<?php

/**
 * @file
 * Adds autocomplete capabilities for Search API searches.
 */

use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;
use Drupal\search_api\Plugin\views\query\SearchApiQuery;
use Drupal\search_api_autocomplete\Search\SearchPluginDeriverBase;
use Drupal\search_api_page\SearchApiPageInterface;
use Drupal\views\ViewEntityInterface;

/**
 * Implements hook_theme().
 */
function search_api_autocomplete_theme() {
  $themes['search_api_autocomplete_suggestion'] = [
    'variables' => [
      'keys' => NULL,
      'url' => NULL,
      'label' => NULL,
      'note' => NULL,
      'results_count' => NULL,
      'suggestion_prefix' => '',
      'suggestion_suffix' => '',
      'user_input' => '',
    ],
  ];

  return $themes;
}

/**
 * Implements hook_entity_operation().
 */
function search_api_autocomplete_entity_operation(EntityInterface $entity) {
  if ($entity->getEntityTypeId() != 'search_api_index') {
    return [];
  }

  $operations = [];
  $operations['autocomplete'] = [
    'title' => t('Autocomplete'),
    'weight' => 30,
    'url' => Url::fromRoute('search_api_autocomplete.admin_overview', ['search_api_index' => $entity->id()]),
  ];
  return $operations;
}

/**
 * Implements hook_hook_info().
 *
 * Allows other modules to place all their hook implementations for this module
 * into a "MODULE.search_api_autocomplete.inc" file.
 */
function search_api_autocomplete_hook_info() {
  $hooks = [
    'search_api_autocomplete_suggestions_alter',
    'search_api_autocomplete_suggester_info_alter',
    'search_api_autocomplete_search_info_alter',
    'search_api_autocomplete_views_fulltext_fields_alter',
  ];
  $info = [
    'group' => 'search_api_autocomplete',
  ];
  return array_fill_keys($hooks, $info);
}

/**
 * Implements hook_form_FORM_ID_alter() for "views_exposed_form".
 *
 * Adds autocompletion to input fields for fulltext keywords on views with
 * exposed filters.
 *
 * @see \Drupal\views\Form\ViewsExposedForm
 * @see \Drupal\search_api_autocomplete\Plugin\search_api_autocomplete\search\Views
 */
function search_api_autocomplete_form_views_exposed_form_alter(array &$form, FormStateInterface $form_state) {
  /** @var \Drupal\views\ViewExecutable $view */
  $view = $form_state->get('view');
  if (substr($view->storage->get('base_table'), 0, 17) != 'search_api_index_') {
    return;
  }

  $plugin_id = 'views:' . $view->id();
  $cache_tag = "search_api_autocomplete_search_list:$plugin_id";
  if (!isset($form['#cache']['tags'])
      || !in_array($cache_tag, $form['#cache']['tags'])) {
    $form['#cache']['tags'][] = $cache_tag;
  }

  /** @var \Drupal\search_api_autocomplete\Entity\SearchStorage $search_storage */
  $search_storage = \Drupal::entityTypeManager()
    ->getStorage('search_api_autocomplete_search');
  $search = $search_storage->loadBySearchPlugin($plugin_id);
  if (!$search || !$search->status()) {
    return;
  }

  $config = $search->getSearchPlugin()->getConfiguration();
  $selected = in_array($view->current_display, $config['displays']['selected']);
  // @todo Replace with \Drupal\search_api\Utility\Utility::matches() once
  //   we can use it (Search API 1.8 dependency).
  if ($selected == $config['displays']['default']) {
    return;
  }

  $fields = $search->getIndex()->getFulltextFields();
  if (!$fields) {
    return;
  }
  // Add the "Search: Fulltext search" filter as another text field.
  $fields[] = 'search_api_fulltext';

  \Drupal::moduleHandler()->alter('search_api_autocomplete_views_fulltext_fields', $fields, $search, $view);

  $base_data = [
    'display' => $view->current_display,
    'arguments' => $view->args,
  ];

  foreach ($view->filter as $filter_name => $filter) {
    if (!in_array($filter->realField, $fields)
        || empty($filter->options['expose']['identifier'])) {
      continue;
    }
    $key = $filter->options['expose']['identifier'];

    if (isset($form[$key])) {
      $element = &$form[$key];
    }
    elseif (isset($form[$key . '_wrapper'][$key])) {
      $element = &$form[$key . '_wrapper'][$key];
    }
    else {
      continue;
    }
    $data = $base_data;

    // The Views filter for individual fulltext fields uses a nested "value"
    // field for the real input, due to Views internals.
    if (!empty($element['value'])) {
      $element = &$element['value'];
      // In this case, we also need to manually pass the fulltext fields, so
      // they will be applied properly.
      $data['field'] = $filter->realField;
    }

    if (isset($element['#type']) && $element['#type'] === 'textfield') {
      $data['filter'] = $key;
      \Drupal::getContainer()
        ->get('search_api_autocomplete.helper')
        ->alterElement($element, $search, $data);
    }

    unset($element);
  }
}

/**
 * Implements hook_form_BASE_FORM_ID_alter() for "search_api_page_block_form".
 *
 * Adds autocompletion to the keywords field on search pages, if enabled by the
 * user.
 *
 * @see \Drupal\search_api_page\Form\SearchApiPageBlockForm
 * @see \Drupal\search_api_autocomplete\Plugin\search_api_autocomplete\search\Page
 */
function search_api_autocomplete_form_search_api_page_block_form_alter(array &$form, FormStateInterface $form_state, $form_id) {
  $page_id = substr($form_id, strlen('search_api_page_block_form_'));
  /** @var \Drupal\search_api_autocomplete\Entity\SearchStorage $search_storage */
  $search_storage = \Drupal::entityTypeManager()
    ->getStorage('search_api_autocomplete_search');
  $plugin_id = 'page:' . $page_id;
  $search = $search_storage->loadBySearchPlugin($plugin_id);

  $cache_tag = "search_api_autocomplete_search_list:$plugin_id";
  if (!isset($form['#cache']['tags'])
      || !in_array($cache_tag, $form['#cache']['tags'])) {
    $form['#cache']['tags'][] = $cache_tag;
  }

  if ($search && $search->status()) {
    \Drupal::getContainer()
      ->get('search_api_autocomplete.helper')
      ->alterElement($form['keys'], $search);
  }
}

/**
 * Implements hook_ENTITY_TYPE_insert() for type "view".
 *
 * Clear the search plugin definitions cache when new search views are created.
 * Could use better support from the Plugin API – see #2633878.
 */
function search_api_autocomplete_view_insert(ViewEntityInterface $view) {
  if (SearchApiQuery::getIndexFromTable($view->get('base_table'))) {
    \Drupal::getContainer()
      ->get('plugin.manager.search_api_autocomplete.search')
      ->clearCachedDefinitions();
    SearchPluginDeriverBase::resetStaticDerivativeCaches('views');
  }
}

/**
 * Implements hook_ENTITY_TYPE_delete() for type "view".
 *
 * Clear the search plugin definitions cache when search views are deleted.
 * Could use better support from the Plugin API – see #2633878.
 */
function search_api_autocomplete_view_delete(ViewEntityInterface $view) {
  if (SearchApiQuery::getIndexFromTable($view->get('base_table'))) {
    \Drupal::getContainer()
      ->get('plugin.manager.search_api_autocomplete.search')
      ->clearCachedDefinitions();
    SearchPluginDeriverBase::resetStaticDerivativeCaches('views');
  }
}

/**
 * Implements hook_ENTITY_TYPE_insert() for type "search_api_page".
 *
 * Clear the search plugin definitions cache when search pages are created.
 * Could use better support from the Plugin API – see #2633878.
 */
function search_api_autocomplete_search_api_page_insert(SearchApiPageInterface $page) {
  \Drupal::getContainer()
    ->get('plugin.manager.search_api_autocomplete.search')
    ->clearCachedDefinitions();
  SearchPluginDeriverBase::resetStaticDerivativeCaches('page');
}

/**
 * Implements hook_ENTITY_TYPE_delete() for type "search_api_page".
 *
 * Clear the search plugin definitions cache when search pages are deleted.
 * Could use better support from the Plugin API – see #2633878.
 */
function search_api_autocomplete_search_api_page_delete(SearchApiPageInterface $page) {
  \Drupal::getContainer()
    ->get('plugin.manager.search_api_autocomplete.search')
    ->clearCachedDefinitions();
  SearchPluginDeriverBase::resetStaticDerivativeCaches('page');
}