// 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:process/process.dart';

import '../base/file_system.dart';
import '../base/io.dart';
import '../base/platform.dart';
import '../base/utils.dart';
import '../base/version.dart';
import '../convert.dart';
import '../doctor_validator.dart';

const String extensionIdentifier = 'Dart-Code.flutter';
const String extensionMarketplaceUrl =
  'https://marketplace.visualstudio.com/items?itemName=$extensionIdentifier';

class VsCode {
  VsCode._(this.directory, this.extensionDirectory, { Version? version, this.edition, required FileSystem fileSystem})
      : version = version ?? Version.unknown {

    if (!fileSystem.isDirectorySync(directory)) {
      _validationMessages.add(ValidationMessage.error('VS Code not found at $directory'));
      return;
    } else {
      _validationMessages.add(ValidationMessage('VS Code at $directory'));
    }

    // If the extensions directory doesn't exist at all, the listSync()
    // below will fail, so just bail out early.
    const ValidationMessage notInstalledMessage = ValidationMessage(
      'Flutter extension can be installed from:',
      contextUrl: extensionMarketplaceUrl,
    );
    if (!fileSystem.isDirectorySync(extensionDirectory)) {
      _validationMessages.add(notInstalledMessage);
      return;
    }

    // Check for presence of extension.
    final String extensionIdentifierLower = extensionIdentifier.toLowerCase();
    final Iterable<FileSystemEntity> extensionDirs = fileSystem
        .directory(extensionDirectory)
        .listSync()
        .whereType<Directory>()
        .where((Directory d) => d.basename.toLowerCase().startsWith(extensionIdentifierLower));

    if (extensionDirs.isNotEmpty) {
      final FileSystemEntity extensionDir = extensionDirs.first;

      _extensionVersion = Version.parse(
          extensionDir.basename.substring('$extensionIdentifier-'.length));
      _validationMessages.add(ValidationMessage('Flutter extension version $_extensionVersion'));
    } else {
      _validationMessages.add(notInstalledMessage);
    }
  }

  factory VsCode.fromDirectory(
    String installPath,
    String extensionDirectory, {
    String? edition,
    required FileSystem fileSystem,
  }) {
    final String packageJsonPath =
        fileSystem.path.join(installPath, 'resources', 'app', 'package.json');
    final String? versionString = _getVersionFromPackageJson(packageJsonPath, fileSystem);
    Version? version;
    if (versionString != null) {
      version = Version.parse(versionString);
    }
    return VsCode._(installPath, extensionDirectory, version: version, edition: edition, fileSystem: fileSystem);
  }

  final String directory;
  final String extensionDirectory;
  final Version version;
  final String? edition;

  Version? _extensionVersion;
  final List<ValidationMessage> _validationMessages = <ValidationMessage>[];

  String get productName => 'VS Code${edition != null ? ', $edition' : ''}';

  Iterable<ValidationMessage> get validationMessages => _validationMessages;

  static List<VsCode> allInstalled(
    FileSystem fileSystem,
    Platform platform,
    ProcessManager processManager,
  ) {
    if (platform.isMacOS) {
      return _installedMacOS(fileSystem, platform, processManager);
    }
    if (platform.isWindows) {
      return _installedWindows(fileSystem, platform);
    }
    if (platform.isLinux) {
      return _installedLinux(fileSystem, platform);
    }
    // VS Code isn't supported on the other platforms.
    return <VsCode>[];
  }

  // macOS:
  //   /Applications/Visual Studio Code.app/Contents/
  //   /Applications/Visual Studio Code - Insiders.app/Contents/
  //   $HOME/Applications/Visual Studio Code.app/Contents/
  //   $HOME/Applications/Visual Studio Code - Insiders.app/Contents/
  // macOS Extensions:
  //   $HOME/.vscode/extensions
  //   $HOME/.vscode-insiders/extensions
  static List<VsCode> _installedMacOS(FileSystem fileSystem, Platform platform, ProcessManager processManager) {
    final String? homeDirPath = FileSystemUtils(fileSystem: fileSystem, platform: platform).homeDirPath;

    String vsCodeSpotlightResult = '';
    String vsCodeInsiderSpotlightResult = '';
    // Query Spotlight for unexpected installation locations.
    try {
      final ProcessResult vsCodeSpotlightQueryResult = processManager.runSync(<String>[
        'mdfind',
        'kMDItemCFBundleIdentifier="com.microsoft.VSCode"',
      ]);
      vsCodeSpotlightResult = vsCodeSpotlightQueryResult.stdout as String;
      final ProcessResult vsCodeInsidersSpotlightQueryResult = processManager.runSync(<String>[
        'mdfind',
        'kMDItemCFBundleIdentifier="com.microsoft.VSCodeInsiders"',
      ]);
      vsCodeInsiderSpotlightResult = vsCodeInsidersSpotlightQueryResult.stdout as String;
    } on ProcessException {
      // The Spotlight query is a nice-to-have, continue checking known installation locations.
    }

    // De-duplicated set.
    return _findInstalled(<VsCodeInstallLocation>{
      VsCodeInstallLocation(
        fileSystem.path.join('/Applications', 'Visual Studio Code.app', 'Contents'),
        '.vscode',
      ),
      if (homeDirPath != null)
        VsCodeInstallLocation(
          fileSystem.path.join(
            homeDirPath,
            'Applications',
            'Visual Studio Code.app',
            'Contents',
          ),
          '.vscode',
        ),
      VsCodeInstallLocation(
        fileSystem.path.join('/Applications', 'Visual Studio Code - Insiders.app', 'Contents'),
        '.vscode-insiders',
      ),
      if (homeDirPath != null)
        VsCodeInstallLocation(
          fileSystem.path.join(
            homeDirPath,
            'Applications',
            'Visual Studio Code - Insiders.app',
            'Contents',
          ),
          '.vscode-insiders',
        ),
      for (final String vsCodePath in LineSplitter.split(vsCodeSpotlightResult))
        VsCodeInstallLocation(
          fileSystem.path.join(vsCodePath, 'Contents'),
          '.vscode',
        ),
      for (final String vsCodeInsidersPath in LineSplitter.split(vsCodeInsiderSpotlightResult))
        VsCodeInstallLocation(
          fileSystem.path.join(vsCodeInsidersPath, 'Contents'),
          '.vscode-insiders',
        ),
    }, fileSystem, platform);
  }

  // Windows:
  //   $programfiles(x86)\Microsoft VS Code
  //   $programfiles(x86)\Microsoft VS Code Insiders
  // User install:
  //   $localappdata\Programs\Microsoft VS Code
  //   $localappdata\Programs\Microsoft VS Code Insiders
  // TODO(dantup): Confirm these are correct for 64bit
  //   $programfiles\Microsoft VS Code
  //   $programfiles\Microsoft VS Code Insiders
  // Windows Extensions:
  //   $HOME/.vscode/extensions
  //   $HOME/.vscode-insiders/extensions
  static List<VsCode> _installedWindows(
    FileSystem fileSystem,
    Platform platform,
  ) {
    final String? progFiles86 = platform.environment['programfiles(x86)'];
    final String? progFiles = platform.environment['programfiles'];
    final String? localAppData = platform.environment['localappdata'];

    final List<VsCodeInstallLocation> searchLocations = <VsCodeInstallLocation>[
      if (localAppData != null)
        VsCodeInstallLocation(
          fileSystem.path.join(localAppData, r'Programs\Microsoft VS Code'),
          '.vscode',
        ),
      if (progFiles86 != null)
        ...<VsCodeInstallLocation>[
          VsCodeInstallLocation(
            fileSystem.path.join(progFiles86, 'Microsoft VS Code'),
            '.vscode',
            edition: '32-bit edition',
          ),
          VsCodeInstallLocation(
            fileSystem.path.join(progFiles86, 'Microsoft VS Code Insiders'),
            '.vscode-insiders',
            edition: '32-bit edition',
          ),
        ],
      if (progFiles != null)
        ...<VsCodeInstallLocation>[
          VsCodeInstallLocation(
            fileSystem.path.join(progFiles, 'Microsoft VS Code'),
            '.vscode',
            edition: '64-bit edition',
          ),
          VsCodeInstallLocation(
            fileSystem.path.join(progFiles, 'Microsoft VS Code Insiders'),
            '.vscode-insiders',
            edition: '64-bit edition',
          ),
        ],
      if (localAppData != null)
        VsCodeInstallLocation(
          fileSystem.path.join(localAppData, r'Programs\Microsoft VS Code Insiders'),
          '.vscode-insiders',
        ),
    ];
    return _findInstalled(searchLocations, fileSystem, platform);
  }

  // Linux:
  //   /usr/share/code/bin/code
  //   /snap/code/current
  //   /usr/share/code-insiders/bin/code-insiders
  // Linux Extensions:
  //   $HOME/.vscode/extensions
  //   $HOME/.vscode-insiders/extensions
  static List<VsCode> _installedLinux(FileSystem fileSystem, Platform platform) {
    return _findInstalled(<VsCodeInstallLocation>[
      const VsCodeInstallLocation('/usr/share/code', '.vscode'),
      const VsCodeInstallLocation('/snap/code/current', '.vscode'),
      const VsCodeInstallLocation(
        '/usr/share/code-insiders',
        '.vscode-insiders',
      ),
    ], fileSystem, platform);
  }

  static List<VsCode> _findInstalled(
    Iterable<VsCodeInstallLocation> allLocations,
    FileSystem fileSystem,
    Platform platform,
  ) {
    final List<VsCode> results = <VsCode>[];

    for (final VsCodeInstallLocation searchLocation in allLocations) {
      final String? homeDirPath = FileSystemUtils(fileSystem: fileSystem, platform: platform).homeDirPath;
      if (homeDirPath != null && fileSystem.isDirectorySync(searchLocation.installPath)) {
        final String extensionDirectory = fileSystem.path.join(
          homeDirPath,
          searchLocation.extensionsFolder,
          'extensions',
        );
        results.add(VsCode.fromDirectory(
          searchLocation.installPath,
          extensionDirectory,
          edition: searchLocation.edition,
          fileSystem: fileSystem,
        ));
      }
    }

    return results;
  }

  @override
  String toString() =>
      'VS Code ($version)${_extensionVersion != Version.unknown ? ', Flutter ($_extensionVersion)' : ''}';

  static String? _getVersionFromPackageJson(String packageJsonPath, FileSystem fileSystem) {
    if (!fileSystem.isFileSync(packageJsonPath)) {
      return null;
    }
    final String jsonString = fileSystem.file(packageJsonPath).readAsStringSync();
    try {
      final Map<String, dynamic>? jsonObject = castStringKeyedMap(json.decode(jsonString));
      if (jsonObject?.containsKey('version') ?? false) {
        return jsonObject!['version'] as String;
      }
    } on FormatException {
      return null;
    }
    return null;
  }
}

@immutable
@visibleForTesting
class VsCodeInstallLocation {
  const VsCodeInstallLocation(
    this.installPath,
    this.extensionsFolder, {
    this.edition,
  });

  final String installPath;
  final String extensionsFolder;
  final String? edition;

  @override
  bool operator ==(Object other) {
    return other is VsCodeInstallLocation &&
        other.installPath == installPath &&
        other.extensionsFolder == extensionsFolder &&
        other.edition == edition;
  }

  @override
  // Lowest bit is for isInsiders boolean.
  int get hashCode => Object.hash(installPath, extensionsFolder, edition);
}