// 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 '../../artifacts.dart';
import '../../base/build.dart';
import '../../base/file_system.dart';
import '../../base/io.dart';
import '../../base/process.dart';
import '../../build_info.dart';
import '../../globals.dart' as globals show xcode;
import '../build_system.dart';
import '../depfile.dart';
import '../exceptions.dart';
import 'assets.dart';
import 'common.dart';
import 'icon_tree_shaker.dart';

/// Copy the macOS framework to the correct copy dir by invoking 'rsync'.
///
/// This class is abstract to share logic between the three concrete
/// implementations. The shelling out is done to avoid complications with
/// preserving special files (e.g., symbolic links) in the framework structure.
///
/// The real implementations are:
///   * [DebugUnpackMacOS]
///   * [ProfileUnpackMacOS]
///   * [ReleaseUnpackMacOS]
abstract class UnpackMacOS extends Target {
  const UnpackMacOS();

  @override
  List<Source> get inputs => const <Source>[
    Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/macos.dart'),
  ];

  @override
  List<Source> get outputs => const <Source>[
    Source.pattern('{OUTPUT_DIR}/FlutterMacOS.framework/Versions/A/FlutterMacOS'),
  ];

  @override
  List<Target> get dependencies => <Target>[];

  @override
  Future<void> build(Environment environment) async {
    final String? buildModeEnvironment = environment.defines[kBuildMode];
    if (buildModeEnvironment == null) {
      throw MissingDefineException(kBuildMode, 'unpack_macos');
    }
    final BuildMode buildMode = getBuildModeForName(buildModeEnvironment);
    final String basePath = environment.artifacts.getArtifactPath(Artifact.flutterMacOSFramework, mode: buildMode);

    final ProcessResult result = environment.processManager.runSync(<String>[
      'rsync',
      '-av',
      '--delete',
      '--filter',
      '- .DS_Store/',
      basePath,
      environment.outputDir.path,
    ]);
    if (result.exitCode != 0) {
      throw Exception(
        'Failed to copy framework (exit ${result.exitCode}:\n'
            '${result.stdout}\n---\n${result.stderr}',
      );
    }

    final File frameworkBinary = environment.outputDir
      .childDirectory('FlutterMacOS.framework')
      .childDirectory('Versions')
      .childDirectory('A')
      .childFile('FlutterMacOS');
    final String frameworkBinaryPath = frameworkBinary.path;
    if (!frameworkBinary.existsSync()) {
      throw Exception('Binary $frameworkBinaryPath does not exist, cannot thin');
    }
    _thinFramework(environment, frameworkBinaryPath);
  }

  void _thinFramework(Environment environment, String frameworkBinaryPath) {
    final String archs = environment.defines[kDarwinArchs] ?? 'x86_64 arm64';
    final List<String> archList = archs.split(' ').toList();
    final ProcessResult infoResult = environment.processManager.runSync(<String>[
      'lipo',
      '-info',
      frameworkBinaryPath,
    ]);
    final String lipoInfo = infoResult.stdout as String;

    final ProcessResult verifyResult = environment.processManager.runSync(<String>[
      'lipo',
      frameworkBinaryPath,
      '-verify_arch',
      ...archList,
    ]);

    if (verifyResult.exitCode != 0) {
      throw Exception('Binary $frameworkBinaryPath does not contain $archs. Running lipo -info:\n$lipoInfo');
    }

    // Skip thinning for non-fat executables.
    if (lipoInfo.startsWith('Non-fat file:')) {
      environment.logger.printTrace('Skipping lipo for non-fat file $frameworkBinaryPath');
      return;
    }

    // Thin in-place.
    final ProcessResult extractResult = environment.processManager.runSync(<String>[
      'lipo',
      '-output',
      frameworkBinaryPath,
      for (final String arch in archList)
        ...<String>[
          '-extract',
          arch,
        ],
      ...<String>[frameworkBinaryPath],
    ]);

    if (extractResult.exitCode != 0) {
      throw Exception('Failed to extract $archs for $frameworkBinaryPath.\n${extractResult.stderr}\nRunning lipo -info:\n$lipoInfo');
    }
  }
}

/// Unpack the release prebuilt engine framework.
class ReleaseUnpackMacOS extends UnpackMacOS {
  const ReleaseUnpackMacOS();

  @override
  String get name => 'release_unpack_macos';

  @override
  List<Source> get inputs => <Source>[
    ...super.inputs,
    const Source.artifact(Artifact.flutterMacOSFramework, mode: BuildMode.release),
  ];
}

/// Unpack the profile prebuilt engine framework.
class ProfileUnpackMacOS extends UnpackMacOS {
  const ProfileUnpackMacOS();

  @override
  String get name => 'profile_unpack_macos';

  @override
  List<Source> get inputs => <Source>[
    ...super.inputs,
    const Source.artifact(Artifact.flutterMacOSFramework, mode: BuildMode.profile),
  ];
}

/// Unpack the debug prebuilt engine framework.
class DebugUnpackMacOS extends UnpackMacOS {
  const DebugUnpackMacOS();

  @override
  String get name => 'debug_unpack_macos';

  @override
  List<Source> get inputs => <Source>[
    ...super.inputs,
    const Source.artifact(Artifact.flutterMacOSFramework, mode: BuildMode.debug),
  ];
}

/// Create an App.framework for debug macOS targets.
///
/// This framework needs to exist for the Xcode project to link/bundle,
/// but it isn't actually executed. To generate something valid, we compile a trivial
/// constant.
class DebugMacOSFramework extends Target {
  const DebugMacOSFramework();

  @override
  String get name => 'debug_macos_framework';

  @override
  Future<void> build(Environment environment) async {
    final File outputFile = environment.fileSystem.file(environment.fileSystem.path.join(
        environment.buildDir.path, 'App.framework', 'App'));

    final Iterable<DarwinArch> darwinArchs = environment.defines[kDarwinArchs]
      ?.split(' ')
      .map(getDarwinArchForName)
      ?? <DarwinArch>[DarwinArch.x86_64, DarwinArch.arm64];

    final Iterable<String> darwinArchArguments =
        darwinArchs.expand((DarwinArch arch) => <String>['-arch', getNameForDarwinArch(arch)]);

    outputFile.createSync(recursive: true);
    final File debugApp = environment.buildDir.childFile('debug_app.cc')
        ..writeAsStringSync(r'''
static const int Moo = 88;
''');
    final RunResult result = await globals.xcode!.clang(<String>[
      '-x',
      'c',
      debugApp.path,
      ...darwinArchArguments,
      '-dynamiclib',
      '-Xlinker', '-rpath', '-Xlinker', '@executable_path/Frameworks',
      '-Xlinker', '-rpath', '-Xlinker', '@loader_path/Frameworks',
      '-install_name', '@rpath/App.framework/App',
      '-o', outputFile.path,
    ]);
    if (result.exitCode != 0) {
      throw Exception('Failed to compile debug App.framework');
    }
  }

  @override
  List<Target> get dependencies => const <Target>[];

  @override
  List<Source> get inputs => const <Source>[
    Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/macos.dart'),
  ];

  @override
  List<Source> get outputs => const <Source>[
    Source.pattern('{BUILD_DIR}/App.framework/App'),
  ];
}

class CompileMacOSFramework extends Target {
  const CompileMacOSFramework();

  @override
  String get name => 'compile_macos_framework';

  @override
  Future<void> build(Environment environment) async {
    final String? buildModeEnvironment = environment.defines[kBuildMode];
    if (buildModeEnvironment == null) {
      throw MissingDefineException(kBuildMode, 'compile_macos_framework');
    }
    final String? targetPlatformEnvironment = environment.defines[kTargetPlatform];
    if (targetPlatformEnvironment == null) {
      throw MissingDefineException(kTargetPlatform, 'kernel_snapshot');
    }
    final BuildMode buildMode = getBuildModeForName(buildModeEnvironment);
    if (buildMode == BuildMode.debug) {
      throw Exception('precompiled macOS framework only supported in release/profile builds.');
    }
    final String buildOutputPath = environment.buildDir.path;
    final String? codeSizeDirectory = environment.defines[kCodeSizeDirectory];
    final String? splitDebugInfo = environment.defines[kSplitDebugInfo];
    final bool dartObfuscation = environment.defines[kDartObfuscation] == 'true';
    final List<String> extraGenSnapshotOptions = decodeCommaSeparated(environment.defines, kExtraGenSnapshotOptions);
    final TargetPlatform targetPlatform = getTargetPlatformForName(targetPlatformEnvironment);
    final List<DarwinArch> darwinArchs = environment.defines[kDarwinArchs]
      ?.split(' ')
      .map(getDarwinArchForName)
      .toList()
      ?? <DarwinArch>[DarwinArch.x86_64, DarwinArch.arm64];
    if (targetPlatform != TargetPlatform.darwin) {
      throw Exception('compile_macos_framework is only supported for darwin TargetPlatform.');
    }

    final AOTSnapshotter snapshotter = AOTSnapshotter(
      fileSystem: environment.fileSystem,
      logger: environment.logger,
      xcode: globals.xcode!,
      artifacts: environment.artifacts,
      processManager: environment.processManager
    );

    final List<Future<int>> pending = <Future<int>>[];
    for (final DarwinArch darwinArch in darwinArchs) {
      if (codeSizeDirectory != null) {
        final File codeSizeFile = environment.fileSystem
          .directory(codeSizeDirectory)
          .childFile('snapshot.${getNameForDarwinArch(darwinArch)}.json');
        final File precompilerTraceFile = environment.fileSystem
          .directory(codeSizeDirectory)
          .childFile('trace.${getNameForDarwinArch(darwinArch)}.json');
        extraGenSnapshotOptions.add('--write-v8-snapshot-profile-to=${codeSizeFile.path}');
        extraGenSnapshotOptions.add('--trace-precompiler-to=${precompilerTraceFile.path}');
      }

      pending.add(snapshotter.build(
        bitcode: false,
        buildMode: buildMode,
        mainPath: environment.buildDir.childFile('app.dill').path,
        outputPath: environment.fileSystem.path.join(buildOutputPath, getNameForDarwinArch(darwinArch)),
        platform: TargetPlatform.darwin,
        darwinArch: darwinArch,
        splitDebugInfo: splitDebugInfo,
        dartObfuscation: dartObfuscation,
        extraGenSnapshotOptions: extraGenSnapshotOptions,
      ));
    }

    final List<int> results = await Future.wait(pending);
    if (results.any((int result) => result != 0)) {
      throw Exception('AOT snapshotter exited with code ${results.join()}');
    }

    final String resultPath = environment.fileSystem.path.join(environment.buildDir.path, 'App.framework', 'App');
    environment.fileSystem.directory(resultPath).parent.createSync(recursive: true);
    final ProcessResult result = await environment.processManager.run(<String>[
      'lipo',
      ...darwinArchs.map((DarwinArch iosArch) =>
          environment.fileSystem.path.join(buildOutputPath, getNameForDarwinArch(iosArch), 'App.framework', 'App')),
      '-create',
      '-output',
      resultPath,
    ]);
    if (result.exitCode != 0) {
      throw Exception('lipo exited with code ${result.exitCode}.\n${result.stderr}');
    }
  }

  @override
  List<Target> get dependencies => const <Target>[
    KernelSnapshot(),
  ];

  @override
  List<Source> get inputs => const <Source>[
    Source.pattern('{BUILD_DIR}/app.dill'),
    Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/macos.dart'),
    Source.artifact(Artifact.genSnapshot, mode: BuildMode.release, platform: TargetPlatform.darwin),
  ];

  @override
  List<Source> get outputs => const <Source>[
    Source.pattern('{BUILD_DIR}/App.framework/App'),
  ];
}

/// Bundle the flutter assets into the App.framework.
///
/// In debug mode, also include the app.dill and precompiled runtimes.
///
/// See https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/BPFrameworks/Concepts/FrameworkAnatomy.html
/// for more information on Framework structure.
abstract class MacOSBundleFlutterAssets extends Target {
  const MacOSBundleFlutterAssets();

  @override
  List<Source> get inputs => const <Source>[
    Source.pattern('{BUILD_DIR}/App.framework/App'),
    ...IconTreeShaker.inputs,
  ];

  @override
  List<Source> get outputs => const <Source>[
    Source.pattern('{OUTPUT_DIR}/App.framework/Versions/A/App'),
    Source.pattern('{OUTPUT_DIR}/App.framework/Versions/A/Resources/Info.plist'),
  ];

  @override
  List<String> get depfiles => const <String>[
    'flutter_assets.d',
  ];

  @override
  Future<void> build(Environment environment) async {
    final String? buildModeEnvironment = environment.defines[kBuildMode];
    if (buildModeEnvironment == null) {
      throw MissingDefineException(kBuildMode, 'compile_macos_framework');
    }
    final BuildMode buildMode = getBuildModeForName(buildModeEnvironment);
    final Directory frameworkRootDirectory = environment
        .outputDir
        .childDirectory('App.framework');
    final Directory outputDirectory = frameworkRootDirectory
        .childDirectory('Versions')
        .childDirectory('A')
        ..createSync(recursive: true);

    // Copy App into framework directory.
    environment.buildDir
      .childDirectory('App.framework')
      .childFile('App')
      .copySync(outputDirectory.childFile('App').path);

    // Copy assets into asset directory.
    final Directory assetDirectory = outputDirectory
      .childDirectory('Resources')
      .childDirectory('flutter_assets');
    assetDirectory.createSync(recursive: true);

    final Depfile assetDepfile = await copyAssets(
      environment,
      assetDirectory,
      targetPlatform: TargetPlatform.darwin,
    );
    final DepfileService depfileService = DepfileService(
      fileSystem: environment.fileSystem,
      logger: environment.logger,
    );
    depfileService.writeToFile(
      assetDepfile,
      environment.buildDir.childFile('flutter_assets.d'),
    );

    // Copy Info.plist template.
    assetDirectory.parent.childFile('Info.plist')
      ..createSync()
      ..writeAsStringSync(r'''
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>CFBundleDevelopmentRegion</key>
	<string>en</string>
	<key>CFBundleExecutable</key>
	<string>App</string>
	<key>CFBundleIdentifier</key>
	<string>io.flutter.flutter.app</string>
	<key>CFBundleInfoDictionaryVersion</key>
	<string>6.0</string>
	<key>CFBundleName</key>
	<string>App</string>
	<key>CFBundlePackageType</key>
	<string>FMWK</string>
	<key>CFBundleShortVersionString</key>
	<string>1.0</string>
	<key>CFBundleVersion</key>
	<string>1.0</string>
</dict>
</plist>

''');
    if (buildMode == BuildMode.debug) {
      // Copy dill file.
      try {
        final File sourceFile = environment.buildDir.childFile('app.dill');
        sourceFile.copySync(assetDirectory.childFile('kernel_blob.bin').path);
      } on Exception catch (err) {
        throw Exception('Failed to copy app.dill: $err');
      }
      // Copy precompiled runtimes.
      try {
        final String vmSnapshotData = environment.artifacts.getArtifactPath(Artifact.vmSnapshotData,
            platform: TargetPlatform.darwin, mode: BuildMode.debug);
        final String isolateSnapshotData = environment.artifacts.getArtifactPath(Artifact.isolateSnapshotData,
            platform: TargetPlatform.darwin, mode: BuildMode.debug);
        environment.fileSystem.file(vmSnapshotData).copySync(
            assetDirectory.childFile('vm_snapshot_data').path);
        environment.fileSystem.file(isolateSnapshotData).copySync(
            assetDirectory.childFile('isolate_snapshot_data').path);
      } on Exception catch (err) {
        throw Exception('Failed to copy precompiled runtimes: $err');
      }
    }
    // Create symlink to current version. These must be relative, from the
    // framework root for Resources/App and from the versions root for
    // Current.
    try {
      final Link currentVersion = outputDirectory.parent
          .childLink('Current');
      if (!currentVersion.existsSync()) {
        final String linkPath = environment.fileSystem.path.relative(outputDirectory.path,
            from: outputDirectory.parent.path);
        currentVersion.createSync(linkPath);
      }
      // Create symlink to current resources.
      final Link currentResources = frameworkRootDirectory
          .childLink('Resources');
      if (!currentResources.existsSync()) {
        final String linkPath = environment.fileSystem.path.relative(environment.fileSystem.path.join(currentVersion.path, 'Resources'),
            from: frameworkRootDirectory.path);
        currentResources.createSync(linkPath);
      }
      // Create symlink to current binary.
      final Link currentFramework = frameworkRootDirectory
          .childLink('App');
      if (!currentFramework.existsSync()) {
        final String linkPath = environment.fileSystem.path.relative(environment.fileSystem.path.join(currentVersion.path, 'App'),
            from: frameworkRootDirectory.path);
        currentFramework.createSync(linkPath);
      }
    } on FileSystemException {
      throw Exception('Failed to create symlinks for framework. try removing '
        'the "${environment.outputDir.path}" directory and rerunning');
    }
  }
}

/// Bundle the debug flutter assets into the App.framework.
class DebugMacOSBundleFlutterAssets extends MacOSBundleFlutterAssets {
  const DebugMacOSBundleFlutterAssets();

  @override
  String get name => 'debug_macos_bundle_flutter_assets';

  @override
  List<Target> get dependencies => const <Target>[
    KernelSnapshot(),
    DebugMacOSFramework(),
    DebugUnpackMacOS(),
  ];

  @override
  List<Source> get inputs => <Source>[
    ...super.inputs,
    const Source.pattern('{BUILD_DIR}/app.dill'),
    const Source.artifact(Artifact.isolateSnapshotData, platform: TargetPlatform.darwin, mode: BuildMode.debug),
    const Source.artifact(Artifact.vmSnapshotData, platform: TargetPlatform.darwin, mode: BuildMode.debug),
  ];

  @override
  List<Source> get outputs => <Source>[
    ...super.outputs,
    const Source.pattern('{OUTPUT_DIR}/App.framework/Versions/A/Resources/flutter_assets/kernel_blob.bin'),
    const Source.pattern('{OUTPUT_DIR}/App.framework/Versions/A/Resources/flutter_assets/vm_snapshot_data'),
    const Source.pattern('{OUTPUT_DIR}/App.framework/Versions/A/Resources/flutter_assets/isolate_snapshot_data'),
  ];
}

/// Bundle the profile flutter assets into the App.framework.
class ProfileMacOSBundleFlutterAssets extends MacOSBundleFlutterAssets {
  const ProfileMacOSBundleFlutterAssets();

  @override
  String get name => 'profile_macos_bundle_flutter_assets';

  @override
  List<Target> get dependencies => const <Target>[
    CompileMacOSFramework(),
    ProfileUnpackMacOS(),
  ];
}


/// Bundle the release flutter assets into the App.framework.
class ReleaseMacOSBundleFlutterAssets extends MacOSBundleFlutterAssets {
  const ReleaseMacOSBundleFlutterAssets();

  @override
  String get name => 'release_macos_bundle_flutter_assets';

  @override
  List<Target> get dependencies => const <Target>[
    CompileMacOSFramework(),
    ReleaseUnpackMacOS(),
  ];
}