<?php

namespace Drupal\bb2b_order\Plugin\views\filter;

use Drupal\Core\Form\FormStateInterface;
use Drupal\views\Plugin\views\filter\FilterPluginBase;

/**
 * Filter products by stock status.
 *
 * @ingroup views_filter_handlers
 *
 * @ViewsFilter("stock_status")
 */
class StockStatus extends FilterPluginBase {

  /**
   * {@inheritDoc}
   */
  public function acceptExposedInput($input) {
    return TRUE;
  }

  /**
   * {@inheritDoc}
   */
  public function buildExposedForm(&$form, FormStateInterface $form_state) {
    if (empty($this->options['exposed'])) {
      return;
    }
    $identifier = $this->options['expose']['identifier'];
    $exposed_input = $this->view->getExposedInput();
    $options = [
      NULL => t('Show all products'),
      'only_available' => t('Show only available products'),
    ];

    $form[$identifier] = [
      '#type' => 'select',
      '#title' => t('Stock status'),
      '#options' => $options,
      '#default_value' => $exposed_input,
    ];
    return $form;
  }

  /**
   * {@inheritDoc}
   */
  public function query() {
    /** @var \Drupal\views\Plugin\views\query\Sql $query */
    $query = $this->query;
    $stock_status = $this->view->getExposedInput();
    if (isset($stock_status['stock_status']) && $stock_status['stock_status'] === 'only_available') {
      $query->addWhereExpression($this->options['group'], "commerce_product_field_data.stock > 0");
    }
  }

}