// 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:dds/dap.dart';
import 'package:dds/src/dap/protocol_generated.dart';
import 'package:file/file.dart';
import 'package:flutter_tools/src/cache.dart';
import 'package:flutter_tools/src/globals.dart' as globals;

import '../../src/common.dart';
import '../test_data/basic_project.dart';
import '../test_data/compile_error_project.dart';
import '../test_utils.dart';
import 'test_client.dart';
import 'test_support.dart';

void main() {
  late Directory tempDir;
  late DapTestSession dap;
  final String relativeMainPath = 'lib${fileSystem.path.separator}main.dart';

  setUpAll(() {
    Cache.flutterRoot = getFlutterRoot();
  });

  setUp(() async {
    tempDir = createResolvedTempDirectorySync('flutter_adapter_test.');
    dap = await DapTestSession.setUp();
  });

  tearDown(() async {
    await dap.tearDown();
    tryToDelete(tempDir);
  });

  group('launch', () {
    testWithoutContext('can run and terminate a Flutter app in debug mode', () async {
      final BasicProject project = BasicProject();
      await project.setUpIn(tempDir);

      // Once the "topLevelFunction" output arrives, we can terminate the app.
      unawaited(
        dap.client.output
            .firstWhere((String output) => output.startsWith('topLevelFunction'))
            .whenComplete(() => dap.client.terminate()),
      );

      final List<OutputEventBody> outputEvents = await dap.client.collectAllOutput(
        launch: () => dap.client
            .launch(
              cwd: project.dir.path,
              toolArgs: <String>['-d', 'flutter-tester'],
            ),
      );

      final String output = _uniqueOutputLines(outputEvents);

      expectLines(output, <Object>[
        'Launching $relativeMainPath on Flutter test device in debug mode...',
        startsWith('Connecting to VM Service at'),
        'topLevelFunction',
        '',
        startsWith('Exited'),
      ]);
    });

    testWithoutContext('can run and terminate a Flutter app in noDebug mode', () async {
      final BasicProject project = BasicProject();
      await project.setUpIn(tempDir);

      // Once the "topLevelFunction" output arrives, we can terminate the app.
      unawaited(
        dap.client.stdoutOutput
            .firstWhere((String output) => output.startsWith('topLevelFunction'))
            .whenComplete(() => dap.client.terminate()),
      );

      final List<OutputEventBody> outputEvents = await dap.client.collectAllOutput(
        launch: () => dap.client
            .launch(
              cwd: project.dir.path,
              noDebug: true,
              toolArgs: <String>['-d', 'flutter-tester'],
            ),
      );

      final String output = _uniqueOutputLines(outputEvents);

      expectLines(output, <Object>[
        'Launching $relativeMainPath on Flutter test device in debug mode...',
        'topLevelFunction',
        '',
        startsWith('Exited'),
      ]);
    });

    testWithoutContext('correctly outputs launch errors and terminates', () async {
      final CompileErrorProject project = CompileErrorProject();
      await project.setUpIn(tempDir);

      final List<OutputEventBody> outputEvents = await dap.client.collectAllOutput(
        launch: () => dap.client
            .launch(
              cwd: project.dir.path,
              toolArgs: <String>['-d', 'flutter-tester'],
            ),
      );

      final String output = _uniqueOutputLines(outputEvents);
      expect(output, contains('this code does not compile'));
      expect(output, contains('Exception: Failed to build'));
      expect(output, contains('Exited (1)'));
    });

    testWithoutContext('can hot reload', () async {
      final BasicProject project = BasicProject();
      await project.setUpIn(tempDir);

      // Launch the app and wait for it to print "topLevelFunction".
      await Future.wait(<Future<void>>[
        dap.client.stdoutOutput.firstWhere((String output) => output.startsWith('topLevelFunction')),
        dap.client.start(
          launch: () => dap.client.launch(
            cwd: project.dir.path,
            noDebug: true,
            toolArgs: <String>['-d', 'flutter-tester'],
          ),
        ),
      ], eagerError: true);

      // Capture the next two output events that we expect to be the Reload
      // notification and then topLevelFunction being printed again.
      final Future<List<String>> outputEventsFuture = dap.client.stdoutOutput
          // But skip any topLevelFunctions that come before the reload.
          .skipWhile((String output) => output.startsWith('topLevelFunction'))
          .take(2)
          .toList();

      await dap.client.hotReload();

      expectLines(
          (await outputEventsFuture).join(),
          <Object>[
            startsWith('Reloaded'),
            'topLevelFunction',
          ],
      );

      await dap.client.terminate();
    });

    testWithoutContext('can hot restart', () async {
      final BasicProject project = BasicProject();
      await project.setUpIn(tempDir);

      // Launch the app and wait for it to print "topLevelFunction".
      await Future.wait(<Future<void>>[
        dap.client.stdoutOutput.firstWhere((String output) => output.startsWith('topLevelFunction')),
        dap.client.start(
          launch: () => dap.client.launch(
            cwd: project.dir.path,
            noDebug: true,
            toolArgs: <String>['-d', 'flutter-tester'],
          ),
        ),
      ], eagerError: true);

      // Capture the next two output events that we expect to be the Restart
      // notification and then topLevelFunction being printed again.
      final Future<List<String>> outputEventsFuture = dap.client.stdoutOutput
          // But skip any topLevelFunctions that come before the restart.
          .skipWhile((String output) => output.startsWith('topLevelFunction'))
          .take(2)
          .toList();

      await dap.client.hotRestart();

      expectLines(
          (await outputEventsFuture).join(),
          <Object>[
            startsWith('Restarted application'),
            'topLevelFunction',
          ],
      );

      await dap.client.terminate();
    });

    testWithoutContext('can hot restart when exceptions occur on outgoing isolates', () async {
      final BasicProjectThatThrows project = BasicProjectThatThrows();
      await project.setUpIn(tempDir);

      // Launch the app and wait for it to stop at an exception.
      late int originalThreadId, newThreadId;
      await Future.wait(<Future<void>>[
        // Capture the thread ID of the stopped thread.
        dap.client.stoppedEvents.first.then((StoppedEventBody event) => originalThreadId = event.threadId!),
        dap.client.start(
          exceptionPauseMode: 'All', // Ensure we stop on all exceptions
          launch: () => dap.client.launch(
            cwd: project.dir.path,
            toolArgs: <String>['-d', 'flutter-tester'],
          ),
        ),
      ], eagerError: true);

      // Hot restart, ensuring it completes and capturing the ID of the new thread
      // to pause.
      await Future.wait(<Future<void>>[
        // Capture the thread ID of the newly stopped thread.
        dap.client.stoppedEvents.first.then((StoppedEventBody event) => newThreadId = event.threadId!),
        dap.client.hotRestart(),
      ], eagerError: true);

      // We should not have stopped on the original thread, but the new thread
      // from after the restart.
      expect(newThreadId, isNot(equals(originalThreadId)));

      await dap.client.terminate();
    });

    testWithoutContext('sends events for extension state updates', () async {
      final BasicProject project = BasicProject();
      await project.setUpIn(tempDir);
      const String debugPaintRpc = 'ext.flutter.debugPaint';

      // Create a future to capture the isolate ID when the debug paint service
      // extension loads, as we'll need that to call it later.
      final Future<String> isolateIdForDebugPaint = dap.client
          .serviceExtensionAdded(debugPaintRpc)
          .then((Map<String, Object?> body) => body['isolateId']! as String);

      // Launch the app and wait for it to print "topLevelFunction" so we know
      // it's up and running.
      await Future.wait(<Future<void>>[
        dap.client.stdoutOutput.firstWhere((String output) => output.startsWith('topLevelFunction')),
        dap.client.start(
          launch: () => dap.client.launch(
            cwd: project.dir.path,
            toolArgs: <String>['-d', 'flutter-tester'],
          ),
        ),
      ], eagerError: true);

      // Capture the next relevant state-change event (which should occur as a
      // result of the call below).
      final Future<Map<String, Object?>> stateChangeEventFuture =
          dap.client.serviceExtensionStateChanged(debugPaintRpc);

      // Enable debug paint to trigger the state change.
      await dap.client.custom(
        'callService',
        <String, Object?>{
          'method': debugPaintRpc,
          'params': <String, Object?>{
            'enabled': true,
            'isolateId': await isolateIdForDebugPaint,
          },
        },
      );

      // Ensure the event occurred, and its value was as expected.
      final Map<String, Object?> stateChangeEvent = await stateChangeEventFuture;
      expect(stateChangeEvent['value'], 'true'); // extension state change values are always strings

      await dap.client.terminate();
    });
  });

  group('attach', () {
    late SimpleFlutterRunner testProcess;
    late BasicProject project;
    late String breakpointFilePath;
    late int breakpointLine;
    setUp(() async {
      project = BasicProject();
      await project.setUpIn(tempDir);
      testProcess = await SimpleFlutterRunner.start(tempDir);

      breakpointFilePath = globals.fs.path.join(project.dir.path, 'lib', 'main.dart');
      breakpointLine = project.buildMethodBreakpointLine;
    });

    tearDown(() async {
      testProcess.process.kill();
      await testProcess.process.exitCode;
    });

    testWithoutContext('can attach to an already-running Flutter app and reload', () async {
      final Uri vmServiceUri = await testProcess.vmServiceUri;

      // Launch the app and wait for it to print "topLevelFunction".
      await Future.wait(<Future<void>>[
        dap.client.stdoutOutput.firstWhere((String output) => output.startsWith('topLevelFunction')),
        dap.client.start(
          launch: () => dap.client.attach(
            cwd: project.dir.path,
            toolArgs: <String>['-d', 'flutter-tester'],
            vmServiceUri: vmServiceUri.toString(),
          ),
        ),
      ], eagerError: true);

      // Capture the "Reloaded" output and events immediately after.
      final Future<List<String>> outputEventsFuture = dap.client.stdoutOutput
          .skipWhile((String output) => !output.startsWith('Reloaded'))
          .take(4)
          .toList();

      // Perform the reload, and expect we get the Reloaded output followed
      // by printed output, to ensure the app is running again.
      await dap.client.hotReload();
      expectLines(
          (await outputEventsFuture).join(),
          <Object>[
            startsWith('Reloaded'),
            'topLevelFunction',
          ],
          allowExtras: true,
      );

      await dap.client.terminate();
    });

    testWithoutContext('can attach to an already-running Flutter app and hit breakpoints', () async {
      final Uri vmServiceUri = await testProcess.vmServiceUri;

      // Launch the app and wait for it to print "topLevelFunction".
      await Future.wait(<Future<void>>[
        dap.client.stdoutOutput.firstWhere((String output) => output.startsWith('topLevelFunction')),
        dap.client.start(
          launch: () => dap.client.attach(
            cwd: project.dir.path,
            toolArgs: <String>['-d', 'flutter-tester'],
            vmServiceUri: vmServiceUri.toString(),
          ),
        ),
      ], eagerError: true);

      // Set a breakpoint and expect to hit it.
      final Future<StoppedEventBody> stoppedFuture = dap.client.stoppedEvents.firstWhere((StoppedEventBody e) => e.reason == 'breakpoint');
      await Future.wait(<Future<void>>[
        stoppedFuture,
        dap.client.setBreakpoint(breakpointFilePath, breakpointLine),
      ], eagerError: true);
      final int threadId = (await stoppedFuture).threadId!;

      // Remove the breakpoint and resume.
      await dap.client.clearBreakpoints(breakpointFilePath);
      await dap.client.continue_(threadId);

      await dap.client.terminate();
    });
  });
}

/// Extracts the output from a set of [OutputEventBody], removing any
/// adjacent duplicates and combining into a single string.
String _uniqueOutputLines(List<OutputEventBody> outputEvents) {
  String? lastItem;
  return outputEvents
      .map((OutputEventBody e) => e.output)
      .where((String output) {
        // Skip the item if it's the same as the previous one.
        final bool isDupe = output == lastItem;
        lastItem = output;
        return !isDupe;
      })
      .join();
}