// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

@TestOn('vm')
library;

import 'dart:async';
import 'dart:convert';

import 'package:async/async.dart';
import 'package:test/test.dart';
import 'package:vm_service/vm_service.dart';
import 'package:vm_service_interface/vm_service_interface.dart';

void main() {
  group('method delegation', () {
    late MockVmService serviceMock;
    late StreamController<Map<String, Object>> requestsController;
    late StreamController<Map<String, Object?>> responsesController;
    late ServiceExtensionRegistry serviceRegistry;

    setUp(() {
      serviceMock = MockVmService();
      requestsController = StreamController();
      responsesController = StreamController();
      serviceRegistry = ServiceExtensionRegistry();

      VmServerConnection(
        requestsController.stream,
        responsesController.sink,
        serviceRegistry,
        serviceMock,
      );
    });

    tearDown(() {
      requestsController.close();
      responsesController.close();
    });

    test('works for simple methods', () {
      var request = rpcRequest('getVersion');
      var version = Version(major: 1, minor: 0);

      serviceMock.version = version;

      expect(responsesController.stream, emits(rpcResponse(version)));
      requestsController.add(request);
    });

    test('works for methods with parameters', () {
      var isolate = Isolate(
        name: 'isolate',
        exceptionPauseMode: ExceptionPauseMode.kNone,
        id: '123',
        number: '0',
        startTime: 1,
        runnable: true,
        livePorts: 2,
        isolateFlags: [],
        pauseOnExit: false,
        pauseEvent: Event(
          kind: EventKind.kResume,
          timestamp: 3,
        ),
        libraries: [],
        breakpoints: [],
        isSystemIsolate: false,
      );
      var request =
          rpcRequest('getIsolate', params: {'isolateId': isolate.id!});

      serviceMock.isolates[isolate.id!] = isolate;

      expect(responsesController.stream, emits(rpcResponse(isolate)));
      requestsController.add(request);
    });

    test('works for methods with list parameters', () {
      var isolate = Isolate(
        name: 'isolate',
        exceptionPauseMode: ExceptionPauseMode.kNone,
        id: '123',
        number: '0',
        startTime: 1,
        runnable: true,
        livePorts: 2,
        isolateFlags: [],
        pauseOnExit: false,
        pauseEvent: Event(
          kind: EventKind.kResume,
          timestamp: 3,
        ),
        libraries: [],
        breakpoints: [],
        isSystemIsolate: false,
      );
      var request = rpcRequest('setVMTimelineFlags', params: {
        'isolateId': isolate.id!,
        // Note: the dynamic list below is intentional in order to exercise the
        // code under test.
        'recordedStreams': <dynamic>['GC', 'Dart', 'Embedder'],
      });

      serviceMock.isolates[isolate.id!] = isolate;
      var response = Success();

      expect(responsesController.stream, emits(rpcResponse(response)));
      requestsController.add(request);
    });
  });

  group('custom service extensions', () {
    late MockVmService serviceMock;
    late StreamController<Map<String, Object>> requestsController;
    late StreamController<Map<String, Object?>> responsesController;
    late ServiceExtensionRegistry serviceRegistry;

    setUp(() {
      serviceMock = MockVmService();
      requestsController = StreamController();
      responsesController = StreamController();
      serviceRegistry = ServiceExtensionRegistry();

      VmServerConnection(
        requestsController.stream,
        responsesController.sink,
        serviceRegistry,
        serviceMock,
      );
    });

    tearDown(() {
      requestsController.close();
      responsesController.close();
    });

    test('with no params or isolateId', () {
      var extension = 'ext.cool';
      var request = rpcRequest(extension, params: null);
      var response = Response()..json = {'hello': 'world'};

      serviceMock.serviceExtensionResponse = response;
      requestsController.add(request);

      expect(responsesController.stream, emits(rpcResponse(response)));
    });

    test('with isolateId and no other params', () {
      var extension = 'ext.cool';
      var request = rpcRequest(extension, params: {'isolateId': '1'});
      var response = Response()..json = {'hello': 'world'};

      serviceMock.serviceExtensionResponse = response;
      requestsController.add(request);

      expect(responsesController.stream, emits(rpcResponse(response)));
    });

    test('with params and no isolateId', () {
      var extension = 'ext.cool';
      var params = {'cool': 'option'};
      var request = rpcRequest(extension, params: params);
      var response = Response()..json = {'hello': 'world'};

      serviceMock.serviceExtensionResponse = response;
      requestsController.add(request);

      expect(responsesController.stream, emits(rpcResponse(response)));
    });

    test('with params and isolateId', () {
      var extension = 'ext.cool';
      var params = {'cool': 'option'};
      var request =
          rpcRequest(extension, params: Map.of(params)..['isolateId'] = '1');
      var response = Response()..json = {'hello': 'world'};

      serviceMock.serviceExtensionResponse = response;
      requestsController.add(request);

      expect(responsesController.stream, emits(rpcResponse(response)));
    });
  });

  group('error handling', () {
    late MockVmService serviceMock;
    late StreamController<Map<String, Object>> requestsController;
    late StreamController<Map<String, Object?>> responsesController;
    late ServiceExtensionRegistry serviceRegistry;

    setUp(() {
      serviceMock = MockVmService();
      requestsController = StreamController();
      responsesController = StreamController();
      serviceRegistry = ServiceExtensionRegistry();

      VmServerConnection(
        requestsController.stream,
        responsesController.sink,
        serviceRegistry,
        serviceMock,
      );
    });

    tearDown(() {
      requestsController.close();
      responsesController.close();
    });

    test('special cases RPCError instances', () {
      var request = rpcRequest('getVersion');
      var error =
          RPCError('getVersion', 1234, 'custom message', {'custom': 'data'});

      serviceMock.versionError = error;
      requestsController.add(request);

      expect(responsesController.stream, emits(rpcErrorResponse(error)));
    });

    test('has a fallback for generic exceptions', () {
      var request = rpcRequest('getVersion');

      requestsController.add(request);

      expect(
          responsesController.stream.map((response) => '$response'),
          emits(startsWith('{jsonrpc: 2.0, id: 1, '
              'error: {code: -32603, message: getVersion: UnimplementedError')));
    });
  });

  group('streams', () {
    late MockVmService serviceMock;
    late StreamController<Map<String, Object>> requestsController;
    late StreamController<Map<String, Object?>> responsesController;
    late ServiceExtensionRegistry serviceRegistry;

    setUp(() {
      serviceMock = MockVmService();
      requestsController = StreamController();
      responsesController = StreamController();
      serviceRegistry = ServiceExtensionRegistry();

      VmServerConnection(
        requestsController.stream,
        responsesController.sink,
        serviceRegistry,
        serviceMock,
      );
    });

    tearDown(() {
      requestsController.close();
      responsesController.close();
    });

    test('can be listened to and canceled', () async {
      StreamController<Event> eventController;
      var responseQueue = StreamQueue(responsesController.stream);

      {
        var request =
            rpcRequest('streamListen', params: {'streamId': 'Isolate'});
        var response = Success();
        requestsController.add(request);

        await expectLater(responseQueue, emitsThrough(rpcResponse(response)));

        eventController = serviceMock.streamControllers['Isolate']!;

        var events = [
          Event(
            kind: EventKind.kIsolateStart,
            timestamp: 0,
          ),
          Event(
            kind: EventKind.kIsolateExit,
            timestamp: 1,
          )
        ];
        events.forEach(eventController.add);
        await expectLater(
            responseQueue,
            emitsInOrder(
                events.map((event) => streamNotifyResponse('Isolate', event))));
      }

      {
        var request =
            rpcRequest('streamCancel', params: {'streamId': 'Isolate'});
        var response = Success();
        requestsController.add(request);

        await expectLater(responseQueue, emitsThrough(rpcResponse(response)));

        var nextEvent = Event(
          kind: EventKind.kIsolateReload,
          timestamp: 2,
        );
        eventController.add(nextEvent);
        expect(responseQueue,
            neverEmits(streamNotifyResponse('Isolate', nextEvent)));

        await pumpEventQueue();
        await eventController.close();
        await responsesController.close();
      }
    });

    test("can't be listened to twice", () {
      var responseQueue = StreamQueue(responsesController.stream);

      {
        var request =
            rpcRequest('streamListen', params: {'streamId': 'Isolate'});
        var response = Success();
        requestsController.add(request);

        expect(responseQueue, emitsThrough(rpcResponse(response)));
      }

      {
        var request =
            rpcRequest('streamListen', params: {'streamId': 'Isolate'});
        requestsController.add(request);

        expect(
          responseQueue,
          emitsThrough(rpcErrorResponse(
              RPCError('streamSubscribe', 103, 'Stream already subscribed', {
            'details': "The stream 'Isolate' is already subscribed",
          }))),
        );
      }
    });

    test("can't cancel a stream that isn't being listened to", () {
      var streamId = 'Isolate';
      var responseQueue = StreamQueue(responsesController.stream);

      var request = rpcRequest('streamCancel', params: {'streamId': streamId});
      requestsController.add(request);

      expect(
        responseQueue,
        emitsThrough(rpcErrorResponse(
            RPCError('streamCancel', 104, 'Stream not subscribed', {
          'details': "The stream '$streamId' is not subscribed",
        }))),
      );
    });

    test('gives register and unregister events', () async {
      var serviceId = 'ext.test.service';
      var serviceRegisteredEvent = streamNotifyResponse(
        'Service',
        Event(
          kind: EventKind.kServiceRegistered,
          timestamp: 0,
          method: serviceId,
          service: serviceId,
        ),
      );
      var serviceUnRegisteredEvent = streamNotifyResponse(
        'Service',
        Event(
          kind: EventKind.kServiceUnregistered,
          timestamp: 0,
          method: serviceId,
          service: serviceId,
        ),
      );

      requestsController
          .add(rpcRequest('streamListen', params: {'streamId': 'Service'}));
      requestsController
          .add(rpcRequest('registerService', params: {'service': serviceId}));
      await expectLater(
          responsesController.stream
              .map((Map response) => stripEventTimestamp(response)),
          emitsThrough(serviceRegisteredEvent));

      // Connect another client to get the previous register events and the
      // unregister event.
      var requestsController2 = StreamController<Map<String, Object>>();
      var responsesController2 = StreamController<Map<String, Object?>>();
      addTearDown(() {
        requestsController2.close();
        responsesController2.close();
      });

      VmServerConnection(
        requestsController2.stream,
        responsesController2.sink,
        serviceRegistry,
        MockVmService(),
      );

      expect(
          responsesController2.stream
              .map((Map response) => stripEventTimestamp(response)),
          emitsThrough(emitsInOrder(
              [serviceRegisteredEvent, serviceUnRegisteredEvent])));

      // Should get the previously registered extension event, as well as
      // the unregister event when the client disconnects.
      requestsController2
          .add(rpcRequest('streamListen', params: {'streamId': 'Service'}));
      // Need to give the client a chance to subscribe.
      await pumpEventQueue();
      unawaited(requestsController.close());
      // Give the old client a chance to shut down
      await pumpEventQueue();

      // Connect yet another client, it should get zero registration or
      // unregistration events.
      var requestsController3 = StreamController<Map<String, Object>>();
      var responsesController3 = StreamController<Map<String, Object?>>();

      VmServerConnection(
        requestsController3.stream,
        responsesController3.sink,
        serviceRegistry,
        MockVmService(),
      );

      expect(responsesController3.stream,
          neverEmits(anyOf(serviceRegisteredEvent, serviceUnRegisteredEvent)));
      // Give it a chance to deliver events.
      await pumpEventQueue();
      // Disconnect the client so the test can shut down.
      unawaited(requestsController3.close());
      unawaited(responsesController3.close());
    });
  });

  group('registerService', () {
    late MockVmService serviceMock;
    late StreamController<Map<String, Object>> requestsController;
    late StreamController<Map<String, Object?>> responsesController;
    late ServiceExtensionRegistry serviceRegistry;

    setUp(() {
      serviceMock = MockVmService();
      requestsController = StreamController();
      responsesController = StreamController();
      serviceRegistry = ServiceExtensionRegistry();

      VmServerConnection(
        requestsController.stream,
        responsesController.sink,
        serviceRegistry,
        serviceMock,
      );
    });

    tearDown(() {
      requestsController.close();
      responsesController.close();
    });

    test('registerService can delegate requests between clients', () async {
      var serviceId = 'ext.test.service';
      var responseQueue = StreamQueue(responsesController.stream);

      var clientInputController =
          StreamController<Map<String, Object?>>.broadcast();
      var clientOutputController =
          StreamController<Map<String, Object>>.broadcast();
      var client = VmService(
          clientInputController.stream.map(jsonEncode),
          (String message) => clientOutputController
              .add(jsonDecode(message).cast<String, Object>()),
          disposeHandler: () async {
        await clientInputController.close();
        await clientOutputController.close();
      });

      var clientConnection = VmServerConnection(clientOutputController.stream,
          clientInputController.sink, serviceRegistry, serviceMock);

      var requestParams = {'foo': 'bar'};
      var expectedResponse = Response()..json = {'zap': 'zip'};
      await client.registerService(serviceId, 'service');
      // Duplicate registrations should fail.
      expect(client.registerService(serviceId, 'service'),
          throwsA(const TypeMatcher<RPCError>()));

      client.registerServiceCallback(serviceId, (request) async {
        expect(request, equals(requestParams));
        return {'result': expectedResponse.toJson()};
      });

      var serviceRequest = rpcRequest(serviceId, params: requestParams);

      requestsController.add(serviceRequest);
      expect(await responseQueue.next, rpcResponse(expectedResponse));

      // Kill the client that registered the handler, it should now fall back
      // on `callServiceExtension`.
      await client.dispose();
      // This should complete as well.
      await clientConnection.done;

      var mockResponse = Response()..json = {'mock': 'response'};
      serviceMock.serviceExtensionResponse = mockResponse;
      requestsController.add(serviceRequest);

      expect(await responseQueue.next, rpcResponse(mockResponse));
    });
  });
}

Map<String, Object> rpcRequest(String method,
        {Map<String, Object>? params = const {}, String id = '1'}) =>
    {
      'jsonrpc': '2.0',
      'method': method,
      if (params != null) 'params': params,
      'id': id,
    };

Map<String, Object> rpcResponse(Response response, {String id = '1'}) => {
      'jsonrpc': '2.0',
      'id': id,
      'result': response.toJson(),
    };

Map<String, Object> rpcErrorResponse(Object error, {String id = '1'}) {
  Map<String, Object> errorJson;
  if (error is RPCError) {
    errorJson = {
      'code': error.code,
      'message': error.message,
    };
    if (error.data != null) {
      errorJson['data'] = error.data!;
    }
  } else {
    errorJson = {
      'code': -32603,
      'message': error.toString(),
    };
  }
  return {
    'jsonrpc': '2.0',
    'id': id,
    'error': errorJson,
  };
}

Map<String, Object> streamNotifyResponse(String streamId, Event event) {
  return {
    'jsonrpc': '2.0',
    'method': 'streamNotify',
    'params': {
      'streamId': streamId,
      'event': event.toJson(),
    },
  };
}

Map<String, Object?> stripEventTimestamp(Map response) {
  if (response.containsKey('params') &&
      response['params'].containsKey('event')) {
    response['params']['event']['timestamp'] = 0;
  }
  return response as Map<String, Object?>;
}

class MockVmService implements VmServiceInterface {
  Version? version;
  RPCError? versionError;
  Response? serviceExtensionResponse;

  final Map<String, Isolate> isolates = {};
  final streamControllers = <String, StreamController<Event>>{};

  // Override `noSuchMethod` to capture any [VmServiceInterface] method we don't
  // explicitly override for testing purposes.
  @override
  dynamic noSuchMethod(Invocation invocation) {
    throw UnimplementedError('$invocation.memberName');
  }

  @override
  Future<Response> callServiceExtension(String method,
      {String? isolateId, Map<String, dynamic>? args}) {
    return Future.value(serviceExtensionResponse!);
  }

  @override
  Future<Isolate> getIsolate(String isolateId) {
    return Future.sync(() => isolates[isolateId]!);
  }

  @override
  Future<Version> getVersion() {
    if (versionError != null) {
      return Future.error(versionError!);
    } else if (version != null) {
      return Future.value(version!);
    } else {
      return Future.error(UnimplementedError('getVersion'));
    }
  }

  @override
  Stream<Event> onEvent(String streamId) {
    return streamControllers
        .putIfAbsent(streamId, () => StreamController<Event>())
        .stream;
  }

  @override
  Future<Success> setVMTimelineFlags(List<String> recordedStreams) {
    return Future.value(Success());
  }

  @override
  Future<Success> streamListen(String streamId) {
    return Future.value(Success());
  }
}