<?php

namespace Drupal\reinstall\Plugin\migrate\source;

use Drupal\Component\Plugin\ConfigurablePluginInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Drupal\migrate\MigrateException;
use Drupal\migrate\Plugin\migrate\source\SourcePluginBase;
use Drupal\migrate\Plugin\MigrationInterface;
use Drupal\migrate\Row;
use Drupal\reinstall\ReinstallEvents;
use Drupal\reinstall\SourceEvent;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
use Symfony\Component\Yaml\Exception\ParseException;
use Symfony\Component\Yaml\Yaml;

/**
 * Class SimpleSource provides the basic mechanisms to load a YML entity dump.
 *
 * @MigrateSource(
 *   id = "reinstall_base"
 * )
 */
class ReinstallSourceBase extends SourcePluginBase implements ContainerFactoryPluginInterface, ConfigurablePluginInterface {
  use SimpleSourceTrait;

  /**
   * The event_dispatcher service.
   *
   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
   */
  protected $eventDispatcher;

  /**
   * The source records.
   *
   * MAY be altered by subscribing to MigrateEvents::PRE_IMPORT.
   *
   * @var array
   */
  public $records;

  /**
   * ReinstallSourceBase constructor.
   *
   * @param array $configuration
   *   The plugin configuration.
   * @param string $plugin_id
   *   The plugin id.
   * @param mixed $plugin_definition
   *   The plugin definition.
   * @param \Drupal\migrate\Plugin\MigrationInterface $migration
   *   The migration on which the plugin is invoked.
   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $eventDispatcher
   *   The event_dispatcher service.
   */
  public function __construct(
    array $configuration,
    $plugin_id,
    $plugin_definition,
    MigrationInterface $migration,
    EventDispatcherInterface $eventDispatcher
  ) {
    parent::__construct($configuration, $plugin_id, $plugin_definition, $migration);
    $this->eventDispatcher = $eventDispatcher;
    $this->records = array_map([$this, 'flattenRecord'], $this->initialParse($configuration));
    $eventDispatcher->dispatch(ReinstallEvents::POST_SOURCE_PARSE, new SourceEvent($this));
  }

  /**
   * {@inheritdoc}
   */
  public static function create(
    ContainerInterface $container,
    array $configuration,
    $pluginId,
    $pluginDefinition,
    MigrationInterface $migration = NULL
  ) {
    $importPath = $container->getParameter('reinstall.path');
    $configuration['importPath'] = $importPath;
    $dispatcher = $container->get('event_dispatcher');
    return new static($configuration, $pluginId, $pluginDefinition, $migration, $dispatcher);
  }

  /**
   * {@inheritdoc}
   */
  public function doCount() {
    return count($this->records);
  }

  /**
   * Flatten the field hierarchy. Not correct for all cases.
   *
   * @param array $record
   *   The raw source values.
   *
   * @return array
   *   The flattened values.
   *
   * @see \Drupal\reinstall\Plugin\migrate\process\TermParent
   */
  protected function flattenRecord(array $record) {
    $row = new Row($record);
    $this->flattenRow($row);
    return $row->getSource();
  }

  /**
   * Flatten a typical Drupal 8 field array to a 1-level array.
   */
  protected function flattenRow(Row $row) {
    $source = $row->getSource();
    foreach ($source as $key => &$item_list) {
      if (is_scalar($item_list)) {
        continue;
      }
      if (count($item_list) > 1) {
        $item = $item_list;
      }
      else {
        $item = reset($item_list);
      }

      // Handle bundle['target_id']
      // Exclude image field to keep metadata (alt / title)
      if (isset($item['target_id']) && !isset($item['alt']) && !isset($item['title'])) {
        $value = $item['target_id'];
      }
      elseif (is_scalar($item) || (count($item) != 1 && !isset($item['width']) && !isset($item['pid']))) {
        $value = $item;
      }
      elseif (isset($item['value'])) {
        $value = $item['value'];
      }
      elseif (isset($item['pid'])) {
        $value = $item['alias'];
      }
      else {
        $value = $item;
      }

      if (empty($item)) {
        $value = NULL;
      }
      $row->setSourceProperty($key, $value);
    }
  }

  /**
   * {@inheritdoc}
   */
  protected function initializeIterator() {
    if (!isset($this->iterator)) {
      $this->iterator = new \ArrayIterator($this->records);
    }
    return $this->iterator;
  }

  /**
   * Load then parse the file requested in configuration and return its records.
   *
   * @param array $configuration
   *   The source configuration from the migration source section.
   * @param string $key
   *   Optional. A top-level key for the source document. If empty, items will
   *   be parsed from the root of the source document.
   *
   * @return array
   *   An array of entity descriptions.
   *
   * @throws \Drupal\migrate\MigrateException
   */
  protected function initialParse(array $configuration, string $key = NULL) {
    $this->sstEntityType = $type = $configuration['type'];
    $bundle = $configuration['bundle'];

    $baseFilePath = $this->configuration['file'] ?? "${type}/${bundle}.yml";

    $importPath = $configuration['importPath'] ?? NULL;
    $filePath = "$importPath/$baseFilePath";
    $realPath = realpath($filePath);
    if (!is_file($realPath) || !is_readable($realPath)) {
      throw new MigrateException("${filePath} is not a readable file.");
    }

    try {
      $raw = file_get_contents($filePath);
      $data = Yaml::parse($raw);
    }
    catch (ParseException $e) {
      throw new MigrateException("Cannot parse the contents of ${filePath}.");
    }

    if ($key) {
      return $data[$key] ?? [];
    }

    return $data ?? [];
  }

  /**
   * {@inheritdoc}
   */
  public function __toString() {
    $current = $this->getIterator()->current();
    $ret = json_encode($current, JSON_PRETTY_PRINT);
    return $ret;
  }

  /**
   * Gets this plugin's configuration.
   *
   * @return array
   *   An array of this plugin's configuration.
   */
  public function getConfiguration() {
    return $this->configuration;
  }

  /**
   * Sets the configuration for this plugin instance.
   *
   * @param array $configuration
   *   An associative array containing the plugin's configuration.
   */
  public function setConfiguration(array $configuration) {
    $this->configuration = $configuration;
  }

  /**
   * Gets default configuration for this plugin.
   *
   * @return array
   *   An associative array with the default configuration.
   */
  public function defaultConfiguration() {
    return [];
  }

  /**
   * Calculates dependencies for the configured plugin.
   *
   * Dependencies are saved in the plugin's configuration entity and are used to
   * determine configuration synchronization order. For example, if the plugin
   * integrates with specific user roles, this method should return an array of
   * dependencies listing the specified roles.
   *
   * @return array
   *   An array of dependencies grouped by type (config, content, module,
   *   theme). For example:
   *
   * @code
   *   array(
   *     'config' => array('user.role.anonymous', 'user.role.authenticated'),
   *     'content' => array('node:article:f0a189e6-55fb-47fb-8005-5bef81c44d6d'),
   *     'module' => array('node', 'user'),
   *     'theme' => array('seven'),
   *   );
   * @endcode
   *
   * @see \Drupal\Core\Config\Entity\ConfigDependencyManager
   * @see \Drupal\Core\Entity\EntityInterface::getConfigDependencyName()
   */
  public function calculateDependencies() {
    return [];
  }

}