import '../core/models.dart';
import '../utils/string_utils.dart';
import 'base_generator.dart';

/// 文档生成器
/// 负责生成API文档
class DocumentationGenerator extends BaseGenerator {
  final SwaggerDocument document;
  final bool includeExamples;
  final bool includeSchemas;
  final bool includeResponses;
  final String? customTitle;

  DocumentationGenerator(
    this.document, {
    this.includeExamples = true,
    this.includeSchemas = true,
    this.includeResponses = true,
    this.customTitle,
  });

  @override
  String get generatorType => 'DocumentationGenerator';

  @override
  String generate() {
    final buffer = StringBuffer();

    // 生成文档头部
    _generateHeader(buffer);

    // 生成目录
    _generateTableOfContents(buffer);

    // 生成API概述
    _generateApiOverview(buffer);

    // 生成认证信息
    _generateAuthenticationInfo(buffer);

    // 生成API端点文档
    _generateEndpointsDocumentation(buffer);

    // 生成数据模型文档
    if (includeSchemas) {
      _generateSchemasDocumentation(buffer);
    }

    // 生成错误代码文档
    _generateErrorCodesDocumentation(buffer);

    // 生成示例代码
    if (includeExamples) {
      _generateExamplesDocumentation(buffer);
    }

    // 生成更新日志
    _generateChangeLog(buffer);

    return generateTypeCheckedCode(buffer.toString());
  }

  /// 生成文档头部
  void _generateHeader(StringBuffer buffer) {
    final title = customTitle ?? document.title;

    buffer.writeln('# $title');
    buffer.writeln('');

    if (document.description.isNotEmpty) {
      buffer.writeln('${document.description}');
      buffer.writeln('');
    }

    buffer.writeln('**版本**: ${document.version}');
    buffer.writeln('**基础URL**: ${_getBaseUrl()}');
    buffer.writeln('**生成时间**: ${DateTime.now().toIso8601String()}');
    buffer.writeln('');

    // 生成徽章
    buffer.writeln(
        '![API版本](https://img.shields.io/badge/API-${document.version}-blue.svg)');
    buffer.writeln('![状态](https://img.shields.io/badge/状态-活跃-green.svg)');
    buffer.writeln('');
  }

  /// 生成目录
  void _generateTableOfContents(StringBuffer buffer) {
    buffer.writeln('## 📋 目录');
    buffer.writeln('');
    buffer.writeln('- [API概述](#api概述)');
    buffer.writeln('- [认证](#认证)');
    buffer.writeln('- [API端点](#api端点)');

    // 按控制器分组的端点
    final controllerGroups = _groupPathsByController();
    for (final controllerName in controllerGroups.keys) {
      final anchor = controllerName.toLowerCase().replaceAll(' ', '-');
      buffer.writeln('  - [$controllerName](#$anchor)');
    }

    if (includeSchemas) {
      buffer.writeln('- [数据模型](#数据模型)');
    }

    buffer.writeln('- [错误代码](#错误代码)');

    if (includeExamples) {
      buffer.writeln('- [示例代码](#示例代码)');
    }

    buffer.writeln('- [更新日志](#更新日志)');
    buffer.writeln('');
  }

  /// 生成API概述
  void _generateApiOverview(StringBuffer buffer) {
    buffer.writeln('## 🚀 API概述');
    buffer.writeln('');

    // 统计信息
    final stats = _generateStats();
    buffer.writeln('### 📊 统计信息');
    buffer.writeln('');
    buffer.writeln('- **总端点数**: ${stats['totalEndpoints']}');
    buffer.writeln('- **控制器数**: ${stats['controllersCount']}');
    buffer.writeln('- **数据模型数**: ${stats['modelsCount']}');
    buffer.writeln('');

    // HTTP方法统计
    final methodStats = stats['methodStats'] as Map<String, int>;
    buffer.writeln('### 🔗 HTTP方法分布');
    buffer.writeln('');
    for (final entry in methodStats.entries) {
      final method = entry.key;
      final count = entry.value;
      final percentage =
          ((count / stats['totalEndpoints']) * 100).toStringAsFixed(1);
      buffer.writeln('- **$method**: $count个 ($percentage%)');
    }
    buffer.writeln('');

    // 支持的格式
    buffer.writeln('### 🌐 服务器配置');
    buffer.writeln('');
    if (document.servers.isNotEmpty) {
      for (final server in document.servers) {
        buffer.writeln('**服务器**: `${server.url}`');
        if (server.description.isNotEmpty) {
          buffer.writeln('- ${server.description}');
        }
        if (server.variables.isNotEmpty) {
          buffer.writeln('- 变量:');
          server.variables.forEach((name, variable) {
            buffer.writeln(
                '  - `$name`: ${variable.description} (默认: ${variable.defaultValue})');
          });
        }
        buffer.writeln('');
      }
    } else {
      buffer.writeln('**服务器**: 相对路径 `/`');
      buffer.writeln('');
    }
  }

  /// 生成认证信息
  void _generateAuthenticationInfo(StringBuffer buffer) {
    buffer.writeln('## 🔐 认证');
    buffer.writeln('');
    buffer.writeln('本API使用以下认证方式：');
    buffer.writeln('');
    buffer.writeln('### Bearer Token');
    buffer.writeln('');
    buffer.writeln('在请求头中包含Authorization字段：');
    buffer.writeln('');
    buffer.writeln('```');
    buffer.writeln('Authorization: Bearer YOUR_TOKEN_HERE');
    buffer.writeln('```');
    buffer.writeln('');
    buffer.writeln('### 获取Token');
    buffer.writeln('');
    buffer.writeln('请使用登录接口获取访问令牌。');
    buffer.writeln('');
  }

  /// 生成端点文档
  void _generateEndpointsDocumentation(StringBuffer buffer) {
    buffer.writeln('## 📡 API端点');
    buffer.writeln('');

    final controllerGroups = _groupPathsByController();

    for (final entry in controllerGroups.entries) {
      final controllerName = entry.key;
      final paths = entry.value;

      buffer.writeln('### $controllerName');
      buffer.writeln('');

      // 按HTTP方法和路径排序
      paths.sort((a, b) {
        final methodOrder = ['GET', 'POST', 'PUT', 'PATCH', 'DELETE'];
        final aIndex = methodOrder.indexOf(a.method.value);
        final bIndex = methodOrder.indexOf(b.method.value);

        if (aIndex != bIndex) {
          return aIndex.compareTo(bIndex);
        }

        return a.path.compareTo(b.path);
      });

      for (final path in paths) {
        _generateEndpointDocumentation(buffer, path);
      }

      buffer.writeln('');
    }
  }

  /// 生成单个端点文档
  void _generateEndpointDocumentation(StringBuffer buffer, ApiPath path) {
    // 端点标题
    final title = path.summary.isNotEmpty ? path.summary : path.operationId;
    buffer.writeln('#### ${path.method.value} ${path.path}');
    buffer.writeln('');

    if (title.isNotEmpty) {
      buffer.writeln('**$title**');
      buffer.writeln('');
    }

    // 描述
    if (path.description.isNotEmpty) {
      buffer.writeln(path.description);
      buffer.writeln('');
    }

    // 标签
    if (path.tags.isNotEmpty) {
      buffer.writeln('**标签**: ${path.tags.join(', ')}');
      buffer.writeln('');
    }

    // 参数
    if (path.parameters.isNotEmpty) {
      buffer.writeln('**参数**:');
      buffer.writeln('');

      // 按参数位置分组
      final paramGroups = <ParameterLocation, List<ApiParameter>>{};
      for (final param in path.parameters) {
        paramGroups.putIfAbsent(param.location, () => []).add(param);
      }

      for (final entry in paramGroups.entries) {
        final location = entry.key;
        final params = entry.value;

        buffer.writeln('*${_getLocationName(location)}参数*:');
        buffer.writeln('');

        buffer.writeln('| 参数名 | 类型 | 必填 | 描述 | 示例 |');
        buffer.writeln('|--------|------|------|------|------|');

        for (final param in params) {
          final required = param.required ? '✅' : '❌';
          final example = param.example?.toString() ?? '-';
          final description =
              param.description.isNotEmpty ? param.description : '-';

          buffer.writeln(
              '| ${param.name} | ${param.type.value} | $required | $description | $example |');
        }

        buffer.writeln('');
      }
    }

    // 响应
    if (includeResponses && path.responses.isNotEmpty) {
      buffer.writeln('**响应**:');
      buffer.writeln('');

      for (final entry in path.responses.entries) {
        final code = entry.key;
        final response = entry.value;

        buffer.writeln('*HTTP $code*:');
        if (response.description.isNotEmpty) {
          buffer.writeln('- ${response.description}');
        }
        buffer.writeln('');
      }
    }

    // 示例
    if (includeExamples) {
      _generateEndpointExample(buffer, path);
    }

    buffer.writeln('---');
    buffer.writeln('');
  }

  /// 生成端点示例
  void _generateEndpointExample(StringBuffer buffer, ApiPath path) {
    buffer.writeln('**示例**:');
    buffer.writeln('');

    // cURL示例
    buffer.writeln('```bash');
    buffer.write('curl -X ${path.method.value} ');
    buffer.write('${_getBaseUrl()}${path.path}');

    if (path.parameters.any((p) => p.location == ParameterLocation.header)) {
      buffer.write(' \\');
      buffer.writeln('');
      buffer.write('  -H "Authorization: Bearer YOUR_TOKEN"');
    }

    if (path.method == HttpMethod.post || path.method == HttpMethod.put) {
      buffer.write(' \\');
      buffer.writeln('');
      buffer.write('  -H "Content-Type: application/json"');
      buffer.write(' \\');
      buffer.writeln('');
      buffer.write('  -d \'{"key": "value"}\'');
    }

    buffer.writeln('');
    buffer.writeln('```');
    buffer.writeln('');

    // Dart示例
    buffer.writeln('```dart');
    buffer.writeln('import \'dart:convert\';');
    buffer.writeln('import \'package:http/http.dart\' as http;');
    buffer.writeln('');
    buffer.writeln('class ApiClient {');
    buffer.writeln('  static const String baseUrl = \'${_getBaseUrl()}\';');
    buffer.writeln('  String? _token;');
    buffer.writeln('');
    buffer.writeln('  void setToken(String token) {');
    buffer.writeln('    _token = token;');
    buffer.writeln('  }');
    buffer.writeln('');
    buffer.writeln('  Map<String, String> get _headers => {');
    buffer.writeln('    \'Content-Type\': \'application/json\',');
    buffer.writeln(
        '    if (_token != null) \'Authorization\': \'Bearer \$_token\',');
    buffer.writeln('  };');
    buffer.writeln('');
    buffer
        .writeln('  Future<Map<String, dynamic>> get(String endpoint) async {');
    buffer.writeln('    final response = await http.get(');
    buffer.writeln('      Uri.parse(\'\$baseUrl\$endpoint\'),');
    buffer.writeln('      headers: _headers,');
    buffer.writeln('    );');
    buffer.writeln('');
    buffer.writeln('    if (response.statusCode == 200) {');
    buffer.writeln('      return jsonDecode(response.body);');
    buffer.writeln('    } else {');
    buffer.writeln(
        '      throw Exception(\'Failed to load data: \${response.statusCode}\');');
    buffer.writeln('    }');
    buffer.writeln('  }');
    buffer.writeln('');
    buffer.writeln(
        '  Future<Map<String, dynamic>> post(String endpoint, Map<String, dynamic> data) async {');
    buffer.writeln('    final response = await http.post(');
    buffer.writeln('      Uri.parse(\'\$baseUrl\$endpoint\'),');
    buffer.writeln('      headers: _headers,');
    buffer.writeln('      body: jsonEncode(data),');
    buffer.writeln('    );');
    buffer.writeln('');
    buffer.writeln(
        '    if (response.statusCode == 200 || response.statusCode == 201) {');
    buffer.writeln('      return jsonDecode(response.body);');
    buffer.writeln('    } else {');
    buffer.writeln(
        '      throw Exception(\'Failed to post data: \${response.statusCode}\');');
    buffer.writeln('    }');
    buffer.writeln('  }');
    buffer.writeln('}');
    buffer.writeln('```');
    buffer.writeln('');
  }

  /// 生成数据模型文档
  void _generateSchemasDocumentation(StringBuffer buffer) {
    if (document.models.isEmpty) return;

    buffer.writeln('## 📋 数据模型');
    buffer.writeln('');

    final sortedModels = document.models.values.toList()
      ..sort((a, b) => a.name.compareTo(b.name));

    for (final model in sortedModels) {
      _generateModelDocumentation(buffer, model);
    }
  }

  /// 生成模型文档
  void _generateModelDocumentation(StringBuffer buffer, ApiModel model) {
    buffer.writeln('### ${model.name}');
    buffer.writeln('');

    if (model.description.isNotEmpty) {
      buffer.writeln(model.description);
      buffer.writeln('');
    }

    if (model.isEnum) {
      buffer.writeln('**枚举值**:');
      buffer.writeln('');

      for (final value in model.enumValues) {
        buffer.writeln('- `$value`');
      }

      buffer.writeln('');
    } else {
      buffer.writeln('**属性**:');
      buffer.writeln('');

      if (model.properties.isNotEmpty) {
        buffer.writeln('| 属性名 | 类型 | 必填 | 描述 |');
        buffer.writeln('|--------|------|------|------|');

        for (final entry in model.properties.entries) {
          final propName = entry.key;
          final prop = entry.value;

          final required = model.required.contains(propName) ? '✅' : '❌';
          final type = _getPropertyTypeDescription(prop);
          final description =
              prop.description.isNotEmpty ? prop.description : '-';

          buffer.writeln('| $propName | $type | $required | $description |');
        }
      }

      buffer.writeln('');
    }

    // JSON示例
    if (includeExamples) {
      buffer.writeln('**JSON示例**:');
      buffer.writeln('');
      buffer.writeln('```json');
      buffer.writeln(_generateModelExample(model));
      buffer.writeln('```');
      buffer.writeln('');
    }

    buffer.writeln('---');
    buffer.writeln('');
  }

  /// 生成错误代码文档
  void _generateErrorCodesDocumentation(StringBuffer buffer) {
    buffer.writeln('## ❌ 错误代码');
    buffer.writeln('');

    // 标准HTTP状态码
    final errorCodes = {
      '400': '请求参数错误',
      '401': '未授权访问',
      '403': '禁止访问',
      '404': '资源不存在',
      '405': '方法不允许',
      '422': '参数验证失败',
      '500': '服务器内部错误',
      '502': '网关错误',
      '503': '服务不可用',
    };

    buffer.writeln('| 状态码 | 描述 |');
    buffer.writeln('|--------|------|');

    for (final entry in errorCodes.entries) {
      buffer.writeln('| ${entry.key} | ${entry.value} |');
    }

    buffer.writeln('');

    // 错误响应格式
    buffer.writeln('### 错误响应格式');
    buffer.writeln('');
    buffer.writeln('```json');
    buffer.writeln('{');
    buffer.writeln('  "error": {');
    buffer.writeln('    "code": "ERROR_CODE",');
    buffer.writeln('    "message": "错误描述",');
    buffer.writeln('    "details": "详细信息"');
    buffer.writeln('  }');
    buffer.writeln('}');
    buffer.writeln('```');
    buffer.writeln('');
  }

  /// 生成示例代码
  void _generateExamplesDocumentation(StringBuffer buffer) {
    buffer.writeln('## 💡 示例代码');
    buffer.writeln('');

    // Dart HTTP客户端示例
    buffer.writeln('### Dart HTTP客户端');
    buffer.writeln('');
    buffer.writeln('```dart');
    buffer.writeln('import \'dart:convert\';');
    buffer.writeln('import \'package:http/http.dart\' as http;');
    buffer.writeln('');
    buffer.writeln('class ApiClient {');
    buffer.writeln('  static const String baseUrl = \'${_getBaseUrl()}\';');
    buffer.writeln('  String? _token;');
    buffer.writeln('');
    buffer.writeln('  void setToken(String token) {');
    buffer.writeln('    _token = token;');
    buffer.writeln('  }');
    buffer.writeln('');
    buffer.writeln('  Map<String, String> get _headers => {');
    buffer.writeln('    \'Content-Type\': \'application/json\',');
    buffer.writeln(
        '    if (_token != null) \'Authorization\': \'Bearer \$_token\',');
    buffer.writeln('  };');
    buffer.writeln('');
    buffer
        .writeln('  Future<Map<String, dynamic>> get(String endpoint) async {');
    buffer.writeln('    final response = await http.get(');
    buffer.writeln('      Uri.parse(\'\$baseUrl\$endpoint\'),');
    buffer.writeln('      headers: _headers,');
    buffer.writeln('    );');
    buffer.writeln('');
    buffer.writeln('    if (response.statusCode == 200) {');
    buffer.writeln('      return jsonDecode(response.body);');
    buffer.writeln('    } else {');
    buffer.writeln(
        '      throw Exception(\'Failed to load data: \${response.statusCode}\');');
    buffer.writeln('    }');
    buffer.writeln('  }');
    buffer.writeln('');
    buffer.writeln(
        '  Future<Map<String, dynamic>> post(String endpoint, Map<String, dynamic> data) async {');
    buffer.writeln('    final response = await http.post(');
    buffer.writeln('      Uri.parse(\'\$baseUrl\$endpoint\'),');
    buffer.writeln('      headers: _headers,');
    buffer.writeln('      body: jsonEncode(data),');
    buffer.writeln('    );');
    buffer.writeln('');
    buffer.writeln(
        '    if (response.statusCode == 200 || response.statusCode == 201) {');
    buffer.writeln('      return jsonDecode(response.body);');
    buffer.writeln('    } else {');
    buffer.writeln(
        '      throw Exception(\'Failed to post data: \${response.statusCode}\');');
    buffer.writeln('    }');
    buffer.writeln('  }');
    buffer.writeln('}');
    buffer.writeln('```');
    buffer.writeln('');
  }

  /// 生成更新日志
  void _generateChangeLog(StringBuffer buffer) {
    buffer.writeln('## 📝 更新日志');
    buffer.writeln('');

    buffer.writeln(
        '### ${document.version} - ${DateTime.now().toIso8601String().split('T')[0]}');
    buffer.writeln('');
    buffer.writeln('- 🎉 初始版本发布');
    buffer.writeln('- 📡 ${document.paths.length} 个API端点');
    buffer.writeln('- 📋 ${document.models.length} 个数据模型');
    buffer.writeln('- 🔧 完整的API文档');
    buffer.writeln('');

    buffer.writeln('---');
    buffer.writeln('');
    buffer.writeln('*文档由 Swagger CLI By Max 自动生成*');
    buffer.writeln('');
  }

  /// 按控制器分组路径
  Map<String, List<ApiPath>> _groupPathsByController() {
    final groups = <String, List<ApiPath>>{};

    for (final path in document.paths.values) {
      final controllerName = StringUtils.extractControllerName(path);
      groups.putIfAbsent(controllerName, () => []).add(path);
    }

    return groups;
  }

  // 已移动到 StringUtils.extractControllerName

  /// 获取基础URL (从 OpenAPI 3.0 servers 配置)
  String _getBaseUrl() {
    if (document.servers.isNotEmpty) {
      return document.servers.first.url;
    }
    return '/'; // 默认相对路径
  }

  /// 获取参数位置名称
  String _getLocationName(ParameterLocation location) {
    switch (location) {
      case ParameterLocation.query:
        return '查询';
      case ParameterLocation.path:
        return '路径';
      case ParameterLocation.header:
        return '请求头';
      case ParameterLocation.body:
        return '请求体';
      case ParameterLocation.form:
        return '表单';
      case ParameterLocation.cookie:
        return 'Cookie';
    }
  }

  /// 获取属性类型描述
  String _getPropertyTypeDescription(ApiProperty prop) {
    String baseType = prop.type.value;

    if (prop.format != null) {
      baseType += ' (${prop.format})';
    }

    if (prop.nullable) {
      baseType += '?';
    }

    return baseType;
  }

  /// 生成模型示例
  String _generateModelExample(ApiModel model) {
    if (model.isEnum) {
      return '"${model.enumValues.first}"';
    }

    final buffer = StringBuffer();
    buffer.writeln('{');

    final properties = model.properties.entries.toList();
    for (int i = 0; i < properties.length; i++) {
      final entry = properties[i];
      final propName = entry.key;
      final prop = entry.value;

      final exampleValue = _generatePropertyExample(prop);
      buffer.write('  "$propName": $exampleValue');

      if (i < properties.length - 1) {
        buffer.write(',');
      }

      buffer.writeln();
    }

    buffer.write('}');
    return buffer.toString();
  }

  /// 生成属性示例
  String _generatePropertyExample(ApiProperty prop) {
    switch (prop.type) {
      case PropertyType.string:
        return '"string"';
      case PropertyType.integer:
        return '0';
      case PropertyType.number:
        return '0.0';
      case PropertyType.boolean:
        return 'true';
      case PropertyType.array:
        return '[]';
      case PropertyType.object:
        return '{}';
      case PropertyType.reference:
        return '{}';
      default:
        return 'null';
    }
  }

  /// 生成统计信息
  Map<String, dynamic> _generateStats() {
    final stats = <String, dynamic>{};

    stats['totalEndpoints'] = document.paths.length;
    stats['controllersCount'] = _groupPathsByController().length;
    stats['modelsCount'] = document.models.length;

    // HTTP方法统计
    final methodStats = <String, int>{};
    for (final path in document.paths.values) {
      final method = path.method.value;
      methodStats[method] = (methodStats[method] ?? 0) + 1;
    }
    stats['methodStats'] = methodStats;

    return stats;
  }
}