<?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',
      'option' => 'string',
      '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. You may enter the title the feed will advertise in the title field here, and the description of the feed in the option field here.'),
    ),
  );
  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, $argtype);
  }
}

/**
 * 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, $argdata = NULL) {
  if ($op == 'argument' && $arg == 'feed') {
    $view->page_type = 'views_rss';

    if ($argdata['options']) {
      $view->description = $argdata['options'];
    }

    // reset the 'real url' to the URL without the feed argument.
    $view_args = array();
    $max = count($view->args);
    foreach ($view->args as $id => $view_arg) {
      ++$count;
      if ($view_arg == $arg && $view->argument[$id]['id'] == $argdata['id']) {
        if ($count != $max) {
          $view_args[] = $argdata['wildcard'];
        }
      }
      else {
        $view_args[] = $view_arg;
      }
    }
    $view->feed_url = views_get_url($view, $view_args);
  }
  else if ($op == 'post_view') {
    $args = views_post_view_make_args($view, $arg, 'feed');
    $url = views_get_url($view, $args);
    $title = filter_xss_admin(views_get_title($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;

  $channel = array(
    'title'       => filter_xss_admin(views_get_title($view, 'page')),
    'link'        => url($view->feed_url ? $view->feed_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',
    '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; 
}