<?php

/**
 * @file
 * Updates Drupal to use the latest version of jQuery.
 */

/**
 * Implements hook_jquery_update_alter().
 *
 * @see hook_jquery_update_alter()
 */
function jquery_update_jquery_update_alter(&$javascript) {
  $path = drupal_get_path('module', 'jquery_update') . '/replace/';
  $scripts = jquery_update_get_replacements();

  // Replace jquery.js first.
  $jquerypath = jquery_update_jquery_path();
  $new_jquery = array($jquerypath => $javascript['core']['misc/jquery.js']);
  $javascript['core'] = array_merge($new_jquery, $javascript['core']);
  $javascript['core'][$jquerypath]['version'] = variable_get('jquery_update_jquery_version', '1.3');
  unset($javascript['core']['misc/jquery.js']);

  // Loop through each of the required replacements.
  foreach ($scripts as $type => $replacements) {
    foreach ($replacements as $find => $replace) {
      // If the file to replace is loaded on this page...
      if (isset($javascript[$type][$find])) {
        // Create a new entry for the replacement file, and unset the original one.
        $javascript[$type][$path . $replace] = $javascript[$type][$find];
        unset($javascript[$type][$find]);
      }
    }
  }
}

/**
 * Array of jQuery files to replace if jQuery is loaded.
 */
function jquery_update_get_replacements() {
  return array(
    'module' => array(
      'misc/farbtastic/farbtastic.js' => 'farbtastic.js',
      'misc/teaser.js' => 'teaser.js',
      'misc/jquery.form.js' => 'jquery.form.js',
      'misc/ahah.js' => 'ahah.js',
      // Certain versions of Views re-add tabledrag.js as $type 'module'.
      'misc/tabledrag.js' => 'tabledrag.js',
    ),
    'core' => array(
      'misc/tabledrag.js' => 'tabledrag.js',
    ),
  );
}

/**
 * Implementation of hook_theme_registry_alter().
 *
 * Make jQuery Update's page preprocess function run *after* everything else's,
 * so that a theme can't call drupal_get_js() and mess everything up.
 */
function jquery_update_theme_registry_alter(&$theme_registry) {
  if (isset($theme_registry['page'])) {
    if (count($theme_registry['page']['preprocess functions']) > 0) {
      // If jquery_update's preprocess function is there already, remove it.
      if ($key = array_search('jquery_update_preprocess_page', $theme_registry['page']['preprocess functions'])) {
        unset($theme_registry['page']['preprocess functions'][$key]);
      }
    }
    // Now tack it on at the end so it runs after everything else.
    $theme_registry['page']['preprocess functions'][] = 'jquery_update_preprocess_page';
  }
}

/**
 * Implementation of moduleName_preprocess_hook().
 *
 * Replace Drupal core's jquery.js with the new one from jQuery Update module.
 */
function jquery_update_preprocess_page(&$variables) {
  // Only do this for pages that have JavaScript on them.
  if (!empty($variables['scripts'])) {

    // Perform the logic if either jQuery Update's jquery.js is newer than core's.
    if (variable_get('jquery_update_replace', TRUE)) {
      // Get an array of all the JavaScript files loaded by Drupal on this page.
      $javascript = drupal_add_js();

      // Invoke hook_js_alter().
      drupal_alter('jquery_update', $javascript);

      // Replace with all the new JavaScript.
      $variables['scripts'] = drupal_get_js('header', $javascript);
    }
  }
}

/**
 * Return the version of jQuery that is installed.
 *
 * This can be used by other modules' hook_requirements() to ensure that the
 * proper version of jQuery is installed.
 *
 * @see version_compare
 */
function jquery_update_get_version($jquery_path = NULL) {
  $version = 0;
  $pattern = '# * jQuery JavaScript Library v([0-9\.a-z]+)#';

  // No file is passed in so default to the file included with this module.
  if (is_null($jquery_path)) {
    $jquery_path = jquery_update_jquery_path();
  }

  // Return the version provided by jQuery Update.
  $jquery = file_get_contents($jquery_path);
  if (preg_match($pattern, $jquery, $matches)) {
    $version = $matches[1];
  }

  return $version;
}

/**
 * Implementation of hook_flush_caches().
 */
function jquery_update_flush_caches() {
  // Find the versions of jQuery provided by core and this module.
  $jquery_update_version = jquery_update_get_version();
  $jquery_core_version = jquery_update_get_version('misc/jquery.js');

  // Set a variable according to whether core's version needs to be replaced.
  $replace = version_compare($jquery_core_version, $jquery_update_version, '<');
  variable_set('jquery_update_replace', $replace);
}

/**
 * Implementation of hook_menu().
 */
function jquery_update_menu() {
  $items['admin/settings/jquery_update'] = array(
    'title' => 'jQuery Update',
    'description' => 'Configure settings for jQuery Update module.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('jquery_update_settings'),
    'access arguments' => array('administer site configuration'),
  );
  return $items;
}

/**
 * Admin settings form.
 */
function jquery_update_settings() {
  // Clear the javascript cache when the setting is updated and check version of jquery file.
  $form['#submit'][] = 'drupal_clear_js_cache';
  $form['#submit'][] = 'jquery_update_flush_caches';

  $form['jquery_update_compression_type'] = array(
    '#type' => 'radios',
    '#title' => t('Choose jQuery compression level'),
    '#options' => array(
      'min' => t('Production (Minified)'),
      'none' => t('Development (Uncompressed Code)'),
    ),
    '#default_value' => variable_get('jquery_update_compression_type', 'min'),
  );
  $form['jquery_update_jquery_version'] = array(
    '#type' => 'select',
    '#title' => t('jQuery Version'),
    '#options' => array(
      '1.3' => '1.3',
      '1.7' => '1.7',
    ),
    '#default_value' => variable_get('jquery_update_jquery_version', '1.3'),
    '#description' => t('Select which jQuery version branch to use.'),
  );

  return system_settings_form($form);
}

/**
 * Return the path to the jQuery file.
 */
function jquery_update_jquery_path() {
  // Check whether we are to retrieve the minified version.
  $jquery_file = array(
    'none' => 'jquery.js',
    'min' => 'jquery.min.js',
  );
  $type = variable_get('jquery_update_compression_type', 'min');

  // Find the jQuery version to use.
  $version = variable_get('jquery_update_jquery_version', '1.3');
  $path = drupal_get_path('module', 'jquery_update') .'/replace/jquery/'. $version .'/';
  return $path . $jquery_file[$type];
}