// 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:file/memory.dart';
import 'package:flutter_tools/src/artifacts.dart';
import 'package:flutter_tools/src/base/io.dart';
import 'package:flutter_tools/src/base/logger.dart';
import 'package:flutter_tools/src/base/platform.dart';
import 'package:flutter_tools/src/build_info.dart';
import 'package:flutter_tools/src/compile.dart';
import 'package:flutter_tools/src/convert.dart';
import 'package:package_config/package_config.dart';
import 'package:process/process.dart';
import 'package:test/fake.dart';

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

void main() {
  late FakeProcessManager processManager;
  late ResidentCompiler generator;
  late MemoryIOSink frontendServerStdIn;
  late StreamController<String> stdErrStreamController;
  late BufferLogger testLogger;
  late MemoryFileSystem fileSystem;

  setUp(() {
    testLogger = BufferLogger.test();
    processManager = FakeProcessManager();
    frontendServerStdIn = MemoryIOSink();
    fileSystem = MemoryFileSystem.test();
    generator = ResidentCompiler(
      'sdkroot',
      buildMode: BuildMode.debug,
      artifacts: Artifacts.test(),
      processManager: processManager,
      logger: testLogger,
      platform: FakePlatform(),
      fileSystem: fileSystem,
    );

    stdErrStreamController = StreamController<String>();
    processManager.process.stdin = frontendServerStdIn;
    processManager.process.stderr = stdErrStreamController.stream.transform(utf8.encoder);
  });

  testWithoutContext('compile expression fails if not previously compiled', () async {
    final CompilerOutput? result = await generator.compileExpression(
        '2+2', null, null, null, null, null, null, null, null, false);

    expect(result, isNull);
  });

  testWithoutContext('compile expression can compile single expression', () async {
    final Completer<List<int>> compileResponseCompleter =
        Completer<List<int>>();
    final Completer<List<int>> compileExpressionResponseCompleter =
        Completer<List<int>>();
    fileSystem.file('/path/to/main.dart.dill')
      ..createSync(recursive: true)
      ..writeAsBytesSync(<int>[1, 2, 3, 4]);

    processManager.process.stdout = Stream<List<int>>.fromFutures(
      <Future<List<int>>>[
        compileResponseCompleter.future,
        compileExpressionResponseCompleter.future,
      ],
    );
    compileResponseCompleter.complete(Future<List<int>>.value(utf8.encode(
      'result abc\nline1\nline2\nabc\nabc /path/to/main.dart.dill 0\n'
    )));

    await generator.recompile(
      Uri.file('/path/to/main.dart'),
      null, /* invalidatedFiles */
      outputPath: '/build/',
      packageConfig: PackageConfig.empty,
      projectRootPath: '',
      fs: fileSystem,
    ).then((CompilerOutput? output) {
      expect(frontendServerStdIn.getAndClear(),
          'compile file:///path/to/main.dart\n');
      expect(testLogger.errorText,
          equals('line1\nline2\n'));
      expect(output!.outputFilename, equals('/path/to/main.dart.dill'));

      compileExpressionResponseCompleter.complete(
          Future<List<int>>.value(utf8.encode(
              'result def\nline1\nline2\ndef\ndef /path/to/main.dart.dill.incremental 0\n'
          )));
      generator.compileExpression(
          '2+2', null, null, null, null, null, null, null, null, false).then(
              (CompilerOutput? outputExpression) {
                expect(outputExpression, isNotNull);
                expect(outputExpression!.expressionData, <int>[1, 2, 3, 4]);
              }
      );
    });
  });

  testWithoutContext('compile expressions without awaiting', () async {
    final Completer<List<int>> compileResponseCompleter = Completer<List<int>>();
    final Completer<List<int>> compileExpressionResponseCompleter1 = Completer<List<int>>();
    final Completer<List<int>> compileExpressionResponseCompleter2 = Completer<List<int>>();


    processManager.process.stdout =
      Stream<List<int>>.fromFutures(
          <Future<List<int>>>[
            compileResponseCompleter.future,
            compileExpressionResponseCompleter1.future,
            compileExpressionResponseCompleter2.future,
          ]);

    // The test manages timing via completers.
    unawaited(
      generator.recompile(
        Uri.parse('/path/to/main.dart'),
        null, /* invalidatedFiles */
        outputPath: '/build/',
        packageConfig: PackageConfig.empty,
        projectRootPath: '',
        fs: MemoryFileSystem(),
      ).then((CompilerOutput? outputCompile) {
        expect(testLogger.errorText,
            equals('line1\nline2\n'));
        expect(outputCompile!.outputFilename, equals('/path/to/main.dart.dill'));

        fileSystem.file('/path/to/main.dart.dill.incremental')
          ..createSync(recursive: true)
          ..writeAsBytesSync(<int>[0, 1, 2, 3]);
        compileExpressionResponseCompleter1.complete(Future<List<int>>.value(utf8.encode(
            'result def\nline1\nline2\ndef /path/to/main.dart.dill.incremental 0\n'
        )));
      }),
    );

    // The test manages timing via completers.
    final Completer<bool> lastExpressionCompleted = Completer<bool>();
    unawaited(
      generator.compileExpression('0+1', null, null, null, null, null, null,
          null, null, false).then(
        (CompilerOutput? outputExpression) {
          expect(outputExpression, isNotNull);
          expect(outputExpression!.expressionData, <int>[0, 1, 2, 3]);

          fileSystem.file('/path/to/main.dart.dill.incremental')
            ..createSync(recursive: true)
            ..writeAsBytesSync(<int>[4, 5, 6, 7]);
          compileExpressionResponseCompleter2.complete(Future<List<int>>.value(utf8.encode(
              'result def\nline1\nline2\ndef /path/to/main.dart.dill.incremental 0\n'
          )));
        },
      ),
    );

    // The test manages timing via completers.
    unawaited(
      generator.compileExpression('1+1', null, null, null, null, null, null,
          null, null, false).then(
        (CompilerOutput? outputExpression) {
          expect(outputExpression, isNotNull);
          expect(outputExpression!.expressionData, <int>[4, 5, 6, 7]);
          lastExpressionCompleted.complete(true);
        },
      ),
    );

    compileResponseCompleter.complete(Future<List<int>>.value(utf8.encode(
        'result abc\nline1\nline2\nabc\nabc /path/to/main.dart.dill 0\n'
    )));

    expect(await lastExpressionCompleted.future, isTrue);
  });
}

class FakeProcess extends Fake implements Process {
  @override
  Stream<List<int>> stdout = const Stream<List<int>>.empty();

  @override
  Stream<List<int>> stderr = const Stream<List<int>>.empty();

  @override
  IOSink stdin = IOSink(StreamController<List<int>>().sink);

  @override
  Future<int> get exitCode => Completer<int>().future;
}

class FakeProcessManager extends Fake implements ProcessManager {
  final FakeProcess process = FakeProcess();

  @override
  bool canRun(dynamic executable, {String? workingDirectory}) {
    return true;
  }

  @override
  Future<Process> start(List<Object> command, {String? workingDirectory, Map<String, String>? environment, bool includeParentEnvironment = true, bool runInShell = false, ProcessStartMode mode = ProcessStartMode.normal}) async {
    return process;
  }
}