// 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:fake_async/fake_async.dart';
import 'package:file/memory.dart';
import 'package:file_testing/file_testing.dart';
import 'package:flutter_tools/src/base/file_system.dart';
import 'package:flutter_tools/src/base/logger.dart';
import 'package:flutter_tools/src/convert.dart';
import 'package:flutter_tools/src/tracing.dart';
import 'package:flutter_tools/src/vmservice.dart';
import 'package:vm_service/vm_service.dart' as vm_service;

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

final vm_service.Isolate fakeUnpausedIsolate = vm_service.Isolate(
  id: '1',
  pauseEvent: vm_service.Event(
    kind: vm_service.EventKind.kResume,
    timestamp: 0
  ),
  breakpoints: <vm_service.Breakpoint>[],
  libraries: <vm_service.LibraryRef>[
    vm_service.LibraryRef(
      id: '1',
      uri: 'file:///hello_world/main.dart',
      name: '',
    ),
  ],
  livePorts: 0,
  name: 'test',
  number: '1',
  pauseOnExit: false,
  runnable: true,
  startTime: 0,
  isSystemIsolate: false,
  isolateFlags: <vm_service.IsolateFlag>[],
);

final FlutterView fakeFlutterView = FlutterView(
  id: 'a',
  uiIsolate: fakeUnpausedIsolate,
);

final FakeVmServiceRequest listViews = FakeVmServiceRequest(
  method: kListViewsMethod,
  jsonResponse: <String, Object>{
    'views': <Object>[
      fakeFlutterView.toJson(),
    ],
  },
);

final List<FakeVmServiceRequest> vmServiceSetup = <FakeVmServiceRequest>[
  const FakeVmServiceRequest(
    method: 'streamListen',
    args: <String, Object>{
      'streamId': vm_service.EventKind.kExtension,
    }
  ),
  listViews,
  // Satisfies didAwaitFirstFrame
  const FakeVmServiceRequest(
    method: 'ext.flutter.didSendFirstFrameRasterizedEvent',
    args: <String, Object>{
      'isolateId': '1',
    },
    jsonResponse: <String, Object>{
      'enabled': 'true',
    },
  ),
];

void main() {
  testWithoutContext('Can trace application startup', () async {
    final BufferLogger logger = BufferLogger.test();
    final FileSystem fileSystem = MemoryFileSystem.test();
    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(requests: <FakeVmServiceRequest>[
      ...vmServiceSetup,
      FakeVmServiceRequest(
        method: 'getVMTimeline',
        jsonResponse: vm_service.Timeline(
          timeExtentMicros: 4,
          timeOriginMicros: 0,
          traceEvents: <vm_service.TimelineEvent>[
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFlutterEngineMainEnterEventName,
              'ts': 0,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFrameworkInitEventName,
              'ts': 1,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFirstFrameBuiltEventName,
              'ts': 2,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFirstFrameRasterizedEventName,
              'ts': 3,
            })!,
          ],
        ).toJson(),
      ),
      const FakeVmServiceRequest(
        method: 'setVMTimelineFlags',
        args: <String, Object>{
          'recordedStreams': <Object>[],
        },
      ),
    ]);

    // Validate that old tracing data is deleted.
    final File outFile = fileSystem.currentDirectory.childFile('start_up_info.json')
      ..writeAsStringSync('stale');

    await downloadStartupTrace(fakeVmServiceHost.vmService,
      output: fileSystem.currentDirectory,
      logger: logger,
    );

    expect(outFile, exists);
    expect(json.decode(outFile.readAsStringSync()), <String, Object>{
      'engineEnterTimestampMicros': 0,
      'timeToFrameworkInitMicros': 1,
      'timeToFirstFrameRasterizedMicros': 3,
      'timeToFirstFrameMicros': 2,
      'timeAfterFrameworkInitMicros': 1,
    });
  });

  testWithoutContext('throws tool exit if the vmservice disconnects', () async {
    final BufferLogger logger = BufferLogger.test();
    final FileSystem fileSystem = MemoryFileSystem.test();
    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(requests: <FakeVmServiceRequest>[
      ...vmServiceSetup,
      const FakeVmServiceRequest(
        method: 'getVMTimeline',
        error: FakeRPCError(code: RPCErrorCodes.kServiceDisappeared),
      ),
      const FakeVmServiceRequest(
        method: 'setVMTimelineFlags',
        args: <String, Object>{
          'recordedStreams': <Object>[],
        },
      ),
    ]);

    await expectLater(() async => downloadStartupTrace(fakeVmServiceHost.vmService,
      output: fileSystem.currentDirectory,
      logger: logger,
    ), throwsToolExit(message: 'The device disconnected before the timeline could be retrieved.'));
  });

  testWithoutContext('throws tool exit if timeline is missing the engine start event', () async {
    final BufferLogger logger = BufferLogger.test();
    final FileSystem fileSystem = MemoryFileSystem.test();
    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(requests: <FakeVmServiceRequest>[
      ...vmServiceSetup,
      FakeVmServiceRequest(
        method: 'getVMTimeline',
        jsonResponse: vm_service.Timeline(
          timeExtentMicros: 4,
          timeOriginMicros: 0,
          traceEvents: <vm_service.TimelineEvent>[],
        ).toJson(),
      ),
      const FakeVmServiceRequest(
        method: 'setVMTimelineFlags',
        args: <String, Object>{
          'recordedStreams': <Object>[],
        },
      ),
    ]);

    await expectLater(() async => downloadStartupTrace(fakeVmServiceHost.vmService,
      output: fileSystem.currentDirectory,
      logger: logger,
    ), throwsToolExit(message: 'Engine start event is missing in the timeline'));
  });

  testWithoutContext('prints when first frame is taking a long time', () async {
    final BufferLogger logger = BufferLogger.test();
    final FileSystem fileSystem = MemoryFileSystem.test();
    final Completer<void> completer = Completer<void>();
    await FakeAsync().run((FakeAsync time) {
      final Map<String, String> extensionData = <String, String>{
        'test': 'data',
        'renderedErrorText': 'error text',
      };
      final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(requests: <VmServiceExpectation>[
        const FakeVmServiceRequest(
          method: 'streamListen',
          args: <String, Object>{
            'streamId': vm_service.EventKind.kExtension,
          }
        ),
        const FakeVmServiceRequest(
          method: kListViewsMethod,
          jsonResponse: <String, Object>{
            'views': <Object>[
              <String, Object?>{
              'id': '1',
              // No isolate, no views.
              'isolate': null,
              }
            ],
          },
        ),
        FakeVmServiceStreamResponse(
          streamId: 'Extension',
          event: vm_service.Event(
            timestamp: 0,
            extensionKind: 'Flutter.Error',
            extensionData: vm_service.ExtensionData.parse(extensionData),
            kind: vm_service.EventStreams.kExtension,
          ),
        ),
      ]);
      unawaited(downloadStartupTrace(fakeVmServiceHost.vmService,
        output: fileSystem.currentDirectory,
        logger: logger,
      ));
      time.elapse(const Duration(seconds: 11));
      time.flushMicrotasks();
      completer.complete();
      return completer.future;
    });
    expect(logger.statusText, contains('First frame is taking longer than expected'));
    expect(logger.traceText, contains('View ID: 1'));
    expect(logger.traceText, contains('No isolate ID associated with the view'));
    expect(logger.traceText, contains('Flutter.Error: [ExtensionData {test: data, renderedErrorText: error text}]'));
  });

  testWithoutContext('throws tool exit if first frame events are missing', () async {
    final BufferLogger logger = BufferLogger.test();
    final FileSystem fileSystem = MemoryFileSystem.test();
    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(requests: <FakeVmServiceRequest>[
      ...vmServiceSetup,
      FakeVmServiceRequest(
        method: 'getVMTimeline',
        jsonResponse: vm_service.Timeline(
          timeExtentMicros: 4,
          timeOriginMicros: 0,
          traceEvents: <vm_service.TimelineEvent>[
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFlutterEngineMainEnterEventName,
              'ts': 0,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFrameworkInitEventName,
              'ts': 1,
            })!,
          ],
        ).toJson(),
      ),
      const FakeVmServiceRequest(
        method: 'setVMTimelineFlags',
        args: <String, Object>{
          'recordedStreams': <Object>[],
        },
      ),
    ]);

    await expectLater(() async => downloadStartupTrace(fakeVmServiceHost.vmService,
      output: fileSystem.currentDirectory,
      logger: logger,
    ), throwsToolExit(message: 'First frame events are missing in the timeline'));
  });

  testWithoutContext('Can trace application startup without awaiting for first frame', () async {
    final BufferLogger logger = BufferLogger.test();
    final FileSystem fileSystem = MemoryFileSystem.test();
    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(requests: <FakeVmServiceRequest>[
      FakeVmServiceRequest(
        method: 'getVMTimeline',
        jsonResponse: vm_service.Timeline(
          timeExtentMicros: 4,
          timeOriginMicros: 0,
          traceEvents: <vm_service.TimelineEvent>[
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFlutterEngineMainEnterEventName,
              'ts': 0,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFrameworkInitEventName,
              'ts': 1,
            })!,
          ],
        ).toJson(),
      ),
      const FakeVmServiceRequest(
        method: 'setVMTimelineFlags',
        args: <String, Object>{
          'recordedStreams': <Object>[],
        },
      ),
    ]);

    final File outFile = fileSystem.currentDirectory.childFile('start_up_info.json');

    await downloadStartupTrace(fakeVmServiceHost.vmService,
      output: fileSystem.currentDirectory,
      logger: logger,
      awaitFirstFrame: false,
    );

    expect(outFile, exists);
    expect(json.decode(outFile.readAsStringSync()), <String, Object>{
      'engineEnterTimestampMicros': 0,
      'timeToFrameworkInitMicros': 1,
    });
  });

  testWithoutContext('downloadStartupTrace also downloads the timeline', () async {
    final BufferLogger logger = BufferLogger.test();
    final FileSystem fileSystem = MemoryFileSystem.test();
    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(requests: <FakeVmServiceRequest>[
      ...vmServiceSetup,
      FakeVmServiceRequest(
        method: 'getVMTimeline',
        jsonResponse: vm_service.Timeline(
          timeExtentMicros: 4,
          timeOriginMicros: 0,
          traceEvents: <vm_service.TimelineEvent>[
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFlutterEngineMainEnterEventName,
              'ts': 0,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFrameworkInitEventName,
              'ts': 1,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFirstFrameBuiltEventName,
              'ts': 2,
            })!,
            vm_service.TimelineEvent.parse(<String, Object>{
              'name': kFirstFrameRasterizedEventName,
              'ts': 3,
            })!,
          ],
        ).toJson(),
      ),
      const FakeVmServiceRequest(
        method: 'setVMTimelineFlags',
        args: <String, Object>{
          'recordedStreams': <Object>[],
        },
      ),
    ]);

    // Validate that old tracing data is deleted.
    final File timelineFile = fileSystem.currentDirectory.childFile('start_up_timeline.json')
      ..writeAsStringSync('stale');

    await downloadStartupTrace(fakeVmServiceHost.vmService,
      output: fileSystem.currentDirectory,
      logger: logger,
    );

    final Map<String, Object> expectedTimeline = <String, Object>{
      'type': 'Timeline',
      'traceEvents': <Object>[
        <String, Object>{
          'name': 'FlutterEngineMainEnter',
          'ts': 0,
          'type': 'TimelineEvent',
        },
        <String, Object>{
          'name': 'Framework initialization',
          'ts': 1,
          'type': 'TimelineEvent',
        },
        <String, Object>{
          'name': 'Widgets built first useful frame',
          'ts': 2,
          'type': 'TimelineEvent',
        },
        <String, Object>{
          'name': 'Rasterized first useful frame',
          'ts': 3,
          'type': 'TimelineEvent',
        },
      ],
      'timeOriginMicros': 0,
      'timeExtentMicros': 4,
    };

    expect(timelineFile, exists);
    expect(json.decode(timelineFile.readAsStringSync()), expectedTimeline);
  });
}