<?php
/**
 * Nav Walker
 *
 * Componentz menu nav walker class.
 *
 * @author Componentz <support@componentz.co>
 * @package Componentz
 * @subpackage Componentz Theme
 * @since 1.0.0
 */

namespace Componentz;

// Do not allow direct access.
if( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * WP Bootstrap Navwalker
 *
 * @package WP-Bootstrap-Navwalker
 * @link https://github.com/wp-bootstrap/wp-bootstrap-navwalker
 */
class NavWalker extends \Walker_Nav_Menu {
    
    /**
     * Starts the list before the elements are added.
     *
     * @since WP 3.0.0
     *
     * @see Walker_Nav_Menu::start_lvl()
     *
     * @param string   $output Used to append additional content (passed by reference).
     * @param int      $depth  Depth of menu item. Used for padding.
     * @param stdClass $args   An object of wp_nav_menu() arguments.
     */
    public function start_lvl( &$output, $depth = 0, $args = array() ) {
        if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {
            $t = '';
            $n = '';
        } else {
            $t = "\t";
            $n = "\n";
        }
        $indent = str_repeat( $t, $depth );
        // Default class to add to the file.
        $classes = array( 'cz-dropdown-menu' );
        /**
         * Filters the CSS class(es) applied to a menu list element.
         *
         * @since WP 4.8.0
         *
         * @param array    $classes The CSS classes that are applied to the menu `<ul>` element.
         * @param stdClass $args    An object of `wp_nav_menu()` arguments.
         * @param int      $depth   Depth of menu item. Used for padding.
         */
        $class_names = join( ' ', apply_filters( 'nav_menu_submenu_css_class', $classes, $args, $depth ) );
        $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
        /**
         * The `.dropdown-menu` container needs to have a labelledby
         * attribute which points to it's trigger link.
         *
         * Form a string for the labelledby attribute from the the latest
         * link with an id that was added to the $output.
         */
        $labelledby = '';
        // find all links with an id in the output.
        preg_match_all( '/(<a.*?id=\"|\')(.*?)\"|\'.*?>/im', $output, $matches );
        // with pointer at end of array check if we got an ID match.
        if ( end( $matches[2] ) ) {
            // build a string to use as aria-labelledby.
            $labelledby = 'aria-labelledby="' . end( $matches[2] ) . '"';
        }
        $output .= "{$n}{$indent}<ul$class_names $labelledby role=\"menu\">{$n}";
    }
    
    /**
     * Starts the element output.
     *
     * @since WP 3.0.0
     * @since WP 4.4.0 The {@see 'nav_menu_item_args'} filter was added.
     *
     * @see Walker_Nav_Menu::start_el()
     *
     * @param string   $output Used to append additional content (passed by reference).
     * @param WP_Post  $item   Menu item data object.
     * @param int      $depth  Depth of menu item. Used for padding.
     * @param stdClass $args   An object of wp_nav_menu() arguments.
     * @param int      $id     Current item ID.
     */
    public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
        if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {
            $t = '';
            $n = '';
        } else {
            $t = "\t";
            $n = "\n";
        }
        $indent = ( $depth ) ? str_repeat( $t, $depth ) : '';
        $classes = empty( $item->classes ) ? array() : (array) $item->classes;
        // Initialize some holder variables to store specially handled item
        // wrappers and icons.
        $linkmod_classes = array();
        $icon_classes    = array();
        /**
         * Get an updated $classes array without linkmod or icon classes.
         *
         * NOTE: linkmod and icon class arrays are passed by reference and
         * are maybe modified before being used later in this function.
         */
        $classes = self::separate_linkmods_and_icons_from_classes( $classes, $linkmod_classes, $icon_classes, $depth );
        // Join any icon classes plucked from $classes into a string.
        $icon_class_string = join( ' ', $icon_classes );
        /**
         * Filters the arguments for a single nav menu item.
         *
         *  WP 4.4.0
         *
         * @param stdClass $args  An object of wp_nav_menu() arguments.
         * @param WP_Post  $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 );
        
        // Add .dropdown or .active classes where they are needed.
        if ( isset( $args->has_children ) && $args->has_children ) {
            $classes[] = 'cz-dropdown';
           
            // Modifications by Jerry
            if( isset( $args->menu_type ) && 'mobile' == $args->menu_type || isset( $args->menu_type ) && 'side' == $args->menu_type ) {
                if( $depth > 0 ) {
                    $classes[] = 'cz-dropdown-submenu';
                } else {
                    $classes[] = 'cz-dropdown';
                }
            }
        }
        if ( in_array( 'current-menu-item', $classes, true ) || in_array( 'current-menu-parent', $classes, true ) ) {
            $classes[] = 'active';
        }
        // Add some additional default classes to the item.
        $classes[] = 'menu-item-' . $item->ID;
        $classes[] = 'cz-nav-item';
        // Allow filtering the classes.
        $classes = apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth );
        // Form a string of classes in format: class="class_names".
        $class_names = join( ' ', $classes );
        $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
        /**
         * Filters the ID applied to a menu item's list item element.
         *
         * @since WP 3.0.1
         * @since WP 4.1.0 The `$depth` parameter was added.
         *
         * @param string   $menu_id The ID that is applied to the menu item's `<li>` element.
         * @param WP_Post  $item    The current menu item.
         * @param stdClass $args    An object of 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 ) . '"' : '';
        $output .= $indent . '<li itemscope="itemscope" itemtype="https://www.schema.org/SiteNavigationElement"' . $id . $class_names . '>';
        // initialize array for holding the $atts for the link item.
        $atts = array();
        // Set title from item to the $atts array - if title is empty then
        // default to item title.
        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 ( isset( $args->has_children ) && $args->has_children && 0 === $depth && $args->depth > 1 ) {
            // $atts['href']          = '#'; - original
            $atts['href']          = ! empty( $item->url ) ? $item->url : '#'; // Added by Jerry
            $atts['data-toggle']   = 'cz-dropdown';
            $atts['aria-haspopup'] = 'true';
            $atts['aria-expanded'] = 'false';
            $atts['class']         = 'cz-dropdown-toggle cz-nav-link';
            $atts['id']            = 'menu-item-dropdown-' . $item->ID;
        } else {
            $atts['href'] = ! empty( $item->url ) ? esc_url( $item->url ) : '#';
            // Items in dropdowns use .dropdown-item instead of .nav-link.
            if ( $depth > 0 ) {
                $atts['class'] = 'cz-dropdown-item'; // Original
                // Added by Jerry
                if( isset( $args->menu_type ) && 'mobile' == $args->menu_type && $depth !== 0 ) {
                    $atts['class'] = 'cz-dropdown-item cz-dropdown-toggle';
                }
                else
                if( isset( $args->menu_type ) && 'side' == $args->menu_type && $depth !== 0 ) {
                    $atts['class'] = 'cz-dropdown-item cz-dropdown-toggle';
                }
            } else {
                $atts['class'] = 'cz-nav-link';
            }
        }
        // update atts of this item based on any custom linkmod classes.
        $atts = self::update_atts_for_linkmod_type( $atts, $linkmod_classes );
        // Allow filtering of the $atts array before using it.
        $atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args, $depth );
        // Build a string of html containing all the atts for the item.
        $attributes = '';
        foreach ( $atts as $attr => $value ) {
            if ( ! empty( $value ) ) {
                $value       = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
                $attributes .= ' ' . $attr . '="' . $value . '"';
            }
        }
        /**
         * Set a typeflag to easily test if this is a linkmod or not.
         */
        $linkmod_type = self::get_linkmod_type( $linkmod_classes );
        /**
         * START appending the internal item contents to the output.
         */
        $item_output = isset( $args->before ) ? $args->before : '';
        /**
         * This is the start of the internal nav item. Depending on what
         * kind of linkmod we have we may need different wrapper elements.
         */
        if ( '' !== $linkmod_type ) {
            // is linkmod, output the required element opener.
            $item_output .= self::linkmod_element_open( $linkmod_type, $attributes );
        } else {
            // With no link mod type set this must be a standard <a> tag.
            $item_output .= '<a' . $attributes . '>';
        }
        /**
         * Initiate empty icon var, then if we have a string containing any
         * icon classes form the icon markup with an <i> element. This is
         * output inside of the item before the $title (the link text).
         */
        $icon_html = '';
        if ( ! empty( $icon_class_string ) ) {
            // append an <i> with the icon classes to what is output before links.
            $icon_html = '<i class="' . esc_attr( $icon_class_string ) . '" aria-hidden="true"></i> ';
        }
        
        // Apply SVG Icon on side menu.
        if( is_object( $args ) && $args->has_children ) {
            $args->link_after = ' ' . Componentz()->svg->icon( 'cz-icon-arrow-right' );
        } else {
            is_object( $args ) ? $args->link_after = '' : '';
        }
        
        /** 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 WP 4.4.0
         *
         * @param string   $title The menu item's title.
         * @param WP_Post  $item  The current menu item.
         * @param stdClass $args  An object 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 );
        /**
         * If the .sr-only class was set apply to the nav items text only.
         */
        if ( in_array( 'cz-sr-only', $linkmod_classes, true ) ) {
            $title         = self::wrap_for_screen_reader( $title );
            $keys_to_unset = array_keys( $linkmod_classes, 'cz-sr-only' );
            foreach ( $keys_to_unset as $k ) {
                unset( $linkmod_classes[ $k ] );
            }
        }
        // Put the item contents into $output.
        $item_output .= isset( $args->link_before ) ? $args->link_before . $icon_html . $title . $args->link_after : '';
        /**
         * This is the end of the internal nav item. We need to close the
         * correct element depending on the type of link or link mod.
         */
        if ( '' !== $linkmod_type ) {
            // is linkmod, output the required element opener.
            $item_output .= self::linkmod_element_close( $linkmod_type, $attributes );
        } else {
            // With no link mod type set this must be a standard <a> tag.
            $item_output .= '</a>';
        }
        $item_output .= isset( $args->after ) ? $args->after : '';
        /**
         * END appending the internal item contents to the output.
         */
        $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. 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 WP 2.5.0
     *
     * @see Walker::start_lvl()
     *
     * @param object $element           Data object.
     * @param array  $children_elements List of elements to continue traversing (passed by reference).
     * @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            Used to append additional content (passed by reference).
     */
    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 ) {
        $location = isset( $args['theme_location'] ) ? $args['theme_location'] : '';
        if( ! has_nav_menu( $location ) ) {
            $args['before'] = '<ul class="cz-nav cz-navbar-nav">';
            $args['echo']   = true;
            $args['walker'] = new PageWalker();
            
            call_user_func( 'wp_page_menu', $args );
        }
    }
    
    /**
     * Find any custom linkmod or icon classes and store in their holder
     * arrays then remove them from the main classes array.
     *
     * Supported linkmods: .disabled, .dropdown-header, .dropdown-divider, .sr-only
     * Supported iconsets: Font Awesome 4/5, Glypicons
     *
     * NOTE: This accepts the linkmod and icon arrays by reference.
     *
     * @since 4.0.0
     *
     * @param array   $classes         an array of classes currently assigned to the item.
     * @param array   $linkmod_classes an array to hold linkmod classes.
     * @param array   $icon_classes    an array to hold icon classes.
     * @param integer $depth           an integer holding current depth level.
     *
     * @return array  $classes         a maybe modified array of classnames.
     */
    private function separate_linkmods_and_icons_from_classes( $classes, &$linkmod_classes, &$icon_classes, $depth ) {
        // Loop through $classes array to find linkmod or icon classes.
        foreach ( $classes as $key => $class ) {
            // If any special classes are found, store the class in it's
            // holder array and and unset the item from $classes.
            if ( preg_match( '/^disabled|^cz-sr-only/i', $class ) ) {
                // Test for .disabled or .sr-only classes.
                $linkmod_classes[] = $class;
                unset( $classes[ $key ] );
            } elseif ( preg_match( '/^cz-dropdown-header|^cz-dropdown-divider|^cz-dropdown-item-text/i', $class ) && $depth > 0 ) {
                // Test for .dropdown-header or .dropdown-divider and a
                // depth greater than 0 - IE inside a dropdown.
                $linkmod_classes[] = $class;
                unset( $classes[ $key ] );
            } elseif ( preg_match( '/^fa-(\S*)?|^fa(s|r|l|b)?(\s?)?$/i', $class ) ) {
                // Font Awesome.
                $icon_classes[] = $class;
                unset( $classes[ $key ] );
            } elseif ( preg_match( '/^glyphicon-(\S*)?|^glyphicon(\s?)$/i', $class ) ) {
                // Glyphicons.
                $icon_classes[] = $class;
                unset( $classes[ $key ] );
            }
        }

        return $classes;
    }
    
    /**
     * Return a string containing a linkmod type and update $atts array
     * accordingly depending on the decided.
     *
     * @since 4.0.0
     *
     * @param array $linkmod_classes array of any link modifier classes.
     *
     * @return string                empty for default, a linkmod type string otherwise.
     */
    private function get_linkmod_type( $linkmod_classes = array() ) {
        $linkmod_type = '';
        // Loop through array of linkmod classes to handle their $atts.
        if ( ! empty( $linkmod_classes ) ) {
            foreach ( $linkmod_classes as $link_class ) {
                if ( ! empty( $link_class ) ) {

                    // check for special class types and set a flag for them.
                    if ( 'cz-dropdown-header' === $link_class ) {
                        $linkmod_type = 'cz-dropdown-header';
                    } elseif ( 'cz-dropdown-divider' === $link_class ) {
                        $linkmod_type = 'cz-dropdown-divider';
                    } elseif ( 'cz-dropdown-item-text' === $link_class ) {
                        $linkmod_type = 'cz-dropdown-item-text';
                    }
                }
            }
        }
        return $linkmod_type;
    }
    
    /**
     * Update the attributes of a nav item depending on the limkmod classes.
     *
     * @since 4.0.0
     *
     * @param array $atts            array of atts for the current link in nav item.
     * @param array $linkmod_classes an array of classes that modify link or nav item behaviors or displays.
     *
     * @return array                 maybe updated array of attributes for item.
     */
    private function update_atts_for_linkmod_type( $atts = array(), $linkmod_classes = array() ) {
        if ( ! empty( $linkmod_classes ) ) {
            foreach ( $linkmod_classes as $link_class ) {
                if ( ! empty( $link_class ) ) {
                    // update $atts with a space and the extra classname...
                    // so long as it's not a sr-only class.
                    if ( 'cz-sr-only' !== $link_class ) {
                        $atts['class'] .= ' ' . esc_attr( $link_class );
                    }
                    // check for special class types we need additional handling for.
                    if ( 'disabled' === $link_class ) {
                        // Convert link to '#' and unset open targets.
                        $atts['href'] = '#';
                        unset( $atts['target'] );
                    } elseif ( 'cz-dropdown-header' === $link_class || 'cz-dropdown-divider' === $link_class || 'cz-dropdown-item-text' === $link_class ) {
                        // Store a type flag and unset href and target.
                        unset( $atts['href'] );
                        unset( $atts['target'] );
                    }
                }
            }
        }
        return $atts;
    }
    
    /**
     * Wraps the passed text in a screen reader only class.
     *
     * @since 4.0.0
     *
     * @param string $text the string of text to be wrapped in a screen reader class.
     * @return string      the string wrapped in a span with the class.
     */
    private function wrap_for_screen_reader( $text = '' ) {
        if ( $text ) {
            $text = '<span class="cz-sr-only">' . $text . '</span>';
        }
        return $text;
    }
    
    /**
     * Returns the correct opening element and attributes for a linkmod.
     *
     * @since 4.0.0
     *
     * @param string $linkmod_type a sting containing a linkmod type flag.
     * @param string $attributes   a string of attributes to add to the element.
     *
     * @return string              a string with the openign tag for the element with attribibutes added.
     */
    private function linkmod_element_open( $linkmod_type, $attributes = '' ) {
        $output = '';
        if ( 'cz-dropdown-item-text' === $linkmod_type ) {
            $output .= '<span class="cz-dropdown-item-text"' . $attributes . '>';
        } elseif ( 'cz-dropdown-header' === $linkmod_type ) {
            // For a header use a span with the .h6 class instead of a real
            // header tag so that it doesn't confuse screen readers.
            $output .= '<span class="cz-dropdown-header h6"' . $attributes . '>';
        } elseif ( 'cz-dropdown-divider' === $linkmod_type ) {
            // this is a divider.
            $output .= '<div class="cz-dropdown-divider"' . $attributes . '>';
        }
        return $output;
    }

    /**
     * Return the correct closing tag for the linkmod element.
     *
     * @since 4.0.0
     *
     * @param string $linkmod_type a string containing a special linkmod type.
     *
     * @return string              a string with the closing tag for this linkmod type.
     */
    private function linkmod_element_close( $linkmod_type ) {
        $output = '';
        if ( 'cz-dropdown-header' === $linkmod_type || 'cz-dropdown-item-text' === $linkmod_type ) {
            // For a header use a span with the .h6 class instead of a real
            // header tag so that it doesn't confuse screen readers.
            $output .= '</span>';
        } elseif ( 'cz-dropdown-divider' === $linkmod_type ) {
            // this is a divider.
            $output .= '</div>';
        }
        return $output;
    }
    
}

/* Omit closing PHP tag to avoid "Headers already sent" issues. */