<?php
// $Id$

function views_rss_help($section = 'admin/help#views_rss') {
  $output = '';
  switch ($section) {
    case 'admin/modules#description':
      return t('RSS plugin for the views feed selector argument.');
  }
}

/**
 * Provide views plugins for the feed types we support.
 */
function views_rss_views_style_plugins() {
  return array(
    'views_rss' => array(
      'name' => t('Views RSS: RSS feed'),
      'theme' => 'views_rss_feed',
      'needs_table_header' => TRUE,
      'needs_fields' => TRUE,
      'even_empty' => TRUE,
    ),
  );
}

/**
 * While we support the global selector, some might want to allow
 * ONLY RSS feeds so we support a stingy selector too
 */
function views_rss_views_arguments() {
  $arguments = array(
    'rss_feed' => array(
      'name' => t('RSS: RSS Feed Selector'),
      'handler' => 'views_handler_arg_rss_feed',
      'help' => t('This argument specifies a specific RSS feed selector; it will only select RSS feeds, unlike the built-in selector which can select pluggable feeds.'),
    ),
  );
  return $arguments;
}

/**
 * handler for our own RSS argument; mimics the feed selector
 */
function views_handler_arg_rss_feed($op, &$query, $argtype, $arg = '') {
  switch($op) {
    case 'summary':
    case 'sort':
    case 'link':
    case 'title':
      break;
    case 'filter':
      // This is a clone of the default selector, but it just invokes ours
      // rather than calling all of them.
      views_rss_views_feed_argument('argument', $GLOBALS['current_view'], $arg);
  }
}

/**
 * post view for our own op -- mimics the feed selector
 */
function views_rss_views_post_view($view, $items, $output) {
  foreach ($view->argument as $id => $argument) {
    if ($argument['type'] == 'rss_feed') {
      $feed = $id;
      break;
    }
  }

  if ($feed !== NULL) {
    return views_rss_views_feed_argument('post_view', $view, 'rss_feed');
  }
}

/**
 * feed argument hook that will convert us to RSS or display an icon.
 * the 4th argument isn't part of the hook, but we use it to differentiate
 * when called as a hook or when called manually from views_rss_views_post_view
 */
function views_rss_views_feed_argument($op, &$view, $arg) {
  if ($op == 'argument' && $arg == 'feed') {
    $view->page_type = 'views_rss';
  }
  else if ($op == 'post_view') {
    $args = views_post_view_make_args($view, $arg, 'feed');
    $url = views_get_url($view, $args);
    $title = views_get_title($view, 'page', $args);

    if ($view->used_filters) {
      $filters = drupal_query_string_encode($view->used_filters);
    }

    drupal_add_link(array('rel' => 'alternate',
                          'type' => 'application/rss+xml',
                          'title' => check_plain($title),
                          'href' => url($url, $filters, NULL, TRUE)));
    if ($view->build_type != 'block') {
      return theme('feed_icon', url($url, $filters));
    }
  }
}

/**
 * plugin that actually displays an RSS feed
 */
function theme_views_rss_feed($view, $nodes, $type) {
  if ($type == 'block') {
    return;
  }
  global $base_url;

  $channel = array(
    'title'       => views_get_title($view, 'page'),
    'link'        => url($view->real_url, NULL, NULL, true),
    'description' => $view->description,
  );

  $item_length = variable_get('feed_item_length', 'teaser');
  $namespaces = array('xmlns:dc="http://purl.org/dc/elements/1.1/"');

  // Except for the original being a while and this being a foreach, this is
  // completely cut & pasted from node.module.
  foreach ($nodes as $node) {
    // Load the specified node:
    $item = node_load($node->nid);
    $link = url("node/$node->nid", NULL, NULL, 1);

    if ($item_length != 'title') {
      $teaser = ($item_length == 'teaser') ? TRUE : FALSE;

      // Filter and prepare node teaser
      if (node_hook($item, 'view')) {
        node_invoke($item, 'view', $teaser, FALSE);
      }
      else {
        $item = node_prepare($item, $teaser);
      }

      // Allow modules to change $node->teaser before viewing.
      node_invoke_nodeapi($item, 'view', $teaser, FALSE);
    }

    // Allow modules to add additional item fields
    $extra = node_invoke_nodeapi($item, 'rss item');
    $extra = array_merge($extra, array(array('key' => 'pubDate', 'value' =>  date('r', $item->created)), array('key' => 'dc:creator', 'value' => $item->name), array('key' => 'guid', 'value' => $item->nid . ' at ' . $base_url, 'attributes' => array('isPermaLink' => 'false'))));
    foreach ($extra as $element) {
      if ($element['namespace']) {
        $namespaces = array_merge($namespaces, $element['namespace']);
      }
    }
    
    // Prepare the item description
    switch ($item_length) {
      case 'fulltext':
        $item_text = $item->body;
        break;
      case 'teaser':
        $item_text = $item->teaser;
        if ($item->readmore) {
          $item_text .= '<p>'. l(t('read more'), 'node/'. $item->nid, NULL, NULL, NULL, TRUE) .'</p>';
        }
        break;
      case 'title':
        $item_text = '';
        break;
    }

    $items .= format_rss_item($item->title, $link, $item_text, $extra);
  }

  $channel_defaults = array(
    'version'     => '2.0',
    'title'       => variable_get('site_name', 'drupal') .' - '. variable_get('site_slogan', ''),
    'link'        => $base_url,
    'description' => variable_get('site_mission', ''),
    'language'    => $GLOBALS['locale'],
  );
  $channel = array_merge($channel_defaults, $channel);

  $output = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
  $output .= "<rss version=\"". $channel["version"] . "\" xml:base=\"". $base_url ."\" ". implode(' ', $namespaces) .">\n";
  $output .= format_rss_channel($channel['title'], $channel['link'], $channel['description'], $items, $channel['language']);
  $output .= "</rss>\n";

  drupal_set_header('Content-Type: text/xml; charset=utf-8');
  print $output;
  module_invoke_all('exit');
  exit; 
}