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
class PathUtils {
  static String? _cachedAppRoot;
  
  /// 获取应用根目录
  /// 在发布模式下，返回 .exe 文件所在目录
  /// 在开发模式下，返回 windows 目录（因为 bin 文件夹在 windows/bin 下）
  static String get appRoot {
    if (_cachedAppRoot != null) {
      return _cachedAppRoot!;
    }
    
    try {
      // 尝试获取可执行文件所在目录
      final exePath = Platform.resolvedExecutable;
      final exeDir = p.dirname(exePath);
      
      // 检查是否是开发模式（可执行文件在 build 目录下）
      if (exeDir.contains('build') || exeDir.contains('windows\\build') || exeDir.contains('windows/build')) {
        // 开发模式：bin 文件夹在 windows/bin 下
        // 从可执行文件路径向上查找 windows 目录
        var currentPath = exeDir;
        var foundWindows = false;
        
        // 向上查找，直到找到包含 'windows' 且不是 'build\windows' 的目录
        while (currentPath.isNotEmpty) {
          final dirName = p.basename(currentPath);
          final parent = p.dirname(currentPath);
          
          // 如果当前目录名是 'windows'，且不在 build 路径中，说明找到了项目根目录下的 windows 目录
          if (dirName == 'windows' && !currentPath.contains('build\\windows') && !currentPath.contains('build/windows')) {
            // 检查这个 windows 目录下是否有 bin 文件夹
            final binPath = p.join(currentPath, 'bin');
            if (Directory(binPath).existsSync()) {
              _cachedAppRoot = currentPath;
              foundWindows = true;
              break;
            }
          }
          
          if (parent == currentPath) break; // 到达根目录
          currentPath = parent;
        }
        
        if (foundWindows) {
          return _cachedAppRoot!;
        }
        
        // 如果向上查找失败，尝试从当前工作目录查找
        final currentDir = Directory.current.path;
        if (currentDir.contains('windows')) {
          // 找到 windows 目录
          final parts = currentDir.split(RegExp(r'[\\/]'));
          var windowsIndex = -1;
          for (int i = 0; i < parts.length; i++) {
            if (parts[i] == 'windows') {
              windowsIndex = i;
              break;
            }
          }
          
          if (windowsIndex >= 0) {
            final windowsDir = parts.sublist(0, windowsIndex + 1).join(Platform.pathSeparator);
            final binPath = p.join(windowsDir, 'bin');
            if (Directory(binPath).existsSync()) {
              _cachedAppRoot = windowsDir;
              return _cachedAppRoot!;
            }
          }
        }
      }
      
      // 发布模式：可执行文件和 bin 文件夹在同一目录
      _cachedAppRoot = exeDir;
      return _cachedAppRoot!;
    } catch (e) {
      // 如果获取失败，尝试使用当前工作目录
      final currentDir = Directory.current.path;
      if (currentDir.contains('windows')) {
        // 找到 windows 目录
        final parts = currentDir.split(RegExp(r'[\\/]'));
        var windowsIndex = -1;
        for (int i = 0; i < parts.length; i++) {
          if (parts[i] == 'windows') {
            windowsIndex = i;
            break;
          }
        }
        
          if (windowsIndex >= 0) {
            final windowsDir = parts.sublist(0, windowsIndex + 1).join(Platform.pathSeparator);
            final binPath = p.join(windowsDir, 'bin');
            if (Directory(binPath).existsSync()) {
              _cachedAppRoot = windowsDir;
              return _cachedAppRoot!;
            }
          }
      }
      _cachedAppRoot = currentDir;
      return _cachedAppRoot!;
    }
  }

  /// 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);
  }
}