<?php
// $Id: oembedcore.module,v 1.7 2010/09/12 19:22:12 voxpelli Exp $

/**
 * @file
 * Core functionality for oEmbed
 */

/**
 * Implementation of hook_perm().
 */
function oembedcore_perm() {
  return array('administer oembed presets');
}

/**
 * Implementation of hook_menu().
 */
function oembedcore_menu() {
  $items = array();

  $base = array(
    'access arguments' => array('administer oembed presets'),
    'file'             => 'oembedcore.admin.inc',
  );

  $items['admin/build/oembed'] = array(
    'title'          => 'OEmbed',
    'description'    => 'Admin overview of OEmbed.',
    'page callback'  => 'oembedcore_list_preset',
  ) + $base;

  $items['admin/build/oembed/preset'] = array(
    'title'          => 'Presets',
    'description'    => 'Add, edit and remove oembed preset from the system.',
    'page callback'  => 'oembedcore_list_preset',
    'type'           => MENU_DEFAULT_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/preset/list'] = array(
    'title'          => 'List presets',
    'page callback'  => 'oembedcore_list_preset',
    'type'           => MENU_DEFAULT_LOCAL_TASK,
    'weight'         => -10,
  ) + $base;
  $items['admin/build/oembed/preset/add'] = array(
    'title'          => 'Add preset',
    'page callback'  => 'oembedcore_add_preset',
    'type'           => MENU_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/preset/%oembedcore_preset/edit'] = array(
    'title'          => 'Edit preset',
    'page callback'  => 'oembedcore_edit_preset',
    'page arguments' => array(4),
    'type'           => MENU_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/preset/%oembedcore_preset/export'] = array(
    'title'          => 'Export preset',
    'page callback'  => 'drupal_get_form',
    'page arguments' => array('oembedcore_export_preset', 4),
    'type'           => MENU_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/preset/%oembedcore_preset/delete'] = array(
    'title'          => 'Delete preset',
    'page callback'  => 'drupal_get_form',
    'page arguments' => array('oembedcore_delete_confirm_preset', 4),
    'type'           => MENU_CALLBACK,
  ) + $base;
  $items['admin/build/oembed/preset/%oembedcore_preset/disable'] = array(
    'page callback'  => 'oembedcore_disable_preset',
    'page arguments' => array(4),
    'type'           => MENU_CALLBACK,
  ) + $base;
  $items['admin/build/oembed/preset/%oembedcore_preset/enable'] = array(
    'page callback'  => 'oembedcore_enable_preset',
    'page arguments' => array(4),
    'type'           => MENU_CALLBACK,
  ) + $base;

  $items['admin/build/oembed/provider'] = array(
    'title'          => 'Providers',
    'description'    => 'Add, edit and remove oembed providers from the system.',
    'page callback'  => 'oembedcore_list_provider',
    'type'           => MENU_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/provider/list'] = array(
    'title'          => 'List providers',
    'page callback'  => 'oembedcore_list_provider',
    'type'           => MENU_DEFAULT_LOCAL_TASK,
    'weight'         => -10,
  ) + $base;
  $items['admin/build/oembed/provider/add'] = array(
    'title'          => 'Add provider',
    'page callback'  => 'oembedcore_add_provider',
    'type'           => MENU_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/provider/%oembedcore_provider/edit'] = array(
    'title'          => 'Edit provider',
    'page callback'  => 'oembedcore_edit_provider',
    'page arguments' => array(4),
    'type'           => MENU_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/provider/%oembedcore_provider/export'] = array(
    'title'          => 'Export provider',
    'page callback'  => 'drupal_get_form',
    'page arguments' => array('oembedcore_export_provider', 4),
    'type'           => MENU_LOCAL_TASK,
  ) + $base;
  $items['admin/build/oembed/provider/%oembedcore_provider/delete'] = array(
    'title'          => 'Delete provider',
    'page callback'  => 'drupal_get_form',
    'page arguments' => array('oembedcore_delete_confirm_provider', 4),
    'type'           => MENU_CALLBACK,
  ) + $base;
  $items['admin/build/oembed/provider/%oembedcore_provider/disable'] = array(
    'page callback'  => 'oembedcore_disable_provider',
    'page arguments' => array(4),
    'type'           => MENU_CALLBACK,
  ) + $base;
  $items['admin/build/oembed/provider/%oembedcore_provider/enable'] = array(
    'page callback'  => 'oembedcore_enable_provider',
    'page arguments' => array(4),
    'type'           => MENU_CALLBACK,
  ) + $base;

  return $items;
}

/**
 * Implementation of hook_theme().
 */
function oembedcore_theme() {
  $path = drupal_get_path('module', 'oembedcore') . '/theme';
  return array(
    'oembed' => array(
      'template' => 'oembed',
      'file' => 'oembedcore_theme.inc',
      'path' => $path,
      'arguments' => array('embed' => NULL),
    ),
  );
}

/**
 * Implementation of hook_default_oembedcore_provider().
 */
function oembedcore_default_oembedcore_provider() {
  $providers = array();

  $provider = new stdClass;
  $provider->disabled = TRUE; /* Edit this to true to make a default provider disabled initially */
  $provider->name = 'viddler';
  $provider->title = 'Viddler';
  $provider->endpoint = 'http://lab.viddler.com/services/oembed/';
  $provider->scheme = 'http://*.viddler.com/*';
  $providers['viddler'] = $provider;

  $provider = new stdClass;
  $provider->disabled = TRUE; /* Edit this to true to make a default provider disabled initially */
  $provider->name = 'flickr';
  $provider->title = 'Flickr';
  $provider->endpoint = 'http://www.flickr.com/services/oembed/';
  $provider->scheme = 'http://*.flickr.com/*
http://flickr.com/*';
  $providers['flickr'] = $provider;

  $provider = new stdClass;
  $provider->disabled = TRUE; /* Edit this to true to make a default provider disabled initially */
  $provider->name = 'qik';
  $provider->title = 'Qik';
  $provider->endpoint = 'http://qik.com/api/oembed.json';
  $provider->scheme = 'http://qik.com/video/*
http://qik.com/*';
  $providers['qik'] = $provider;

  $provider = new stdClass;
  $provider->disabled = TRUE; /* Edit this to true to make a default provider disabled initially */
  $provider->name = 'revision3';
  $provider->title = 'Revision3';
  $provider->endpoint = 'http://revision3.com/api/oembed/';
  $provider->scheme = 'http://*.revision3.com/*';
  $providers['revision3'] = $provider;

  $provider = new stdClass;
  $provider->disabled = TRUE; /* Edit this to true to make a default provider disabled initially */
  $provider->name = 'vimeo';
  $provider->title = 'Vimeo';
  $provider->endpoint = 'http://www.vimeo.com/api/oembed.json';
  $provider->scheme = 'http://www.vimeo.com/groups/*/videos/*
http://www.vimeo.com/*
http://vimeo.com/groups/*/videos/*
http://vimeo.com/*';
  $providers['vimeo'] = $provider;

  $provider = new stdClass;
  $provider->disabled = TRUE; /* Edit this to true to make a default provider disabled initially */
  $provider->name = 'youtube';
  $provider->title = 'YouTube';
  $provider->endpoint = 'http://www.youtube.com/oembed';
  $provider->scheme = 'http://*.youtube.com/watch*';
  $providers['youtube'] = $provider;

  return $providers;
}

/**
 * Returns the provider for a url.
 *
 * @param string $url
 *  Teh url to get the provider for.
 * @return mixed
 *  A valid callback or FALSE
 */
function oembedcore_get_provider($url, &$matches) {
  $host = _oembedcore_get_host($url);
  if ($host) {
    $providers = oembedcore_providers($host);
    foreach ($providers as $regex => $info) {
      if (preg_match($regex, $url, $matches)) {
        return $info;
      }
    }
  }
  return FALSE;
}

/**
 * A utility function to get the base domain from a url.
 *
 * @param string $uri
 *  The uri to get the domain form
 * @return string
 *  The domain or NULL
 */
function _oembedcore_get_host($uri) {
  $matches = array();
  if (preg_match('/^https?\:\/\/([^\/]+)/', $uri, $matches)) {
    $matches = explode('.', $matches[1]);
    $match_count = count($matches);
    if ($match_count > 1) {
      return $matches[$match_count - 2] . '.' . $matches[$match_count - 1];
    }
    else {
      return $matches[0];
    }
  }
  return NULL;
}

/**
 * Returns all the registered providers, or the providers for a specific host.
 *
 * @param string $host
 *  Optional. Supply a hostname if you only want the provider patterns for a specific host.
 * @return array
 */
function oembedcore_providers($url_host = NULL) {
  static $providers;

  if (!$providers) {
    $cache_key = 'oembedcore:providers';

    if (($cache = cache_get($cache_key)) && isset($cache->data)) {
      $providers = $cache->data;
    }
    else {
      $providers = array();
      $modules = module_implements('oembedprovider');
      foreach ($modules as $module) {
        $ps = call_user_func($module . '_oembedprovider');
        foreach ($ps as $pattern => $info) {
          $host = _oembedcore_get_host($pattern);
          $regex_pattern = '/' . str_replace('\*', '(.+)', preg_quote($pattern, '/')) . '/';
          $providers[$host][$regex_pattern] = $info;
        }
      }
      $provider_definitions = oembedcore_provider_load_all();
      foreach ($provider_definitions as $provider_definition) {
        if (!$provider_definition->disabled) {
          $schemes = explode("\n", $provider_definition->scheme);
          foreach ($schemes as $scheme) {
            $host = _oembedcore_get_host($scheme);
            $regex_pattern = '/' . str_replace('\*', '(.+)', preg_quote($scheme, '/')) . '/';
            $providers[$host][$regex_pattern] = array('endpoint' => $provider_definition->endpoint);
          }
        }
      }
      drupal_alter('oembedprovider', $providers);
      foreach ($providers as $host => &$patterns) {
        uksort($patterns, '_oembedcore_specificity_compare');
      }
      cache_set($cache_key, $providers);
    }
  }

  if ($url_host) {
    return isset($providers[$url_host]) ? $providers[$url_host] : array();
  }
  return $providers;
}

/**
 * Helper function that compares the length of match expressions.
 */
function _oembedcore_specificity_compare($a, $b) {
  return strlen($b) - strlen($a);
}

/**
 * Fetch data for an embeddable URL.
 *
 * @param string $url
 *   An external URL for the content to embed.
 * @param array $attributes
 *   An associative array of attributes, with the following keys:
 *   - 'maxwidth'
 *       The maximum width of the embed, in pixels.
 *   - 'maxheight'
 *       The maximum height of the embed, in pixels.
 * @return
 *   False or an object representing the embeddable data of the URL.
 */
function oembedcore_oembed_data($url, $attributes = array()) {
  $matches = array();
  if ($provider = oembedcore_get_provider($url, $matches)) {
    return oembedcore_oembed_fetch($provider, $url, $matches, $attributes);
  }
  return FALSE;
}

function oembedcore_oembed_fetch($provider, $url, $matches, $attributes = array()) {
  global $_oembed_default_attributes;

  $embed = FALSE;

  if (!empty($_oembed_default_attributes)) {
    $attributes = array_merge($_oembed_default_attributes, $attributes);
  }
  $attributes['url'] = $url;
  $query = http_build_query($attributes, NULL, '&');

  $source = isset($provider['callback']) ? $provider['callback'] : $provider['endpoint'];
  $cache_key = 'oembedcore:embed:' . md5($source . $url . $query);
  $cache = cache_get($cache_key);

  if ($cache && isset($cache->data)) {
    $embed = $cache->data;
  }
  else {
    if (!empty($provider['callback'])) {
      $embed = call_user_func($provider['callback'], $provider, $url, $matches, $attributes);
      if ($embed) {
        $embed = (object)$embed;
      }
    }
    else {
      $fetch_url = $provider['endpoint'] . '?' . $query;

      //TODO: Add alternative ways of fetching the content - like http client?
      $response = drupal_http_request($fetch_url);
      if (!$response->error) {
        $embed = json_decode($response->data);
        if (!is_object($embed)) {
          //TODO: Better error handling here
          $embed = new SimpleXMLElement($response->data);
          $embed = (object)get_object_vars($embed);
          if (!is_string($embed->title)) {
            $embed->title = '';
          }
        }
      }
    }

    if ($embed) {
      $embed->original_url = $url;
    }

    $max_age = isset($embed->cache_age) ? intval($embed->cache_age) : empty($provider['callback']) ? 600 : 60;
    cache_set($cache_key, $embed, 'cache', time() + $max_age);
  }

  return $embed;
}

/**
 * To be used for HTML in cases where the HTML is cached independent of the theme - like in the case of input filters.
 */
function oembedcore_oembed_html($embed, $url) {
  //TODO: Maybe refactor into something that uses drupal_render()?
  $return = '';
  switch ($embed->type) {
    case 'photo':
      $return  = '<span class="oembed">';
        if (!empty($embed->title)) {
          $return .= l($embed->title, $url, array('absolute' => TRUE, 'attributes' => array('class' => 'oembed-title')));
        }
        $alttext = empty($embed->title) ? t('Embedded image') : $embed->title;
        if (!empty($embed->provider_name)) {
            $alttext .= t(', on ') . $embed->provider_name;
        }
        $return .= ' ' . l('<img src="' . check_url($embed->url) . '" alt="'. $alttext .'" />', $url,
                array('html' => TRUE, 'absolute' => TRUE, 'attributes' => array('class' => 'oembed-photo oembed-content')));
      $return .= '</span>';
      break;
    case 'rich':
    case 'video':
      $return  = '<div class="oembed">';
        if (!empty($embed->title)) {
          $return .= l($embed->title, $url, array('absolute' => TRUE, 'attributes' => array('class' => 'oembed-title')));
        }
        $return .= ' <span class="oembed-content oembed-' . ($embed->type == 'video' ? 'video' : 'rich') . '">' . $embed->html . '</span>';
      $return .= '</div>';
      break;
    case 'link':
      $return .= l($embed->title, $url, array('absolute' => TRUE, 'attributes' => array('class' => 'oembed-title oembed-link')));
      break;
    default:
  }

  return $return;
}

// --------------------------------------------------------------------------
// Preset database info.

/**
 * Clear presets cache on admin/build/modules form.
 */
function oembedcore_form_system_modules_alter(&$form, $form_state) {
  //Copied from imagecache - needed because other modules might contain presets which oembedfield uses and cck caches
  //TODO: Extract this and move to oembedfield
  if (module_exists('content')) {
    content_clear_type_cache();
  }
}

/**
 * Create a new preset with defaults appropriately set from schema.
 */
function oembedcore_preset_new() {
  ctools_include('export');
  return ctools_export_new_object('oembedcore_preset');
}

/**
 * Load a single preset
 */
function oembedcore_preset_load($name) {
  ctools_include('export');
  $result = ctools_export_load_object('oembedcore_preset', 'names', array($name));
  if (isset($result[$name])) {
    return $result[$name];
  }
  else {
    return FALSE;
  }
}

/**
 * Load all presets.
 */
function oembedcore_preset_load_all() {
  ctools_include('export');
  return ctools_export_load_object('oembedcore_preset');
}

/**
 * Write a preset to the database.
 */
function oembedcore_preset_save(&$preset) {
  $update = (isset($preset->pid)) ? array('pid') : array();
  drupal_write_record('oembedcore_preset', $preset, $update);
  // Clear the content.module cache (refreshes the list of formatters provided by oembedfield.module).
  //TODO: Extract this and move to oembedfield
  if (module_exists('content')) {
    content_clear_type_cache();
    drupal_rebuild_theme_registry();
  }
  return $preset;
}

/**
 * Remove a preset.
 */
function oembedcore_preset_delete($preset) {
  db_query("DELETE FROM {oembedcore_preset} WHERE name = '%s' AND pid = %d", $preset->name, $preset->pid);
  // Clear the content.module cache (refreshes the list of formatters provided by oembedfield.module).
  //TODO: Extract this and move to oembedfield
  if (module_exists('content')) {
    content_clear_type_cache();
    drupal_rebuild_theme_registry();
  }
}

/**
 * Export a preset
 */
function oembedcore_preset_export($preset, $indent = '') {
  ctools_include('export');
  $output = ctools_export_object('oembedcore_preset', $preset, $indent);
  return $output;
}

/**
 * Lists all available presets
 */
function oembedcore_preset_list() {
  $return = array();
  $presets = oembedcore_preset_load_all();
  foreach ($presets as $preset) {
    $return[$preset->name] = $preset->name;
  }
  return $return;
}

// --------------------------------------------------------------------------
// Preset database info.

/**
 * Create a new provider with defaults appropriately set from schema.
 */
function oembedcore_provider_new() {
  ctools_include('export');
  return ctools_export_new_object('oembedcore_provider');
}

/**
 * Load a single provider.
 */
function oembedcore_provider_load($name) {
  ctools_include('export');
  $result = ctools_export_load_object('oembedcore_provider', 'names', array($name));
  if (isset($result[$name])) {
    return $result[$name];
  }
  else {
    return FALSE;
  }
}

/**
 * Load all providers.
 */
function oembedcore_provider_load_all() {
  ctools_include('export');
  return ctools_export_load_object('oembedcore_provider');
}

/**
 * Write a provider to the database.
 */
function oembedcore_provider_save(&$provider) {
  $update = (isset($provider->pid)) ? array('pid') : array();
  drupal_write_record('oembedcore_provider', $provider, $update);
  cache_clear_all('oembedcore:providers');
  return $preset;
}

/**
 * Remove a provider.
 */
function oembedcore_provider_delete($provider) {
  db_query("DELETE FROM {oembedcore_provider} WHERE name = '%s' AND pid = %d", $provider->name, $provider->pid);
  cache_clear_all('oembedcore:providers');
}

/**
 * Export a provider.
 */
function oembedcore_provider_export($provider, $indent = '') {
  ctools_include('export');
  $output = ctools_export_object('oembedcore_provider', $provider, $indent);
  return $output;
}

/**
 * Lists all available providers.
 */
function oembedcore_provider_list() {
  $return = array();
  $providers = oembedcore_provider_load_all();
  foreach ($providers as $provider) {
    $return[$provider->name] = $provider->name;
  }
  return $return;
}