// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// @dart = 2.8

import 'package:flutter_tools/src/base/io.dart';
import 'package:flutter_tools/src/base/logger.dart';
import 'package:flutter_tools/src/build_info.dart';
import 'package:flutter_tools/src/device.dart';
import 'package:flutter_tools/src/ios/devices.dart';
import 'package:flutter_tools/src/mdns_discovery.dart';
import 'package:flutter_tools/src/project.dart';
import 'package:flutter_tools/src/reporting/reporting.dart';
import 'package:multicast_dns/multicast_dns.dart';
import 'package:test/fake.dart';

import '../src/common.dart';

void main() {
  group('mDNS Discovery', () {
    final int year3000 = DateTime(3000).millisecondsSinceEpoch;

    setUp(() {
      setNetworkInterfaceLister(
        ({
          bool includeLoopback,
          bool includeLinkLocal,
          InternetAddressType type,
        }) async => <NetworkInterface>[],
      );
    });

    tearDown(() {
      resetNetworkInterfaceLister();
    });


    testWithoutContext('No ports available', () async {
      final MDnsClient client = FakeMDnsClient(<PtrResourceRecord>[], <String, List<SrvResourceRecord>>{});

      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      final int port = (await portDiscovery.query())?.port;
      expect(port, isNull);
    });

    testWithoutContext('Prints helpful message when there is no ipv4 link local address.', () async {
      final MDnsClient client = FakeMDnsClient(<PtrResourceRecord>[], <String, List<SrvResourceRecord>>{});
      final BufferLogger logger = BufferLogger.test();
      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: logger,
        flutterUsage: TestUsage(),
      );
      final Uri uri = await portDiscovery.getObservatoryUri(
        '',
        FakeIOSDevice(),
      );
      expect(uri, isNull);
      expect(logger.errorText, contains('Personal Hotspot'));
    });

    testWithoutContext('One port available, no appId', () async {
      final MDnsClient client = FakeMDnsClient(
        <PtrResourceRecord>[
          PtrResourceRecord('foo', year3000, domainName: 'bar'),
        ],
        <String, List<SrvResourceRecord>>{
          'bar': <SrvResourceRecord>[
            SrvResourceRecord('bar', year3000, port: 123, weight: 1, priority: 1, target: 'appId'),
          ],
        },
      );

      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      final int port = (await portDiscovery.query())?.port;
      expect(port, 123);
    });

    testWithoutContext('One port available, no appId, with authCode', () async {
      final MDnsClient client = FakeMDnsClient(
        <PtrResourceRecord>[
          PtrResourceRecord('foo', year3000, domainName: 'bar'),
        ],
        <String, List<SrvResourceRecord>>{
          'bar': <SrvResourceRecord>[
            SrvResourceRecord('bar', year3000, port: 123, weight: 1, priority: 1, target: 'appId'),
          ],
        },
        txtResponse: <String, List<TxtResourceRecord>>{
          'bar': <TxtResourceRecord>[
            TxtResourceRecord('bar', year3000, text: 'authCode=xyz\n'),
          ],
        },
      );

      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      final MDnsObservatoryDiscoveryResult result = await portDiscovery.query();
      expect(result?.port, 123);
      expect(result?.authCode, 'xyz/');
    });

    testWithoutContext('Multiple ports available, without appId', () async {
      final MDnsClient client = FakeMDnsClient(
        <PtrResourceRecord>[
          PtrResourceRecord('foo', year3000, domainName: 'bar'),
          PtrResourceRecord('baz', year3000, domainName: 'fiz'),
        ],
        <String, List<SrvResourceRecord>>{
          'bar': <SrvResourceRecord>[
            SrvResourceRecord('bar', year3000, port: 123, weight: 1, priority: 1, target: 'appId'),
          ],
          'fiz': <SrvResourceRecord>[
            SrvResourceRecord('fiz', year3000, port: 321, weight: 1, priority: 1, target: 'local'),
          ],
        },
      );

      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      expect(portDiscovery.query, throwsToolExit());
    });

    testWithoutContext('Multiple ports available, with appId', () async {
      final MDnsClient client = FakeMDnsClient(
        <PtrResourceRecord>[
          PtrResourceRecord('foo', year3000, domainName: 'bar'),
          PtrResourceRecord('baz', year3000, domainName: 'fiz'),
        ],
        <String, List<SrvResourceRecord>>{
          'bar': <SrvResourceRecord>[
            SrvResourceRecord('bar', year3000, port: 123, weight: 1, priority: 1, target: 'appId'),
          ],
          'fiz': <SrvResourceRecord>[
            SrvResourceRecord('fiz', year3000, port: 321, weight: 1, priority: 1, target: 'local'),
          ],
        },
      );

      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      final int port = (await portDiscovery.query(applicationId: 'fiz'))?.port;
      expect(port, 321);
    });

    testWithoutContext('Multiple ports available per process, with appId', () async {
      final MDnsClient client = FakeMDnsClient(
        <PtrResourceRecord>[
          PtrResourceRecord('foo', year3000, domainName: 'bar'),
          PtrResourceRecord('baz', year3000, domainName: 'fiz'),
        ],
        <String, List<SrvResourceRecord>>{
          'bar': <SrvResourceRecord>[
            SrvResourceRecord('bar', year3000, port: 1234, weight: 1, priority: 1, target: 'appId'),
            SrvResourceRecord('bar', year3000, port: 123, weight: 1, priority: 1, target: 'appId'),
          ],
          'fiz': <SrvResourceRecord>[
            SrvResourceRecord('fiz', year3000, port: 4321, weight: 1, priority: 1, target: 'local'),
            SrvResourceRecord('fiz', year3000, port: 321, weight: 1, priority: 1, target: 'local'),
          ],
        },
      );

      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      final int port = (await portDiscovery.query(applicationId: 'bar'))?.port;
      expect(port, 1234);
    });

    testWithoutContext('Query returns null', () async {
      final MDnsClient client = FakeMDnsClient(
        <PtrResourceRecord>[],
         <String, List<SrvResourceRecord>>{},
      );

      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      final int port = (await portDiscovery.query(applicationId: 'bar'))?.port;
      expect(port, isNull);
    });

    testWithoutContext('Throws Exception when client throws OSError on start', () async {
      final MDnsClient client = FakeMDnsClient(<PtrResourceRecord>[], <String, List<SrvResourceRecord>>{}, osErrorOnStart: true);


      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      expect(
        () async => portDiscovery.query(),
        throwsA(isA<Exception>()),
      );
    });

    testWithoutContext('Correctly builds Observatory URI with hostVmservicePort == 0', () async {
      final MDnsClient client = FakeMDnsClient(
        <PtrResourceRecord>[
          PtrResourceRecord('foo', year3000, domainName: 'bar'),
        ],
        <String, List<SrvResourceRecord>>{
          'bar': <SrvResourceRecord>[
            SrvResourceRecord('bar', year3000, port: 123, weight: 1, priority: 1, target: 'appId'),
          ],
        },
      );

      final FakeIOSDevice device = FakeIOSDevice();
      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(
        mdnsClient: client,
        logger: BufferLogger.test(),
        flutterUsage: TestUsage(),
      );
      final Uri uri = await portDiscovery.getObservatoryUri('bar', device, hostVmservicePort: 0);
      expect(uri.toString(), 'http://127.0.0.1:123/');
    });
  });
}

class FakeMDnsClient extends Fake implements MDnsClient {
  FakeMDnsClient(this.ptrRecords, this.srvResponse, {
    this.txtResponse = const <String, List<TxtResourceRecord>>{},
    this.osErrorOnStart = false,
  });

  final List<PtrResourceRecord> ptrRecords;
  final Map<String, List<SrvResourceRecord>> srvResponse;
  final Map<String, List<TxtResourceRecord>> txtResponse;
  final bool osErrorOnStart;

  @override
  Future<void> start({
    InternetAddress listenAddress,
    NetworkInterfacesFactory interfacesFactory,
    int mDnsPort = 5353,
    InternetAddress mDnsAddress,
  }) async {
    if (osErrorOnStart) {
      throw const OSError('Operation not suppoted on socket', 102);
    }
  }

  @override
  Stream<T> lookup<T extends ResourceRecord>(
    ResourceRecordQuery query, {
    Duration timeout = const Duration(seconds: 5),
  }) {
    if (T == PtrResourceRecord && query.fullyQualifiedName == MDnsObservatoryDiscovery.dartObservatoryName) {
      return Stream<PtrResourceRecord>.fromIterable(ptrRecords) as Stream<T>;
    }
    if (T == SrvResourceRecord) {
      final String key = query.fullyQualifiedName;
      return Stream<SrvResourceRecord>.fromIterable(srvResponse[key] ?? <SrvResourceRecord>[]) as Stream<T>;
    }
    if (T == TxtResourceRecord) {
      final String key = query.fullyQualifiedName;
      return Stream<TxtResourceRecord>.fromIterable(txtResponse[key] ?? <TxtResourceRecord>[]) as Stream<T>;
    }
    throw UnsupportedError('Unsupported query type $T');
  }

  @override
  void stop() {}
}

class FakeIOSDevice extends Fake implements IOSDevice {
  @override
  Future<TargetPlatform> get targetPlatform async => TargetPlatform.ios;

  @override
  bool isSupported() => true;

  @override
  bool isSupportedForProject(FlutterProject flutterProject) => true;

  @override
  DevicePortForwarder get portForwarder => const NoOpDevicePortForwarder();
}