import 'package:logging/logging.dart';
import 'package:nc_photos/account.dart';
import 'package:nc_photos/connectivity_util.dart' as connectivity_util;
import 'package:nc_photos/entity/album.dart';
import 'package:nc_photos/entity/exif.dart';
import 'package:nc_photos/entity/file.dart';
import 'package:nc_photos/entity/file/data_source.dart';
import 'package:nc_photos/mobile/platform.dart'
    if (dart.library.html) 'package:nc_photos/web/platform.dart' as platform;
import 'package:nc_photos/use_case/scan_missing_metadata.dart';
import 'package:nc_photos/use_case/update_metadata.dart';

class UpdateMissingMetadata {
  UpdateMissingMetadata(this.fileRepo);

  /// Update metadata for all files that support one under a dir recursively
  ///
  /// Dirs with a .nomedia/.noimage file will be ignored. The returned stream
  /// would emit either File data (for each updated files) or an exception
  Stream<dynamic> call(Account account, File root) async* {
    final dataStream = ScanMissingMetadata(fileRepo)(account, root);
    final metadataLoader = platform.MetadataLoader();
    await for (final d in dataStream) {
      if (d is Exception || d is Error) {
        yield d;
        continue;
      }
      final File file = d;
      try {
        // since we need to download multiple images in their original size,
        // we only do it with WiFi
        await connectivity_util.waitUntilWifi();
        if (!shouldRun) {
          return;
        }
        _log.fine("[call] Updating metadata for ${file.path}");
        final metadata = await metadataLoader.loadFile(account, file);
        int imageWidth, imageHeight;
        Exif exif;
        if (metadata.containsKey("resolution")) {
          imageWidth = metadata["resolution"]["width"];
          imageHeight = metadata["resolution"]["height"];
        }
        if (metadata.containsKey("exif")) {
          exif = Exif(metadata["exif"]);
        }
        final metadataObj = Metadata(
          fileEtag: file.etag,
          imageWidth: imageWidth,
          imageHeight: imageHeight,
          exif: exif,
        );

        await UpdateMetadata(FileRepo(FileCachedDataSource()),
            AlbumRepo(AlbumCachedDataSource()))(account, file, metadataObj);
        yield file;
      } catch (e, stacktrace) {
        _log.shout(
            "[call] Failed while getting metadata for ${file.contentType} file",
            e,
            stacktrace);
        yield e;
      }
    }
  }

  void stop() {
    shouldRun = false;
  }

  final FileRepo fileRepo;

  bool shouldRun = true;

  static final _log =
      Logger("use_case.update_missing_metadata.UpdateMissingMetadata");
}