<?php
/**
 * @file
 * Provides API integration with the Twitter microblogging service.
 */

/**
 * Implements hook_menu().
 */
function twitter_menu() {
  $items['twitter/oauth'] = array(
    'title' => 'Twitter',
    'access callback' => TRUE,
    'page callback' => 'drupal_get_form',
    'page arguments' => array('twitter_oauth_callback'),
    'type' => MENU_CALLBACK,
    'file' => 'twitter.pages.inc',
  );

  $items['admin/config/services/twitter'] = array(
    'title' => 'Twitter',
    'description' => 'Configure integration with Twitter (and compatible) API services.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('twitter_admin_form'),
    'access arguments' => array('administer site configuration'),
    'file' => 'twitter.pages.inc',
  );

  $items['admin/config/services/twitter/default'] = array(
    'title' => 'Twitter',
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );

  $items['user/%user_category/edit/twitter'] = array(
    'title' => 'Twitter accounts',
    'page callback' => 'twitter_user_settings',
    'page arguments' => array(1),
    'access callback' => 'twitter_edit_access',
    'access arguments' => array(1),
    'load arguments' => array('%map', '%index'),
    'weight' => 10,
    'file' => 'twitter.pages.inc',
    'type' => MENU_LOCAL_TASK,
  );

  $items['user/%user/edit/twitter/global/%'] = array(
    'title' => 'Twitter accounts',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('twitter_user_make_global', 1, 5),
    'access arguments' => array('make twitter accounts global'),
    'file' => 'twitter.pages.inc',
  );

  return $items;
}

/**
 * Access callback for twitter account editing.
 */
function twitter_edit_access($account) {
  return user_edit_access($account) && user_access('add twitter accounts');
}

/**
 * Implements hook_permission().
 */
function twitter_permission() {
  return array(
    'add twitter accounts' => array(
      'title' => t('Add Twitter accounts'),
    ),
    'use global twitter account' => array(
      'title' => t('Use the site global Twitter account'),
    ),
    'make twitter accounts global' => array(
      'title' => t('Assign a Twitter account as the site global account.'),
    ),
    'import own tweets' => array(
      'title' => t('Import own tweets to the site.'),
    ),
  );
}

/**
 * Implements hook_user_categories().
 */
function twitter_user_categories() {
  return array(
    array(
      'name' => 'twitter',
      'title' => t('Twitter accounts'),
      'weight' => 3,
    ),
  );
}

/**
 * Implements hook_theme().
 */
function twitter_theme() {
  return array(
    'twitter_account_list_form' => array(
      'render element' => 'form',
    ),
  );
}

/**
 * Very lightweight helper function to generate a TinyURL for a given post.
 */
function twitter_shorten_url($url) {
  if (module_exists('shorten')) {
    return shorten_url($url);
  }
  else {
    $conf = TwitterConf::instance();
    $response = drupal_http_request("http://" . $conf->get('tiny_url') . "/api-create.php?url=" . $url);
    if ($response->code == 200) {
      return $response->data;
    }
    else {
      return $url;
    }
  }
}

/**
 * Implements hook_cron().
 *
 * Imports new Twitter statuses for site users, and deletes expired tweets.
 */
function twitter_cron() {
  if (!variable_get('twitter_import', TRUE)) {
    return;
  }

  // Pull up a list of Twitter accounts that are flagged for updating,
  // sorted by how long it's been since we last updated them. This ensures
  // that the most out-of-date accounts get updated first.
  module_load_include('inc', 'twitter');
  $result = db_query_range("SELECT twitter_uid FROM {twitter_account} WHERE import = :import ORDER BY last_refresh ASC", 0, 20, array(':import' => 1));
  foreach ($result as $account) {
    twitter_fetch_user_timeline($account->twitter_uid);
  }

  // Nuke old statuses.
  if ($age = variable_get('twitter_expire', 0)) {
    db_delete('twitter')
      ->condition('created_time', REQUEST_TIME - $age, '<')
      ->execute();
  }
}

/**
 * Implements hook_filter_info().
 */
function twitter_filter_info() {
  $filters['twitter_username'] = array(
    'title' => t('Twitter @username converter'),
    'description' => t('Converts Twitter-style @usernames into links to Twitter account pages.'),
    'process callback' => '_twitter_filter_username',
    'tips callback' => '_twitter_filter_tip_username',
  );
  $filters['twitter_hashtag'] = array(
    'title' => t('Twitter #hashtag converter'),
    'description' => t('Converts Twitter-style #hashtags into links to hashtags.org.'),
    'process callback' => '_twitter_filter_hashtag',
    'tips callback' => '_twitter_filter_tip_hashtag',
  );
  return $filters;
}

/**
 * Filter tips callback function for $filters[0] in hook_filter_info().
 */
function _twitter_filter_tip_username($filter, $format, $long = FALSE) {
  return t('Twitter-style @usernames are linked to their Twitter account pages.');
}

/**
 * Filter tips callback function for $filters[1] in hook_filter_info().
 */
function _twitter_filter_tip_hashtag($format, $long = FALSE) {
  return t('Twitter-style #hashtags are linked to !url.', array(
    '!url' => '<a href="http://search.twitter.com/">search.twitter.com</a>')
  );
}

/**
 * Callback for twitter @username converter
 */
function _twitter_filter_username($text, $filter) {
  $prefix = '@';
  $conf = TwitterConf::instance();
  $destination = 'http://' . $conf->get('host') . '/';
  return _twitter_filter_text($text, $prefix, $destination);
}

/**
 * Callback for twitter #hashtag converter
 */
function _twitter_filter_hashtag($text, $filter) {
  $prefix = '#';
  $conf = TwitterConf::instance();
  $destination = 'http://' . $conf->get('search') . '/search?q=%23';
  return _twitter_filter_text($text, $prefix, $destination);
}

/**
 * This helper function converts Twitter-style @usernames and #hashtags into
 * actual links.
 */
function _twitter_filter_text($text, $prefix, $destination) {
  $matches = array(
    '/\>' . $prefix . '([a-z0-9_]+)/i',
    '/^' . $prefix . '([a-z0-9_]+)/i',
    '/(\s+)' . $prefix . '([a-z0-9_]+)/i',
  );
  $replacements = array(
    '><a href="' . $destination . '/${1}">' . $prefix . '${1}</a>',
    '<a href="' . $destination . '/${1}">' . $prefix . '${1}</a>',
    '${1}<a href="' . $destination . '/${2}">' . $prefix . '${2}</a>',
  );
  return preg_replace($matches, $replacements, $text);
}

/**
 * Implements hook_user_load().
 */
function twitter_user_load($accounts) {
  foreach ($accounts as $uid => $account) {
    $accounts[$uid]->twitter_accounts = module_invoke_all('twitter_accounts', $account);
  }
}

/**
 * An implementation of hook_twitter_accounts. We want to move this into a
 * separate module eventually, but sticking the code here and using a hook
 * lets other modules solve the 'what accounts can a user post with' problem
 * in cleaner ways.
 *
 * @return
 *   array with Twitter accounts
 */
function twitter_twitter_accounts($account) {
  module_load_include('inc', 'twitter');

  $query = db_select('twitter_account', 'ta')
    ->fields('ta', array('twitter_uid'));
  if (user_access('use global twitter account', $account)) {
    $or = db_or();
    $or->condition('ta.uid', $account->uid);
    $or->condition('ta.is_global', 1);
    $query->condition($or);
  }
  else {
    $query->condition('ta.uid', $account->uid);
  }

  $twitter_accounts = array();
  foreach ($query->execute()->fetchCol() as $twitter_uid) {
    $twitter_accounts[] = twitter_account_load($twitter_uid);
  }
  return $twitter_accounts;
}

/**
 * Detect whether we should use oauth. This can probably just go now :)
 */
function _twitter_use_oauth() {
  return module_exists('oauth_common') && variable_get('twitter_consumer_key', '') &&
         variable_get('twitter_consumer_secret', '');
}

/**
 * Implements hook_views_api().
 */
function twitter_views_api() {
  return array('api' => 2);
}

/**
 * Implements hook_admin_paths_alter().
 *
 * OAuth callback disagrees with overlay.
 */
function twitter_admin_paths_alter(&$paths) {
  $paths['user/*/edit/twitter'] = FALSE;
}