// 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.

import 'dart:async';

import 'package:flutter_tools/src/artifacts.dart';
import 'package:flutter_tools/src/base/async_guard.dart';
import 'package:flutter_tools/src/base/logger.dart';
import 'package:flutter_tools/src/cache.dart';
import 'package:flutter_tools/src/convert.dart';
import 'package:flutter_tools/src/device.dart';
import 'package:flutter_tools/src/ios/devices.dart';
import 'package:flutter_tools/src/ios/ios_deploy.dart';
import 'package:flutter_tools/src/ios/mac.dart';
import 'package:flutter_tools/src/vmservice.dart';
import 'package:test/fake.dart';
import 'package:vm_service/vm_service.dart';

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

void main() {
  late FakeProcessManager processManager;
  late Artifacts artifacts;
  late Cache fakeCache;
  late BufferLogger logger;
  late String ideviceSyslogPath;

  setUp(() {
    processManager = FakeProcessManager.empty();
    fakeCache = Cache.test(processManager: FakeProcessManager.any());
    artifacts = Artifacts.test();
    logger = BufferLogger.test();
    ideviceSyslogPath = artifacts.getHostArtifact(HostArtifact.idevicesyslog).path;
  });

  group('syslog stream', () {
    testWithoutContext('decodeSyslog decodes a syslog-encoded line', () {
      final String decoded = decodeSyslog(
          r'I \M-b\M^]\M-$\M-o\M-8\M^O syslog '
          r'\M-B\M-/\134_(\M-c\M^C\M^D)_/\M-B\M-/ \M-l\M^F\240!');

      expect(decoded, r'I ❤️ syslog ¯\_(ツ)_/¯ 솠!');
    });

    testWithoutContext('decodeSyslog passes through un-decodeable lines as-is', () {
      final String decoded = decodeSyslog(r'I \M-b\M^O syslog!');

      expect(decoded, r'I \M-b\M^O syslog!');
    });

    testWithoutContext('IOSDeviceLogReader suppresses non-Flutter lines from output with syslog', () async {
      processManager.addCommand(
        FakeCommand(
            command: <String>[
              ideviceSyslogPath, '-u', '1234',
            ],
            stdout: '''
Runner(Flutter)[297] <Notice>: A is for ari
Runner(libsystem_asl.dylib)[297] <Notice>: libMobileGestalt MobileGestaltSupport.m:153: pid 123 (Runner) does not have sandbox access for frZQaeyWLUvLjeuEK43hmg and IS NOT appropriately entitled
Runner(libsystem_asl.dylib)[297] <Notice>: libMobileGestalt MobileGestalt.c:550: no access to InverseDeviceID (see <rdar://problem/11744455>)
Runner(Flutter)[297] <Notice>: I is for ichigo
Runner(UIKit)[297] <Notice>: E is for enpitsu"
'''
        ),
      );
      final DeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
      );
      final List<String> lines = await logReader.logLines.toList();

      expect(lines, <String>['A is for ari', 'I is for ichigo']);
    });

    testWithoutContext('IOSDeviceLogReader includes multi-line Flutter logs in the output with syslog', () async {
      processManager.addCommand(
        FakeCommand(
            command: <String>[
              ideviceSyslogPath, '-u', '1234',
            ],
            stdout: '''
Runner(Flutter)[297] <Notice>: This is a multi-line message,
  with another Flutter message following it.
Runner(Flutter)[297] <Notice>: This is a multi-line message,
  with a non-Flutter log message following it.
Runner(libsystem_asl.dylib)[297] <Notice>: libMobileGestalt
'''
        ),
      );
      final DeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
      );
      final List<String> lines = await logReader.logLines.toList();

      expect(lines, <String>[
        'This is a multi-line message,',
        '  with another Flutter message following it.',
        'This is a multi-line message,',
        '  with a non-Flutter log message following it.',
      ]);
    });

    testWithoutContext('includes multi-line Flutter logs in the output', () async {
      processManager.addCommand(
        FakeCommand(
          command: <String>[
            ideviceSyslogPath, '-u', '1234',
          ],
          stdout: '''
Runner(Flutter)[297] <Notice>: This is a multi-line message,
  with another Flutter message following it.
Runner(Flutter)[297] <Notice>: This is a multi-line message,
  with a non-Flutter log message following it.
Runner(libsystem_asl.dylib)[297] <Notice>: libMobileGestalt
''',
        ),
      );

      final DeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
      );
      final List<String> lines = await logReader.logLines.toList();

      expect(lines, <String>[
        'This is a multi-line message,',
        '  with another Flutter message following it.',
        'This is a multi-line message,',
        '  with a non-Flutter log message following it.',
      ]);
    });
  });

  group('VM service', () {
    testWithoutContext('IOSDeviceLogReader can listen to VM Service logs', () async {
      final Event stdoutEvent = Event(
        kind: 'Stdout',
        timestamp: 0,
        bytes: base64.encode(utf8.encode('  This is a message ')),
      );
      final Event stderrEvent = Event(
        kind: 'Stderr',
        timestamp: 0,
        bytes: base64.encode(utf8.encode('  And this is an error ')),
      );
      final FlutterVmService vmService = FakeVmServiceHost(requests: <VmServiceExpectation>[
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Debug',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stdout',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stderr',
        }),
        FakeVmServiceStreamResponse(event: stdoutEvent, streamId: 'Stdout'),
        FakeVmServiceStreamResponse(event: stderrEvent, streamId: 'Stderr'),
      ]).vmService;
      final DeviceLogReader logReader = IOSDeviceLogReader.test(
        useSyslog: false,
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
      );
      logReader.connectedVMService = vmService;

      // Wait for stream listeners to fire.
      await expectLater(logReader.logLines, emitsInAnyOrder(<Matcher>[
        equals('  This is a message '),
        equals('  And this is an error '),
      ]));
    });

    testWithoutContext('IOSDeviceLogReader ignores VM Service logs when attached to and received flutter logs from debugger', () async {
      final Event stdoutEvent = Event(
        kind: 'Stdout',
        timestamp: 0,
        bytes: base64.encode(utf8.encode('  This is a message ')),
      );
      final Event stderrEvent = Event(
        kind: 'Stderr',
        timestamp: 0,
        bytes: base64.encode(utf8.encode('  And this is an error ')),
      );
      final FlutterVmService vmService = FakeVmServiceHost(requests: <VmServiceExpectation>[
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Debug',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stdout',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stderr',
        }),
        FakeVmServiceStreamResponse(event: stdoutEvent, streamId: 'Stdout'),
        FakeVmServiceStreamResponse(event: stderrEvent, streamId: 'Stderr'),
      ]).vmService;
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        useSyslog: false,
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
      );
      logReader.connectedVMService = vmService;

      final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
      iosDeployDebugger.debuggerAttached = true;

      final Stream<String> debuggingLogs = Stream<String>.fromIterable(<String>[
        'flutter: Message from debugger',
      ]);
      iosDeployDebugger.logLines = debuggingLogs;
      logReader.debuggerStream = iosDeployDebugger;

      // Wait for stream listeners to fire.
      await expectLater(logReader.logLines, emitsInAnyOrder(<Matcher>[
        equals('flutter: Message from debugger'),
      ]));
    });
  });

  group('debugger stream', () {
    testWithoutContext('IOSDeviceLogReader removes metadata prefix from lldb output', () async {
      final Stream<String> debuggingLogs = Stream<String>.fromIterable(<String>[
        '2020-09-15 19:15:10.931434-0700 Runner[541:226276] Did finish launching.',
        '2020-09-15 19:15:10.931434-0700 Runner[541:226276] [Category] Did finish launching from logging category.',
        'stderr from dart',
        '',
      ]);

      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        useSyslog: false,
      );
      final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
      iosDeployDebugger.logLines = debuggingLogs;
      logReader.debuggerStream = iosDeployDebugger;
      final Future<List<String>> logLines = logReader.logLines.toList();

      expect(await logLines, <String>[
        'Did finish launching.',
        '[Category] Did finish launching from logging category.',
        'stderr from dart',
        '',
      ]);
    });

    testWithoutContext('errors on debugger stream closes log stream', () async {
      final Stream<String> debuggingLogs = Stream<String>.error('ios-deploy error');
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        useSyslog: false,
      );
      final Completer<void> streamComplete = Completer<void>();
      final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
      iosDeployDebugger.logLines = debuggingLogs;
      logReader.logLines.listen(null, onError: (Object error) => streamComplete.complete());
      logReader.debuggerStream = iosDeployDebugger;

      await streamComplete.future;
    });

    testWithoutContext('detaches debugger', () async {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        useSyslog: false,
      );
      final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
      logReader.debuggerStream = iosDeployDebugger;

      logReader.dispose();
      expect(iosDeployDebugger.detached, true);
    });

    testWithoutContext('Does not throw if debuggerStream set after logReader closed', () async {
      final Stream<String> debuggingLogs = Stream<String>.fromIterable(<String>[
        '2020-09-15 19:15:10.931434-0700 Runner[541:226276] Did finish launching.',
        '2020-09-15 19:15:10.931434-0700 Runner[541:226276] [Category] Did finish launching from logging category.',
        'stderr from dart',
        '',
      ]);

      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        useSyslog: false,
      );
      Object? exception;
      StackTrace? trace;
      await asyncGuard(
          () async {
            await logReader.linesController.close();
            final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
            iosDeployDebugger.logLines = debuggingLogs;
            logReader.debuggerStream = iosDeployDebugger;
            await logReader.logLines.drain<void>();
          },
          onError: (Object err, StackTrace stackTrace) {
            exception = err;
            trace = stackTrace;
          }
      );
      expect(
        exception,
        isNull,
        reason: trace.toString(),
      );
    });
  });

  group('Determine which loggers to use', () {
    testWithoutContext('for physically attached CoreDevice', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        majorSdkVersion: 17,
        isCoreDevice: true,
      );

      expect(logReader.useSyslogLogging, isTrue);
      expect(logReader.useUnifiedLogging, isTrue);
      expect(logReader.useIOSDeployLogging, isFalse);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.idevicesyslog);
      expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.unifiedLogging);
    });

    testWithoutContext('for wirelessly attached CoreDevice', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        majorSdkVersion: 17,
        isCoreDevice: true,
        isWirelesslyConnected: true,
      );

      expect(logReader.useSyslogLogging, isFalse);
      expect(logReader.useUnifiedLogging, isTrue);
      expect(logReader.useIOSDeployLogging, isFalse);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.unifiedLogging);
      expect(logReader.logSources.fallbackSource, isNull);
    });

    testWithoutContext('for iOS 12 or less device', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        majorSdkVersion: 12,
      );

      expect(logReader.useSyslogLogging, isTrue);
      expect(logReader.useUnifiedLogging, isFalse);
      expect(logReader.useIOSDeployLogging, isFalse);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.idevicesyslog);
      expect(logReader.logSources.fallbackSource, isNull);
    });

    testWithoutContext('for iOS 13 or greater non-CoreDevice and _iosDeployDebugger not attached', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        majorSdkVersion: 13,
      );

      expect(logReader.useSyslogLogging, isFalse);
      expect(logReader.useUnifiedLogging, isTrue);
      expect(logReader.useIOSDeployLogging, isTrue);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
      expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.unifiedLogging);
    });

    testWithoutContext('for iOS 13 or greater non-CoreDevice, _iosDeployDebugger not attached, and VM is connected', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        majorSdkVersion: 13,
      );

      final FlutterVmService vmService = FakeVmServiceHost(requests: <VmServiceExpectation>[
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Debug',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stdout',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stderr',
        }),
      ]).vmService;

      logReader.connectedVMService = vmService;

      expect(logReader.useSyslogLogging, isFalse);
      expect(logReader.useUnifiedLogging, isTrue);
      expect(logReader.useIOSDeployLogging, isTrue);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.unifiedLogging);
      expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.iosDeploy);
    });

    testWithoutContext('for iOS 13 or greater non-CoreDevice and _iosDeployDebugger is attached', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        majorSdkVersion: 13,
      );

      final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
      iosDeployDebugger.debuggerAttached = true;
      logReader.debuggerStream = iosDeployDebugger;

      final FlutterVmService vmService = FakeVmServiceHost(requests: <VmServiceExpectation>[
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Debug',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stdout',
        }),
        const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
          'streamId': 'Stderr',
        }),
      ]).vmService;

      logReader.connectedVMService = vmService;

      expect(logReader.useSyslogLogging, isFalse);
      expect(logReader.useUnifiedLogging, isTrue);
      expect(logReader.useIOSDeployLogging, isTrue);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
      expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.unifiedLogging);
    });

    testWithoutContext('for iOS 16 or greater non-CoreDevice', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        majorSdkVersion: 16,
      );

      final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
      iosDeployDebugger.debuggerAttached = true;
      logReader.debuggerStream = iosDeployDebugger;

      expect(logReader.useSyslogLogging, isFalse);
      expect(logReader.useUnifiedLogging, isTrue);
      expect(logReader.useIOSDeployLogging, isTrue);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
      expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.unifiedLogging);
    });

    testWithoutContext('for iOS 16 or greater non-CoreDevice in CI', () {
      final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
        iMobileDevice: IMobileDevice(
          artifacts: artifacts,
          processManager: processManager,
          cache: fakeCache,
          logger: logger,
        ),
        usingCISystem: true,
        majorSdkVersion: 16,
      );

      expect(logReader.useSyslogLogging, isTrue);
      expect(logReader.useUnifiedLogging, isFalse);
      expect(logReader.useIOSDeployLogging, isTrue);
      expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
      expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.idevicesyslog);
    });

    group('when useSyslogLogging', () {

      testWithoutContext('is true syslog sends flutter messages to stream', () async {
        processManager.addCommand(
          FakeCommand(
              command: <String>[
                ideviceSyslogPath, '-u', '1234',
              ],
              stdout: '''
  Runner(Flutter)[297] <Notice>: A is for ari
  Runner(Flutter)[297] <Notice>: I is for ichigo
  May 30 13:56:28 Runner(Flutter)[2037] <Notice>: flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/
  May 30 13:56:28 Runner(Flutter)[2037] <Notice>: flutter: This is a test
  May 30 13:56:28 Runner(Flutter)[2037] <Notice>: [VERBOSE-2:FlutterDarwinContextMetalImpeller.mm(39)] Using the Impeller rendering backend.
  '''
          ),
        );
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: processManager,
            cache: fakeCache,
            logger: logger,
          ),
          usingCISystem: true,
          majorSdkVersion: 16,
        );
        final List<String> lines = await logReader.logLines.toList();

        expect(logReader.useSyslogLogging, isTrue);
        expect(processManager, hasNoRemainingExpectations);
        expect(lines, <String>[
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/',
          'flutter: This is a test'
        ]);
      });

      testWithoutContext('is false syslog does not send flutter messages to stream', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: processManager,
            cache: fakeCache,
            logger: logger,
          ),
          majorSdkVersion: 16,
        );

        final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
        iosDeployDebugger.logLines =  Stream<String>.fromIterable(<String>[]);
        logReader.debuggerStream = iosDeployDebugger;

        final List<String> lines = await logReader.logLines.toList();

        expect(logReader.useSyslogLogging, isFalse);
        expect(processManager, hasNoRemainingExpectations);
        expect(lines, isEmpty);
      });
    });

    group('when useIOSDeployLogging', () {

      testWithoutContext('is true ios-deploy sends flutter messages to stream', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: processManager,
            cache: fakeCache,
            logger: logger,
          ),
          majorSdkVersion: 16,
        );

        final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
        final Stream<String> debuggingLogs = Stream<String>.fromIterable(<String>[
          'flutter: Message from debugger',
        ]);
        iosDeployDebugger.logLines = debuggingLogs;
        logReader.debuggerStream = iosDeployDebugger;

        final List<String> lines = await logReader.logLines.toList();

        expect(logReader.useIOSDeployLogging, isTrue);
        expect(processManager, hasNoRemainingExpectations);
        expect(lines, <String>[
          'flutter: Message from debugger',
        ]);
      });

      testWithoutContext('is false ios-deploy does not send flutter messages to stream', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: FakeProcessManager.any(),
            cache: fakeCache,
            logger: logger,
          ),
          majorSdkVersion: 12,
        );

        final FakeIOSDeployDebugger iosDeployDebugger = FakeIOSDeployDebugger();
        final Stream<String> debuggingLogs = Stream<String>.fromIterable(<String>[
          'flutter: Message from debugger',
        ]);
        iosDeployDebugger.logLines = debuggingLogs;
        logReader.debuggerStream = iosDeployDebugger;

        final List<String> lines = await logReader.logLines.toList();

        expect(logReader.useIOSDeployLogging, isFalse);
        expect(processManager, hasNoRemainingExpectations);
        expect(lines, isEmpty);
      });
    });

    group('when useUnifiedLogging', () {


      testWithoutContext('is true Dart VM sends flutter messages to stream', () async {
        final Event stdoutEvent = Event(
          kind: 'Stdout',
          timestamp: 0,
          bytes: base64.encode(utf8.encode('flutter: A flutter message')),
        );
        final Event stderrEvent = Event(
          kind: 'Stderr',
          timestamp: 0,
          bytes: base64.encode(utf8.encode('flutter: A second flutter message')),
        );
        final FlutterVmService vmService = FakeVmServiceHost(requests: <VmServiceExpectation>[
          const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
            'streamId': 'Debug',
          }),
          const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
            'streamId': 'Stdout',
          }),
          const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
            'streamId': 'Stderr',
          }),
          FakeVmServiceStreamResponse(event: stdoutEvent, streamId: 'Stdout'),
          FakeVmServiceStreamResponse(event: stderrEvent, streamId: 'Stderr'),
        ]).vmService;
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          useSyslog: false,
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: processManager,
            cache: fakeCache,
            logger: logger,
          ),
        );
        logReader.connectedVMService = vmService;

        // Wait for stream listeners to fire.
        expect(logReader.useUnifiedLogging, isTrue);
        expect(processManager, hasNoRemainingExpectations);
        await expectLater(logReader.logLines, emitsInAnyOrder(<Matcher>[
          equals('flutter: A flutter message'),
          equals('flutter: A second flutter message'),
        ]));
      });

      testWithoutContext('is false Dart VM does not send flutter messages to stream', () async {
        final Event stdoutEvent = Event(
          kind: 'Stdout',
          timestamp: 0,
          bytes: base64.encode(utf8.encode('flutter: A flutter message')),
        );
        final Event stderrEvent = Event(
          kind: 'Stderr',
          timestamp: 0,
          bytes: base64.encode(utf8.encode('flutter: A second flutter message')),
        );
        final FlutterVmService vmService = FakeVmServiceHost(requests: <VmServiceExpectation>[
          const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
            'streamId': 'Debug',
          }),
          const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
            'streamId': 'Stdout',
          }),
          const FakeVmServiceRequest(method: 'streamListen', args: <String, Object>{
            'streamId': 'Stderr',
          }),
          FakeVmServiceStreamResponse(event: stdoutEvent, streamId: 'Stdout'),
          FakeVmServiceStreamResponse(event: stderrEvent, streamId: 'Stderr'),
        ]).vmService;
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: FakeProcessManager.any(),
            cache: fakeCache,
            logger: logger,
          ),
          majorSdkVersion: 12,
        );
        logReader.connectedVMService = vmService;

        final List<String> lines = await logReader.logLines.toList();

        // Wait for stream listeners to fire.
        expect(logReader.useUnifiedLogging, isFalse);
        expect(processManager, hasNoRemainingExpectations);
        expect(lines, isEmpty);
      });
    });

    group('and when to exclude logs:', () {

      testWithoutContext('all primary messages are included except if fallback sent flutter message first', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: FakeProcessManager.any(),
            cache: fakeCache,
            logger: logger,
          ),
          usingCISystem: true,
          majorSdkVersion: 16,
        );

        expect(logReader.useSyslogLogging, isTrue);
        expect(logReader.useIOSDeployLogging, isTrue);
        expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
        expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.idevicesyslog);

        final Future<List<String>> logLines = logReader.logLines.toList();

        logReader.addToLinesController(
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/',
          IOSDeviceLogSource.idevicesyslog,
        );
        // Will be excluded because was already added by fallback.
        logReader.addToLinesController(
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/',
          IOSDeviceLogSource.iosDeploy,
        );
        logReader.addToLinesController(
          'A second non-flutter message',
          IOSDeviceLogSource.iosDeploy,
        );
        logReader.addToLinesController(
          'flutter: Another flutter message',
          IOSDeviceLogSource.iosDeploy,
        );
        final List<String> lines = await logLines;

        expect(lines, containsAllInOrder(<String>[
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/', // from idevicesyslog
          'A second non-flutter message', // from iosDeploy
          'flutter: Another flutter message', // from iosDeploy
        ]));
      });

      testWithoutContext('all primary messages are included when there is no fallback', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: FakeProcessManager.any(),
            cache: fakeCache,
            logger: logger,
          ),
          majorSdkVersion: 12,
        );

        expect(logReader.useSyslogLogging, isTrue);
        expect(logReader.logSources.primarySource, IOSDeviceLogSource.idevicesyslog);
        expect(logReader.logSources.fallbackSource, isNull);

        final Future<List<String>> logLines = logReader.logLines.toList();

        logReader.addToLinesController(
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/',
          IOSDeviceLogSource.idevicesyslog,
        );
        logReader.addToLinesController(
          'A non-flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        logReader.addToLinesController(
          'A non-flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        final List<String> lines = await logLines;

        expect(lines, containsAllInOrder(<String>[
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/',
          'A non-flutter message',
          'A non-flutter message',
          'flutter: A flutter message',
          'flutter: A flutter message',
        ]));
      });

      testWithoutContext('primary messages are not added if fallback already added them, otherwise duplicates are allowed', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: FakeProcessManager.any(),
            cache: fakeCache,
            logger: logger,
          ),
          usingCISystem: true,
          majorSdkVersion: 16,
        );

        expect(logReader.useSyslogLogging, isTrue);
        expect(logReader.useIOSDeployLogging, isTrue);
        expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
        expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.idevicesyslog);

        final Future<List<String>> logLines = logReader.logLines.toList();

        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        logReader.addToLinesController(
          'A non-flutter message',
          IOSDeviceLogSource.iosDeploy,
        );
        logReader.addToLinesController(
          'A non-flutter message',
          IOSDeviceLogSource.iosDeploy,
        );
        // Will be excluded because was already added by fallback.
        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.iosDeploy,
        );
        // Will be excluded because was already added by fallback.
        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.iosDeploy,
        );
        // Will be included because, although the message is the same, the
        // fallback only added it twice so this third one is considered new.
        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.iosDeploy,
        );

        final List<String> lines = await logLines;

        expect(lines, containsAllInOrder(<String>[
          'flutter: A flutter message', // from idevicesyslog
          'flutter: A flutter message', // from idevicesyslog
          'A non-flutter message', // from iosDeploy
          'A non-flutter message', // from iosDeploy
          'flutter: A flutter message', // from iosDeploy
        ]));
      });

      testWithoutContext('flutter fallback messages are included until a primary flutter message is received', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: FakeProcessManager.any(),
            cache: fakeCache,
            logger: logger,
          ),
          usingCISystem: true,
          majorSdkVersion: 16,
        );

        expect(logReader.useSyslogLogging, isTrue);
        expect(logReader.useIOSDeployLogging, isTrue);
        expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
        expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.idevicesyslog);

        final Future<List<String>> logLines = logReader.logLines.toList();

        logReader.addToLinesController(
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/',
          IOSDeviceLogSource.idevicesyslog,
        );
        logReader.addToLinesController(
          'A second non-flutter message',
          IOSDeviceLogSource.iosDeploy,
        );
        // Will be included because the first log from primary source wasn't a
        // flutter log.
        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        // Will be excluded because was already added by fallback, however, it
        // will be used to determine a flutter log was received by the primary source.
        logReader.addToLinesController(
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/',
          IOSDeviceLogSource.iosDeploy,
        );
        // Will be excluded because flutter log from primary was received.
        logReader.addToLinesController(
          'flutter: A third flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );

        final List<String> lines = await logLines;

        expect(lines, containsAllInOrder(<String>[
          'flutter: The Dart VM service is listening on http://127.0.0.1:63098/35ZezGIQLnw=/', // from idevicesyslog
          'A second non-flutter message', // from iosDeploy
          'flutter: A flutter message', // from idevicesyslog
        ]));
      });

      testWithoutContext('non-flutter fallback messages are not included', () async {
        final IOSDeviceLogReader logReader = IOSDeviceLogReader.test(
          iMobileDevice: IMobileDevice(
            artifacts: artifacts,
            processManager: FakeProcessManager.any(),
            cache: fakeCache,
            logger: logger,
          ),
          usingCISystem: true,
          majorSdkVersion: 16,
        );

        expect(logReader.useSyslogLogging, isTrue);
        expect(logReader.useIOSDeployLogging, isTrue);
        expect(logReader.logSources.primarySource, IOSDeviceLogSource.iosDeploy);
        expect(logReader.logSources.fallbackSource, IOSDeviceLogSource.idevicesyslog);

        final Future<List<String>> logLines = logReader.logLines.toList();

        logReader.addToLinesController(
          'flutter: A flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );
        // Will be excluded because it's from fallback and not a flutter message.
        logReader.addToLinesController(
          'A non-flutter message',
          IOSDeviceLogSource.idevicesyslog,
        );

        final List<String> lines = await logLines;

        expect(lines, containsAllInOrder(<String>[
          'flutter: A flutter message',
        ]));
      });
    });
  });
}

class FakeIOSDeployDebugger extends Fake implements IOSDeployDebugger {
  bool detached = false;

  @override
  bool debuggerAttached = false;

  @override
  Stream<String> logLines = const Stream<String>.empty();

  @override
  Future<void> detach() async {
    detached = true;
  }
}
