<?php
define( 'DIR_URI', get_template_directory_uri() . '/theme-modules/multilanguage-tracker' );

/*
* Multilanguage URL tracker
 */
function mlt_url_tracker_menu() {
  add_menu_page(
    'URL Tracker',
    'URL Tracker',
    'manage_network_options',
    'imm_url_tracker',
    'mlt_url_tracker_callback'
  );
}

add_action( 'network_admin_menu', 'mlt_url_tracker_menu' );

/*
* Callback function to call template
 */
function mlt_url_tracker_callback() {
  //Add empty options
  $items = array();
  $language_options = get_site_option('imm_language_options');
  if( !$language_options ) {
    foreach ( get_sites() as $key => $site ) {
      $items[] = array(
        'site_id' => $site->blog_id,
        'code'    => '',
        'label'   => ''
      );
    }

    add_site_option('imm_language_options', $items);
  }

  require_once 'template.php';
}

/*
* Add Metabox on edit pages or post
 */
 add_action('add_meta_boxes', 'mlt_add_edit_metabox');

 function mlt_add_edit_metabox() {
   if( !is_multisite() ) {
     return;
   }

   $post_types = array('post','page');

   $args = array(
    'public'   => true,
    '_builtin' => false,
   );

   $output = 'objects';
   $operator = 'and';

   $custom_post_types = get_post_types( $args, $output, $operator );

   foreach ($custom_post_types as $key => $type) {
     $post_types[] = $type->name;
   }

   add_meta_box(
     'mlt_edit_content',
     'Multilanguage Tracker',
     'mlt_metabox_callback',
     $post_types,
     'side',
     'high'
   );
 }

 function mlt_metabox_callback($post, $metabox) {
   $url_tracker = get_post_meta($post->ID, 'mlt_url_tracker')[0];
   if( $url_tracker ) {
      foreach ($url_tracker as $page) {
        if( get_current_blog_id() != $page['site_id'] && $page['post_id'] != '' ) :
          switch_to_blog($page['site_id']);
          $post_id = $page['post_id'];
          $title = site_url();
        ?>
          <div class="mlt-tracker-item">
            <p class="site-name"><?php echo $title; ?></p>
            <p class="post-title"><?php echo get_the_title($post_id); ?> <a href="<?php echo get_edit_post_link($post_id) ?>" target="_blank">Edit</a></p>
          </div>
        <?php
        restore_current_blog();
        endif;
      }
   }else{
     echo '<p>Edit the multilanguage tracker to show linked pages</p>';
   }
 }

/*
* Get post list with pagination
 */
function mlt_get_posts_list( $blog_id, $paged, $post_type ) {
  switch_to_blog( $blog_id );
  $post_list = array();

  $args = array(
    'post_type'       => $post_type,
    'post_status'     => 'publish',
    'posts_per_page'  => 10,
    'paged'           => $paged,
  );

  $query = new WP_Query( $args );

  if( $query->have_posts() ) {
    while( $query->have_posts() ) {
      $query->the_post();
      $post_list['posts'][] = array(
        'id'        => get_the_ID(),
        'title'     => get_the_title(),
        'permalink' => get_permalink()
      );
    }

    $big = 999999999;
    $post_list['pagination'] = paginate_links( array(
      'base' => str_replace( array($big, '#038;'), array('%#%', ''), esc_url( get_pagenum_link( $big ) ) ),
      'prev_text' => __( '&laquo;', 'imm-starter-theme' ),
      'next_text' => __( '&raquo;', 'imm-starter-theme' ),
      'format' => '?paged=%#%',
      'current' => max( 1, $paged ),
      'total' => $query->max_num_pages
    ) );
  }
  wp_reset_postdata();

  return $post_list;
}

/*
* Enqueue scripts & styles on admin
 */
function mlt_enqueue_scripts_admin( $hook ) {
  if( 'toplevel_page_imm_url_tracker' == $hook ) {
    wp_enqueue_script('jquery-ui-sortable');

    wp_enqueue_script('mlt_select2', DIR_URI . '/select2/select2.min.js', array('jquery'), time(), true);
    wp_enqueue_style('mlt_select2', DIR_URI . '/select2/select2.min.css');

    wp_enqueue_script('mlt_scripts', DIR_URI . '/assets/scripts.js', array('jquery'), time(), true);
    wp_localize_script( 'mlt_scripts', 'mltAjax', array( 'ajaxurl' => admin_url( 'admin-ajax.php' ), 'nonce' => wp_create_nonce('ajax-nonce') ));

    wp_enqueue_style('mlt_style', DIR_URI . '/assets/style.css');
  }

  wp_enqueue_style('mlt_admin_style', DIR_URI . '/assets/admin.css');
}

add_action('admin_enqueue_scripts', 'mlt_enqueue_scripts_admin');

/*
* Enqueue script & style on frontend
 */
 function mlt_enqueue_scripts_frontend( $hook ) {
   $language_options = get_site_option('imm_language_options');
   if( $language_options ) {
     wp_enqueue_style('mlt_switcher', DIR_URI . '/assets/language-switcher.css');
     wp_enqueue_script( 'mlt_switcher', DIR_URI . '/assets/language-switcher.js', array('jquery'), false, true );
   }
 }

 add_action('wp_enqueue_scripts', 'mlt_enqueue_scripts_frontend');

/*
* Get post list from AJAX request
 */
function mlt_get_posts_list_ajax() {
  $nonce = $_GET['nonce'];
  if ( ! wp_verify_nonce( $nonce, 'ajax-nonce' ) )
      die ( 'Your action is not verified');

  $site_id = $_GET['site_id'];
  $post_type = $_GET['post_type'];
  $paged = $_GET['page'];

  $result = array();
  $result['pagination']['more'] = false;

  switch_to_blog( $site_id );
  $args = array(
    'post_type'       => $post_type,
    'post_status'     => 'publish',
    'posts_per_page'  => 10,
    'paged'           => $paged
  );

  if( isset($_GET['q']) ) {
    $args['s'] = $_GET['q'];
  }

  $query = new WP_Query( $args );

  if( $paged < $query->max_num_pages ) {
    $result['pagination']['more'] = true;
  }

  if( $query->have_posts() ) {
    while( $query->have_posts() ) {
      $query->the_post();
      $result['results'][] = array(
        'id'     => get_the_ID(),
        'text'   => get_the_title()
      );
    }
  }

  wp_reset_postdata();

  echo wp_json_encode( $result );

  die();
}

add_action('wp_ajax_nopriv_mlt_get_posts_list_ajax', 'mlt_get_posts_list_ajax');
add_action('wp_ajax_mlt_get_posts_list_ajax', 'mlt_get_posts_list_ajax');

/*
* Update URL tracker on all sites
 */
function mlt_update_tracker() {
  $nonce = $_POST['nonce'];
  if ( ! wp_verify_nonce( $nonce, 'ajax-nonce' ) )
      die ( 'Your action is not verified');

  $items = $_POST['items'];

  foreach ($items as $key => $item) {
    switch_to_blog($item['site_id']);
    update_post_meta( $item['post_id'], 'mlt_url_tracker', $items );
  }

  die();
}

add_action('wp_ajax_nopriv_mlt_update_tracker', 'mlt_update_tracker');
add_action('wp_ajax_mlt_update_tracker', 'mlt_update_tracker');

/*
* Update language options
 */
function mlt_update_language_options() {
  $nonce = $_POST['nonce'];
  if ( ! wp_verify_nonce( $nonce, 'ajax-nonce' ) )
      die ( 'Your action is not verified');

  $items = $_POST['items'];

  delete_site_option('imm_language_options');
  add_site_option('imm_language_options', $items);

  die();
}

add_action('wp_ajax_nopriv_mlt_update_language_options', 'mlt_update_language_options');
add_action('wp_ajax_mlt_update_language_options', 'mlt_update_language_options');

/*
* Language switcher shortcode
 */
function mlt_language_switcher( $atts ) {
  $a = shortcode_atts( array(
        'type' => 'list',
    ), $atts );

  ob_start();
    require 'language-switcher-template.php';
  return ob_get_clean();
}

add_shortcode('mlt-language-switcher', 'mlt_language_switcher');

/*
* Get linked pages based on post id
 */
function mlt_get_linked_pages() {
  $result = array();
  $language_options = get_site_option('imm_language_options');
  $post_obj = get_queried_object();

  if( $language_options && isset($post_obj->ID) ) {
    $post_id = $post_obj->ID;

    foreach ($language_options as $option_key => $option) {
      $url_tracker = get_post_meta($post_id, 'mlt_url_tracker')[0];

      /*
      * If linked pages not exists, use the current site url for each site
       */
      if( $url_tracker ) {
        foreach ($url_tracker as $url_key => $url) {
          if( $option['site_id'] == $url['site_id'] ) {
            switch_to_blog($option['site_id']);

            $permalink = get_permalink($url['post_id']);

            $result[] = array(
              'site_id'     => $option['site_id'],
              'permalink'   => $permalink,
              'code'        => $option['code'],
              'label'       => $option['label']
            );

            restore_current_blog();
          }
        }
      }else{
        switch_to_blog($option['site_id']);

        $permalink = site_url();

        $result[] = array(
          'site_id'     => $option['site_id'],
          'permalink'   => $permalink,
          'code'        => $option['code'],
          'label'       => $option['label']
        );

        restore_current_blog();
      }
    }
  }

  return $result;
}

/*
* Add Hreflang tag in header
 */

function add_href_lang_tag() {
  $template = '';

  $linked_pages = mlt_get_linked_pages();

  if( empty($linked_pages) ) {
    return;
  }

  foreach ($linked_pages as $key => $page) {
    switch_to_blog($option['site_id']);

    //Don't render the tag if there is no linked pages on current page
    if( !is_front_page() && ( site_url() != $option['permalink'] ) ) {
      $template .= '<link rel="alternate" href="'. $page['permalink'] .'" hreflang="'. $page['code'] .'" />';
    }

    restore_current_blog();
  }

  echo $template;
}

add_action('wp_head', 'add_href_lang_tag');