<?php

use Drupal\Core\Asset\AttachedAssetsInterface;
use Drupal\Core\Form\FormStateInterface;

/**
 * Implements hook_page_attachments_alter().
 *
 * Add the livereload.js script to the site.
 */
function livereload_page_attachments_alter(array &$page) {
  if (\Drupal::currentUser()->hasPermission('use livereload') && \Drupal::config('livereload.settings')->get('livereload_js')) {
    // Checking whether the file exists before including it. Because it can be
    // external, we have to use @fopen instead of file_exists().
    if (@fopen(livereload_get_path(), "r")) {
      $page['#attached']['library'][] = 'livereload/drupal.livereload';
    }
    else {
      drupal_set_message(t('Livereload.js could not be included.'), 'warning');
    }
  }
}

/**
 * Build and prepare the path, we suggest the livereload script to be.
 *
 * @return string
 *   The path, we suggest livereload script to be.
 */
function livereload_get_path() {
  $http_host = explode(':', $_SERVER['HTTP_HOST']);
  return 'http://' . reset($http_host) . ':35729/livereload.js?snipver=1';
}

/**
 * Implements hook_css_alter().
 *
 * Force CSS to be added with link tags, rather than @import.
 */
function livereload_css_alter(&$css, AttachedAssetsInterface $assets) {
  if (\Drupal::currentUser()->hasPermission('use livereload') && \Drupal::config('livereload.settings')->get('livereload_css')) {
    foreach ($css as $key => $value) {
      $css[$key]['preprocess'] = FALSE;
    }
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Add the possibility to en- and disable the livereload.js.
 */
function livereload_form_system_performance_settings_alter(&$form, FormStateInterface $form_state, $form_id) {
  $form['livereload'] = array(
    '#type' => 'fieldset',
    '#title' => 'LiveReload',
  );
  $form['livereload']['livereload_js'] = array(
    '#type' => 'checkbox',
    '#title' => t('Add livereload.js. <em>Note: this will only work if css aggregation is disabled.</em>'),
    '#default_value' => \Drupal::config('livereload.settings')->get('livereload_js'),
    '#disabled' => FALSE,
  );
  $form['livereload']['livereload_css'] = array(
    '#type' => 'checkbox',
    '#title' => t('Force CSS to be added with link tags, rather than @import. <em>Note: if this option is enabled, the "%aggregate_css" functionallity of Drupal will not work.</em>', array('%aggregate_css' => t('Aggregate and compress CSS files.'))),
    '#default_value' => \Drupal::config('livereload.settings')->get('livereload_css'),
    '#disabled' => FALSE,
  );

  // Add submit handler to save contact configuration.
  $form['#submit'][] = 'livereload_form_system_performance_settings_submit';
}

/**
 * @see livereload_form_system_performance_settings_alter()
 */
function livereload_form_system_performance_settings_submit($form, FormStateInterface &$form_state) {
  \Drupal::configFactory()->getEditable('livereload.settings')
    ->set('livereload_js', $form_state->getValue('livereload_js'))
    ->set('livereload_css', $form_state->getValue('livereload_css'))
    ->save();
}

/**
 * Implements hook_library_info_alter().
 */
function livereload_library_info_alter(&$libraries, $extension) {
  if ($extension === 'livereload' && isset($libraries['drupal.livereload'])) {
    $libraries['drupal.livereload']['js'][livereload_get_path()] = [];
  }
}