import 'package:bloc_test/bloc_test.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:lightmeter/interactors/metering_interactor.dart';
import 'package:lightmeter/screens/metering/communication/bloc_communication_metering.dart';
import 'package:lightmeter/screens/metering/communication/event_communication_metering.dart'
    as communication_events;
import 'package:lightmeter/screens/metering/communication/state_communication_metering.dart'
    as communication_states;
import 'package:lightmeter/screens/metering/components/camera_container/bloc_container_camera.dart';
import 'package:lightmeter/screens/metering/components/camera_container/event_container_camera.dart';
import 'package:lightmeter/screens/metering/components/camera_container/models/camera_error_type.dart';
import 'package:lightmeter/screens/metering/components/camera_container/state_container_camera.dart';
import 'package:mocktail/mocktail.dart';

class _MockMeteringCommunicationBloc extends MockBloc<
    communication_events.MeteringCommunicationEvent,
    communication_states.MeteringCommunicationState> implements MeteringCommunicationBloc {}

class _MockMeteringInteractor extends Mock implements MeteringInteractor {}

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  late _MockMeteringInteractor meteringInteractor;
  late _MockMeteringCommunicationBloc communicationBloc;
  late CameraContainerBloc bloc;

  setUpAll(() {
    meteringInteractor = _MockMeteringInteractor();
    communicationBloc = _MockMeteringCommunicationBloc();
  });

  setUp(() {
    bloc = CameraContainerBloc(
      meteringInteractor,
      communicationBloc,
    );
  });

  tearDown(() {
    bloc.close();
  });

  group(
    '`RequestPermissionEvent` tests',
    () {
      blocTest<CameraContainerBloc, CameraContainerState>(
        'Request denied',
        build: () => bloc,
        setUp: () {
          when(() => meteringInteractor.requestPermission()).thenAnswer((_) async => false);
        },
        act: (bloc) => bloc.add(const RequestPermissionEvent()),
        verify: (_) {
          verify(() => meteringInteractor.requestPermission()).called(1);
        },
        expect: () => [
          isA<CameraErrorState>()
              .having((state) => state.error, "error", CameraErrorType.permissionNotGranted),
        ],
      );

      blocTest<CameraContainerBloc, CameraContainerState>(
        'Request granted -> check denied',
        build: () => bloc,
        setUp: () {
          when(() => meteringInteractor.requestPermission()).thenAnswer((_) async => true);
          when(() => meteringInteractor.checkCameraPermission()).thenAnswer((_) async => false);
        },
        act: (bloc) => bloc.add(const RequestPermissionEvent()),
        verify: (_) {
          verify(() => meteringInteractor.requestPermission()).called(1);
          verify(() => meteringInteractor.checkCameraPermission()).called(1);
        },
        expect: () => [
          isA<CameraLoadingState>(),
          isA<CameraErrorState>()
              .having((state) => state.error, "error", CameraErrorType.permissionNotGranted),
        ],
      );

      blocTest<CameraContainerBloc, CameraContainerState>(
        'Request granted -> check granted',
        build: () => bloc,
        setUp: () {
          when(() => meteringInteractor.requestPermission()).thenAnswer((_) async => true);
          when(() => meteringInteractor.checkCameraPermission()).thenAnswer((_) async => true);
        },
        act: (bloc) => bloc.add(const RequestPermissionEvent()),
        verify: (_) {
          verify(() => meteringInteractor.requestPermission()).called(1);
          verify(() => meteringInteractor.checkCameraPermission()).called(1);
        },
        expect: () => [
          isA<CameraLoadingState>(),
          // Proceed to `InitializeEvent` tests from here
        ],
      );
    },
  );

  group(
    '`InitializeEvent` tests',
    () {
      const cameraMethodChannel = MethodChannel('plugins.flutter.io/camera');
      const cameraIdMethodChannel = MethodChannel('flutter.io/cameraPlugin/camera1');
      const availableCameras = [
        {
          "name": "front",
          "lensFacing": "front",
          "sensorOrientation": 0,
        },
        {
          "name": "back",
          "lensFacing": "back",
          "sensorOrientation": 0,
        },
      ];

      blocTest<CameraContainerBloc, CameraContainerState>(
        'No cameras detected error',
        setUp: () {
          when(() => meteringInteractor.checkCameraPermission()).thenAnswer((_) async => true);
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
              .setMockMethodCallHandler(
            cameraMethodChannel,
            (methodCall) async {
              switch (methodCall.method) {
                case "availableCameras":
                  return const [];
                default:
                  return null;
              }
            },
          );
        },
        tearDown: () {
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
              .setMockMethodCallHandler(cameraMethodChannel, null);
        },
        build: () => bloc,
        act: (bloc) => bloc.add(const InitializeEvent()),
        verify: (_) {
          verify(() => meteringInteractor.checkCameraPermission()).called(1);
        },
        expect: () => [
          isA<CameraLoadingState>(),
          isA<CameraErrorState>()
              .having((state) => state.error, "error", CameraErrorType.noCamerasDetected),
        ],
      );

      blocTest<CameraContainerBloc, CameraContainerState>(
        'Catch other initialization errors',
        setUp: () {
          when(() => meteringInteractor.checkCameraPermission()).thenAnswer((_) async => true);
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
              .setMockMethodCallHandler(
            cameraMethodChannel,
            (methodCall) async {
              switch (methodCall.method) {
                case "availableCameras":
                  return availableCameras;
                default:
                  return null;
              }
            },
          );
        },
        tearDown: () {
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
              .setMockMethodCallHandler(cameraMethodChannel, null);
        },
        build: () => bloc,
        act: (bloc) => bloc.add(const InitializeEvent()),
        verify: (_) {
          verify(() => meteringInteractor.checkCameraPermission()).called(1);
        },
        expect: () => [
          isA<CameraLoadingState>(),
          isA<CameraErrorState>().having((state) => state.error, "error", CameraErrorType.other),
        ],
      );

      blocTest<CameraContainerBloc, CameraContainerState>(
        'Successful initialization',
        setUp: () {
          when(() => meteringInteractor.checkCameraPermission()).thenAnswer((_) async => true);
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
              .setMockMethodCallHandler(
            cameraMethodChannel,
            (methodCall) async {
              switch (methodCall.method) {
                case "availableCameras":
                  return availableCameras;
                case "create":
                  return {"cameraId": 1};
                case "initialize":
                  await cameraIdMethodChannel.invokeMockMethod("initialized", {
                    'cameraId': 1,
                    'previewWidth': 2160.0,
                    'previewHeight': 3840.0,
                    'exposureMode': 'auto',
                    'exposurePointSupported': true,
                    'focusMode': 'auto',
                    'focusPointSupported': true,
                  });
                  return {};
                case "setFlashMode":
                  return '';
                // TODO: implement responses for other methods used initialization
                default:
                  return null;
              }
            },
          );
        },
        tearDown: () {
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
              .setMockMethodCallHandler(cameraMethodChannel, null);
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
              .setMockMethodCallHandler(cameraIdMethodChannel, null);
        },
        build: () => bloc,
        act: (bloc) => bloc.add(const InitializeEvent()),
        verify: (_) {
          verify(() => meteringInteractor.checkCameraPermission()).called(1);
        },
        expect: () => [
          isA<CameraLoadingState>(),
          isA<CameraInitializedState>(),
          isA<CameraActiveState>(),
        ],
      );
    },
  );
}

extension _MethodChannelMock on MethodChannel {
  Future<void> invokeMockMethod(String method, dynamic arguments) async {
    final data = const StandardMethodCodec().encodeMethodCall(MethodCall(method, arguments));
    await TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger.handlePlatformMessage(
      name,
      data,
      (ByteData? data) {},
    );
  }
}