<?php
// $Id: syndication.module,v 1.47.2.2 2007/05/02 04:21:47 andremolnar Exp $

/**
 * Implementation of hook_menu().
 */
function syndication_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array('path' => 'syndication', 'title' => t('RSS feeds'),
    'access' => user_access('access content'),
    'callback' => 'syndication_page',
    'weight' => 6);

    $items[] = array('path' => 'admin/content/syndication',
                     'title' => t('RSS feed syndication'),
                     'access' => user_access('access administration pages'),
                     'callback' => 'drupal_get_form',
                     'callback arguments' => array('syndication_admin_settings'),
                     'type' => MENU_NORMAL_ITEM);
  }
  return $items;
}

function syndication_block($op = 'list', $delta = 0) {
  if($op == 'list') {
    $blocks[0]['info'] = 'Syndicate (more)';
    return $blocks;
  }
  elseif ($op == 'view') {
    if (user_access('access content')) {
      $block['subject'] = t('Syndicate');
      $pagetype = arg(0);
      if ($pagetype == 'blog') {
        $userid = arg(1);
        $linkurl = is_numeric($userid) ? "blog/$userid/feed" : 'blog/feed';
      } else {
        $linkurl = 'rss.xml';
      }
      $block['content'] = theme('feed_icon', url($linkurl));
      $block['content'] .= '<div class="more-link">'. l(t('more'), 'syndication', array ('title' => t("Review all XML feeds exported by %sn", array ("%sn" => variable_get('site_name', 'Drupal'))))). "</div>\n";
      return $block;
    }
  }
}

function syndication_page () {
  $output = '';
  if (module_exists('atom')) {
    $output .= theme('box', t('Atom feed'), l(t('Atom front page feed'), 'atom/feed'));
  }
  if (function_exists('blog_feed_user')) {
    $output .= theme('box', t('Blogs'), syndication_blogs());
  }
  if (module_exists('aggregator') && user_access('access news feeds')) {
    $output .= theme('box', t('External feeds'), syndication_opml());
  }
  if (module_exists('taxonomy') && user_access('access content')) {
    $output .= theme('box', t('Categories'), syndication_vocabularies());
  }
  if (module_exists('views') && module_exists('views_rss') && user_access('access content')){
    if ($views = syndication_views_rss()){ //only bother generating the box if there are enabled views feeds
      $output .= theme('box', t('Views'), $views);
    }
  }

  // modules may add their own syndication boxes
  $result = array();
  foreach (module_list() as $name) {
    $result = module_invoke($name, 'syndication', $edit);
    if (isset($result)) {
      foreach ($result as $box) {
        $output .= theme('box', $box['subject'], $box['content']);
      }
    }
  }
  if (empty($output)) {
    $output = t('Sorry, there are no feeds available.');
  }
  return $output;
}

function syndication_users() {
  if(module_exists('atom')) {
    $prefix = '<p>'. t("At <i>%sn</i>, all users have a %rss and %atom feed for their blog, as well as each individual user.", array ('%sn' => variable_get('site_name', 'Drupal'), '%rss' => l(t('RSS'), 'blog/feed'), '%atom' => l(t('Atom'), 'blog/atom/feed'))). '</p>';
  } else {
    $prefix = '<p>'. t('At <i>%sn</i>, %all and each user, have an RSS feed for their blog.', array ('%sn' => variable_get('site_name', 'Drupal'), '%all' => l(t('all users'), 'blog/feed'))). '</p>';
  }
  $form['name'] = array('#type' => 'textfield',
    '#title' => t('Search users'),
    '#prefix' => $prefix,
    '#description' => t('Enter a username to view her blog feed, and other details.'));
  $form['submit'] = array('#type' => 'button', '#value' => t('Search'));
  return $form;
}

function syndication_blogs() {
  $result = db_query_range("SELECT DISTINCT(u.uid), u.name FROM {users} u INNER JOIN {node} n ON u.uid = n.uid WHERE n.type = 'blog' AND n.status = 1", 0, 16);
  while ($account = db_fetch_object($result)) {
    $author = $account->name .': '. l(t('RSS feed'), "blog/$account->uid/feed");
    $author .= module_exists('atom') ? ', '. l(t('Atom feed'), "blog/$account->uid/atom/feed") : '';
    $authors[] = $author;
  }
  if ($authors) {
    $output =  theme('item_list', $authors, t('Recent Blog Authors'));
  }

  $output .= drupal_get_form('syndication_users');

  if ($name = $_POST['name']) {
    // TODO: this query was already executed in validate hook. if i knew what i was doing, i would not run it again here.
    $result = db_query("SELECT uid, name FROM {users} WHERE uid > 0 and name LIKE '%s' ORDER BY access DESC", '%'. $name. '%');
    $i=0;
    while ($account = db_fetch_object($result)) {;
   	  $rows[$i][] = theme('username', $account). ':';
   	  $rows[$i][] = l(t("RSS feed"), "blog/$account->uid/feed");
      if (module_exists('atom')) {
        $rows[$i][] = l(t("Atom feed"), "blog/$account->uid/atom/feed");
      }
      $rows[$i][] = l(t("blog"), "blog/$account->uid");
      $i++;
    }
    if ($rows) {
  	  $output .= theme('table', array(), $rows);
    }
  }
  $output .= $frm;
  return $output;
}

// follows a similar pattern from og_vocab.module
// should ideally be in taxonomy.module
function syndication_vocabularies() {
  foreach (variable_get('syndication_vocabularies', array()) as $vid) {
    $vocab = taxonomy_get_vocabulary($vid);
    $tree = taxonomy_get_tree($vid);
    // only show first 30 terms. wary of huge vocabs. not ideal.
    $tree = array_slice($tree, 0, 30);
    $items = syndication_taxonomy_build_list_items($index = 0, $tree);
    if ($items) {
      $output .= theme('item_list', $items, $vocab->name);
    }
  }
  return $output;
}

// helper function for syndication_taxonomy
function syndication_taxonomy_build_list_items(&$index, $tree) {
  $items = array();
  $current_depth = $tree[$index]->depth;
  while ($index < count($tree) && $tree[$index]->depth >= $current_depth) {
    $term = $tree[$index];
    $count = taxonomy_term_count_nodes($term->tid);
    if ($count) {
      $term_path = "taxonomy/term/$term->tid/0/feed";
      $term_link = l(t($term->name), $term_path, array('title' => t($term->description)));
      if ($term->depth) {
        $prefix = str_repeat('--', $term->depth). ' ';
      }
      $item = $prefix. $term_link . " ($count)";
      $items[] = $item;
      $index++;
    }
    else {
      $index++;
    }
  }
  return $items;
}

function syndication_users_validate($form_id, &$form) {
  $result = db_query("SELECT uid, name FROM {users} WHERE name LIKE '%s' AND uid > 0 ORDER BY access DESC", '%'. $form["name"]. '%');
  if (db_num_rows($result)) {
    $form['result'] = $result;
  }
  else {
    form_set_error('name', t('Username not found.'));
	  drupal_goto('syndication');
  }
}

function syndication_opml() {
  $url = l(t('this OPML file'), 'aggregator/opml');
  $output = t('In addition to displaying RSS feeds, <i>%sn</i> offers %link which lists all RSS feeds that are collected here.', array ('%sn' => variable_get('site_name', 'Drupal'), '%link' => $url));
  return $output;
}

function syndication_views_rss() {
  $vids = variable_get('syndication_views', array());
  foreach ($vids as $key => $value){
    if (!$value) unset($vids[$key]); //throw away the vids that aren't enabled
  }
  if ($vids) { //only bother getting results if at least one vid is enabled
    $result = _syndication_return_views_rss_feeds($vids);
    while ($view = db_fetch_object($result)) {
      $rows[] = l($view->page_title, $view->url . '/feed', array('class' => 'syndication_view_rss'));
    }
    $output = theme('syndication_views_rss', $rows);
  }
  return $output;
}

/**
 * Helper function to get all views that generate rss feeds from the database
 * Accepts an array of views ids (vids) to limit the results
 *
 * @param  $args - an array of views ids
 * @return  $result - database result object or null if no feeds exist
 */
function _syndication_return_views_rss_feeds($args = array()){
  if (count($args) > 0) {
    for($i == 1; $i <= count($args); $i++){
      $where[] =  '%d';
    }
  }
  if ($where){
    $where_clause = ' AND arg.vid IN ('. implode(', ', $where) .')';
  }
  array_unshift($args, 'rss_feed'); //first query argument is always rss_feed
  $query = "SELECT v.vid, v.page_title, v.url FROM {view_view} v LEFT JOIN {view_argument} arg ON arg.vid = v.vid WHERE arg.type = '%s'" . $where_clause;
  $result = db_query($query, $args);

  if (db_num_rows($result) > 0){
    return $result;
  }
}

function theme_syndication_views_rss($rows){
  if (is_array($rows)){
    $output = theme('item_list', $rows, '', 'ul');
  }
  return $output;
}

function syndication_admin_settings() {
  foreach (taxonomy_get_vocabularies() as $vid => $vocab) {
    $options[$vid] = $vocab->name;
  }
  $description = t('Select the vocabularies which should appear in the <em>Categories</em> block on the %page', array('%page' => l(t('syndication page'), 'syndication')));
  $form['syndication_vocabularies'] = array('#type' => 'checkboxes',
                                      '#title' => t('Vocabularies'),
                                      '#options' => $options,
                                      '#default_value' => variable_get('syndication_vocabularies', array()),
                                      '#description' => $description);

  if(module_exists('views') && module_exists('views_rss')){
    $options = array();
    $result = _syndication_return_views_rss_feeds();
    while ($view = db_fetch_object($result)){
      $options[$view->vid] = $view->page_title;
    }

    $description = t('Select the views which should appear in the <em>Views</em> block on the %page', array('%page' => l(t('syndication page'), 'syndication')));
    $form['syndication_views'] = array('#type' => 'checkboxes',
                                 '#title' => t('Views'),
                                 '#options' => $options,
                                 '#default_value' => variable_get('syndication_views', array()),
                                 '#description' => $description);
  }
  $form['array_filter'] = array('#type' => 'value', '#value' => TRUE);
  return system_settings_form($form);
}

function syndication_help($section) {
  $output = '';
  switch ($section) {
    case 'admin/help#syndication':
      $output = syndication_help_intro();
      $output .= syndication_help_api(); //TODO move this to Doxygen
      break;
    case 'admin/modules#description':
      $output .= t("Adds a Syndication block, links to more feeds");
      break;
  }
  return $output;
}

function syndication_help_intro() {
  $output = '
<p>Syndication.module offers a web page which centralizes all of the RSS feeds
generated by Drupal. This helps users find interesting feeds from your web site.</p>

<p>Currently, the syndication page helps visitors find the following feeds.
<ul>
<li>the blog feed of any user or all users
<li>node feeds for any taxonomy terms, including composites of terms (requires <i>taxonomy_dhtml.module</i>)
<li>a directory of all feeds being consumed by the <i>import.module</i>
</ul>
</p>

<h3>For Module Developers - Syndication hook</h3>';
  return $output;
}

// TODO: move this to Doxygen
function syndication_help_api() {

  $output = '

    Any module can export boxes to the syndication page. You do so
    by creating a <i>modulename</i>_syndication function which returns
    an associative array of boxes, much like the block module. Each box
    in the array requires <i>subject</i> and <i>content</i> fields. Example:
    <pre>
    function mymodule_syndication() {

      // Creating the first box

      $box[0]["subject"] = "Existentialism";
      $box[0]["content"] = "So many feeds in this world";

      // Lets create a one box more

      $box[1]["subject"] = "Got any question?";
      $box[1]["content"] = "Who, Where, Why, When";
      return  $block;
    }
    </pre>';
  return $output;
}

?>