import 'dart:convert';
import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:http/http.dart';
import 'package:paperless_mobile/core/bloc/document_status_cubit.dart';
import 'package:paperless_mobile/core/model/document_processing_status.dart';
import 'package:paperless_mobile/di_initializer.dart';
import 'package:paperless_mobile/features/documents/model/document.model.dart';
import 'package:paperless_mobile/features/documents/model/paged_search_result.dart';
import 'package:paperless_mobile/features/login/model/authentication_information.dart';
import 'package:paperless_mobile/util.dart';
import 'package:injectable/injectable.dart';
import 'package:web_socket_channel/io.dart';

abstract class StatusService {
  Future<void> startListeningBeforeDocumentUpload(String httpUrl,
      AuthenticationInformation credentials, String documentFileName);
}

@Singleton(as: StatusService)
@Named("webSocketStatusService")
class WebSocketStatusService implements StatusService {
  late WebSocket? socket;
  late IOWebSocketChannel? _channel;

  WebSocketStatusService();

  @override
  Future<void> startListeningBeforeDocumentUpload(
    String httpUrl,
    AuthenticationInformation credentials,
    String documentFileName,
  ) async {
    socket = await WebSocket.connect(
      httpUrl.replaceFirst("http", "ws") + "/ws/status/",
      customClient: getIt<HttpClient>(),
      headers: {
        'Authorization': 'Token ${credentials.token}',
      },
    ).catchError((_) {
      // Use long polling if connection could not be established
    });

    if (socket != null) {
      socket!.where(isNotNull).listen((event) {
        final status = DocumentProcessingStatus.fromJson(event);
        getIt<DocumentStatusCubit>().updateStatus(status);
        if (status.currentProgress == 100) {
          socket!.close();
        }
      });
    }
  }
}

@Injectable(as: StatusService)
@Named("longPollingStatusService")
class LongPollingStatusService implements StatusService {
  static const maxRetries = 60;

  final BaseClient httpClient;
  LongPollingStatusService(@Named("timeoutClient") this.httpClient);

  @override
  Future<void> startListeningBeforeDocumentUpload(
    String httpUrl,
    AuthenticationInformation credentials,
    String documentFileName,
  ) async {
    final today = DateTime.now();
    bool consumptionFinished = false;
    int retryCount = 0;

    getIt<DocumentStatusCubit>().updateStatus(
      DocumentProcessingStatus(
        currentProgress: 0,
        filename: documentFileName,
        maxProgress: 100,
        message: ProcessingMessage.new_file,
        status: ProcessingStatus.working,
        taskId: DocumentProcessingStatus.unknownTaskId,
        documentId: null,
        isApproximated: true,
      ),
    );

    do {
      final response = await httpClient.get(
        Uri.parse(
            '$httpUrl/api/documents/?query=$documentFileName added:${formatDate(today)}'),
      );
      final data = await compute(
        PagedSearchResult.fromJson,
        PagedSearchResultJsonSerializer(
            jsonDecode(response.body), DocumentModel.fromJson),
      );
      if (data.count > 0) {
        consumptionFinished = true;
        final docId = data.results[0].id;
        getIt<DocumentStatusCubit>().updateStatus(
          DocumentProcessingStatus(
            currentProgress: 100,
            filename: documentFileName,
            maxProgress: 100,
            message: ProcessingMessage.finished,
            status: ProcessingStatus.success,
            taskId: DocumentProcessingStatus.unknownTaskId,
            documentId: docId,
            isApproximated: true,
          ),
        );
        return;
      }
      sleep(const Duration(seconds: 1));
    } while (!consumptionFinished && retryCount < maxRetries);
  }
}