<?php

/**
 * @file
 * Contains draggableviews.module.
 */

use Drupal\draggableviews\DraggableViews;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Database\Database;
use Drupal\Core\Cache\Cache;

/**
 * Implements hook_views_data_alter().
 */
function draggableviews_views_data_alter(&$data) {
  $data['draggableviews_structure']['weight'] = [
    'title' => t('DraggableViews Weight'),
    'group' => t('Draggableviews'),
    'help' => t('Display the weight value.'),
    'field' => [
      'id' => 'numeric',
    ],
    'sort' => [
      'id' => 'standard',
    ],
    'filter' => [
      'help' => t('Filter by the draggableviews weight value (Native handler only).'),
      'id' => 'numeric',
    ],
    'argument' => [
      'id' => 'numeric',
    ],
  ];
  $data['draggableviews_structure']['parent'] = [
    'title' => t('Parent'),
    'help' => t('The parent entity id.'),
    'group' => t('Draggableviews'),
    'field' => [
      'id' => 'numeric',
    ],
    'filter' => [
      'help' => t("Filter by the draggableviews parent's entity id (Native handler only)."),
      'id' => 'numeric',
    ],
    'argument' => [
      'id' => 'numeric',
    ],
  ];

  foreach (\Drupal::entityTypeManager()->getDefinitions() as $entity_type) {
    $base_table = $entity_type->getDataTable() ?: $entity_type->getBaseTable();
    $entity_keys = $entity_type->getKeys();
    if ($base_table && isset($data[$base_table]['table'])) {
      $data[$base_table]['draggableviews'] = [
        'title' => $data[$base_table]['table']['group'],
        'group' => t('Draggableviews'),
        'help' => t('Provide a draggable functionality.'),
        'entity field' => $entity_keys['id'],
        'field' => [
          'id' => 'draggable_views_field',
          'click sortable' => FALSE,
        ],
      ];
      // Explain to every entity how to join with draggableviews_structure
      // table.
      $data['draggableviews_structure']['table']['join'][$base_table] = [
        'handler' => 'draggableviews_join_handler',
        // Because this is a direct link it could be left out.
        'left_table' => $base_table,
        'left_field' => $entity_keys['id'],
        'field' => 'entity_id',
      ];
    }
  }
}

/**
 * Implements hook_preprocess_views_view_table().
 */
function draggableviews_preprocess_views_view_table(&$variables) {
  $view = $variables['view'];

  // If this view is not the sort view, then stop here.
  if (!isset($view->field['draggableviews'])) {
    return;
  }

  $draggableviews = new DraggableViews($variables['view']);

  // Add hierarchy.
  foreach ($variables['rows'] as $key => $row) {
    $columns = array_keys($row['columns']);
    // Find the first column that is not the draggableviews field.
    do {
      $first_column = current($columns);
      if ($first_column !== 'draggableviews') {
        break;
      }
      // Set the first column.
      $first_column = each($columns);
    } while ($first_column);

    // Indent the first column that is not the draggableviews field.
    $columns_title = $row['columns'][$first_column]['content'][0]['field_output']['#markup'];
    $indent = [
      '#theme' => 'indentation',
      '#size' => $draggableviews->getDepth($key),
    ];
    $variables['rows'][$key]['columns'][$first_column]['content'][0]['field_output']['#markup'] = (string) (render($indent) . $columns_title);
  }

  // Add table attributes.
  $variables['attributes']['id'] = $draggableviews->getHtmlId();

  // Add rows attributes.
  foreach ($variables['rows'] as &$row) {
    $row['attributes']->addClass('draggable');
  }
  unset($row);
}

/**
 * Implements hook_form_alter().
 */
function draggableviews_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  // Filter the right form.
  if (strpos($form_id, 'views_form_') === FALSE) {
    return;
  }

  // Check whether the view is draggable.
  $view = $form_state->getBuildInfo()['args'][0];
  if (!isset($view->field['draggableviews'])) {
    return;
  }

  // Remove default submit button.
  $form['actions']['submit']['#access'] = FALSE;

  if (\Drupal::currentUser()->hasPermission('access draggableviews')) {
    // Create draggableviews save order button.
    $form['actions']['save_order'] = [
      '#value' => t('Save order'),
      '#type' => 'submit',
    ];
  }

  // If there is no results remove the save-order button.
  if (!isset($form['draggableviews'][0])) {
    $form['actions']['save_order']['#access'] = FALSE;
    return;
  }

  $form['actions']['save_order']['#submit'][] = 'draggableviews_views_submit';
}

/**
 * Submit handler.
 */
function draggableviews_views_submit(&$form, FormStateInterface $form_state) {
  $input = $form_state->getUserInput();

  /** @var \Drupal\views\ViewExecutable $view */
  $view = $form_state->getBuildInfo()['args'][0];
  $view_name = $view->id();
  $view_display = $view->current_display;

  $weight = 0;

  $connection = Database::getConnection();
  $transaction = $connection->startTransaction();
  try {
    foreach ($input['draggableviews'] as $item) {
      // Remove old data.
      $connection->delete('draggableviews_structure')
        ->condition('view_name', $view_name)
        ->condition('view_display', $view_display)
        ->condition('entity_id', $item['id'])
        ->execute();

      // Add new data.
      $record = [
        'view_name' => $view_name,
        'view_display' => $view_display,
        'args' => '[]',
        'entity_id' => $item['id'],
        'weight' => $weight,
      ];
      // Save parent if exists.
      if (isset($item['parent'])) {
        $record['parent'] = $item['parent'];
      }
      $connection->insert('draggableviews_structure')->fields($record)->execute();
      $weight++;
    }
    // We invalidate the entity list cache, so other views are also aware of the
    // cache.
    $views_entity_table_info = $view->query->getEntityTableInfo();
    // Find the entity type used by the view.
    $result = array_keys(array_filter($views_entity_table_info, function ($info) {
      return $info['relationship_id'] == 'none';
    }));
    $entity_type_id = reset($result);
    $list_cache_tags = \Drupal::entityTypeManager()->getDefinition($entity_type_id)->getListCacheTags();
    Cache::invalidateTags($list_cache_tags);
  }
  catch (\Exception $e) {
    $transaction->rollback();
    \Drupal::logger('draggableviews')->error('Failed with @message', ['@message' => $e->getMessage()]);
    drupal_set_message(t('There was an error while saving the data. Please, try gain.'), 'warning');
  }
}