// 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 'package:meta/meta.dart';
import 'package:xml/xml.dart';
import 'package:yaml/yaml.dart';

import '../src/convert.dart';
import 'android/gradle_utils.dart' as gradle;
import 'base/common.dart';
import 'base/error_handling_io.dart';
import 'base/file_system.dart';
import 'base/logger.dart';
import 'base/utils.dart';
import 'bundle.dart' as bundle;
import 'cmake_project.dart';
import 'features.dart';
import 'flutter_manifest.dart';
import 'flutter_plugins.dart';
import 'globals.dart' as globals;
import 'platform_plugins.dart';
import 'reporting/reporting.dart';
import 'template.dart';
import 'xcode_project.dart';

export 'cmake_project.dart';
export 'xcode_project.dart';

/// Emum for each officially supported platform.
enum SupportedPlatform {
  android,
  ios,
  linux,
  macos,
  web,
  windows,
  fuchsia,
  root, // Special platform to represent the root project directory
}

class FlutterProjectFactory {
  FlutterProjectFactory({
    required Logger logger,
    required FileSystem fileSystem,
  }) : _logger = logger,
       _fileSystem = fileSystem;

  final Logger _logger;
  final FileSystem _fileSystem;

  @visibleForTesting
  final Map<String, FlutterProject> projects =
      <String, FlutterProject>{};

  /// Returns a [FlutterProject] view of the given directory or a ToolExit error,
  /// if `pubspec.yaml` or `example/pubspec.yaml` is invalid.
  FlutterProject fromDirectory(Directory directory) {
    assert(directory != null);
    return projects.putIfAbsent(directory.path, () {
      final FlutterManifest manifest = FlutterProject._readManifest(
        directory.childFile(bundle.defaultManifestPath).path,
        logger: _logger,
        fileSystem: _fileSystem,
      );
      final FlutterManifest exampleManifest = FlutterProject._readManifest(
        FlutterProject._exampleDirectory(directory)
            .childFile(bundle.defaultManifestPath)
            .path,
        logger: _logger,
        fileSystem: _fileSystem,
      );
      return FlutterProject(directory, manifest, exampleManifest);
    });
  }
}

/// Represents the contents of a Flutter project at the specified [directory].
///
/// [FlutterManifest] information is read from `pubspec.yaml` and
/// `example/pubspec.yaml` files on construction of a [FlutterProject] instance.
/// The constructed instance carries an immutable snapshot representation of the
/// presence and content of those files. Accordingly, [FlutterProject] instances
/// should be discarded upon changes to the `pubspec.yaml` files, but can be
/// used across changes to other files, as no other file-level information is
/// cached.
class FlutterProject {
  @visibleForTesting
  FlutterProject(this.directory, this.manifest, this._exampleManifest)
    : assert(directory != null),
      assert(manifest != null),
      assert(_exampleManifest != null);

  /// Returns a [FlutterProject] view of the given directory or a ToolExit error,
  /// if `pubspec.yaml` or `example/pubspec.yaml` is invalid.
  static FlutterProject fromDirectory(Directory directory) => globals.projectFactory.fromDirectory(directory);

  /// Returns a [FlutterProject] view of the current directory or a ToolExit error,
  /// if `pubspec.yaml` or `example/pubspec.yaml` is invalid.
  static FlutterProject current() => globals.projectFactory.fromDirectory(globals.fs.currentDirectory);

  /// Create a [FlutterProject] and bypass the project caching.
  @visibleForTesting
  static FlutterProject fromDirectoryTest(Directory directory, [Logger? logger]) {
    final FileSystem fileSystem = directory.fileSystem;
    logger ??= BufferLogger.test();
    final FlutterManifest manifest = FlutterProject._readManifest(
      directory.childFile(bundle.defaultManifestPath).path,
      logger: logger,
      fileSystem: fileSystem,
    );
    final FlutterManifest exampleManifest = FlutterProject._readManifest(
      FlutterProject._exampleDirectory(directory)
        .childFile(bundle.defaultManifestPath)
        .path,
      logger: logger,
      fileSystem: fileSystem,
    );
    return FlutterProject(directory, manifest, exampleManifest);
  }

  /// The location of this project.
  final Directory directory;

  /// The manifest of this project.
  final FlutterManifest manifest;

  /// The manifest of the example sub-project of this project.
  final FlutterManifest _exampleManifest;

  /// The set of organization names found in this project as
  /// part of iOS product bundle identifier, Android application ID, or
  /// Gradle group ID.
  Future<Set<String>> get organizationNames async {
    final List<String> candidates = <String>[];

    if (ios.existsSync()) {
      // Don't require iOS build info, this method is only
      // used during create as best-effort, use the
      // default target bundle identifier.
      final String? bundleIdentifier = await ios.productBundleIdentifier(null);
      if (bundleIdentifier != null) {
        candidates.add(bundleIdentifier);
      }
    }
    if (android.existsSync()) {
      final String? applicationId = android.applicationId;
      final String? group = android.group;
      candidates.addAll(<String>[
        if (applicationId != null)
          applicationId,
        if (group != null)
          group,
      ]);
    }
    if (example.android.existsSync()) {
      final String? applicationId = example.android.applicationId;
      if (applicationId != null) {
        candidates.add(applicationId);
      }
    }
    if (example.ios.existsSync()) {
      final String? bundleIdentifier = await example.ios.productBundleIdentifier(null);
      if (bundleIdentifier != null) {
        candidates.add(bundleIdentifier);
      }
    }
    return Set<String>.of(candidates.map<String?>(_organizationNameFromPackageName).whereType<String>());
  }

  String? _organizationNameFromPackageName(String packageName) {
    if (packageName != null && 0 <= packageName.lastIndexOf('.')) {
      return packageName.substring(0, packageName.lastIndexOf('.'));
    }
    return null;
  }

  /// The iOS sub project of this project.
  late final IosProject ios = IosProject.fromFlutter(this);

  /// The Android sub project of this project.
  late final AndroidProject android = AndroidProject._(this);

  /// The web sub project of this project.
  late final WebProject web = WebProject._(this);

  /// The MacOS sub project of this project.
  late final MacOSProject macos = MacOSProject.fromFlutter(this);

  /// The Linux sub project of this project.
  late final LinuxProject linux = LinuxProject.fromFlutter(this);

  /// The Windows sub project of this project.
  late final WindowsProject windows = WindowsProject.fromFlutter(this);

  /// The Fuchsia sub project of this project.
  late final FuchsiaProject fuchsia = FuchsiaProject._(this);

  /// The `pubspec.yaml` file of this project.
  File get pubspecFile => directory.childFile('pubspec.yaml');

  /// The `.packages` file of this project.
  File get packagesFile => directory.childFile('.packages');

  /// The `package_config.json` file of the project.
  ///
  /// This is the replacement for .packages which contains language
  /// version information.
  File get packageConfigFile => directory.childDirectory('.dart_tool').childFile('package_config.json');

  /// The `.metadata` file of this project.
  File get metadataFile => directory.childFile('.metadata');

  /// The `.flutter-plugins` file of this project.
  File get flutterPluginsFile => directory.childFile('.flutter-plugins');

  /// The `.flutter-plugins-dependencies` file of this project,
  /// which contains the dependencies each plugin depends on.
  File get flutterPluginsDependenciesFile => directory.childFile('.flutter-plugins-dependencies');

  /// The `.dart-tool` directory of this project.
  Directory get dartTool => directory.childDirectory('.dart_tool');

  /// The directory containing the generated code for this project.
  Directory get generated => directory
    .absolute
    .childDirectory('.dart_tool')
    .childDirectory('build')
    .childDirectory('generated')
    .childDirectory(manifest.appName);

  /// The generated Dart plugin registrant for non-web platforms.
  File get dartPluginRegistrant => dartTool
    .childDirectory('flutter_build')
    .childFile('dart_plugin_registrant.dart');

  /// The example sub-project of this project.
  FlutterProject get example => FlutterProject(
    _exampleDirectory(directory),
    _exampleManifest,
    FlutterManifest.empty(logger: globals.logger),
  );

  /// True if this project is a Flutter module project.
  bool get isModule => manifest.isModule;

  /// True if this project is a Flutter plugin project.
  bool get isPlugin => manifest.isPlugin;

  /// True if the Flutter project is using the AndroidX support library.
  bool get usesAndroidX => manifest.usesAndroidX;

  /// True if this project has an example application.
  bool get hasExampleApp => _exampleDirectory(directory).existsSync();

  /// Returns a list of platform names that are supported by the project.
  List<SupportedPlatform> getSupportedPlatforms({bool includeRoot = false}) {
    final List<SupportedPlatform> platforms = includeRoot ? <SupportedPlatform>[SupportedPlatform.root] : <SupportedPlatform>[];
    if (android.existsSync()) {
      platforms.add(SupportedPlatform.android);
    }
    if (ios.exists) {
      platforms.add(SupportedPlatform.ios);
    }
    if (web.existsSync()) {
      platforms.add(SupportedPlatform.web);
    }
    if (macos.existsSync()) {
      platforms.add(SupportedPlatform.macos);
    }
    if (linux.existsSync()) {
      platforms.add(SupportedPlatform.linux);
    }
    if (windows.existsSync()) {
      platforms.add(SupportedPlatform.windows);
    }
    if (fuchsia.existsSync()) {
      platforms.add(SupportedPlatform.fuchsia);
    }
    return platforms;
  }

  /// The directory that will contain the example if an example exists.
  static Directory _exampleDirectory(Directory directory) => directory.childDirectory('example');

  /// Reads and validates the `pubspec.yaml` file at [path], asynchronously
  /// returning a [FlutterManifest] representation of the contents.
  ///
  /// Completes with an empty [FlutterManifest], if the file does not exist.
  /// Completes with a ToolExit on validation error.
  static FlutterManifest _readManifest(String path, {
    required Logger logger,
    required FileSystem fileSystem,
  }) {
    FlutterManifest? manifest;
    try {
      manifest = FlutterManifest.createFromPath(
        path,
        logger: logger,
        fileSystem: fileSystem,
      );
    } on YamlException catch (e) {
      logger.printStatus('Error detected in pubspec.yaml:', emphasis: true);
      logger.printError('$e');
    } on FormatException catch (e) {
      logger.printError('Error detected while parsing pubspec.yaml:', emphasis: true);
      logger.printError('$e');
    } on FileSystemException catch (e) {
      logger.printError('Error detected while reading pubspec.yaml:', emphasis: true);
      logger.printError('$e');
    }
    if (manifest == null) {
      throwToolExit('Please correct the pubspec.yaml file at $path');
    }
    return manifest;
  }

  /// Reapplies template files and regenerates project files and plugin
  /// registrants for app and module projects only.
  ///
  /// Will not create project platform directories if they do not already exist.
  Future<void> regeneratePlatformSpecificTooling({DeprecationBehavior deprecationBehavior = DeprecationBehavior.none}) async {
    return ensureReadyForPlatformSpecificTooling(
      androidPlatform: android.existsSync(),
      iosPlatform: ios.existsSync(),
      // TODO(stuartmorgan): Revisit the conditions here once the plans for handling
      // desktop in existing projects are in place.
      linuxPlatform: featureFlags.isLinuxEnabled && linux.existsSync(),
      macOSPlatform: featureFlags.isMacOSEnabled && macos.existsSync(),
      windowsPlatform: featureFlags.isWindowsEnabled && windows.existsSync(),
      webPlatform: featureFlags.isWebEnabled && web.existsSync(),
      deprecationBehavior: deprecationBehavior,
    );
  }

  /// Applies template files and generates project files and plugin
  /// registrants for app and module projects only for the specified platforms.
  Future<void> ensureReadyForPlatformSpecificTooling({
    bool androidPlatform = false,
    bool iosPlatform = false,
    bool linuxPlatform = false,
    bool macOSPlatform = false,
    bool windowsPlatform = false,
    bool webPlatform = false,
    DeprecationBehavior deprecationBehavior = DeprecationBehavior.none,
  }) async {
    if (!directory.existsSync() || isPlugin) {
      return;
    }
    await refreshPluginsList(this, iosPlatform: iosPlatform, macOSPlatform: macOSPlatform);
    if (androidPlatform) {
      await android.ensureReadyForPlatformSpecificTooling(deprecationBehavior: deprecationBehavior);
    }
    if (iosPlatform) {
      await ios.ensureReadyForPlatformSpecificTooling();
    }
    if (linuxPlatform) {
      await linux.ensureReadyForPlatformSpecificTooling();
    }
    if (macOSPlatform) {
      await macos.ensureReadyForPlatformSpecificTooling();
    }
    if (windowsPlatform) {
      await windows.ensureReadyForPlatformSpecificTooling();
    }
    if (webPlatform) {
      await web.ensureReadyForPlatformSpecificTooling();
    }
    await injectPlugins(
      this,
      androidPlatform: androidPlatform,
      iosPlatform: iosPlatform,
      linuxPlatform: linuxPlatform,
      macOSPlatform: macOSPlatform,
      windowsPlatform: windowsPlatform,
    );
  }

  void checkForDeprecation({DeprecationBehavior deprecationBehavior = DeprecationBehavior.none}) {
    if (android.existsSync() && pubspecFile.existsSync()) {
      android.checkForDeprecation(deprecationBehavior: deprecationBehavior);
    }
  }

  /// Returns a json encoded string containing the [appName], [version], and [buildNumber] that is used to generate version.json
  String getVersionInfo()  {
    final String? buildName = manifest.buildName;
    final String? buildNumber = manifest.buildNumber;
    final Map<String, String> versionFileJson = <String, String>{
      'app_name': manifest.appName,
      if (buildName != null)
        'version': buildName,
      if (buildNumber != null)
        'build_number': buildNumber,
      'package_name': manifest.appName,
    };
    return jsonEncode(versionFileJson);
  }
}

/// Base class for projects per platform.
abstract class FlutterProjectPlatform {

  /// Plugin's platform config key, e.g., "macos", "ios".
  String get pluginConfigKey;

  /// Whether the platform exists in the project.
  bool existsSync();
}

/// Represents the Android sub-project of a Flutter project.
///
/// Instances will reflect the contents of the `android/` sub-folder of
/// Flutter applications and the `.android/` sub-folder of Flutter module projects.
class AndroidProject extends FlutterProjectPlatform {
  AndroidProject._(this.parent);

  /// The parent of this project.
  final FlutterProject parent;

  @override
  String get pluginConfigKey => AndroidPlugin.kConfigKey;

  static final RegExp _applicationIdPattern = RegExp('^\\s*applicationId\\s+[\'"](.*)[\'"]\\s*\$');
  static final RegExp _kotlinPluginPattern = RegExp('^\\s*apply plugin\\:\\s+[\'"]kotlin-android[\'"]\\s*\$');
  static final RegExp _groupPattern = RegExp('^\\s*group\\s+[\'"](.*)[\'"]\\s*\$');

  /// The Gradle root directory of the Android host app. This is the directory
  /// containing the `app/` subdirectory and the `settings.gradle` file that
  /// includes it in the overall Gradle project.
  Directory get hostAppGradleRoot {
    if (!isModule || _editableHostAppDirectory.existsSync()) {
      return _editableHostAppDirectory;
    }
    return ephemeralDirectory;
  }

  /// The Gradle root directory of the Android wrapping of Flutter and plugins.
  /// This is the same as [hostAppGradleRoot] except when the project is
  /// a Flutter module with an editable host app.
  Directory get _flutterLibGradleRoot => isModule ? ephemeralDirectory : _editableHostAppDirectory;

  Directory get ephemeralDirectory => parent.directory.childDirectory('.android');
  Directory get _editableHostAppDirectory => parent.directory.childDirectory('android');

  /// True if the parent Flutter project is a module.
  bool get isModule => parent.isModule;

  /// True if the parent Flutter project is a plugin.
  bool get isPlugin => parent.isPlugin;

  /// True if the Flutter project is using the AndroidX support library.
  bool get usesAndroidX => parent.usesAndroidX;

  /// Returns true if the current version of the Gradle plugin is supported.
  late final bool isSupportedVersion = _computeSupportedVersion();

  bool _computeSupportedVersion() {
    final FileSystem fileSystem = hostAppGradleRoot.fileSystem;
    final File plugin = hostAppGradleRoot.childFile(
        fileSystem.path.join('buildSrc', 'src', 'main', 'groovy', 'FlutterPlugin.groovy'));
    if (plugin.existsSync()) {
      return false;
    }
    final File appGradle = hostAppGradleRoot.childFile(
        fileSystem.path.join('app', 'build.gradle'));
    if (!appGradle.existsSync()) {
      return false;
    }
    for (final String line in appGradle.readAsLinesSync()) {
      if (line.contains(RegExp(r'apply from: .*/flutter.gradle')) ||
          line.contains("def flutterPluginVersion = 'managed'")) {
        return true;
      }
    }
    return false;
  }

  /// True, if the app project is using Kotlin.
  bool get isKotlin {
    final File gradleFile = hostAppGradleRoot.childDirectory('app').childFile('build.gradle');
    return firstMatchInFile(gradleFile, _kotlinPluginPattern) != null;
  }

  File get appManifestFile {
    return isUsingGradle
        ? globals.fs.file(globals.fs.path.join(hostAppGradleRoot.path, 'app', 'src', 'main', 'AndroidManifest.xml'))
        : hostAppGradleRoot.childFile('AndroidManifest.xml');
  }

  File get gradleAppOutV1File => gradleAppOutV1Directory.childFile('app-debug.apk');

  Directory get gradleAppOutV1Directory {
    return globals.fs.directory(globals.fs.path.join(hostAppGradleRoot.path, 'app', 'build', 'outputs', 'apk'));
  }

  /// Whether the current flutter project has an Android sub-project.
  @override
  bool existsSync() {
    return parent.isModule || _editableHostAppDirectory.existsSync();
  }

  bool get isUsingGradle {
    return hostAppGradleRoot.childFile('build.gradle').existsSync();
  }

  String? get applicationId {
    final File gradleFile = hostAppGradleRoot.childDirectory('app').childFile('build.gradle');
    return firstMatchInFile(gradleFile, _applicationIdPattern)?.group(1);
  }

  String? get group {
    final File gradleFile = hostAppGradleRoot.childFile('build.gradle');
    return firstMatchInFile(gradleFile, _groupPattern)?.group(1);
  }

  /// The build directory where the Android artifacts are placed.
  Directory get buildDirectory {
    return parent.directory.childDirectory('build');
  }

  Future<void> ensureReadyForPlatformSpecificTooling({DeprecationBehavior deprecationBehavior = DeprecationBehavior.none}) async {
    if (isModule && _shouldRegenerateFromTemplate()) {
      await _regenerateLibrary();
      // Add ephemeral host app, if an editable host app does not already exist.
      if (!_editableHostAppDirectory.existsSync()) {
        await _overwriteFromTemplate(globals.fs.path.join('module', 'android', 'host_app_common'), ephemeralDirectory);
        await _overwriteFromTemplate(globals.fs.path.join('module', 'android', 'host_app_ephemeral'), ephemeralDirectory);
      }
    }
    if (!hostAppGradleRoot.existsSync()) {
      return;
    }
    gradle.updateLocalProperties(project: parent, requireAndroidSdk: false);
  }

  bool _shouldRegenerateFromTemplate() {
    return globals.fsUtils.isOlderThanReference(
      entity: ephemeralDirectory,
      referenceFile: parent.pubspecFile,
    ) || globals.cache.isOlderThanToolsStamp(ephemeralDirectory);
  }

  File get localPropertiesFile => _flutterLibGradleRoot.childFile('local.properties');

  Directory get pluginRegistrantHost => _flutterLibGradleRoot.childDirectory(isModule ? 'Flutter' : 'app');

  Future<void> _regenerateLibrary() async {
    ErrorHandlingFileSystem.deleteIfExists(ephemeralDirectory, recursive: true);
    await _overwriteFromTemplate(globals.fs.path.join(
      'module',
      'android',
      'library_new_embedding',
    ), ephemeralDirectory);
    await _overwriteFromTemplate(globals.fs.path.join('module', 'android', 'gradle'), ephemeralDirectory);
    globals.gradleUtils?.injectGradleWrapperIfNeeded(ephemeralDirectory);
  }

  Future<void> _overwriteFromTemplate(String path, Directory target) async {
    final Template template = await Template.fromName(
      path,
      fileSystem: globals.fs,
      templateManifest: null,
      logger: globals.logger,
      templateRenderer: globals.templateRenderer,
    );
    final String androidIdentifier = parent.manifest.androidPackage ?? 'com.example.${parent.manifest.appName}';
    template.render(
      target,
      <String, Object>{
        'android': true,
        'projectName': parent.manifest.appName,
        'androidIdentifier': androidIdentifier,
        'androidX': usesAndroidX,
        'agpVersion': gradle.templateAndroidGradlePluginVersion,
        'kotlinVersion': gradle.templateKotlinGradlePluginVersion,
        'gradleVersion': gradle.templateDefaultGradleVersion,
        'gradleVersionForModule': gradle.templateDefaultGradleVersionForModule,
        'compileSdkVersion': gradle.compileSdkVersion,
        'minSdkVersion': gradle.minSdkVersion,
        'ndkVersion': gradle.ndkVersion,
        'targetSdkVersion': gradle.targetSdkVersion,
      },
      printStatusWhenWriting: false,
    );
  }

  void checkForDeprecation({DeprecationBehavior deprecationBehavior = DeprecationBehavior.none}) {
    if (deprecationBehavior == DeprecationBehavior.none) {
      return;
    }
    final AndroidEmbeddingVersionResult result = computeEmbeddingVersion();
    if (result.version != AndroidEmbeddingVersion.v1) {
      return;
    }
    globals.printStatus(
'''
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Warning
──────────────────────────────────────────────────────────────────────────────
Your Flutter application is created using an older version of the Android
embedding. It is being deprecated in favor of Android embedding v2. To migrate
your project, follow the steps at:

https://github.com/flutter/flutter/wiki/Upgrading-pre-1.12-Android-projects

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
The detected reason was:

  ${result.reason}
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
''');
    if (deprecationBehavior == DeprecationBehavior.ignore) {
      BuildEvent('deprecated-v1-android-embedding-ignored', type: 'gradle', flutterUsage: globals.flutterUsage).send();
    } else { // DeprecationBehavior.exit
      BuildEvent('deprecated-v1-android-embedding-failed', type: 'gradle', flutterUsage: globals.flutterUsage).send();
      throwToolExit(
        'Build failed due to use of deprecated Android v1 embedding.',
        exitCode: 1,
      );
    }
  }

  AndroidEmbeddingVersion getEmbeddingVersion() {
    return computeEmbeddingVersion().version;
  }

  AndroidEmbeddingVersionResult computeEmbeddingVersion() {
    if (isModule) {
      // A module type's Android project is used in add-to-app scenarios and
      // only supports the V2 embedding.
      return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v2, 'Is add-to-app module');
    }
    if (isPlugin) {
      // Plugins do not use an appManifest, so we stop here.
      //
      // TODO(garyq): This method does not currently check for code references to
      // the v1 embedding, we should check for this once removal is further along.
      return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v2, 'Is plugin');
    }
    if (appManifestFile == null || !appManifestFile.existsSync()) {
      return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v1, 'No `${appManifestFile.absolute.path}` file');
    }
    XmlDocument document;
    try {
      document = XmlDocument.parse(appManifestFile.readAsStringSync());
    } on XmlException {
      throwToolExit('Error parsing $appManifestFile '
                    'Please ensure that the android manifest is a valid XML document and try again.');
    } on FileSystemException {
      throwToolExit('Error reading $appManifestFile even though it exists. '
                    'Please ensure that you have read permission to this file and try again.');
    }
    for (final XmlElement application in document.findAllElements('application')) {
      final String? applicationName = application.getAttribute('android:name');
      if (applicationName == 'io.flutter.app.FlutterApplication') {
        return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v1, '${appManifestFile.absolute.path} uses `android:name="io.flutter.app.FlutterApplication"`');
      }
    }
    for (final XmlElement metaData in document.findAllElements('meta-data')) {
      final String? name = metaData.getAttribute('android:name');
      if (name == 'flutterEmbedding') {
        final String? embeddingVersionString = metaData.getAttribute('android:value');
        if (embeddingVersionString == '1') {
          return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v1, '${appManifestFile.absolute.path} `<meta-data android:name="flutterEmbedding"` has value 1');
        }
        if (embeddingVersionString == '2') {
          return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v2, '${appManifestFile.absolute.path} `<meta-data android:name="flutterEmbedding"` has value 2');
        }
      }
    }
    return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v1, 'No `<meta-data android:name="flutterEmbedding" android:value="2"/>` in ${appManifestFile.absolute.path}');
  }
}

/// Iteration of the embedding Java API in the engine used by the Android project.
enum AndroidEmbeddingVersion {
  /// V1 APIs based on io.flutter.app.FlutterActivity.
  v1,
  /// V2 APIs based on io.flutter.embedding.android.FlutterActivity.
  v2,
}

/// Data class that holds the results of checking for embedding version.
///
/// This class includes the reason why a particular embedding was selected.
class AndroidEmbeddingVersionResult {
  AndroidEmbeddingVersionResult(this.version, this.reason);

  /// The embedding version.
  AndroidEmbeddingVersion version;

  /// The reason why the embedding version was selected.
  String reason;
}

// What the tool should do when encountering deprecated API in applications.
enum DeprecationBehavior {
  // The command being run does not care about deprecation status.
  none,
  // The command should continue and ignore the deprecation warning.
  ignore,
  // The command should exit the tool.
  exit,
}

/// Represents the web sub-project of a Flutter project.
class WebProject extends FlutterProjectPlatform {
  WebProject._(this.parent);

  final FlutterProject parent;

  @override
  String get pluginConfigKey => WebPlugin.kConfigKey;

  /// Whether this flutter project has a web sub-project.
  @override
  bool existsSync() {
    return parent.directory.childDirectory('web').existsSync()
      && indexFile.existsSync();
  }

  /// The 'lib' directory for the application.
  Directory get libDirectory => parent.directory.childDirectory('lib');

  /// The directory containing additional files for the application.
  Directory get directory => parent.directory.childDirectory('web');

  /// The html file used to host the flutter web application.
  File get indexFile => parent.directory
      .childDirectory('web')
      .childFile('index.html');

  /// The .dart_tool/dartpad directory
  Directory get dartpadToolDirectory => parent.directory
      .childDirectory('.dart_tool')
      .childDirectory('dartpad');

  Future<void> ensureReadyForPlatformSpecificTooling() async {
    /// Create .dart_tool/dartpad/web_plugin_registrant.dart.
    /// See: https://github.com/dart-lang/dart-services/pull/874
    await injectBuildTimePluginFiles(
      parent,
      destination: dartpadToolDirectory,
      webPlatform: true,
    );
  }
}

/// The Fuchsia sub project.
class FuchsiaProject {
  FuchsiaProject._(this.project);

  final FlutterProject project;

  Directory? _editableHostAppDirectory;
  Directory get editableHostAppDirectory =>
      _editableHostAppDirectory ??= project.directory.childDirectory('fuchsia');

  bool existsSync() => editableHostAppDirectory.existsSync();

  Directory? _meta;
  Directory get meta =>
      _meta ??= editableHostAppDirectory.childDirectory('meta');
}