<?php
// $Id: twitter.module,v 1.10.2.7 2010-10-21 15:12:17 walkah Exp $

/**
 * Implementation of hook_meu()
 */
function twitter_menu() {
  $items = array();

  $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/settings/twitter'] = array(
    'title' => 'Twitter setup',
    'description' => 'Twitter module settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('twitter_admin_form'),
    'access arguments' => array('administer site configuration'),
    'file' => 'twitter.pages.inc'
  );
  
  $items['admin/settings/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 arguments' => array('add twitter accounts'),
    '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',
    'type' => MENU_CALLBACK,
  );
  
  return $items;
}

/**
 * Implementation of hook_perm()
 */
function twitter_perm() {
  return array('add twitter accounts', 'use global twitter account', 'make twitter accounts global', 'import own tweets');
}

/**
 * Implementation of hook_user().
 */
function twitter_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {
    case 'categories':
      return array(
        array(
          'name' => 'twitter',
          'title' => 'Twitter accounts',
          'weight' => 3,
        ),
      );
  }
}

function twitter_theme() {
  return array(
    'twitter_account_list_form' => array(
      'arguments' => array('form' => NULL),
    )
  );
}

/**
 * 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 {
    $response = drupal_http_request("http://tinyurl.com/api-create.php?url=" . $url);
    if ($response->code == 200) {
      return $response->data;
    }
    else {
      return $url;
    }
  }
}

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

  module_load_include('inc', 'twitter');

  // 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.

  $sql  = "SELECT twitter_uid FROM {twitter_account} WHERE import = 1 ORDER BY last_refresh ASC";

  $results = db_query_range($sql, 0, 20);
  while ($account = db_fetch_object($results)) {
    twitter_fetch_user_timeline($account->twitter_uid);
  }

  // Nuke old statuses.
  if ($age = variable_get('twitter_expire', 0)) {
    db_query('DELETE FROM {twitter} WHERE created_time < %d', time() - $age);
  }
}


/**
 * Implementation of hook_filter().
 * - Twitter @username converter:
 *     .Converts Twitter-style @usernames into links to Twitter account pages.
 * - Twitter #hashtag converter:
 *     .Converts Twitter-style #hashtags into links to hashtags.org.
 */
function twitter_filter($op, $delta = 0, $format = -1, $text = '') {
  switch ($op) {
    case 'list':
      return array(0 => t('Twitter @username converter'), 1 => t('Twitter #hashtag converter'));

    case 'description':
      switch ($delta) {
        case 0:
          return t('Converts Twitter-style @usernames into links to Twitter account pages.');
        case 1:
          return t('Converts Twitter-style #hashtags into links to hashtags.org.');
        default:
          return;
      }

    case 'process':
      switch ($delta) {
        case 0:
          return twitter_link_filter($text);
        case 1:
          return twitter_link_filter($text, '#', 'http://search.twitter.com/search?q=%23');
        default:
          return $text;
      }

    default:
      return $text;
  }
}

/**
 * Implementation of hook_filter_tips().
 */
function twitter_filter_tips($delta, $format, $long = FALSE) {
  global $base_url;
  switch ($delta) {
    case 0:
      return t('Twitter-style @usersnames are linked to their Twitter account pages.');

    case 1:
      return t('Twitter-style #hashtags are linked to !url.', array('!url' => '<a href="http://search.twitter.com/">search.twitter.com</a>'));
  }
}

/**
 * This helper function converts Twitter-style @usernames and #hashtags into 
 * actual links.
 */
function twitter_link_filter($text, $prefix = '@', $destination = 'http://twitter.com/') {
  $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); 
}

/**
 * Get a list of twitter accounts available to the current user.
 *
 * @return Array containing TwitterAccount objects
 */
function twitter_get_user_accounts($uid) {
  $drupal_user = user_load($uid);
  return module_invoke_all('twitter_accounts', $drupal_user);
}


/**
 * 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.
 */
function twitter_twitter_accounts($account) {
  module_load_include('inc', 'twitter');
  
  $twitter_accounts = array();
  
  $sql = "SELECT twitter_uid FROM {twitter_account} WHERE uid = %d";
  if (user_access('use global twitter account')) {
    $sql.= " OR is_global=1";
  }
  $results = db_query($sql, $account->uid);

  while ($row = db_fetch_array($results)) {
    $key = $row['twitter_uid'];
    $twitter_accounts[] = twitter_account_load($key);
  }
  return $twitter_accounts;
}

function _twitter_use_oauth() {
  if (!module_exists('oauth')) {
    return FALSE;
  }
  
  return (variable_get('twitter_consumer_key', '') && variable_get('twitter_consumer_secret', ''));
}

/**
 * Implementation of hook_views_api.
 * Notifies the Views module that we're compatible with a particular API revision.
 */
function twitter_views_api() {
  return array('api' => 2);
}