<?php
/**
 * Breadcrumb Trail - A breadcrumb menu script for WordPress.
 *
 * Breadcrumb Trail is a script for showing a breadcrumb trail for any type of page.  It tries to 
 * anticipate any type of structure and display the best possible trail that matches your site's 
 * permalink structure.  While not perfect, it attempts to fill in the gaps left by many other 
 * breadcrumb scripts.
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU 
 * General Public License as published by the Free Software Foundation; either version 2 of the License, 
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without 
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * @package   BreadcrumbTrail
 * @version   0.6.1
 * @author    Justin Tadlock <justin@justintadlock.com>
 * @copyright Copyright (c) 2008 - 2013, Justin Tadlock
 * @link      http://themehybrid.com/plugins/breadcrumb-trail
 * @license   http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

/**
 * Shows a breadcrumb for all types of pages.  This is a wrapper function for the Breadcrumb_Trail class, 
 * which should be used in theme templates.
 *
 * @since  0.1.0
 * @access public
 * @param  array $args Arguments to pass to Breadcrumb_Trail.
 * @return void
 */
function breadcrumb_trail( $args = array() ) {

    if ( function_exists( 'is_bbpress' ) && is_bbpress() )
        $breadcrumb = new bbPress_Breadcrumb_Trail( $args );
    else
        $breadcrumb = new Breadcrumb_Trail( $args );

    return $breadcrumb->trail();
}

/**
 * Creates a breadcrumbs menu for the site based on the current page that's being viewed by the user.
 *
 * @since 0.6.0
 */
class Breadcrumb_Trail {

    /**
     * Array of items belonging to the current breadcrumb trail.
     *
     * @since  0.1.0
     * @access public
     * @var    array
     */
    public $items = array();

    /**
     * Arguments used to build the breadcrumb trail.
     *
     * @since  0.1.0
     * @access public
     * @var    array
     */
    public $args = array();

    /**
     * Sets up the breadcrumb trail.
     *
     * @since  0.6.0
     * @access public
     * @param  array  $args The arguments for how to build the breadcrumb trail.
     * @return void
     */
    public function __construct( $args = array() ) {

        /* Remove the bbPress breadcrumbs. */
        add_filter( 'bbp_get_breadcrumb', '__return_false' );

        $defaults = array(
            'container'       => 'div',
            'separator'       => '&#47;',
            'before'          => '',
            'after'           => '',
            'show_on_front'   => true,
            'network'         => false,
            //'show_edit_link'  => false,
            'show_title'      => true,
            'show_browse'     => true,
            'echo'            => true,

            /* Post taxonomy (examples follow). */
            'post_taxonomy' => array(
                // 'post'  => 'post_tag',
                // 'book'  => 'genre',
            ),

            /* Labels for text used (see Breadcrumb_Trail::default_labels). */
            'labels' => array()
        );

        $this->args = apply_filters( 'breadcrumb_trail_args', wp_parse_args( $args, $defaults ) );

        /* Merge the user-added labels with the defaults. */
        $this->args['labels'] = wp_parse_args( $this->args['labels'], $this->default_labels() );

        $this->do_trail_items();
    }

    /**
     * Formats and outputs the breadcrumb trail.
     *
     * @since  0.6.0
     * @access public
     * @return string
     */
    public function trail() {

        $breadcrumb = '';

        /* Connect the breadcrumb trail if there are items in the trail. */
        if ( !empty( $this->items ) && is_array( $this->items ) ) {

            /* Make sure we have a unique array of items. */
            $this->items = array_unique( $this->items );

            /* Open the breadcrumb trail containers. */
            $breadcrumb = "\n\t\t" . '<' . tag_escape( $this->args['container'] ) . ' class="breadcrumb-trail breadcrumbs" itemprop="breadcrumb">';

            /* If $before was set, wrap it in a container. */
            $breadcrumb .= ( !empty( $this->args['before'] ) ? "\n\t\t\t" . '<span class="trail-before">' . $this->args['before'] . '</span> ' . "\n\t\t\t" : '' );

            /* Add 'browse' label if it should be shown. */
            if ( true === $this->args['show_browse'] )
                $breadcrumb .= "\n\t\t\t" . '<span class="trail-browse">' . $this->args['labels']['browse'] . '</span> ';

            /* Adds the 'trail-begin' class around first item if there's more than one item. */
            if ( 1 < count( $this->items ) )
                array_unshift( $this->items, '<span class="trail-begin">' . array_shift( $this->items ) . '</span>' );

            /* Adds the 'trail-end' class around last item. */
            array_push( $this->items, '<span class="trail-end">' . array_pop( $this->items ) . '</span>' );

            /* Format the separator. */
            $separator = ( !empty( $this->args['separator'] ) ? '<span class="sep">' . $this->args['separator'] . '</span>' : '<span class="sep">/</span>' );

            /* Join the individual trail items into a single string. */
            $breadcrumb .= join( "\n\t\t\t {$separator} ", $this->items );

            /* If $after was set, wrap it in a container. */
            $breadcrumb .= ( !empty( $this->args['after'] ) ? "\n\t\t\t" . ' <span class="trail-after">' . $this->args['after'] . '</span>' : '' );

            /* Close the breadcrumb trail containers. */
            $breadcrumb .= "\n\t\t" . '</' . tag_escape( $this->args['container'] ) . '>';
        }

        /* Allow developers to filter the breadcrumb trail HTML. */
        $breadcrumb = apply_filters( 'breadcrumb_trail', $breadcrumb, $this->args );

        if ( true === $this->args['echo'] )
            echo $breadcrumb;
        else
            return $breadcrumb;
    }

    /**
     * Returns an array of the default labels.
     *
     * @since  0.6.0
     * @access public
     * @return array
     */
    public function default_labels() {

        $labels = array(
            'browse'              => __( 'Browse:',                             'ultra' ),
            'home'                => __( 'Home',                                'ultra' ),
            'error_404'           => __( '404 Not Found',                       'ultra' ),
            'archives'            => __( 'Archives',                            'ultra' ),
            /* Translators: %s is the search query. The HTML entities are opening and closing curly quotes. */
            'search'              => __( 'Search results for &#8220;%s&#8221;', 'ultra' ),
            /* Translators: %s is the page number. */
            'paged'               => __( 'Page %s',                             'ultra' ),
            /* Translators: Minute archive title. %s is the minute time format. */
            'archive_minute'      => __( 'Minute %s',                           'ultra' ),
            /* Translators: Weekly archive title. %s is the week date format. */
            'archive_week'        => __( 'Week %s',                             'ultra' ),

            /* "%s" is replaced with the translated date/time format. */
            'archive_minute_hour' => '%s',
            'archive_hour'        => '%s',
            'archive_day'         => '%s',
            'archive_month'       => '%s',
            'archive_year'        => '%s',
        );

        return $labels;
    }

    /**
     * Runs through the various WordPress conditional tags to check the current page being viewed.  Once 
     * a condition is met, a specific method is launched to add items to the $items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_trail_items() {

        /* If viewing the front page. */
        if ( is_front_page() ) {
            $this->do_front_page_items();
        }

        /* If not viewing the front page. */
        else {

            /* Add the network and site home links. */
            $this->do_network_home_link();
            $this->do_site_home_link();

            /* If viewing the home/blog page. */
            if ( is_home() ) {
                $this->do_posts_page_items();
            }

            /* If viewing a single post. */
            elseif ( is_singular() ) {
                $this->do_singular_items();
            }

            /* If viewing an archive page. */
            elseif ( is_archive() ) {

                if ( is_post_type_archive() )
                    $this->do_post_type_archive_items();

                elseif ( is_category() || is_tag() || is_tax() )
                    $this->do_term_archive_items();

                elseif ( is_author() )
                    $this->do_user_archive_items();

                elseif ( get_query_var( 'minute' ) && get_query_var( 'hour' ) )
                    $this->do_minute_hour_archive_items();

                elseif ( get_query_var( 'minute' ) )
                    $this->do_minute_archive_items();

                elseif ( get_query_var( 'hour' ) )
                    $this->do_hour_archive_items();

                elseif ( is_day() )
                    $this->do_day_archive_items();

                elseif ( get_query_var( 'w' ) )
                    $this->do_week_archive_items();

                elseif ( is_month() )
                    $this->do_month_archive_items();

                elseif ( is_year() )
                    $this->do_year_archive_items();

                else
                    $this->do_default_archive_items();
            }

            /* If viewing a search results page. */
            elseif ( is_search() ) {
                $this->do_search_items();
            }

            /* If viewing the 404 page. */
            elseif ( is_404() ) {
                $this->do_404_items();
            }
        }

        /* Add paged items if they exist. */
        $this->do_paged_items();

        /* Allow developers to overwrite the items for the breadcrumb trail. */
        $this->items = apply_filters( 'breadcrumb_trail_items', $this->items, $this->args );
    }

    /**
     * Gets front items based on $wp_rewrite->front.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_rewrite_front_items() {
        global $wp_rewrite;

        if ( $wp_rewrite->front )
            $this->do_path_parents( $wp_rewrite->front );
    }

    /**
     * Adds the page/paged number to the items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_paged_items() {

        /* If viewing a paged singular post. */
        if ( is_singular() && 1 < get_query_var( 'page' ) && true === $this->args['show_title'] )
            $this->items[] = sprintf( $this->args['labels']['paged'], number_format_i18n( absint( get_query_var( 'page' ) ) ) );

        /* If viewing a paged archive-type page. */
        elseif ( is_paged() && true === $this->args['show_title'] )
            $this->items[] = sprintf( $this->args['labels']['paged'], number_format_i18n( absint( get_query_var( 'paged' ) ) ) );

    }

    /**
     * Adds the network (all sites) home page link to the items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_network_home_link() {
        if ( is_multisite() && !is_main_site() && true === $this->args['network'] )
            $this->items[] = '<a href="' . network_home_url() . '" title="' . esc_attr( $this->args['labels']['home'] ) . '" rel="home">' . $this->args['labels']['home'] . '</a>';
    }

    /**
     * Adds the current site's home page link to the items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_site_home_link() {
        $label = ( is_multisite() && !is_main_site() && true === $this->args['network'] ) ? get_bloginfo( 'name' ) : $this->args['labels']['home'];
        $rel   = ( is_multisite() && !is_main_site() && true === $this->args['network'] ) ? '' : ' rel="home"';
        $this->items[] = '<a href="' . home_url() . '" title="' . esc_attr( get_bloginfo( 'name' ) ) . '"' . $rel .'>' . $label . '</a>';
    }

    /**
     * Adds items for the front page to the items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_front_page_items() {

        /* Only show front items if the 'show_on_front' argument is set to 'true'. */
        if ( true === $this->args['show_on_front'] || is_paged() || ( is_singular() && 1 < get_query_var( 'page' ) ) ) {

            /* If on a paged view, add the home link items. */
            if ( is_paged() ) {
                $this->do_network_home_link();
                $this->do_site_home_link();
            }

            /* If on the main front page, add the network home link item and the home item. */
            else {
                $this->do_network_home_link();

                if ( true === $this->args['show_title'] )
                    $this->items[] = ( is_multisite() && true === $this->args['network'] ) ? get_bloginfo( 'name' ) : $this->args['labels']['home'];
            }
        }
    }

    /**
     * Adds items for the posts page (i.e., is_home()) to the items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_posts_page_items() {

        /* Get the post ID and post. */
        $post_id = get_queried_object_id();
        $post    = get_page( $post_id );

        /* If the post has parents, add them to the trail. */
        if ( 0 < $post->post_parent )
            $this->do_post_parents( $post->post_parent );

        /* Get the page title. */
        $title = get_the_title( $post_id );

        /* Add the posts page item. */
        if ( is_paged() )
            $this->items[]  = '<a href="' . get_permalink( $post_id ) . '" title="' . esc_attr( $title ) . '">' . $title . '</a>';

        elseif ( $title && true === $this->args['show_title'] )
            $this->items[] = $title;
    }

    /**
     * Adds singular post items to the items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_singular_items() {

        /* Get the queried post. */
        $post    = get_queried_object();
        $post_id = get_queried_object_id();

        /* If the post has a parent, follow the parent trail. */
        if ( 0 < $post->post_parent )
            $this->do_post_parents( $post->post_parent );

        /* If the post doesn't have a parent, get its hierarchy based off the post type. */
        else
            $this->do_post_hierarchy( $post_id );

        /* Display terms for specific post type taxonomy if requested. */
        $this->do_post_terms( $post_id );

        /* End with the post title. */
        if ( $post_title = single_post_title( '', false ) ) {

            if ( 1 < get_query_var( 'page' ) )
                $this->items[] = '<a href="' . get_permalink( $post_id ) . '" title="' . esc_attr( $post_title ) . '">' . $post_title . '</a>';

            elseif ( true === $this->args['show_title'] )
                $this->items[] = $post_title;
        }
    }

    /**
     * Adds a specific post's parents to the items array.
     *
     * @since  0.6.0
     * @access public
     * @param  int    $post_id The ID of the post to get the parents of.
     * @return void
     */
    public function do_post_parents( $post_id ) {
        $parents = array();

        while ( $post_id ) {

            /* Get the post by ID. */
            $post = get_post( $post_id );

            /* Add the formatted post link to the array of parents. */
            $parents[] = '<a href="' . get_permalink( $post_id ) . '" title="' . esc_attr( get_the_title( $post_id ) ) . '">' . get_the_title( $post_id ) . '</a>';

            /* If there's no longer a post parent, brea out of the loop. */
            if ( 0 >= $post->post_parent )
                break;

            /* Change the post ID to the parent post to continue looping. */
            $post_id = $post->post_parent;
        }

        /* Get the post hierarchy based off the final parent post. */
        $this->do_post_hierarchy( $post_id );

        /* Merge the parent items into the items array. */
        $this->items = array_merge( $this->items, array_reverse( $parents ) );
    }

    /**
     * Adds a post's terms from a specific taxonomy to the items array.
     *
     * @since  0.6.0
     * @access public
     * @param  int    $post_id The ID of the post to get the terms for.
     * @return void
     */
    public function do_post_terms( $post_id ) {

        /* Get the post type. */
        $post_type = get_post_type( $post_id );

        /* Add the terms of the taxonomy for this post. */
        if ( !empty( $this->args['post_taxonomy'][ $post_type ] ) )
            $this->items[] = get_the_term_list( $post_id, $this->args['post_taxonomy'][ $post_type ], '', ', ', '' );
    }

    /**
     * Adds a specific post's hierarchy to the items array.  The hierarchy is determined by post type's 
     * rewrite arguments and whether it has an archive page.
     *
     * @since  0.6.0
     * @access public
     * @param  int    $post_id The ID of the post to get the hierarchy for.
     * @return void
     */
    public function do_post_hierarchy( $post_id ) {

        /* Get the post type. */
        $post_type        = get_post_type( $post_id );
        $post_type_object = get_post_type_object( $post_type );

        /* If this is the 'post' post type, get the rewrite front items and map the rewrite tags. */
        if ( 'post' === $post_type ) {

            /* Add $wp_rewrite->front to the trail. */
            $this->do_rewrite_front_items();

            /* Map the rewrite tags. */
            $this->map_rewrite_tags( $post_id, get_option( 'permalink_structure' ) );
        }

        /* If the post type has rewrite rules. */
        elseif ( false !== $post_type_object->rewrite ) {

            /* If 'with_front' is true, add $wp_rewrite->front to the trail. */
            if ( $post_type_object->rewrite['with_front'] )
                $this->do_rewrite_front_items();

            /* If there's a path, check for parents. */
            if ( !empty( $post_type_object->rewrite['slug'] ) )
                $this->do_path_parents( $post_type_object->rewrite['slug'] );
        }

        /* If there's an archive page, add it to the trail. */
        if ( !empty( $post_type_object->has_archive ) ) {

            /* Add support for a non-standard label of 'archive_title' (special use case). */
            $label = !empty( $post_type_object->labels->archive_title ) ? $post_type_object->labels->archive_title : $post_type_object->labels->name;

            $this->items[] = '<a href="' . get_post_type_archive_link( $post_type ) . '">' . $label . '</a>';
        }
    }

    /**
     * Gets post types by slug.  This is needed because the get_post_types() function doesn't exactly 
     * match the 'has_archive' argument when it's set as a string instead of a boolean.
     *
     * @since  0.6.0
     * @access public
     * @param  int    $slug  The post type archive slug to search for.
     * @return void
     */
    public function get_post_types_by_slug( $slug ) {

        $return = array();

        $post_types = get_post_types( array(), 'objects' );

        foreach ( $post_types as $type ) {

            if ( $slug === $type->has_archive || ( true === $type->has_archive && $slug === $type->rewrite['slug'] ) )
                $return[] = $type;
        }

        return $return;
    }

    /**
     * Adds the items to the trail items array for taxonomy term archives.
     *
     * @since  0.6.0
     * @access public
     * @global object $wp_rewrite
     * @return void
     */
    public function do_term_archive_items() {
        global $wp_rewrite;

        /* Get some taxonomy and term variables. */
        $term     = get_queried_object();
        $taxonomy = get_taxonomy( $term->taxonomy );

        /* If there are rewrite rules for the taxonomy. */
        if ( false !== $taxonomy->rewrite ) {

            /* If 'with_front' is true, dd $wp_rewrite->front to the trail. */
            if ( $taxonomy->rewrite['with_front'] && $wp_rewrite->front )
                $this->do_rewrite_front_items();

            /* Get parent pages by path if they exist. */
            $this->do_path_parents( $taxonomy->rewrite['slug'] );

            /* Add post type archive if its 'has_archive' matches the taxonomy rewrite 'slug'. */
            if ( $taxonomy->rewrite['slug'] ) {

                $slug = trim( $taxonomy->rewrite['slug'], '/' );

                /**
                 * Deals with the situation if the slug has a '/' between multiple strings. For 
                 * example, "movies/genres" where "movies" is the post type archive.
                 */
                $matches = explode( '/', $slug );

                /* If matches are found for the path. */
                if ( isset( $matches ) ) {

                    /* Reverse the array of matches to search for posts in the proper order. */
                    $matches = array_reverse( $matches );

                    /* Loop through each of the path matches. */
                    foreach ( $matches as $match ) {

                        /* If a match is found. */
                        $slug = $match;

                        /* Get public post types that match the rewrite slug. */
                        $post_types = $this->get_post_types_by_slug( $match );

                        if ( !empty( $post_types ) ) {

                            $post_type_object = $post_types[0];

                            /* Add support for a non-standard label of 'archive_title' (special use case). */
                            $label = !empty( $post_type_object->labels->archive_title ) ? $post_type_object->labels->archive_title : $post_type_object->labels->name;

                            /* Add the post type archive link to the trail. */
                            $this->items[] = '<a href="' . get_post_type_archive_link( $post_type_object->name ) . '" title="' . esc_attr( $label ) . '">' . $label . '</a>';

                            /* Break out of the loop. */
                            break;
                        }
                    }
                }
            }
        }

        /* If the taxonomy is hierarchical, list its parent terms. */
        if ( is_taxonomy_hierarchical( $term->taxonomy ) && $term->parent )
            $this->do_term_parents( $term->parent, $term->taxonomy );

        /* Add the term name to the trail end. */
        if ( is_paged() )
            $this->items[] = '<a href="' . esc_url( get_term_link( $term, $term->taxonomy ) ) . '" title="' . esc_attr( single_term_title( '', false ) ) . '">' . single_term_title( '', false ) . '</a>';

        elseif ( true === $this->args['show_title'] )
            $this->items[] = single_term_title( '', false );
    }

    /**
     * Adds the items to the trail items array for post type archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_post_type_archive_items() {

        /* Get the post type object. */
        $post_type_object = get_post_type_object( get_query_var( 'post_type' ) );

        if ( false !== $post_type_object->rewrite ) {

            /* If 'with_front' is true, add $wp_rewrite->front to the trail. */
            if ( $post_type_object->rewrite['with_front'] )
                $this->do_rewrite_front_items();

            /* If there's a rewrite slug, check for parents. */
            if ( !empty( $post_type_object->rewrite['slug'] ) )
                $this->do_path_parents( $post_type_object->rewrite['slug'] );
        }

        /* Add the post type [plural] name to the trail end. */
        if ( is_paged() )
            $this->items[] = '<a href="' . esc_url( get_post_type_archive_link( $post_type_object->name ) ) . '" title="' . esc_attr( post_type_archive_title( '', false ) ) . '">' . post_type_archive_title( '', false ) . '</a>';

        elseif ( true === $this->args['show_title'] )
            $this->items[] = post_type_archive_title( '', false );
    }

    /**
     * Adds the items to the trail items array for user (author) archives.
     *
     * @since  0.6.0
     * @access public
     * @global object $wp_rewrite
     * @return void
     */
    public function do_user_archive_items() {
        global $wp_rewrite;

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Get the user ID. */
        $user_id = get_query_var( 'author' );

        /* If $author_base exists, check for parent pages. */
        if ( !empty( $wp_rewrite->author_base ) )
            $this->do_path_parents( $wp_rewrite->author_base );

        /* Add the author's display name to the trail end. */
        if ( is_paged() )
            $this->items[] = '<a href="'. esc_url( get_author_posts_url( $user_id ) ) . '" title="' . esc_attr( get_the_author_meta( 'display_name', $user_id ) ) . '">' . get_the_author_meta( 'display_name', $user_id ) . '</a>';

        elseif ( true === $this->args['show_title'] )
            $this->items[] = get_the_author_meta( 'display_name', $user_id );
    }

    /**
     * Adds the items to the trail items array for minute + hour archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_minute_hour_archive_items() {

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Add the minute + hour item. */
        if ( true === $this->args['show_title'] )
            $this->items[] = sprintf( $this->args['labels']['archive_minute_hour'], get_the_time( _x( 'g:i a', 'minute and hour archives time format', 'ultra' ) ) );
    }

    /**
     * Adds the items to the trail items array for minute archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_minute_archive_items() {

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Add the minute item. */
        if ( true === $this->args['show_title'] )
            $this->items[] = sprintf( $this->args['labels']['archive_minute'], get_the_time( _x( 'i', 'minute archives time format', 'ultra' ) ) );
    }

    /**
     * Adds the items to the trail items array for hour archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_hour_archive_items() {

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Add the hour item. */
        if ( true === $this->args['show_title'] )
            $this->items[] = sprintf( $this->args['labels']['archive_hour'], get_the_time( _x( 'g a', 'hour archives time format', 'ultra' ) ) );
    }

    /**
     * Adds the items to the trail items array for day archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_day_archive_items() {

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Get year, month, and day. */
        $year  = sprintf( $this->args['labels']['archive_year'],  get_the_time( _x( 'Y', 'yearly archives date format',  'ultra' ) ) );
        $month = sprintf( $this->args['labels']['archive_month'], get_the_time( _x( 'F', 'monthly archives date format', 'ultra' ) ) );
        $day   = sprintf( $this->args['labels']['archive_day'],   get_the_time( _x( 'j', 'daily archives date format',   'ultra' ) ) );

        /* Add the year and month items. */
        $this->items[] = '<a href="' . get_year_link( get_the_time( 'Y' ) ) . '" title="' . esc_attr( $year ) . '">' . $year . '</a>';
        $this->items[] = '<a href="' . get_month_link( get_the_time( 'Y' ), get_the_time( 'm' ) ) . '" title="' . esc_attr( $month ) . '">' . $month . '</a>';

        /* Add the day item. */
        if ( is_paged() )
            $this->items[] = '<a href="' . get_day_link( get_the_time( 'Y' ), get_the_time( 'm' ), get_the_time( 'd' ) ) . '" title="' . esc_attr( $day ) . '">' . $day . '</a>';

        elseif ( true === $this->args['show_title'] )
            $this->items[] = $day;
    }

    /**
     * Adds the items to the trail items array for week archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_week_archive_items() {

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Get the year and week. */
        $year = sprintf( $this->args['labels']['archive_year'],  get_the_time( _x( 'Y', 'yearly archives date format', 'ultra' ) ) );
        $week = sprintf( $this->args['labels']['archive_week'],  get_the_time( _x( 'W', 'weekly archives date format', 'ultra' ) ) );

        /* Add the year item. */
        $this->items[] = '<a href="' . get_year_link( get_the_time( 'Y' ) ) . '" title="' . esc_attr( $year ) . '">' . $year . '</a>';

        /* Add the week item. */
        if ( is_paged() )
            $this->items[] = get_archives_link( add_query_arg( array( 'm' => get_the_time( 'Y' ), 'w' => get_the_time( 'W' ) ), home_url() ), $week, false );

        elseif ( true === $this->args['show_title'] )
            $this->items[] = $week;
    }

    /**
     * Adds the items to the trail items array for month archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_month_archive_items() {

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Get the year and month. */
        $year  = sprintf( $this->args['labels']['archive_year'],  get_the_time( _x( 'Y', 'yearly archives date format',  'ultra' ) ) );
        $month = sprintf( $this->args['labels']['archive_month'], get_the_time( _x( 'F', 'monthly archives date format', 'ultra' ) ) );

        /* Add the year item. */
        $this->items[] = '<a href="' . get_year_link( get_the_time( 'Y' ) ) . '" title="' . esc_attr( $year ) . '">' . $year . '</a>';

        /* Add the month item. */
        if ( is_paged() )
            $this->items[] = '<a href="' . get_month_link( get_the_time( 'Y' ), get_the_time( 'm' ) ) . '" title="' . esc_attr( $month ) . '">' . $month . '</a>';

        elseif ( true === $this->args['show_title'] )
            $this->items[] = $month;
    }

    /**
     * Adds the items to the trail items array for year archives.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_year_archive_items() {

        /* Add $wp_rewrite->front to the trail. */
        $this->do_rewrite_front_items();

        /* Get the year. */
        $year  = sprintf( $this->args['labels']['archive_year'],  get_the_time( _x( 'Y', 'yearly archives date format',  'ultra' ) ) );

        /* Add the year item. */
        if ( is_paged() )
            $this->items[] = '<a href="' . get_year_link( get_the_time( 'Y' ) ) . '" title="' . esc_attr( $year ) . '">' . $year . '</a>';

        elseif ( true === $this->args['show_title'] )
            $this->items[] = $year;
    }

    /**
     * Adds the items to the trail items array for archives that don't have a more specific method
     * defined in this class.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_default_archive_items() {

        /* If this is a date-/time-based archive, add $wp_rewrite->front to the trail. */
        if ( is_date() || is_time() )
            $this->do_rewrite_front_items();

        if ( true === $this->args['show_title'] )
            $this->items[] = $this->args['labels']['archives'];
    }

    /**
     * Adds the items to the trail items array for search results.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_search_items() {

        if ( is_paged() )
            $this->items[] = '<a href="' . get_search_link() . '" title="' . esc_attr( sprintf( $this->args['labels']['search'], get_search_query() ) ) . '">' . sprintf( $this->args['labels']['search'], get_search_query() ) . '</a>';

        elseif ( true === $this->args['show_title'] )
            $this->items[] = sprintf( $this->args['labels']['search'], get_search_query() );
    }

    /**
     * Adds the items to the trail items array for 404 pages.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_404_items() {

        if ( true === $this->args['show_title'] )
            $this->items[] = $this->args['labels']['error_404'];
    }

    /**
     * Get parent posts by path.  Currently, this method only supports getting parents of the 'page' 
     * post type.  The goal of this function is to create a clear path back to home given what would 
     * normally be a "ghost" directory.  If any page matches the given path, it'll be added.
     *
     * @since  0.6.0
     * @access public
     * @param  string $path The path (slug) to search for posts by.
     * @return void
     */
    function do_path_parents( $path ) {

        /* Trim '/' off $path in case we just got a simple '/' instead of a real path. */
        $path = trim( $path, '/' );

        /* If there's no path, return. */
        if ( empty( $path ) )
            return;

        /* Get parent post by the path. */
        $post = get_page_by_path( $path );

        if ( !empty( $post ) ) {
            $this->do_post_parents( $post->ID );
        }

        elseif ( is_null( $post ) ) {

            /* Separate post names into separate paths by '/'. */
            $path = trim( $path, '/' );
            preg_match_all( "/\/.*?\z/", $path, $matches );

            /* If matches are found for the path. */
            if ( isset( $matches ) ) {

                /* Reverse the array of matches to search for posts in the proper order. */
                $matches = array_reverse( $matches );

                /* Loop through each of the path matches. */
                foreach ( $matches as $match ) {

                    /* If a match is found. */
                    if ( isset( $match[0] ) ) {

                        /* Get the parent post by the given path. */
                        $path = str_replace( $match[0], '', $path );
                        $post = get_page_by_path( trim( $path, '/' ) );

                        /* If a parent post is found, set the $post_id and break out of the loop. */
                        if ( !empty( $post ) && 0 < $post->ID ) {
                            $this->do_post_parents( $post->ID );
                            break;
                        }
                    }
                }
            }
        }
    }

    /**
     * Searches for term parents of hierarchical taxonomies.  This function is similar to the WordPress 
     * function get_category_parents() but handles any type of taxonomy.
     *
     * @since  0.6.0
     * @param  int    $term_id  ID of the term to get the parents of.
     * @param  string $taxonomy Name of the taxonomy for the given term.
     * @return void
     */
    function do_term_parents( $term_id, $taxonomy ) {

        /* Set up some default arrays. */
        $parents = array();

        /* While there is a parent ID, add the parent term link to the $parents array. */
        while ( $term_id ) {

            /* Get the parent term. */
            $term = get_term( $term_id, $taxonomy );

            /* Add the formatted term link to the array of parent terms. */
            $parents[] = '<a href="' . get_term_link( $term, $taxonomy ) . '" title="' . esc_attr( $term->name ) . '">' . $term->name . '</a>';

            /* Set the parent term's parent as the parent ID. */
            $term_id = $term->parent;
        }

        /* If we have parent terms, reverse the array to put them in the proper order for the trail. */
        if ( !empty( $parents ) )
            $this->items = array_merge( $this->items, $parents );
    }

    /**
     * Turns %tag% from permalink structures into usable links for the breadcrumb trail.  This feels kind of
     * hackish for now because we're checking for specific %tag% examples and only doing it for the 'post' 
     * post type.  In the future, maybe it'll handle a wider variety of possibilities, especially for custom post
     * types.
     *
     * @since  0.6.0
     * @access public
     * @param  int    $post_id ID of the post whose parents we want.
     * @param  string $path    Path of a potential parent page.
     * @param  array  $args    Mixed arguments for the menu.
     * @return array
     */
    public function map_rewrite_tags( $post_id, $path ) {

        /* Get the post based on the post ID. */
        $post = get_post( $post_id );

        /* If no post is returned, an error is returned, or the post does not have a 'post' post type, return. */
        if ( empty( $post ) || is_wp_error( $post ) || 'post' !== $post->post_type )
            return $trail;

        /* Trim '/' from both sides of the $path. */
        $path = trim( $path, '/' );

        /* Split the $path into an array of strings. */
        $matches = explode( '/', $path );

        /* If matches are found for the path. */
        if ( is_array( $matches ) ) {

            /* Loop through each of the matches, adding each to the $trail array. */
            foreach ( $matches as $match ) {

                /* Trim any '/' from the $match. */
                $tag = trim( $match, '/' );

                /* If using the %year% tag, add a link to the yearly archive. */
                if ( '%year%' == $tag )
                    $this->items[] = '<a href="' . get_year_link( get_the_time( 'Y', $post_id ) ) . '">' . sprintf( $this->args['labels']['archive_year'], get_the_time( _x( 'Y', 'yearly archives date format',  'ultra' ) ) ) . '</a>';

                /* If using the %monthnum% tag, add a link to the monthly archive. */
                elseif ( '%monthnum%' == $tag )
                    $this->items[] = '<a href="' . get_month_link( get_the_time( 'Y', $post_id ), get_the_time( 'm', $post_id ) ) . '">' . sprintf( $this->args['labels']['archive_month'], get_the_time( _x( 'F', 'monthly archives date format', 'ultra' ) ) ) . '</a>';

                /* If using the %day% tag, add a link to the daily archive. */
                elseif ( '%day%' == $tag )
                    $this->items[] = '<a href="' . get_day_link( get_the_time( 'Y', $post_id ), get_the_time( 'm', $post_id ), get_the_time( 'd', $post_id ) ) . '">' . sprintf( $this->args['labels']['archive_day'], get_the_time( _x( 'j', 'daily archives date format', 'ultra' ) ) ) . '</a>';

                /* If using the %author% tag, add a link to the post author archive. */
                elseif ( '%author%' == $tag )
                    $this->items[] = '<a href="' . get_author_posts_url( $post->post_author ) . '" title="' . esc_attr( get_the_author_meta( 'display_name', $post->post_author ) ) . '">' . get_the_author_meta( 'display_name', $post->post_author ) . '</a>';

                /* If using the %category% tag, add a link to the first category archive to match permalinks. */
                elseif ( '%category%' == $tag ) {

                    /* Force override terms in this post type. */
                    $this->args['post_taxonomy'][ $post->post_type ] = false;

                    /* Get the post categories. */
                    $terms = get_the_category( $post_id );

                    /* Check that categories were returned. */
                    if ( $terms ) {

                        /* Sort the terms by ID and get the first category. */
                        usort( $terms, '_usort_terms_by_ID' );
                        $term = get_term( $terms[0], 'category' );

                        /* If the category has a parent, add the hierarchy to the trail. */
                        if ( 0 < $term->parent )
                            $this->do_term_parents( $term->parent, 'category' );

                        /* Add the category archive link to the trail. */
                        $this->items[] = '<a href="' . get_term_link( $term, 'category' ) . '" title="' . esc_attr( $term->name ) . '">' . $term->name . '</a>';
                    }
                }
            }
        }
    }
}

/**
 * Extends the Breadcrumb_Trail class for bbPress.  Only use this if bbPress is in use.  This should 
 * serve as an example for other plugin developers to build custom breadcrumb items.
 *
 * @since  0.6.0
 * @access public
 */
class bbPress_Breadcrumb_Trail extends Breadcrumb_Trail {

    /**
     * Runs through the various bbPress conditional tags to check the current page being viewed.  Once 
     * a condition is met, add items to the $items array.
     *
     * @since  0.6.0
     * @access public
     * @return void
     */
    public function do_trail_items() {

        /* Add the network and site home links. */
        $this->do_network_home_link();
        $this->do_site_home_link();

        /* Get the forum post type object. */
        $post_type_object = get_post_type_object( bbp_get_forum_post_type() );

        /* If not viewing the forum root/archive page and a forum archive exists, add it. */
        if ( !empty( $post_type_object->has_archive ) && !bbp_is_forum_archive() )
            $this->items[] = '<a href="' . get_post_type_archive_link( bbp_get_forum_post_type() ) . '">' . bbp_get_forum_archive_title() . '</a>';

        /* If viewing the forum root/archive. */
        if ( bbp_is_forum_archive() ) {

            if ( true === $this->args['show_title'] )
                $this->items[] = bbp_get_forum_archive_title();
        }

        /* If viewing the topics archive. */
        elseif ( bbp_is_topic_archive() ) {

            if ( true === $this->args['show_title'] )
                $this->items[] = bbp_get_topic_archive_title();
        }

        /* If viewing a topic tag archive. */
        elseif ( bbp_is_topic_tag() ) {

            if ( true === $this->args['show_title'] )
                $this->items[] = bbp_get_topic_tag_name();
        }

        /* If viewing a topic tag edit page. */
        elseif ( bbp_is_topic_tag_edit() ) {
            $this->items[] = '<a href="' . bbp_get_topic_tag_link() . '">' . bbp_get_topic_tag_name() . '</a>';

            if ( true === $this->args['show_title'] )
                $this->items[] = __( 'Edit', 'ultra' );
        }

        /* If viewing a "view" page. */
        elseif ( bbp_is_single_view() ) {

            if ( true === $this->args['show_title'] )
                $this->items[] = bbp_get_view_title();
        }

        /* If viewing a single topic page. */
        elseif ( bbp_is_single_topic() ) {

            /* Get the queried topic. */
            $topic_id = get_queried_object_id();

            /* Get the parent items for the topic, which would be its forum (and possibly forum grandparents). */
            $this->do_post_parents( bbp_get_topic_forum_id( $topic_id ) );

            /* If viewing a split, merge, or edit topic page, show the link back to the topic.  Else, display topic title. */
            if ( bbp_is_topic_split() || bbp_is_topic_merge() || bbp_is_topic_edit() )
                $this->items[] = '<a href="' . bbp_get_topic_permalink( $topic_id ) . '">' . bbp_get_topic_title( $topic_id ) . '</a>';

            elseif ( true === $this->args['show_title'] )
                $this->items[] = bbp_get_topic_title( $topic_id );

            /* If viewing a topic split page. */
            if ( bbp_is_topic_split() && true === $this->args['show_title'] )
                $this->items[] = __( 'Split', 'ultra' );

            /* If viewing a topic merge page. */
            elseif ( bbp_is_topic_merge() && true === $this->args['show_title'] )
                $this->items[] = __( 'Merge', 'ultra' );

            /* If viewing a topic edit page. */
            elseif ( bbp_is_topic_edit() && true === $this->args['show_title'] )
                $this->items[] = __( 'Edit', 'ultra' );
        }

        /* If viewing a single reply page. */
        elseif ( bbp_is_single_reply() ) {

            /* Get the queried reply object ID. */
            $reply_id = get_queried_object_id();

            /* Get the parent items for the reply, which should be its topic. */
            $this->do_post_parents( bbp_get_reply_topic_id( $reply_id ) );

            /* If viewing a reply edit page, link back to the reply. Else, display the reply title. */
            if ( bbp_is_reply_edit() ) {
                $this->items[] = '<a href="' . bbp_get_reply_url( $reply_id ) . '">' . bbp_get_reply_title( $reply_id ) . '</a>';

                if ( true === $this->args['show_title'] )
                    $this->items[] = __( 'Edit', 'ultra' );

            } elseif ( true === $this->args['show_title'] ) {
                $this->items[] = bbp_get_reply_title( $reply_id );
            }

        }

        /* If viewing a single forum. */
        elseif ( bbp_is_single_forum() ) {

            /* Get the queried forum ID and its parent forum ID. */
            $forum_id = get_queried_object_id();
            $forum_parent_id = bbp_get_forum_parent_id( $forum_id );

            /* If the forum has a parent forum, get its parent(s). */
            if ( 0 !== $forum_parent_id)
                $this->do_post_parents( $forum_parent_id );

            /* Add the forum title to the end of the trail. */
            if ( true === $this->args['show_title'] )
                $this->items[] = bbp_get_forum_title( $forum_id );
        }

        /* If viewing a user page or user edit page. */
        elseif ( bbp_is_single_user() || bbp_is_single_user_edit() ) {

            if ( bbp_is_single_user_edit() ) {
                $this->items[] = '<a href="' . bbp_get_user_profile_url() . '">' . bbp_get_displayed_user_field( 'display_name' ) . '</a>';

                if ( true === $this->args['show_title'] )
                    $this->items[] = __( 'Edit', 'ultra' );
            } elseif ( true === $this->args['show_title'] ) {
                $this->items[] = bbp_get_displayed_user_field( 'display_name' );
            }
        }

        /* Return the bbPress breadcrumb trail items. */
        $this->items = apply_filters( 'breadcrumb_trail_get_bbpress_items', $this->items, $this->args );
    }
}

?>
