
				$item_output .= ( $args->has_children && 0 === $depth ) ? ' <span class="caret"></span></a>' : '</a>';
				$item_output .= $args->after;
				$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
			}
		}

		/**
		 * 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.
		 *
		 * This method shouldn't be called directly, use the walk() method instead.
		 *
		 * @see Walker::start_el()
		 * @since 2.5.0
		 *
		 * @access public
		 * @param mixed $element Data object.
		 * @param mixed $children_elements List of elements to continue traversing.
		 * @param mixed $max_depth Max depth to traverse.
		 * @param mixed $depth Depth of current element.
		 * @param mixed $args Arguments.
		 * @param mixed $output Passed by reference. Used to append additional content.
		 * @return null Null on failure with no changes to parameters.
		 */
		public function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
			if ( ! $element ) {
				return; }
			$id_field = $this->db_fields['id'];
			// Display this element.
			if ( is_object( $args[0] ) ) {
				$args[0]->has_children = ! empty( $children_elements[ $element->$id_field ] ); }
			parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
		}

		/**
		 * Menu Fallback
		 * =============
		 * If this function is assigned to the wp_nav_menu's fallback_cb variable
		 * and a menu has not been assigned to the theme location in the WordPress
		 * menu manager the function with display nothing to a non-logged in user,
		 * and will add a link to the WordPress menu manager if logged in as an admin.
		 *
		 * @param array $args passed from the wp_nav_menu function.
		 */
		public static function fallback( $args ) {
			if ( current_user_can( 'edit_theme_options' ) ) {

				/* Get Arguments. */
				$container = $args['container'];
				$container_id = $args['container_id'];
				$container_class = $args['container_class'];
				$menu_class = $args['menu_class'];
				$menu_id = $args['menu_id'];

				if ( $container ) {
					echo '<' . esc_attr( $container );
					if ( $container_id ) {
						echo ' id="' . esc_attr( $container_id ) . '"';
					}
					if ( $container_class ) {
						echo ' class="' . sanitize_html_class( $container_class ) . '"'; }
					echo '>';
				}
				echo '<ul';
				if ( $menu_id ) {
					echo ' id="' . esc_attr( $menu_id ) . '"'; }
				if ( $menu_class ) {
					echo ' class="' . esc_attr( $menu_class ) . '"'; }
				echo '>';
				echo '<li><a href="' . esc_url( admin_url( 'nav-menus.php' ) ) . '" title="">' . esc_attr( 'Add a menu', '' ) . '</a></li>';
				echo '</ul>';
				if ( $container ) {
					echo '</' . esc_attr( $container ) . '>'; }
			}
		}
	}
}
