import 'dart:io';
import 'package:flutter/material.dart';
import 'package:file_picker/file_picker.dart';
import 'package:path_provider/path_provider.dart';
import 'package:win_text_editor/app/models/file_node.dart';
import 'package:win_text_editor/app/providers/logger.dart';
import 'package:win_text_editor/app/services/file_service.dart';

class FileProvider with ChangeNotifier {
  List<FileNode> _fileNodes = [];
  bool _isLoading = false;
  String _searchQuery = '';
  String? _currentRootPath; // 跟踪当前根路径

  bool get isLoading => _isLoading;
  bool get hasRoot => _fileNodes.isNotEmpty && _fileNodes[0].isRoot;

  // 移除构造函数的_initFileTree调用
  FileProvider();

  // 新增方法：手动设置根路径
  Future<void> setRootPath(String path) async {
    _currentRootPath = path;
    await _loadRootDirectory();
  }

  List<FileNode> get fileNodes =>
      _searchQuery.isEmpty ? _fileNodes : _fileNodes.where((node) => _filterNode(node)).toList();

  bool _filterNode(FileNode node) {
    if (node.name.toLowerCase().contains(_searchQuery.toLowerCase())) {
      return true;
    }
    return node.children.any(_filterNode);
  }

  void searchFiles(String query) {
    _searchQuery = query;
    notifyListeners();
  }

  void toggleExpand(FileNode node) {
    node.isExpanded = !node.isExpanded;
    notifyListeners();
  }

  Future<void> pickAndOpenFile() async {
    final result = await FilePicker.platform.pickFiles();
    if (result != null && result.files.single.path != null) {
      // 这里需要与编辑器提供者交互来打开文件
      Logger().info('File selected: ${result.files.single.path}');
    }
  }

  Future<void> loadDirectory(String path) async {
    _isLoading = true;
    notifyListeners();

    try {
      final directory = Directory(path);
      final rootNode = FileNode(
        name: directory.path.split(Platform.pathSeparator).last,
        path: directory.path,
        isDirectory: true,
        isRoot: true, // 添加根节点标识
        children: await FileService.buildFileTree(directory.path),
      );
      _fileNodes = [rootNode]; // 将根节点作为唯一顶层节点
    } catch (e) {
      Logger().error('Error loading directory: $e');
      _fileNodes = [];
    }

    _isLoading = false;
    notifyListeners();
  }

  Future<void> _loadRootDirectory() async {
    if (_currentRootPath == null) return;

    _isLoading = true;
    notifyListeners();

    try {
      _fileNodes = [
        FileNode(
          name: _currentRootPath!.split(Platform.pathSeparator).last,
          path: _currentRootPath!,
          isDirectory: true,
          isRoot: true,
          depth: 0, // 根节点深度为0
          children: [], // 初始为空，不加载内容
        ),
      ];
    } catch (e) {
      Logger().error('Error loading root directory: $e');
      _fileNodes = [];
    }

    _isLoading = false;
    notifyListeners();
  }

  Future<void> loadRootDirectory(String path) async {
    _isLoading = true;
    notifyListeners();

    try {
      _fileNodes = [
        FileNode(
          name: path.split(Platform.pathSeparator).last,
          path: path,
          isDirectory: true,
          isRoot: true,
          children: [], // 初始为空
        ),
      ];
    } catch (e) {
      Logger().error('Error loading root: $e');
      _fileNodes = [];
    }

    _isLoading = false;
    notifyListeners();
  }

  Future<void> toggleDirectory(FileNode dirNode) async {
    if (dirNode.children.isEmpty) {
      // 首次点击：加载内容
      _isLoading = true;
      notifyListeners();

      try {
        dirNode.children = await FileService.listDirectory(dirNode.path);
        dirNode.isExpanded = true;
      } catch (e) {
        Logger().error('Error loading directory: $e');
        dirNode.children = [];
      }

      _isLoading = false;
      notifyListeners();
    } else {
      // 已加载过：只切换展开状态
      dirNode.isExpanded = !dirNode.isExpanded;
      notifyListeners();
    }
  }

  Future<void> loadDirectoryContents(FileNode dirNode) async {
    if (dirNode.children.isNotEmpty && dirNode.isExpanded) {
      // 如果已经加载过且是展开状态，只切换展开状态
      dirNode.isExpanded = !dirNode.isExpanded;
      notifyListeners();
      return;
    }

    _isLoading = true;
    notifyListeners();

    try {
      final contents = await FileService.listDirectory(
        dirNode.path,
        parentDepth: dirNode.depth, // 确保传递父节点深度
      );

      final updatedNode = dirNode.copyWith(
        children: contents,
        isExpanded: true,
        // 不需要设置 depth，因为 copyWith 会自动保留原值
      );

      _replaceNodeInTree(dirNode, updatedNode);
    } catch (e) {
      Logger().error('Error loading directory contents: $e');
      final updatedNode = dirNode.copyWith(children: []);
      _replaceNodeInTree(dirNode, updatedNode);
    }

    _isLoading = false;
    notifyListeners();
  }

  void _replaceNodeInTree(FileNode oldNode, FileNode newNode) {
    for (int i = 0; i < _fileNodes.length; i++) {
      if (_fileNodes[i] == oldNode) {
        _fileNodes[i] = newNode;
        return;
      }
      _replaceNodeInChildren(_fileNodes[i], oldNode, newNode);
    }
  }

  void _replaceNodeInChildren(FileNode parent, FileNode oldNode, FileNode newNode) {
    for (int i = 0; i < parent.children.length; i++) {
      if (parent.children[i] == oldNode) {
        parent.children[i] = newNode;
        return;
      }
      _replaceNodeInChildren(parent.children[i], oldNode, newNode);
    }
  }

  Future<void> refreshFileTree({bool loadContent = false}) async {
    _isLoading = true;
    notifyListeners();

    try {
      final rootDir = await getApplicationDocumentsDirectory();
      _fileNodes = [
        FileNode(
          name: rootDir.path.split(Platform.pathSeparator).last,
          path: rootDir.path,
          isDirectory: true,
          isRoot: true,
          // 初始不加载内容
          children: loadContent ? await FileService.listDirectory(rootDir.path) : [],
        ),
      ];
    } catch (e) {
      Logger().error('Error refreshing file tree: $e');
      _fileNodes = [];
    }

    _isLoading = false;
    notifyListeners();
  }
}