import 'dart:io';

import 'package:path/path.dart' as path;
import 'package:yaml/yaml.dart';
import 'package:yx_icon_fonts/src/config/generator_config.dart';

/// 配置加载器
///
/// 负责从 YAML 文件加载配置
class ConfigLoader {
  /// 默认配置文件名
  static const String defaultConfigFileName = 'icon_generator_config.yaml';

  /// 加载配置文件
  ///
  /// [configPath] 配置文件路径，如果为 null 则使用默认路径
  /// [workingDir] 工作目录，默认为当前目录
  static GeneratorConfig load({
    String? configPath,
    String? workingDir,
  }) {
    final directory = workingDir ?? Directory.current.path;
    final filePath = configPath ?? path.join(directory, defaultConfigFileName);
    final file = File(filePath);

    if (!file.existsSync()) {
      throw ConfigNotFoundException(
        '配置文件不存在: $filePath\n'
        '请运行 "dart run yx_icon_fonts init" 创建配置文件',
      );
    }

    try {
      final content = file.readAsStringSync();
      final yamlMap = loadYaml(content) as YamlMap?;

      if (yamlMap == null) {
        throw ConfigParseException('配置文件为空或格式错误');
      }

      // 将 YamlMap 转换为 Map<String, dynamic>
      final map = _convertYamlMap(yamlMap);
      return GeneratorConfig.fromMap(map);
    } on YamlException catch (e) {
      throw ConfigParseException('YAML 解析错误: ${e.message}');
    }
  }

  /// 检查配置文件是否存在
  static bool exists({String? configPath, String? workingDir}) {
    final directory = workingDir ?? Directory.current.path;
    final filePath = configPath ?? path.join(directory, defaultConfigFileName);
    return File(filePath).existsSync();
  }

  /// 将 YamlMap 递归转换为 Map<String, dynamic>
  static Map<String, dynamic> _convertYamlMap(YamlMap yamlMap) {
    final result = <String, dynamic>{};
    for (final key in yamlMap.keys) {
      final value = yamlMap[key];
      if (value is YamlMap) {
        result[key.toString()] = _convertYamlMap(value);
      } else if (value is YamlList) {
        result[key.toString()] = _convertYamlList(value);
      } else {
        result[key.toString()] = value;
      }
    }
    return result;
  }

  /// 将 YamlList 递归转换为 List<dynamic>
  static List<dynamic> _convertYamlList(YamlList yamlList) {
    return yamlList.map((item) {
      if (item is YamlMap) {
        return _convertYamlMap(item);
      } else if (item is YamlList) {
        return _convertYamlList(item);
      }
      return item;
    }).toList();
  }
}

/// 配置文件未找到异常
class ConfigNotFoundException implements Exception {
  ConfigNotFoundException(this.message);

  final String message;

  @override
  String toString() => 'ConfigNotFoundException: $message';
}

/// 配置解析异常
class ConfigParseException implements Exception {
  ConfigParseException(this.message);

  final String message;

  @override
  String toString() => 'ConfigParseException: $message';
}