<?php
// $Id: emfield.module,v 1.1 2007/06/26 01:15:26 aaron Exp $

/**
 * Implement hook_menu
 */
function emfield_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/content/emfield',
      'title' => t('Embedded Media Field configuration'),
      'description' => t('Configure Embedded Media Field: Allow content types to use various 3rd party providers, enter API keys, etc.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => 'emfield_settings',
      'access' => user_access('administer site configuration'));
  }
  return $items;
}

/**
 * Implement hook_settings
 */
function emfield_settings() {
  $form = array();
  $header = array(t('Feature'), t('Supported'), t('Notes'));
  foreach (module_implements('emfield_info', true) as $module) {
    $emfield_info = module_invoke($module, 'emfield_info');
    $providers = emfield_system_list($module);
    $form[$module] = array(
      '#type' => 'fieldset',
      '#title' => t('@neighborhood', array('@neighborhood' => $emfield_info['#name'])),
      '#description' => $emfield_info['#settings_description'],
      '#collapsible' => true,
      '#collapsed' => true,
    );
    $form[$module]['providers'] = array(
      '#type' => 'fieldset',
      '#title' => t('Providers'),
      '#description' => t('The following settings determine what providers are allowed, and what provider-specific options, if any, are set.'),
      '#collapsible' => true,
      '#collapsed' => false,
    );
    foreach ($providers as $provider) {
      $info = emfield_include_invoke($module, $provider->name, 'info');
      $form[$module]['providers'][$provider->name] = array(
        '#type' => 'fieldset',
        '#title' => t('@provider configuration', array('@provider' => $info['name'])),
        '#description' => $info['settings_description'],
        '#collapsible' => true,
        '#collapsed' => true,
      );
      if (is_array($info['supported_features']) && !empty($info['supported_features'])) {
        $form[$module]['providers'][$provider->name]['supported_features'] = array(
          '#type' => 'fieldset',
          '#title' => t('Supported features'),
          '#description' => t('This is a list of the current state of support for the following features by %provider:', array('%provider' => $info['name'])),
          '#collapsible' => true,
          '#collapsed' => true,
          '#weight' => 7,
        );
        $form[$module]['providers'][$provider->name]['supported_features']['features'] = array(
          '#type' => 'markup',
          '#value' => theme('table', $header, $info['supported_features']),
        );
      }
      $form[$module]['providers'][$provider->name]['emfield_' . $module . '_allow_' . $provider->name] = array(
        '#type' => 'checkbox',
        '#title' => t('Allow content from %provider', array('%provider' => $info['name'])),
        '#description' => t('If checked, then content types may be created that allow content to be provided by %provider.', array('%provider' => $info['name'])),
        '#weight' => -10,
        '#default_value' => variable_get('emfield_' . $module . '_allow_' . $provider->name, true),
      );
      $form[$module]['providers'][$provider->name][] = emfield_include_invoke($module, $provider->name, 'settings');
    }
    $form[$module] = array_merge($form[$module], module_invoke($module, 'emfield_settings'));
  }
  return system_settings_form($form);
}

function emfield_field_columns() {
  $columns = array(
    'embed' => array('type' => 'longtext', 'not null' => TRUE, 'default' => "''", 'sortable' => TRUE),
    'value' => array('type' => 'varchar', 'length' => 255, 'not null' => TRUE, 'default' => "''", 'sortable' => TRUE),
    'provider' => array('type' => 'varchar', 'length' => 255, 'not null' => TRUE, 'default' => "''", 'sortable' => TRUE),
    'data' => array('type' => 'longtext', 'not null' => TRUE, 'default' => "''", 'sortable' => false),
  );
  return $columns;
}

/** Implementation of hook_emfield_field **/
function emfield_emfield_field($op, &$node, $field, &$items, $teaser, $page, $module) {
  switch ($op) {

  // TODO: nothing to validate at the moment. we need to have different api's have a chance to validate
  case 'validate':
    if ($field['multiple']) {
      foreach ($items as $delta => $item) {
        $error_field = $field['field_name'].']['.$delta.'][embed';

        _emfield_field_validate_id($field, $item, $error_field, $module);
      }
    }
    else {
      $error_field = $field['field_name'];

      _emfield_field_validate_id($field, $items[0], $error_field, $module);
    }
    break;

  case 'submit':
    if ($field['multiple']) {
      foreach ($items as $delta => $item) {
        $list = _emfield_field_submit_id($field, $item, $module);
        $items[$delta]['provider'] = $list['provider'];
        $items[$delta]['value'] = $list['value'];
        $items[$delta]['data'] = $list['data'];
      }
    }
    else {
      $list = _emfield_field_submit_id($field, $items[0], $module);
      $items[0]['provider'] = $list['provider'];
      $items[0]['value'] = $list['value'];
      $items[0]['data'] = $list['data'];
    }
    break;

  case 'insert':
  case 'update':
    // we need to manually serialize the 'data' array
    if ($field['multiple']) {
      foreach ($items as $delta => $item) {
        $items[$delta]['data'] = serialize($items[$delta]['data']);
      }
    }
    else {
      $items[0]['data'] = serialize($items[0]['data']);
    }
    break;

  case 'load':
    // We need to unserialize the 'data' column manually
    $field_name = $field['field_name'];
    $node_field = $node->$field_name;
    if ($field['multiple']) {
      foreach ($items as $delta => $item) {
        $data = (array)unserialize($items[$delta]['data']);
        $items[$delta]['data'] = $data;
        $node_field[$delta]['data'] = $data;
      }
    }
    else {
      $data = (array)unserialize($items[0]['data']);
      $items[0]['data'] = $data;
      $node_field[0]['data'] = $data;
    }
    $node->$field_name = $node_field;
    $return = array();
    $return[$field_name] = $items;
    return $return;
    break;
  }
}

/**
 * return a list of providers allowed for a specific field
 */
function emfield_allowed_providers($field, $module) {
//   $module = $field['widget']['helper_module'];
  $allowed_providers = emfield_system_list($module);
  $providers = array();
  $allow_all = true;
  foreach ($allowed_providers as $test) {
    if (!variable_get('emfield_allow_' . $module . '_' . $test->name, true)) {
      unset($allowed_providers[$test->name]);
    }
    else {
      $allow_all &= !$field['widget']['providers'][$test->name];
    }
  }
  if (!$allow_all) {
    foreach ($allowed_providers as $test) {
      if (!$field['widget']['providers'][$test->name]) {
        unset($allowed_providers[$test->name]);
      }
    }
  }
  return $allowed_providers;
}

/**
 *  This will parse the url or embedded code pasted by the node submitter.
 *  returns either an empty array (if no match), or an array of provider and value.
 */
function emfield_parse_embed($field, $embed = '', $module) {
  if ($embed) {
//     $module = $field['widget']['helper_module'];
    $providers = emfield_allowed_providers($field, $module);
    foreach ($providers as $provider) {
      $success = emfield_include_invoke($module, $provider->name, 'extract', $embed);
      // we've been given an array of regex strings, so let's see if we can find a match
      if (is_array($success)) {
        foreach ($success as $regex) {
          $matches = NULL;
          if (preg_match($regex, $embed, $matches)) {
            return array('provider' => $provider->name, 'value' => $matches[1]);
          }
        }
      }
      // the invoked include module did its own parsing and found a match
      else if ($success) {
        return array('provider' => $provider->name, 'value' => $success);
      }
    }
  }
  // we found no match
  return array();
}

/**
 *  extract the id from embedded code or url
 */
function _emfield_field_validate_id($field, $item, $error_field, $module) {
  // does nothing at this time... TODO: fix this up
  return _emfield_field_submit_id($field, $item, $module);
}

/**
 *  replace embedded code with the extracted id. this goes in the field 'value'
 *  also allows you to grab directly from the URL to display the content from field 'provider'
 */
function _emfield_field_submit_id($field, $item, $module) {
//  $module = $field['widget']['helper_module'];
  $item = array_merge($item, emfield_parse_embed($field, $item['embed'], $module));
  $item['data'] = (array)emfield_include_invoke($module, $item['provider'], 'data', $field, $item);
  return $item;
}

function emfield_emfield_field_formatter($field, $item, $formatter, $node, $module) {
  // if we're coming from a preview, we need to extract our new embedded value...
  if ($item['in_preview']) {
    $item = emfield_parse_embed($field, $item['embed'], $module);
  }

  // if we have no value, then return an empty string
  if (!isset($item['value'])) {
    return '';
  }

  // unfortunately, when we come from a view, we don't get all the widget fields
  if (!$node->type) {
    $type = content_types($field['type_name']);
    $field['widget'] = $type['fields'][$field['field_name']]['widget'];
  }

  // and sometimes our data is still unserialized, again from views
  if (!is_array($item['data'])) {
    $item['data'] = (array)unserialize($item['data']);
  }

//  $module = $field['widget']['helper_module'];

  $output .= theme($module . '_' . $formatter, $field, $item, $formatter, $node);

  return $output;
}

/** Widgets **/
function emfield_emfield_widget_settings($op, $widget, $module) {
  switch ($op) {
    case 'form':
      $form = array();
//       $form['helper_module'] = array(
//         '#type' => 'value',
//         '#value' => $module,
//       );
      $options = array();
      $providers = emfield_system_list($module);
      foreach ($providers as $provider) {
        if (variable_get('emfield_allow_' . $module . '_' . $provider->name, true)) {
          $info = emfield_include_invoke($module, $provider->name, 'info');
          $options[$provider->name] = $info['name'];
        }
      }
      $form['provider_list'] = array(
        '#type' => 'fieldset',
        '#title' => t('Providers Supported'),
        '#description' => t('Select which third party providers you wish to allow for this content type from the list below. If no checkboxes are checked, then all providers will be supported. When a user submits new content, the URL they enter will be matched to the provider, assuming that provider is allowed here.'),
        '#collapsible' => true,
        '#collapsed' => false,
      );
      $form['provider_list']['providers'] = array(
        '#type' => 'checkboxes',
        '#title' => t('Providers'),
        '#default_value' => $widget['providers'] ? $widget['providers'] : array(),
        '#options' => $options,
      );
      return $form;

    case 'save':
      $columns = array('providers'); //, 'helper_module', );
      return $columns;
  }
}

function emfield_emfield_widget($op, &$node, $field, &$node_field, $module) {
//  $module = $field['widget']['helper_module'];
  switch ($op) {
    case 'form':
      $form = array();

      $form[$field['field_name']] = array('#tree' => TRUE);
      $textfield = 'embed';
      $field['required'] = FALSE;
      $providers = emfield_allowed_providers($field, $module);
      $urls = array();
      foreach ($providers as $provider) {
        // don't check providers not allowed
        if (variable_get('emfield_allow_' . $module . '_' . $provider->name, true)) {
          $info = emfield_include_invoke($module, $provider->name, 'info');
          $urls[] = l($info['name'], $info['url'], array('target' => '_blank'));
        }
      }
      $textfield_title = t($field['widget']['label']);
      $textfield_description = t('Enter the URL or Embed Code here. The embedded third party content will be parsed and displayed appropriately from this.');
      $textfield_description .= '<br />' . t('The following services are provided: !urls', array('!urls' => implode(', ', $urls)));

      if ($field['multiple']) {
        $form[$field['field_name']]['#type'] = 'fieldset';
        $form[$field['field_name']]['#title'] = t($field['widget']['label']);
        $delta = 0;
        foreach ($node_field as $data) {
          if (isset($data[$textfield])) {
            $form[$field['field_name']][$delta][$textfield] = array(
              '#type' => 'textfield',
              '#title' => $textfield_title,
              '#description' => $textfield_description,
              '#default_value' => $data[$textfield],
              '#required' => ($delta == 0) ? $field['required'] : FALSE,
              '#maxlength' => 1024,
            );
            $form[$field['field_name']][$delta]['value'] = array(
              '#type' => 'value',
              '#value' => $data['value'],
            );
            if ($data['value']) {
              $info = emfield_include_invoke($module, $data['provider'], 'info');
              $form[$field['field_name']][$delta]['markup_value'] = array(
                '#type' => 'item',
                '#value' => t('(@provider ID: !value)', array('@provider' => $info['name'], '!value' => l($data['value'], emfield_include_invoke($module, $info['provider'], 'embedded_link', $data['value'], $data['data']), array('target' => '_blank')))),
              );
            }
            $delta++;
          }
        }
        foreach (range($delta, $delta + 2) as $delta) {
           $form[$field['field_name']][$delta][$textfield] = array(
            '#type' => 'textfield',
            '#title' => $textfield_title,
            '#description' => $textfield_description,
            '#default_value' => '',
            '#required' => ($delta == 0) ? $field['required'] : FALSE,
            '#maxlength' => 1024,
          );
          $form[$field['field_name']][$delta]['value'] = array(
            '#type' => 'value',
            '#title' => '',
          );
        }
      }
      else {
        $form[$field['field_name']][0][$textfield] = array(
          '#type' => 'textfield',
          '#title' => $textfield_title, //t($field['widget']['label']),
          '#description' => $textfield_description,
          '#default_value' => isset($node_field[0][$textfield]) ? $node_field[0][$textfield] : '',
          '#required' => $field['required'],
          '#maxlength' => 1024,
        );
        if ($textfield == 'embed') {
          $value = isset($node_field[0]['value']) ? $node_field[0]['value'] : '';
          $form[$field['field_name']][0]['value'] = array(
            '#type' => 'value',
            '#value' => $value,
          );
          if ($value) {
            $info = emfield_include_invoke($module, $node_field[0]['provider'], 'info');
            $form[$field['field_name']][0]['value_markup'] = array(
              '#type' => 'item',
              '#value' => t('(@provider ID: !value)', array('@provider' => $info['provider'], '!value' => l($value, emfield_include_invoke($module, $info['provider'], 'embedded_link', $value, $node_field[0]['data']), array('target' => '_blank')))),
            );
          }
        }
      }
      return $form;
    default:
      break;
  }
}

/**
 * When an include file requires to read an xml to receive information, such as for thumbnails,
 * this script can be used to request the xml and return it as an array.
 * i suspect it could be done easier (and more quickly) in php 5.
 *   @param $provider
 *     the string of the third party provider, such as 'youtube', 'flikr', or 'google'
 *   @param $url
 *     the url for the xml request
 *   @param $args
 *     an array of args to pass to the xml url
 *   @param $cached
 *     optional; if true, the result of this xml request will be cached. good to play nice w/
 *     the third party folks so they don't stop providing service to your site...
 *   @return
 *     the xml results returned as an array
 */
function emfield_request_xml($provider, $url, $args = array(), $cached = true, $return_errors = FALSE, $hash_extra = false, $serialized = false) {
  ksort($args);

  // build an argument hash that we'll use for the cache id and api signing
  $arghash = $provider . ':';
  foreach($args as $k => $v){
    $arghash .= $k . $v;
  }

  // build the url
  foreach ($args as $k => $v){
    $encoded_params[] = urlencode($k).'='.urlencode($v);
  }
  if (!empty($encoded_params)) {
    $url .= '?'. implode('&', $encoded_params);
  }

  // some providers, such as bliptv, actually change the url, and not just the queries.
  // we provide an extra section for a unique identifier in that case
  if (isset($hash_extra)) {
    $arghash .= ':' . $hash_extra;
  }

  // if it's a cachable request, try to load a cached value
  if ($cached && $cache = cache_get($arghash, 'cache')) {
    return unserialize($cache->data);
  }

  // connect and fetch a value
  $result = drupal_http_request($url);

  if ($result->code != 200) {
    if ($return_errors) {
      return array(
        'stat' => 'error',
        'code' => $result->code,
        'message' => 'HTTP Error: '. $result->error,
      );
    }
    emfield_set_error(t("Could not connect to @provider, HTTP error @error", array('@error' => $result->code, '@provider' => $provider)));
    return array();
  }

  if ($serialized) {
    // Flickr gives us a serialized php array. Make sure it unserializes.
    $response = unserialize($result->data);
    if (!$response) {
      if ($return_errors) {
        return array(
          'stat' => 'error',
          'code' => '-1',
          'message' => 'The response was corrupted, it could not be unserialized.',
        );
      }
      emfield_set_error(t("The response from @provider was corrupted and could not be unserialized.", array('@provider' => $provider)));
      return array();
    }
  }
  else {
    $parser = drupal_xml_parser_create($result->data);
    $vals = array();
    $index = array();
    xml_parse_into_struct($parser, $result->data, $vals, $index);
    xml_parser_free($parser);

    $response = array();
    $level = array();
    $start_level = 1;
    foreach ($vals as $xml_elem) {
      if ($xml_elem['type'] == 'open') {
        if (array_key_exists('attributes',$xml_elem)) {
          list($level[$xml_elem['level']],$extra) = array_values($xml_elem['attributes']);
        } else {
          $level[$xml_elem['level']] = $xml_elem['tag'];
        }
      }
      if ($xml_elem['type'] == 'complete') {
        $php_stmt = '$response';
        while($start_level < $xml_elem['level']) {
          $php_stmt .= '[$level['.$start_level.']]';
          $start_level++;
        }
        $php_stmt .= '[$xml_elem[\'tag\']][] = $xml_elem[\'value\'];' . $php_stmt . '[$xml_elem[\'tag\']][] = $xml_elem[\'attributes\'];';
        eval($php_stmt);
        $start_level--;
      }
    }
  }

  cache_set($arghash, 'cache', serialize($response), time() + variable_get('emfield_cache_duration', 3600));
  return $response;
}

function emfield_set_error($error) {
  watchdog('emfield', $error, WATCHDOG_WARNING);
}

/**
 * Return an array of installed .inc files and/or loads them upon request.
 * This routine is modeled after drupal_system_listing() (and also depends on it).
 * It's major difference, however, is that it loads .inc files by default.
 *
 * @param $provider
 *   Optional; name of the passed $provider to find (e.g. "youtube", "google", etc.).
 * @param $load
 *   Defaults to true; whether to include matching files into memory.
 * @return
 *   An array of file objects optionally matching $provider.
 */
function emfield_system_list($module, $provider = NULL, $load = true) {
  $files = drupal_system_listing("$provider\.inc", drupal_get_path('module', $module) . "/providers", 'name', 0);

  ksort($files);

  if ($load) {
    foreach ($files as $file) {
      emfield_include_list($file);
    }
  }

  return $files;
}

/**
 * Maintains a list of all loaded include files.
 *
 * @param $file
 *   Optional; a file object (from emfield_system_list()) to be included.
 * @return
 *   An array of all loaded includes (without the .inc extension).
 */
function emfield_include_list($file = NULL) {
  static $list = array();

  if ($file && !isset($list[$file->name])) {
    include_once('./' . $file->filename);
    $list[$file->name] = $file->name;
  }

  return $list;
}

/**
 * Determine whether an include implements a hook, cf. module_hook.
 *
 * @param $provider
 *   The name of the provider file (without the .inc extension), such as 'youtube' or 'google'.
 * @param $hook
 *   The name of the hook (e.g. "thumbnail", "settings", etc.).
 * @return
 *   TRUE if the provider is loaded and the hook is implemented.
 */
function emfield_include_hook($module, $provider, $hook) {
  return function_exists($module . '_' . $provider .'_'. $hook);
}

/**
 * Invoke hook in a particular include.
 *
 * @param $module
 *  the helper module
 * @param $provider
 *   The name of the provider (without the .inc extension).
 * @param $hook
 *   The name of the hook (e.g. "settings", "thumbnail", etc.).
 * @param ...
 *   Arguments to pass to the hook implementation.
 * @return
 *   The return value of the hook implementation.
 */
function emfield_include_invoke() {
  $args     = func_get_args();
  $module = array_shift($args);
  $provider  = array_shift($args);
  $hook     = array_shift($args);
  $function = $module . '_' . $provider . '_' . $hook;
  emfield_system_list($module, $provider);
  return emfield_include_hook($module, $provider, $hook) ? call_user_func_array($function, $args) : NULL;
}