// Copyright 2013 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/file.dart';
import 'package:path/path.dart' as p;
import 'package:platform/platform.dart';
import 'common.dart';

/// A command to run the example applications for packages via Flutter driver.
class DriveExamplesCommand extends PluginCommand {
  /// Creates an instance of the drive command.
  DriveExamplesCommand(
    Directory packagesDir, {
    ProcessRunner processRunner = const ProcessRunner(),
  }) : super(packagesDir, processRunner: processRunner) {
    argParser.addFlag(kPlatformFlagAndroid,
        help: 'Runs the Android implementation of the examples');
    argParser.addFlag(kPlatformFlagIos,
        help: 'Runs the iOS implementation of the examples');
    argParser.addFlag(kPlatformFlagLinux,
        help: 'Runs the Linux implementation of the examples');
    argParser.addFlag(kPlatformFlagMacos,
        help: 'Runs the macOS implementation of the examples');
    argParser.addFlag(kPlatformFlagWeb,
        help: 'Runs the web implementation of the examples');
    argParser.addFlag(kPlatformFlagWindows,
        help: 'Runs the Windows implementation of the examples');
    argParser.addOption(
      kEnableExperiment,
      defaultsTo: '',
      help:
          'Runs the driver tests in Dart VM with the given experiments enabled.',
    );
  }

  @override
  final String name = 'drive-examples';

  @override
  final String description = 'Runs driver tests for plugin example apps.\n\n'
      'For each *_test.dart in test_driver/ it drives an application with a '
      'corresponding name in the test/ or test_driver/ directories.\n\n'
      'For example, test_driver/app_test.dart would match test/app.dart.\n\n'
      'This command requires "flutter" to be in your path.\n\n'
      'If a file with a corresponding name cannot be found, this driver file'
      'will be used to drive the tests that match '
      'integration_test/*_test.dart.';

  @override
  Future<void> run() async {
    final List<String> failingTests = <String>[];
    final List<String> pluginsWithoutTests = <String>[];
    final bool isLinux = getBoolArg(kPlatformFlagLinux);
    final bool isMacos = getBoolArg(kPlatformFlagMacos);
    final bool isWeb = getBoolArg(kPlatformFlagWeb);
    final bool isWindows = getBoolArg(kPlatformFlagWindows);
    await for (final Directory plugin in getPlugins()) {
      final String pluginName = plugin.basename;
      if (pluginName.endsWith('_platform_interface') &&
          !plugin.childDirectory('example').existsSync()) {
        // Platform interface packages generally aren't intended to have
        // examples, and don't need integration tests, so silently skip them
        // unless for some reason there is an example directory.
        continue;
      }
      print('\n==========\nChecking $pluginName...');
      if (!(await _pluginSupportedOnCurrentPlatform(plugin))) {
        print('Not supported for the target platform; skipping.');
        continue;
      }
      int examplesFound = 0;
      bool testsRan = false;
      final String flutterCommand =
          const LocalPlatform().isWindows ? 'flutter.bat' : 'flutter';
      for (final Directory example in getExamplesForPlugin(plugin)) {
        ++examplesFound;
        final String packageName =
            p.relative(example.path, from: packagesDir.path);
        final Directory driverTests = example.childDirectory('test_driver');
        if (!driverTests.existsSync()) {
          print('No driver tests found for $packageName');
          continue;
        }
        // Look for driver tests ending in _test.dart in test_driver/
        await for (final FileSystemEntity test in driverTests.list()) {
          final String driverTestName =
              p.relative(test.path, from: driverTests.path);
          if (!driverTestName.endsWith('_test.dart')) {
            continue;
          }
          // Try to find a matching app to drive without the _test.dart
          final String deviceTestName = driverTestName.replaceAll(
            RegExp(r'_test.dart$'),
            '.dart',
          );
          String deviceTestPath = p.join('test', deviceTestName);
          if (!example.fileSystem
              .file(p.join(example.path, deviceTestPath))
              .existsSync()) {
            // If the app isn't in test/ folder, look in test_driver/ instead.
            deviceTestPath = p.join('test_driver', deviceTestName);
          }

          final List<String> targetPaths = <String>[];
          if (example.fileSystem
              .file(p.join(example.path, deviceTestPath))
              .existsSync()) {
            targetPaths.add(deviceTestPath);
          } else {
            final Directory integrationTests =
                example.childDirectory('integration_test');

            if (await integrationTests.exists()) {
              await for (final FileSystemEntity integrationTest
                  in integrationTests.list()) {
                if (!integrationTest.basename.endsWith('_test.dart')) {
                  continue;
                }
                targetPaths
                    .add(p.relative(integrationTest.path, from: example.path));
              }
            }

            if (targetPaths.isEmpty) {
              print('''
Unable to infer a target application for $driverTestName to drive.
Tried searching for the following:
1. test/$deviceTestName
2. test_driver/$deviceTestName
3. test_driver/*_test.dart
''');
              failingTests.add(p.relative(test.path, from: example.path));
              continue;
            }
          }

          final List<String> driveArgs = <String>['drive'];

          final String enableExperiment = getStringArg(kEnableExperiment);
          if (enableExperiment.isNotEmpty) {
            driveArgs.add('--enable-experiment=$enableExperiment');
          }

          if (isLinux && isLinuxPlugin(plugin)) {
            driveArgs.addAll(<String>[
              '-d',
              'linux',
            ]);
          }
          if (isMacos && isMacOsPlugin(plugin)) {
            driveArgs.addAll(<String>[
              '-d',
              'macos',
            ]);
          }
          if (isWeb && isWebPlugin(plugin)) {
            driveArgs.addAll(<String>[
              '-d',
              'web-server',
              '--web-port=7357',
              '--browser-name=chrome',
            ]);
          }
          if (isWindows && isWindowsPlugin(plugin)) {
            driveArgs.addAll(<String>[
              '-d',
              'windows',
            ]);
          }

          for (final String targetPath in targetPaths) {
            testsRan = true;
            final int exitCode = await processRunner.runAndStream(
                flutterCommand,
                <String>[
                  ...driveArgs,
                  '--driver',
                  p.join('test_driver', driverTestName),
                  '--target',
                  targetPath,
                ],
                workingDir: example,
                exitOnError: true);
            if (exitCode != 0) {
              failingTests.add(p.join(packageName, deviceTestPath));
            }
          }
        }
      }
      if (!testsRan) {
        pluginsWithoutTests.add(pluginName);
        print(
            'No driver tests run for $pluginName ($examplesFound examples found)');
      }
    }
    print('\n\n');

    if (failingTests.isNotEmpty) {
      print('The following driver tests are failing (see above for details):');
      for (final String test in failingTests) {
        print(' * $test');
      }
      throw ToolExit(1);
    }

    if (pluginsWithoutTests.isNotEmpty) {
      print('The following plugins did not run any integration tests:');
      for (final String plugin in pluginsWithoutTests) {
        print(' * $plugin');
      }
      print('If this is intentional, they must be explicitly excluded.');
      throw ToolExit(1);
    }

    print('All driver tests successful!');
  }

  Future<bool> _pluginSupportedOnCurrentPlatform(
      FileSystemEntity plugin) async {
    final bool isAndroid = getBoolArg(kPlatformFlagAndroid);
    final bool isIOS = getBoolArg(kPlatformFlagIos);
    final bool isLinux = getBoolArg(kPlatformFlagLinux);
    final bool isMacos = getBoolArg(kPlatformFlagMacos);
    final bool isWeb = getBoolArg(kPlatformFlagWeb);
    final bool isWindows = getBoolArg(kPlatformFlagWindows);
    if (isAndroid) {
      return isAndroidPlugin(plugin);
    }
    if (isIOS) {
      return isIosPlugin(plugin);
    }
    if (isLinux) {
      return isLinuxPlugin(plugin);
    }
    if (isMacos) {
      return isMacOsPlugin(plugin);
    }
    if (isWeb) {
      return isWebPlugin(plugin);
    }
    if (isWindows) {
      return isWindowsPlugin(plugin);
    }
    // When we are here, no flags are specified. Only return true if the plugin
    // supports Android for legacy command support.
    // TODO(cyanglaz): Make Android flag also required like other platforms
    // (breaking change). https://github.com/flutter/flutter/issues/58285
    return isAndroidPlugin(plugin);
  }
}