<?php

/**
 * @file
 * Main hooks for twitter post module
 */

/**
 * Implements hook_menu().
 */
function twitter_post_menu() {
  $items['admin/config/services/twitter/post'] = array(
    'title' => 'Post',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('twitter_post_admin_settings'),
    'access arguments' => array('administer site configuration'),
    'file' => 'twitter_post.pages.inc',
    'type' => MENU_LOCAL_TASK,
    'weight' => 3,
  );

  return $items;
}

/**
 * Implements hook_permission().
 */
function twitter_post_permission() {
  return array(
    'post to twitter' => array(
      'title' => t('Post a message to Twitter'),
    ),
  );
}

/**
 * Implements hook_form_alter().
 */
function twitter_post_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;
    $allowed_types = variable_get('twitter_post_types', array('story' => 'story', 'blog' => 'blog'));
    if (empty($allowed_types[$type])) {
      return;
    }

    module_load_include('inc', 'twitter');

    $twitter_form = twitter_post_form();
    if (!$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_post_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.');
    $form['twitter']['status']['#maxlength'] = 150;
  }
}

/**
 * Implementation of hook_node_insert().
 *
 * Intercepts newly published nodes and posts noticed to Twitter.
 */
function twitter_post_node_insert($node) {
  if (!empty($node->status) && !empty($node->twitter) && !empty($node->twitter['post'])) {
    module_load_include('inc', 'twitter');

    $twitter_account = twitter_account_load($node->twitter['account']);
    $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);
    try {
      $result = twitter_set_status($twitter_account, $status);
      drupal_set_message(t('Successfully posted to Twitter'));
    }
    catch (TwitterException $e) {
      drupal_set_message(t('An error occurred when posting to twitter: %code %error',
                           array('%code' => $result->code, '%error' => $result->error)), 'warning');
    }
  }
}

/**
 * Implementation of hook_node_update().
 */
function twitter_post_node_update($node) {
  twitter_post_node_insert($node);
}


/**
 * Generate a twitter posting form for the given user.
 *
 * @param $account
 *   A Drupal user object.
 */
function twitter_post_form($account = NULL) {
  drupal_add_js(drupal_get_path('module', 'twitter_post') . '/twitter_post.js');

  if (empty($account)) {
    $account = user_load($GLOBALS['user']->uid);
  }

  if (!user_access('post to twitter', $account)) {
    return;
  }

  $options = array();
  foreach ($account->twitter_accounts as $twitter_account) {
    $options[$twitter_account->id] = $twitter_account->screen_name;
  }

  if (count($options)) {
    $form = array();
    $form['status'] = array(
      '#type' => 'textfield',
      '#id' => 'twitter-textfield',
    );

    if (count($options) > 1) {
      $form['account'] = array(
        '#type' => 'select',
        '#title' => t('Account'),
        '#options' => $options,
        '#id' => 'twitter-account',
      );
    }
    else {
      $form['account'] = array(
        '#type' => 'value',
        '#value' => array_pop(array_keys($options)),
      );
    }
    return $form;
  }
}