windows-application/lib/utils/path_utils.dart

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

/// 路径工具类 - 获取应用根目录和 bin 目录
///
/// 约定：
/// - Windows 开发模式：`windows/bin` 目录下放置配置和数据文件
/// - Windows 发布模式：可执行文件同级目录下放置 `bin` 目录
/// - Linux 开发模式：项目根目录下放置 `bin` 目录
/// - Linux 发布模式：可执行文件同级目录下放置 `bin` 目录
class PathUtils {
  static String? _cachedAppRoot;
  
  /// 获取应用根目录
  static String get appRoot {
    if (_cachedAppRoot != null) {
      return _cachedAppRoot!;
    }

    try {
      final exePath = Platform.resolvedExecutable;
      final exeDir = p.dirname(exePath);

      if (Platform.isWindows) {
        _cachedAppRoot = _resolveWindowsAppRoot(exeDir);
      } else if (Platform.isLinux) {
        _cachedAppRoot = _resolveLinuxAppRoot(exeDir);
      } else {
        // 其他平台暂时按当前工作目录 + bin 处理
        _cachedAppRoot = _resolveGenericAppRoot(exeDir);
      }

      return _cachedAppRoot!;
    } catch (_) {
      // 兜底：使用当前工作目录
      _cachedAppRoot = Directory.current.path;
      return _cachedAppRoot!;
    }
  }

  /// Windows 平台下解析根目录
  static String _resolveWindowsAppRoot(String exeDir) {
    // 开发模式：可执行文件在 build 目录下，需要回溯到 windows 目录
    if (exeDir.contains('build') || exeDir.contains('windows\\build') || exeDir.contains('windows/build')) {
      var currentPath = exeDir;
      
      while (currentPath.isNotEmpty) {
        final dirName = p.basename(currentPath);
        final parent = p.dirname(currentPath);

        if (dirName == 'windows' &&
            !currentPath.contains('build\\windows') &&
            !currentPath.contains('build/windows')) {
          final binPath = p.join(currentPath, 'bin');
          if (Directory(binPath).existsSync()) {
            return currentPath;
          }
        }

        if (parent == currentPath) break;
        currentPath = parent;
      }

      // 回退到通过当前工作目录查找
      final fromCwd = _findDirWithBinFromCwd('windows');
      if (fromCwd != null) return fromCwd;
    }

    // 发布模式：可执行文件和 bin 文件夹在同一目录
    return exeDir;
  }

  /// Linux 平台下解析根目录
  static String _resolveLinuxAppRoot(String exeDir) {
    // 如果可执行文件目录下有 bin，优先使用（发布模式）
    final binInExeDir = p.join(exeDir, 'bin');
    if (Directory(binInExeDir).existsSync()) {
      return exeDir;
    }

    // 开发模式：从当前工作目录向上查找包含 bin 的目录（项目根目录）
    final fromCwd = _findDirWithBinFromCwd(null);
    if (fromCwd != null) return fromCwd;

    // 再退回到 exeDir
    return exeDir;
  }

  /// 通用平台兜底逻辑：优先找当前工作目录上的 bin
  static String _resolveGenericAppRoot(String exeDir) {
    final fromCwd = _findDirWithBinFromCwd(null);
    if (fromCwd != null) return fromCwd;
    return exeDir;
  }

  /// 从当前工作目录向上查找，直到找到满足条件的目录
  /// 如果 [expectDirName] 不为空，则必须匹配目录名，例如 'windows'
  static String? _findDirWithBinFromCwd(String? expectDirName) {
    var currentPath = Directory.current.path;

    while (currentPath.isNotEmpty) {
      final dirName = p.basename(currentPath);
      final binPath = p.join(currentPath, 'bin');

      if ((expectDirName == null || dirName == expectDirName) &&
          Directory(binPath).existsSync()) {
        return currentPath;
      }

      final parent = p.dirname(currentPath);
      if (parent == currentPath) break;
      currentPath = parent;
    }

    return null;
  }

  /// 获取 bin 目录路径
  static String get binDir {
    final root = appRoot;
    return p.join(root, 'bin');
  }

  /// 获取 bin 目录下的文件路径
  static String binFile(String filename) {
    return p.join(binDir, filename);
  }
}