<?php
// $Id: twitter.module,v 1.3.2.14 2009-07-02 14:54:18 eaton Exp $

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

  $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['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,
  );

  return $items;
}

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

/**
 * 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),
    )
  );
}

/**
 * Implementation of hook_form_alter().
 */
function twitter_form_alter(&$form, $form_state, $form_id) {
  // Alter any node forms.
  if (isset($form['#node']) && $form['#node']->type .'_node_form' == $form_id) {
    // If we haven't enabled Twitter posting on this node type, nothing to do
    // here.
    $type = $form['#node']->type;
    $allowed_types = variable_get('twitter_types', array('story' => 'story', 'blog' => 'blog'));
    if (empty($allowed_types[$type])) {
      return;
    }

    module_load_include('inc', 'twitter');

    $twitter_form = twitter_form();
    if (!$twitter_form) {
      return;
    }
    $form['twitter'] = array(
      '#type' => 'fieldset',
      '#title' => t('Post to twitter.com'),
      '#collapsible' => TRUE,
      '#collapsed' => FALSE,
      '#tree' => TRUE,
    );
    $form['twitter']['post'] = array(
      '#type' => 'checkbox',
      '#title' => t('Announce this post on Twitter'),
      '#default_value' => (empty($form['nid']['#value'])),
      '#id' => 'twitter-toggle',
    );
    $form['twitter'] += $twitter_form;
    $form['twitter']['status']['#default_value'] = variable_get('twitter_default_format', 'New post: !title !tinyurl');
    $form['twitter']['status']['#description'] = t('The given text will be posted to twitter.com. You can use !url, !url-alias, !tinyurl, !title and !user as replacement text.');
  }
}

/**
 * Implementation of hook_nodeapi().
 *
 * Intercepts newly published nodes and posts noticed to Twitter.
 */
function twitter_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  module_load_include('inc', 'twitter');

  switch ($op) {
    case 'insert':
    case 'update':
      if (!empty($node->status) && !empty($node->twitter) && !empty($node->twitter['post'])) {
        $twitter_accounts = twitter_get_user_accounts($node->uid, TRUE);
        $pass = $twitter_accounts[$node->twitter['account']]['password'];

        $replacements = array('!title' => $node->title,
                              '!url' => url('node/'. $node->nid, array('absolute' => TRUE, 'alias' => TRUE)),
                              '!url-alias' => url('node/'. $node->nid, array('absolute' => TRUE)),
                              '!user' => $node->name);
        // Only generate the shortened URL if it's going to be used. No sense
        // burning through TinyURLs without a good reason.
        if (strstr($node->twitter['status'], '!tinyurl') !== FALSE) {
          $replacements['!tinyurl'] = twitter_shorten_url(url('node/'. $node->nid, array('absolute' => TRUE)));
        }

        $status = strtr($node->twitter['status'], $replacements);
        $result = twitter_set_status($node->twitter['account'], $pass, $status);
        if (_twitter_request_failure($result)) {
          drupal_set_message(t('An error occurred when posting to twitter: %code %error',
                               array('%code' => $result->code, '%error' => $result->error)), 'warning');
        }
        else {
          drupal_set_message(t('Successfully posted to Twitter'));
        }
      }
      break;
  }
}

/**
 * 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 tu.screen_name, tu.password, ta.protected FROM {twitter_user} tu ";
  $sql .= "LEFT JOIN {twitter_account} ta ON tu.screen_name = ta.screen_name ";
  $sql .= "WHERE tu.import = 1 ORDER BY ta.last_refresh ASC";

  $results = db_query_range($sql, 0, 20);
  while ($account = db_fetch_array($results)) {
    // Use the 'cheaper' unauthenticated version if the account isn't protected,
    // or if a password hasn't been specified.
    if (empty($account['protected']) || empty($account['password'])) {
      $statuses = twitter_fetch_timeline($account['screen_name']);
    }
    else {
      $statuses = twitter_fetch_statuses($account['screen_name'], $account['password']);
    }

    // If we got results back, update the account information with the latest
    // follower count, location, user picture, etc. Also, touch the account's
    // last_refreshed timestamp so it won't get thrashed before other, staler
    // accounts.
    if (!empty($statuses)) {
      twitter_cache_account($statuses[0]['account']);
    }
    twitter_touch_account($account['screen_name']);
  }

  // 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_]{0,15})/i',
    '/^' . $prefix . '([a-z0-9_]{0,15})/i',
    '/(\s+)' . $prefix . '([a-z0-9_]{0,15})/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); 
}

/**
 * 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($drupal_user, $full_access = FALSE) {
  $accounts = array();
  if (user_access('use global twitter account') &&
      ($name = variable_get('twitter_global_name', NULL)) &&
      ($pass = variable_get('twitter_global_password', NULL))) {
    
    $accounts[$name] = array(
      'screen_name' => $name,
      'password' => $pass,
    );
  }
  
  $sql = "SELECT ta.*, tu.uid, tu.password, tu.import FROM {twitter_user} tu LEFT JOIN {twitter_account} ta ON (tu.screen_name = ta.screen_name) WHERE tu.uid = %d";
  if ($full_access) {
    $sql .= " AND tu.password IS NOT NULL";
  }
  $args = array($drupal_user->uid);
  $results = db_query($sql, $args);

  while ($account = db_fetch_array($results)) {
    $accounts[$account['screen_name']] = $account;
  }
  return $accounts;
}


/**
 * 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);
}