// 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 'dart:io';

import 'package:path/path.dart' as path;

import '../framework/devices.dart';
import '../framework/framework.dart';
import '../framework/task_result.dart';
import '../framework/utils.dart';
import '../microbenchmarks.dart';

/// Creates a device lab task that runs benchmarks in
/// `dev/benchmarks/microbenchmarks` reports results to the dashboard.
TaskFunction createMicrobenchmarkTask({
  bool? enableImpeller,
  Map<String, String> environment = const <String, String>{},
}) {

  // Generate a seed for this test stable around the date.
  final DateTime seedDate = DateTime.now().toUtc().subtract(const Duration(hours: 7));
  final int seed = DateTime(seedDate.year, seedDate.month, seedDate.day).hashCode;

  return () async {
    final Device device = await devices.workingDevice;
    await device.unlock();
    await device.clearLogs();

    final Directory appDir =
        dir(path.join(flutterDirectory.path, 'dev/benchmarks/microbenchmarks'));

    // Hard-uninstall any prior apps.
    await inDirectory(appDir, () async {
      section('Uninstall previous microbenchmarks app');
      await flutter(
        'install',
        options: <String>[
          '-v',
          '--uninstall-only',
          '-d',
          device.deviceId,
        ],
      );
    });

    Future<Map<String, double>> runMicrobench(String benchmarkPath) async {
      Future<Map<String, double>> run() async {
        print('Running $benchmarkPath with seed $seed');

        final Process flutterProcess = await inDirectory(appDir, () async {
          final List<String> options = <String>[
            '-v',
            // --release doesn't work on iOS due to code signing issues
            '--profile',
            '--no-publish-port',
            if (enableImpeller != null && enableImpeller) '--enable-impeller',
            if (enableImpeller != null && !enableImpeller) '--no-enable-impeller',
            '-d',
            device.deviceId,
            '--dart-define=seed=$seed',
            benchmarkPath,
          ];
          return startFlutter(
            'run',
            options: options,
            environment: environment,
          );
        });
        return readJsonResults(flutterProcess);
      }

      return run();
    }

    final Map<String, double> allResults = <String, double>{
      ...await runMicrobench('lib/benchmark_collection.dart'),
    };

    return TaskResult.success(allResults,
        benchmarkScoreKeys: allResults.keys.toList());
  };
}