<?php
// $Id: feed_field.module,v 1.2 2009/04/27 06:20:55 primerg Exp $

/**
 * @file
 * Defines a field type for referencing an Amazon product.
 */

/**
 * Implementation of hook_theme().
 */
function feed_field_theme() {
  return array(
    'feed_field_text' => array(
      'arguments' => array('element'),
    ),
    'feed_field_formatter_default' => array(
      'arguments' => array('element'),
    ),
    'feed_field_formatter_teaser' => array(
      'arguments' => array('element'),
    ),
    'feed_field_formatter_full' => array(
      'arguments' => array('element'),
    ),
  );
}

/**
 * Implementation of hook_field_info().
 *
 * Here we indicate that the content module will use its default
 * handling for the view of this field.
 *
 * Callbacks can be omitted if default handing is used.
 * They're included here just so this module can be used
 * as an example for custom modules that might do things
 * differently.
 */
function feed_field_field_info() {
  return array(
    'feed_field' => array(
      'label' => t('Feed item'),
      'description' => t('Store feed url'),
    ),
  );
}

/**
 * Implementation of hook_field_settings().
 */
function feed_field_field_settings($op, $field) {
  switch ($op) {
    case 'database columns':
      $columns['feed_field_title'] = array('type' => 'varchar', 'length' => 255, 'not null' => FALSE);
      $columns['feed_field_url'] = array('type' => 'varchar', 'length' => 255, 'not null' => FALSE);
      $columns['feed_field_display'] = array('type' => 'int', 'not null' => FALSE);
      $columns['feed_field_freq'] = array('type' => 'int', 'not null' => FALSE);
      $columns['feed_field_excerpt'] = array('type' => 'varchar', 'not null' => FALSE, 'length' => 50);
      $columns['feed_field_update'] = array('type' => 'int', 'not null' => FALSE);
      return $columns;
  }
}

/**
 * Implementation of hook_field().
 */
function feed_field_field($op, &$node, $field, &$items, $teaser, $page) {
  switch ($op) {
    case 'validate':
      foreach ($items as $delta => $item) {
        $url = $item['feed_field_url'];
        $display = (int)$item['feed_field_display'];
        if (empty($url)) continue;
        if (!valid_url($url, TRUE)) {
          form_set_error($field['field_name'] .']['. $delta .'][feed_field_url', 'Invalid Feed URL');
        }
        
        if (empty($display)) {
          form_set_error($field['field_name'] .']['. $delta .'][feed_field_display', 'Number of headlines to be displayed in is required.');
        }
      }
      break;
  }
}

/**
 * Implementation of hook_content_is_empty().
 */
function feed_field_content_is_empty($item, $field) {
  if (empty($item['feed_field_url'])) {
    return TRUE;
  }
  return FALSE;
}

/**
 * Implementation of hook_field_formatter_info().
 */
function feed_field_field_formatter_info() {
  return array(
    'default' => array(
      'label' => t('Title only'),
      'field types' => array('feed_field'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
    'teaser' => array(
      'label' => t('Title and Teaser'),
      'field types' => array('feed_field'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
    'full' => array(
      'label' => t('Title with full content'),
      'field types' => array('feed_field'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
  );
}

function _feed_field_content($nid, $item, &$settings) {
  // search db
  $settings = db_fetch_array(db_query("SELECT id, modified FROM {feed_field_settings} AS ffs WHERE url='%s' AND nid=%d AND delta=%d", $item['feed_field_url'], $nid, $item['#delta']));
  if (!empty($settings)) {
    if ((time() - $settings['modified']) > $item['feed_field_freq']) {
      $settings['modified'] = time();
      db_query("UPDATE {feed_field_settings} SET modified='%s' WHERE nid=%d AND delta=%d", $settings['modified'], $nid, $item['#delta']);
      _feed_field_refresh_items($settings['id'], $item);
    }
  } else {
    $settings['modified'] = time();
    db_query("INSERT INTO {feed_field_settings} SET url='%s', nid=%d, modified='%s', delta=%d", $item['feed_field_url'], $nid, $settings['modified'], $item['#delta']);
    $settings['id'] = db_last_insert_id('feed_field_settings', 'id');
    $settings['nid'] = $nid;
    $settings['url'] = $item['feed_field_url'];
    _feed_field_refresh_items($settings['id'], $item);
  }
  
  $res = db_query("SELECT * FROM {feed_field_items} WHERE ff_id=%d ORDER BY timestamp DESC", $settings['id']);
  $data = array();
  while ($row = db_fetch_array($res)) {
    $data[] = $row;
  }
  return $data;
}

/**
 */
function theme_feed_field_formatter_teaser($element) {
  $nid = arg(1);
  $item = $element['#item'];
  $item['nid'] = $nid;
  $settings = array();
  
  $data = _feed_field_content($nid, $item, $settings);
  
  $out = '';
  $cnt=0;
  if ($data) {
    $out .= '<div id="aggregator">';
    $out .= '<div class="feed-source">'.
              '<div class="feed-description">'. $item['feed_field_title'] . '</div>'.
              '<div class="feed-updated">'.'<em>'. t('Updated:'). '</em> '. t('@time ago', array('@time' => format_interval(time() - $settings['modified']))) .'</div>'.
           '</div>';
    foreach ($data as $row) {
      $row = (object)$row;
      //drupal_set_message(print_r($row, true));
      $row->iid = $row->id;
      $row->description = truncate_utf8(trim(strip_tags($row->description, array('br', 'strong', 'b'))), 200, true, true);
      $row->categories = array();
      $out .= theme('aggregator_item', $row);
    }
    $out .= '</div>';
  }
  
  return $out;
}

function theme_feed_field_formatter_full($element) {
  $nid = arg(1);
  $item = $element['#item'];
  $item['nid'] = $nid;
  $settings = array();
  
  $data = _feed_field_content($nid, $item, $settings);
  
  $out = '';
  $cnt=0;
  $out .= '<h2>' . $item['feed_field_title'] . '</h2>';
  foreach ($data as $row) {
    $out .= '<div class="feed-wrapper">';
        $out .= '<div class="feed-title">'.l($row['title'], $row['link']).'</div>';
        $out .= '<div class="feed-content">'.$row['description'].'</div>';
        $out .= '</div>';
  }
  
  return $out;
}

function theme_feed_field_formatter_default($element) {
  $nid = arg(1);
  $item = $element['#item'];
  $item['nid'] = $nid;
  $settings = array();
  
  $data = _feed_field_content($nid, $item, $settings);
  
  $out = '';
  $cnt=0;
  $out .= '<h2>' . $item['feed_field_title'] . '</h2>';
  foreach ($data as $row) {
    $out .= '<div class="feed-wrapper">';
        $out .= '<div class="feed-title">'.l($row['title'], $row['link']).'</div>';
        
        if (!empty($item['feed_field_excerpt'])) {
          switch ($item['feed_field_excerpt']) {
            case 'truncate':
              $out .= '<div class="feed-content">'.truncate_utf8(strip_tags($row['description'], array('br')), 200, true, true).'</div>';
              break;
            case 'all':
              $out .= '<div class="feed-content">'.$row['description'].'</div>';
              break;
          }
        }
        
        $out .= '</div>';
  }
  
  return $out;
}

function _feed_field_refresh_items($ff_id, $item) {
  db_query("DELETE FROM {feed_field_items} WHERE ff_id=%d", $ff_id);
  
  // Generate one
  $result = drupal_http_request($item['feed_field_url']);
  if ($result->error) return false;
  
  $info = array(
    'parenturl' => $item['feed_field_url'],
    'nid' => $item['nid'],
    'max' => $item['feed_field_display'],
    'ff_id' => $ff_id,
  );
  
  $posts = _feed_field_parse_feed($result->data, $info);
  if ($posts) {
    _feed_field_save_parsed_feed($posts, $info);
  }
}

/**
 * Implementation of hook_widget_info().
 *
 * We need custom handling of multiple values for the feed_field_text
 * widget because we need to combine them into a options list rather
 * than display multiple elements.
 *
 * We will use the content module's default handling for default value.
 *
 * Callbacks can be omitted if default handing is used.
 * They're included here just so this module can be used
 * as an example for custom modules that might do things
 * differently.
 */
function feed_field_widget_info() {
  return array(
    'feed_field_text' => array(
      'label' => t('Feed item'),
      'field types' => array('feed_field'),
      'multiple values' => CONTENT_HANDLE_CORE,
    ),
  );
}

/**
 * Implementation of FAPI hook_elements().
 *
 * Any FAPI callbacks needed for individual widgets can be declared here,
 * and the element will be passed to those callbacks for processing.
 *
 * Drupal will automatically theme the element using a theme with
 * the same name as the hook_elements key.
 */
function feed_field_elements() {
  return array(
    'feed_field_text' => array(
      '#input' => TRUE,
      '#process' => array('feed_field_text_process'),
    ),
  );
}

/**
 * Implementation of hook_widget().
 *
 * Attach a single form element to the form. It will be built out and
 * validated in the callback(s) listed in hook_elements. We build it
 * out in the callbacks rather than here in hook_widget so it can be
 * plugged into any module that can provide it with valid
 * $field information.
 *
 * Content module will set the weight, field name and delta values
 * for each form element. This is a change from earlier CCK versions
 * where the widget managed its own multiple values.
 *
 * If there are multiple values for this field, the content module will
 * call this function as many times as needed.
 *
 * @param $form
 *   the entire form array, $form['#node'] holds node information
 * @param $form_state
 *   the form_state, $form_state['values'][$field['field_name']]
 *   holds the field's form values.
 * @param $field
 *   the field array
 * @param $items
 *   array of default values for this field
 * @param $delta
 *   the order of this item in the array of subelements (0, 1, 2, etc)
 *
 * @return
 *   the form item for a single element for this field
 */
function feed_field_widget(&$form, &$form_state, $field, $items, $delta = 0) {
  $element = array(
    '#type' => $field['widget']['type'],
    '#default_value' => isset($items[$delta]) ? $items[$delta] : '',
  );
  return $element;
}

/**
 * Process an individual element.
 *
 * Build the form element. When creating a form using FAPI #process,
 * note that $element['#value'] is already set.
 *
 * The $fields array is in $form['#field_info'][$element['#field_name']].
 */
function feed_field_text_process($element, $edit, $form_state, $form) {
  $field = $form['#field_info'][$element['#field_name']];
  $delta = $element['#delta'];
  
  $field = $element['#columns'][0];
  $element[$field] = array(
    '#type' => 'textfield',
    '#title' => t('Give your module a title. Titles can only be one line, so keep it short'),
    '#required' => $element['#required'],
    '#default_value' => isset($element['#value'][$field]) ? $element['#value'][$field] : NULL,
  );
  
  $field = $element['#columns'][1];
  $element[$field] = array(
    '#type' => 'textfield',
    '#title' => t('What URL would you like to pull RSS from?'),
    '#required' => $element['#required'],
    '#default_value' => isset($element['#value'][$field]) ? $element['#value'][$field] : NULL,
  );
  
  $field = $element['#columns'][2];
  $element[$field] = array(
    '#type' => 'textfield',
    '#title' => t('How many headlines would you like to show?'),
    '#default_value' => isset($element['#value'][$field]) ? $element['#value'][$field] : NULL,
  );
  
  $period[''] = t('never');
  $period += drupal_map_assoc(array(1800, 3600, 21600, 43200, 172800, 604800), 'format_interval');
  $field = $element['#columns'][3];
  $element[$field] = array(
    '#type' => 'select',
    '#title' => t('How frequently should the module be updated?'),
    '#options' => $period,
    '#default_value' => isset($element['#value'][$field]) ? $element['#value'][$field] : NULL,
  );
  
  $period = array('blank' => t('No excerpt'), 'truncate' => t('excerpt (100 characters)'), 'all' => t('everything available'));
  $field = $element['#columns'][4];
  
  $element[$field] = array(
    '#type' => 'select',
    '#title' => t('Would you like to include an excerpt from each link in the feed?'),
    '#options' => $period,
    '#default_value' => isset($element['#value'][$field]) ? $element['#value'][$field] : NULL,
  );
  
  return $element;
}


/**
 * Validate an select element.
 *
 * Remove the wrapper layer and set the right element's value.
 */
function feed_field_text_validate($element, &$form_state) {
  die('validate');
}


function theme_feed_field_text($element) {
  $output = '<fieldset class="collapsible"><legend>'. t('RSS Feed') .'</legend>'.$element['#children'].'</fieldset>';
  return $output;
}

function _feed_field_parse_feed($data, $feed_info) {
  global $channel, $image;
  global $items, $image, $channel;
  
  if (empty($data)) return '';

  // Unset the global variables before we use them:
  unset($GLOBALS['element'], $GLOBALS['item'], $GLOBALS['tag']);
  $items = array();
  $image = array();
  $channel = array();

  // parse the data:
  $xml_parser = drupal_xml_parser_create($data);
  xml_set_element_handler($xml_parser, 'aggregator_element_start', 'aggregator_element_end');
  xml_set_character_data_handler($xml_parser, 'aggregator_element_data');
  
  if (!xml_parse($xml_parser, $data, 1)) {
    watchdog('aggregator', 'The feed from %site seems to be broken, due to an error "%error" on line %line.', array('%site' => $feed_info['parenturl'], '%error' => xml_error_string(xml_get_error_code($xml_parser)), '%line' => xml_get_current_line_number($xml_parser)), WATCHDOG_WARNING);
    drupal_set_message(t('The feed from %site seems to be broken, because of error "%error" on line %line.', array('%site' => $feed_info['parenturl'], '%error' => xml_error_string(xml_get_error_code($xml_parser)), '%line' => xml_get_current_line_number($xml_parser))), 'error');
    return 0;
  }
  xml_parser_free($xml_parser);

  // Initialize variables.
  $new_items = array();
  $title = $link = $author = $description = $guid = NULL;
  foreach ($items as $item) {
    unset($title, $link, $author, $description, $guid);

    // Prepare the item:
    foreach ($item as $key => $value) {
      $item[$key] = trim($value);
    }

    // Resolve the item's title. If no title is found, we use up to 40
    // characters of the description ending at a word boundary but not
    // splitting potential entities.
    if (!empty($item['TITLE'])) {
      $title = $item['TITLE'];
    }
    elseif (!empty($item['DESCRIPTION'])) {
      $title = preg_replace('/^(.*)[^\w;&].*?$/', "\\1", truncate_utf8($item['DESCRIPTION'], 40));
    }
    else {
      $title = '';
    }

    // Resolve the items link.
    if (!empty($item['LINK'])) {
      $link = $item['LINK'];
    }
    else {
      $link = $feed_info['parenturl'];
    }
    $guid = isset($item['GUID']) ? $item['GUID'] : '';

    // Atom feeds have a CONTENT and/or SUMMARY tag instead of a DESCRIPTION tag.
    if (!empty($item['CONTENT:ENCODED'])) {
      $item['DESCRIPTION'] = $item['CONTENT:ENCODED'];
    }
    else if (!empty($item['SUMMARY'])) {
      $item['DESCRIPTION'] = $item['SUMMARY'];
    }
    else if (!empty($item['CONTENT'])) {
      $item['DESCRIPTION'] = $item['CONTENT'];
    }

    // Try to resolve and parse the item's publication date. If no date is
    // found, we use the current date instead.
    $date = 'now';
    foreach (array('PUBDATE', 'DC:DATE', 'DCTERMS:ISSUED', 'DCTERMS:CREATED', 'DCTERMS:MODIFIED', 'ISSUED', 'CREATED', 'MODIFIED', 'PUBLISHED', 'UPDATED') as $key) {
      if (!empty($item[$key])) {
        $date = $item[$key];
        break;
      }
    }

    $timestamp = strtotime($date); // As of PHP 5.1.0, strtotime returns FALSE on failure instead of -1.
    if ($timestamp <= 0) {
      $timestamp = aggregator_parse_w3cdtf($date); // Returns FALSE on failure
      if (!$timestamp) {
        $timestamp = time(); // better than nothing
      }
    }

    if (empty($title)) continue;
    
    $item += array('AUTHOR' => '', 'DESCRIPTION' => '');
    $new_items[] = array(
      'timestamp' => $timestamp,
      'title' => $title,
      'link' => $link,
      'author' => $item['AUTHOR'],
      'description' => $item['DESCRIPTION'],
      'guid' => $guid);
  }

  return $new_items;
}

function _feed_field_save_parsed_feed($items, $feed_info) {
  $cnt = 0;
  foreach ($items as $item) {
    // Save this item. Try to avoid duplicate entries as much as possible. If
    // we find a duplicate entry, we resolve it and pass along its ID is such
    // that we can update it if needed.
    $guid = $item['guid'];
    if (!empty($guid)) {
      $entry = db_fetch_object(db_query("SELECT id FROM {feed_field_items} WHERE ff_id=%d AND guid = '%s'", $feed_info['ff_id'], $guid));
    }
    else if ($link && $link != $feed['link'] && $link != $feed['url']) {
      $entry = db_fetch_object(db_query("SELECT id FROM {feed_field_items} WHERE ff_id=%d AND link = '%s'", $feed_info['ff_id'], $item['link']));
    }
    else {
      $entry = db_fetch_object(db_query("SELECT id FROM {feed_field_items} WHERE ff_id=%d AND title = '%s'", $feed_info['ff_id'], $item['title']));
    }
    
    if (isset($entry->id)) {
      continue;
    }
    
    $item['ff_id'] = $feed_info['ff_id'];
    _feed_field_save_item($item);
    $cnt++;
    
    if ($cnt >= $feed_info['max']) break;
  }
}

/**
 * Add/edit/delete an aggregator item.
 *
 * @param $edit
 *   An associative array describing the item to be added/edited/deleted.
 */
function _feed_field_save_item($edit) {
  db_query("INSERT INTO {feed_field_items} (ff_id, title, link, author, description, timestamp, guid) VALUES (%d, '%s', '%s', '%s', '%s', %d, '%s')", $edit['ff_id'], $edit['title'], $edit['link'], $edit['author'], $edit['description'], $edit['timestamp'], $edit['guid']);
  $edit['id'] = db_last_insert_id('feed_field_items', 'id');
}