<?php

declare(strict_types=1);

namespace Drupal\islandora_collection_harvest\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\File\FileSystemInterface;
use Drupal\flysystem\FlysystemFactory;
use Drupal\islandora\IslandoraUtils;
use Drupal\Core\TempStore\PrivateTempStoreFactory;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Form for selecting Collection and Media Use and preparing ZIP download.
 */
final class CollectionHarvestForm extends FormBase {

  protected EntityTypeManagerInterface $entityTypeManager;

  protected IslandoraUtils $utils;

  protected FileSystemInterface $fileSystem;

  protected FlysystemFactory $flysystemFactory;

  protected PrivateTempStoreFactory $tempStoreFactory;

  /**
   * {@inheritdoc}
   */
  public function __construct(
    EntityTypeManagerInterface $entity_type_manager,
    IslandoraUtils $utils,
    FileSystemInterface $file_system,
    FlysystemFactory $flysystem_factory,
    PrivateTempStoreFactory $temp_store_factory
  ) {
    $this->entityTypeManager = $entity_type_manager;
    $this->utils = $utils;
    $this->fileSystem = $file_system;
    $this->flysystemFactory = $flysystem_factory;
    $this->tempStoreFactory = $temp_store_factory;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container): self {
    return new self(
      $container->get('entity_type.manager'),
      $container->get('islandora.utils'),
      $container->get('file_system'),
      $container->get('flysystem_factory'),
      $container->get('tempstore.private')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function getFormId(): string {
    return 'islandora_collection_harvest_form';
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state): array {
    $term = $this->utils->getTermForUri('http://purl.org/dc/dcmitype/Collection');
    $collections = [];
    if ($term) {
      $query = $this->entityTypeManager->getStorage('node')->getQuery();
      $query->condition('type', 'islandora_object');
      $query->condition('field_model', $term->id(), 'IN');
      $query->accessCheck(FALSE);
      $nids = $query->execute();
      $nodes = $this->entityTypeManager->getStorage('node')
        ->loadMultiple($nids);
      foreach ($nodes as $node) {
        $collections[$node->id()] = $node->label();
      }
    }

    $vid = 'islandora_media_use';
    $terms = $this->entityTypeManager->getStorage('taxonomy_term')
      ->loadTree($vid);
    $media_use_options = [];
    foreach ($terms as $term) {
      $media_use_options[$term->tid] = $term->name;
    }

    $form['#attributes']['id'] = 'collection-harvest-form';
    $form['collection'] = [
      '#type' => 'select',
      '#title' => $this->t('Collection'),
      '#options' => $collections,
      '#required' => TRUE,
    ];

    $form['media_use'] = [
      '#type' => 'select',
      '#title' => $this->t('Media Use'),
      '#options' => $media_use_options,
      '#required' => TRUE,
    ];

    $form['actions'] = [
      '#type' => 'actions',
      'submit' => [
        '#type' => 'submit',
        '#value' => $this->t('Build Download'),
        '#button_type' => 'primary',
      ],
    ];
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state): void {
    $collection_id = $form_state->getValue('collection');
    $media_use_tid = $form_state->getValue('media_use');

    $term = $this->entityTypeManager->getStorage('taxonomy_term')
      ->load($media_use_tid);
    if (!$term) {
      $this->messenger()->addError($this->t('Media use term not found.'));
      return;
    }

    // Load nodes in collection
    $query = $this->entityTypeManager->getStorage('node')->getQuery();
    $query->condition('type', 'islandora_object');
    $query->condition('field_member_of', $collection_id);
    $query->accessCheck(FALSE);
    $nids = $query->execute();

    $media_entities = [];
    foreach ($nids as $nid) {
      $node = $this->entityTypeManager->getStorage('node')->load($nid);
      $media = $this->utils->getMediaWithTerm($node, $term);
      if ($media) {
        $source_field = $media->getSource()
          ->getConfiguration()['source_field'] ?? NULL;
        if ($source_field && $media->hasField($source_field) && !$media->get($source_field)
            ->isEmpty()) {
          $media_entities[] = $media;
        }
      }
    }

    if (empty($media_entities)) {
      $this->messenger()
        ->addError($this->t('No media found for this collection.'));
      return;
    }

    // Store in tempstore
    $temp_store = $this->tempStoreFactory->get('islandora_collection_harvest');
    $zip_filename = 'collection_' . time() . '.zip';
    $temp_store->set($zip_filename, $media_entities);
    $this->messenger()
      ->addStatus($this->t('Your ZIP download has been initiated. Please wait for the download to start.'));

    // Redirect to download route
    $form_state->setRedirect('islandora_collection_harvest.download_zip', ['filename' => $zip_filename]);
  }

}