// ignore_for_file: invalid_use_of_protected_member, invalid_use_of_visible_for_testing_member

part of 'chat_bloc.dart';

extension _ChatBlocAttachments on ChatBloc {
  void _syncUploadedAttachments({
    required String messageId,
    required List<UploadedAttachment> uploadedAttachments,
  }) {
    if (uploadedAttachments.isEmpty) {
      _markAttachmentUploadDone(messageId);
      return;
    }
    final items = state.items.map((item) {
      if (item is! TextMessageItem || item.id != messageId) {
        return item;
      }
      final synced = item.attachments.map((attachment) {
        final localPath = attachment['path'];
        if (localPath is! String || localPath.isEmpty) {
          return <String, dynamic>{...attachment, 'uploading': false};
        }
        UploadedAttachment? matched;
        for (final candidate in uploadedAttachments) {
          if (candidate.localPath == localPath) {
            matched = candidate;
            break;
          }
        }
        if (matched == null) {
          return <String, dynamic>{...attachment, 'uploading': false};
        }
        return <String, dynamic>{
          ...attachment,
          'url': matched.url,
          'mimeType': matched.mimeType,
          'uploading': false,
        };
      }).toList();
      return item.copyWith(attachments: synced);
    }).toList();
    emit(state.copyWith(items: items));
  }

  void _markAttachmentUploadDone(String messageId) {
    final items = state.items.map((item) {
      if (item is! TextMessageItem || item.id != messageId) {
        return item;
      }
      final done = item.attachments
          .map(
            (attachment) => <String, dynamic>{
              ...attachment,
              'uploading': false,
            },
          )
          .toList();
      return item.copyWith(attachments: done);
    }).toList();
    emit(state.copyWith(items: items));
  }

  Future<Uint8List?> _loadAttachmentPreview(String previewPath) async {
    final cached = _attachmentPreviewCache[previewPath];
    if (cached != null) {
      return cached;
    }
    final pending = _attachmentPreviewInflight[previewPath];
    if (pending != null) {
      return pending;
    }

    final future = (() async {
      try {
        final bytes = await _service.fetchAttachmentPreview(previewPath);
        _attachmentPreviewCache[previewPath] = bytes;
        return bytes;
      } catch (e, stackTrace) {
        _logger.error(
          message: 'Failed to load attachment preview',
          error: e,
          stackTrace: stackTrace,
          extra: {'preview_path': previewPath},
        );
        return null;
      } finally {
        _attachmentPreviewInflight.remove(previewPath);
      }
    })();

    _attachmentPreviewInflight[previewPath] = future;
    return future;
  }
}