<?php
// $Id: ad_external.module,v 1.1.2.6.2.7 2009/02/17 18:56:26 jeremy Exp $

/**
 * @file
 * Enhances the ad module to support externally hosted ads, served via IFrames.
 * It is recommended that you configure "Administer >> Content management >>
 *  Ads >> Settings >> Global settings >> Display type" to "Raw".
 * If you configure the "Display type" to IFrame, you will be serving IFrames
 * within IFrames.
 *
 * Copyright (c) 2005-2009.
 *   Jeremy Andrews <jeremy@tag1consulting.com>.
 */

/**
 * Function used to display the selected ad.
 */
function ad_external_display_ad($ad) {
  return theme('ad_external_ad', $ad);
}

/**
 * Return a themed ad of type ad_remote.
 *
 * @param @ad
 *  The ad object.
 * @return
 *  A string containing the ad markup.
 */
function theme_ad_external_ad($ad) {
  global $base_url;

  if (isset($ad->aid)) {
    $output = '<div class="external-advertisement" id="ad-'. $ad->aid .'">';
    // For now, we hard code this to only support caching with the file cache.
    // As more cache types are introduced, we'll expand this.  Ideally it should
    // be cache type agnostic, but that seems to be unrealistic.
    if (variable_get('ad_cache', 'none') == 'file') {
      $adserve = variable_get('adserve', '');
      $display_variables = '&amp;c=file'. module_invoke('ad_cache_file', 'adcacheapi', 'display_variables', array());
      $external = url("$base_url/$adserve?o=external&amp;n=$ad->aid&amp;$display_variables");
    }
    else {
      $external = db_result(db_query('SELECT url FROM {ad_external} WHERE aid = %d', $ad->aid));
    }
    $append = 'frameborder="'. variable_get('ad_iframe_frameborder', 0) .'" ';
    $append .= 'scrolling="'. variable_get('ad_iframe_scroll', 'auto') .'" ';
    if ($height = variable_get('ad_iframe_height', '')) {
      $append .= "height=\"$height\" ";
    }
    if ($width = variable_get('ad_iframe_width', '')) {
      $append .= "width=\"$width\" ";
    }
    $output .= "<iframe src=\"$external\" $append></iframe>";
    $output .= '</div>';
    return $output;
  }
}

/**
 * Implementation of hook_theme().
 */
function ad_external_theme() {
  return array(
    'ad_external_ad' => array(
      'file' => 'ad_external.module',
      'arguments' => array(
        'ad' => NULL,
      ),
    ),
  );
}

/**
 * Implementation of hook_help().
 */
function ad_external_help($path, $arg) {
  $output = '';
  switch ($path) {
    case 'node/add/ad#external':
      $output = t('An external advertisement, displayed in an IFrame.');
      break;
  }
  return $output;
}

/**
 * Implementation of hook_access().
 */
function ad_external_access($op, $node, $account) {
  return ad_access($op, $node, $account);
}

/**
 * Implementation of hook_adapi().
 */
function ad_external_adapi($op, &$node) {
  switch ($op) {
    case 'load':
      return db_fetch_array(db_query('SELECT * FROM {ad_external} WHERE aid = %d', $node['aid']));

    case 'insert':
      db_query("INSERT INTO {ad_external} (aid, url) VALUES(%d, '%s')", $node->nid, $node->url);
      break;

    case 'update':
      db_query("UPDATE {ad_external} SET url = '%s' WHERE aid = %d", $node->url, $node->nid);
      break;

    case 'delete':
      db_query('DELETE FROM {ad_external} WHERE aid = %d', $node->nid);
      break;

    case 'form':
      return ad_external_node_form($node);

    case 'view':
      return ad_external_node_view($node);

    case 'redirect':
      // TODO: Would it ever make sense to have redirects for this ad type?
      watchdog('ad', 'Unexpected redirect attempt in external ad type.');
      return;

    case 'type':
      return array(
        'external' => array(
          'name' => t('External ad'),
          'module' => 'ad_external',
          'description' => t('An external advertisement, displayed in an IFrame.'),
          'help' => t('An external advertisement, displayed in an IFrame.'),
        ),
      );
  }
}

/**
 * Adapi helper function for displaying a node form.
 */
function ad_external_node_form(&$node) {
  $form = array();

  $form['ad_external'] = array(
    '#type' => 'fieldset',
    '#title' => t('External'),
    '#collapsible' => TRUE,
  );

  $form['ad_external']['preview'] = array(
    '#type' => 'markup',
    '#value' => ad_external_display_ad($node),
  );

  if ((arg(1) == 'add' || arg(2) == 'edit') &&
       user_access('create advertisements')) {
    $form['ad_external']['url'] = array(
      '#type' => 'textfield',
      '#title' => t('External Source URL'),
      '#required' => TRUE,
      '#default_value' => isset($node->url) ? $node->url : '',
      '#description' => t('Enter the complete URL where your external ad his hosted.  The URL must begin with http:// or https://.  For example, %url.', array('%url' => t('http://www.sample.org/external/ad.php'))),
    );

  }

  return $form;
}

/**
 * Adapi helper function for displaying ad itself.
 */
function ad_external_node_view(&$node) {
  $node->content['ad'] = array(
    '#value' => theme('box', '', stripslashes(ad_external_display_ad($node))),
    '#weight' => -1,
  );
  $link = t('Links to !url.', array('!url' => $node->url));
  if (variable_get('ad_filter', 0)) {
    $link = check_markup($link, $node->format, FALSE);
  }
  $node->content['ad-link'] = array(
    '#value' => "<div class=\"links-to\">$link<div>",
    '#weight' => 1,
  );
}

/**
 * Download external pages and store them in the filecache.
 */
function ad_external_ad_build_cache() {
  $cache = array();
  $result = db_query('SELECT * FROM {ad_external}');
  while ($external = db_fetch_object($result)) {
    $contents = file_get_contents($external->url);
    if ($contents === FALSE) {
      // Failed to download external url, don't cache the error page.
      // TODO: Watchdog log this.
      // TODO: Would it be possible to obtain the old version from the cache,
      //       if we already downloaded this page once?
      continue;
    }
    $cache['ad_external'][$external->aid]['url'] = $external->url;
    $cache['ad_external'][$external->aid]['contents'] = $contents;
  }
  return $cache;
}