<?php

namespace Drupal\views\Plugin\views\sort;

use Drupal\Core\Cache\Cache;
use Drupal\Core\Cache\CacheableDependencyInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\views\Plugin\views\HandlerBase;

/**
 * @defgroup views_sort_handlers Views sort handler plugins
 * @{
 * Plugins that handle sorting for Views.
 *
 * Sort handlers extend \Drupal\views\Plugin\views\sort:SortPluginBase. They
 * must be annotated with \Drupal\views\Annotation\ViewsSort annotation, and
 * they must be in plugin directory Plugin\views\sort.
 *
 * @ingroup views_plugins
 * @see plugin_api
 */

/**
 * Base sort handler that has no options and performs a simple sort.
 */
abstract class SortPluginBase extends HandlerBase implements CacheableDependencyInterface {

  /**
   * Determine if a sort can be exposed.
   */
  public function canExpose() {
    return TRUE;
  }

  /**
   * Called to add the sort to a query.
   */
  public function query() {
    $this->ensureMyTable();
    // Add the field.
    $this->query->addOrderBy($this->tableAlias, $this->realField, $this->options['order']);
  }

  protected function defineOptions() {
    $options = parent::defineOptions();

    $options['order'] = ['default' => 'ASC'];
    $options['exposed'] = ['default' => FALSE];
    $options['expose'] = [
      'contains' => [
        'label' => ['default' => ''],
        'field_identifier' => ['default' => ''],
      ],
    ];
    return $options;
  }

  /**
   * Display whether or not the sort order is ascending or descending.
   */
  public function adminSummary() {
    if (!empty($this->options['exposed'])) {
      return $this->t('Exposed');
    }
    switch ($this->options['order']) {
      case 'ASC':
      case 'asc':
      default:
        return $this->t('asc');

      case 'DESC';
      case 'desc';
        return $this->t('desc');
    }
  }

  /**
   * Basic options for all sort criteria.
   */
  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
    parent::buildOptionsForm($form, $form_state);
    if ($this->canExpose()) {
      $this->showExposeButton($form, $form_state);
    }
    $form['op_val_start'] = ['#value' => '<div class="clearfix">'];
    $this->showSortForm($form, $form_state);
    $form['op_val_end'] = ['#value' => '</div>'];
    if ($this->canExpose()) {
      $this->showExposeForm($form, $form_state);
    }
  }

  /**
   * Shortcut to display the expose/hide button.
   */
  public function showExposeButton(&$form, FormStateInterface $form_state) {
    $form['expose_button'] = [
      '#prefix' => '<div class="views-expose clearfix">',
      '#suffix' => '</div>',
      // Should always come first
      '#weight' => -1000,
    ];

    // Add a checkbox for JS users, which will have behavior attached to it
    // so it can replace the button.
    $form['expose_button']['checkbox'] = [
      '#theme_wrappers' => ['container'],
      '#attributes' => ['class' => ['js-only']],
    ];
    $form['expose_button']['checkbox']['checkbox'] = [
      '#title' => $this->t('Expose this sort to visitors, to allow them to change it'),
      '#type' => 'checkbox',
    ];

    // Then add the button itself.
    if (empty($this->options['exposed'])) {
      $form['expose_button']['markup'] = [
        '#markup' => '<div class="description exposed-description" style="float: left; margin-right:10px">' . $this->t('This sort is not exposed. Expose it to allow the users to change it.') . '</div>',
      ];
      $form['expose_button']['button'] = [
        '#limit_validation_errors' => [],
        '#type' => 'submit',
        '#value' => $this->t('Expose sort'),
        '#submit' => [[$this, 'displayExposedForm']],
      ];
      $form['expose_button']['checkbox']['checkbox']['#default_value'] = 0;
    }
    else {
      $form['expose_button']['markup'] = [
        '#markup' => '<div class="description exposed-description">' . $this->t('This sort is exposed. If you hide it, users will not be able to change it.') . '</div>',
      ];
      $form['expose_button']['button'] = [
        '#limit_validation_errors' => [],
        '#type' => 'submit',
        '#value' => $this->t('Hide sort'),
        '#submit' => [[$this, 'displayExposedForm']],
      ];
      $form['expose_button']['checkbox']['checkbox']['#default_value'] = 1;
    }
  }

  /**
   * Simple validate handler.
   */
  public function validateOptionsForm(&$form, FormStateInterface $form_state) {
    $this->sortValidate($form, $form_state);
    if (!empty($this->options['exposed'])) {
      $this->validateExposeForm($form, $form_state);
    }

  }

  /**
   * Simple submit handler.
   */
  public function submitOptionsForm(&$form, FormStateInterface $form_state) {
    // Do not store this values.
    $form_state->unsetValue('expose_button');

    $this->sortSubmit($form, $form_state);
    if (!empty($this->options['exposed'])) {
      $this->submitExposeForm($form, $form_state);
    }
  }

  /**
   * Shortcut to display the value form.
   */
  protected function showSortForm(&$form, FormStateInterface $form_state) {
    $options = $this->sortOptions();
    if (!empty($options)) {
      $form['order'] = [
        '#title' => $this->t('Order', [], ['context' => 'Sort order']),
        '#type' => 'radios',
        '#options' => $options,
        '#default_value' => $this->options['order'],
      ];
    }
  }

  protected function sortValidate(&$form, FormStateInterface $form_state) {}

  public function sortSubmit(&$form, FormStateInterface $form_state) {}

  /**
   * Provide a list of options for the default sort form.
   *
   * Should be overridden by classes that don't override sort_form
   */
  protected function sortOptions() {
    return [
      'ASC' => $this->t('Sort ascending'),
      'DESC' => $this->t('Sort descending'),
    ];
  }

  public function buildExposeForm(&$form, FormStateInterface $form_state) {
    // #flatten will move everything from $form['expose'][$key] to $form[$key]
    // prior to rendering. That's why the preRender for it needs to run first,
    // so that when the next preRender (the one for fieldsets) runs, it gets
    // the flattened data.
    array_unshift($form['#pre_render'], [static::class, 'preRenderFlattenData']);
    $form['expose']['#flatten'] = TRUE;

    $form['expose']['label'] = [
      '#type' => 'textfield',
      '#default_value' => $this->options['expose']['label'],
      '#title' => $this->t('Label'),
      '#required' => TRUE,
      '#size' => 40,
      '#weight' => -1,
    ];

    $form['expose']['field_identifier'] = [
      '#type' => 'textfield',
      '#default_value' => $this->options['expose']['field_identifier'],
      '#title' => $this->t('Sort field identifier'),
      '#required' => TRUE,
      '#size' => 40,
      '#description' => $this->t("This will appear in the URL after the ?, as value of 'sort_by' parameter, to identify this sort field. Cannot be blank. Only letters, digits and the dot ('.'), hyphen ('-'), underscore ('_'), and tilde ('~') characters are allowed."),
    ];
  }

  /**
   * Validate the options form.
   */
  public function validateExposeForm($form, FormStateInterface $form_state) {
    $field_identifier = $form_state->getValue([
      'options',
      'expose',
      'field_identifier',
    ]);
    if (!preg_match('/^[a-zA-Z][a-zA-Z0-9_~.\-]*$/', $field_identifier)) {
      $form_state->setErrorByName('expose][field_identifier', $this->t('This identifier has illegal characters.'));
      return;
    }

    // Validate that the sort field identifier is unique within the sort
    // handlers. Note that the sort field identifier is different that other
    // identifiers because it is used as a query string value of the 'sort_by'
    // parameter, while the others are used as query string parameter keys.
    // Therefore we can have a sort field identifier be the same as an exposed
    // filter identifier. This prevents us from using
    // DisplayPluginInterface::isIdentifierUnique() to test for uniqueness.
    // @see \Drupal\views\Plugin\views\display\DisplayPluginInterface::isIdentifierUnique()
    foreach ($this->view->display_handler->getHandlers('sort') as $key => $handler) {
      if ($handler->canExpose() && $handler->isExposed()) {
        if ($form_state->get('id') !== $key && isset($handler->options['expose']['field_identifier']) && $field_identifier === $handler->options['expose']['field_identifier']) {
          $form_state->setErrorByName('expose][field_identifier', $this->t('This identifier is already used by %label sort handler.', [
            '%label' => $handler->adminLabel(TRUE),
          ]));
          return;
        }
      }
    }
  }

  /**
   * {@inheritdoc}
   */
  public static function trustedCallbacks() {
    $callbacks = parent::trustedCallbacks();
    $callbacks[] = 'preRenderFlattenData';
    return $callbacks;
  }

  /**
   * Provide default options for exposed sorts.
   */
  public function defaultExposeOptions() {
    $this->options['expose'] = [
      'label' => $this->definition['title'],
      'field_identifier' => $this->options['id'],
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function getCacheMaxAge() {
    // The result of a sort does not depend on outside information, so by
    // default it is cacheable.
    return Cache::PERMANENT;
  }

  /**
   * {@inheritdoc}
   */
  public function getCacheContexts() {
    $cache_contexts = [];
    // Exposed sorts use GET parameters, so it depends on the current URL.
    if ($this->isExposed()) {
      $cache_contexts[] = 'url.query_args:sort_by';
    }
    return $cache_contexts;
  }

  /**
   * {@inheritdoc}
   */
  public function getCacheTags() {
    return [];
  }

}

/**
 * @}
 */
