/**
 * 登录控制器
 * 
 * 功能描述：
 * - 处理登录相关的HTTP请求和响应
 * - 提供RESTful API接口
 * - 数据验证和格式化
 * 
 * 职责分离：
 * - 专注于HTTP请求处理和响应格式化
 * - 调用业务服务完成具体功能
 * - 处理API文档和参数验证
 * 
 * API端点：
 * - POST /auth/login - 用户登录
 * - POST /auth/register - 用户注册
 * - POST /auth/github - GitHub OAuth登录
 * - POST /auth/forgot-password - 发送密码重置验证码
 * - POST /auth/reset-password - 重置密码
 * - PUT /auth/change-password - 修改密码
 * - POST /auth/refresh-token - 刷新访问令牌
 * 
 * 最近修改：
 * - 2026-01-07: 代码规范优化 - 文件夹扁平化，移除单文件文件夹结构
 * - 2026-01-07: 代码规范优化 - 更新注释规范，修正文件引用路径
 * 
 * @author moyin
 * @version 1.0.2
 * @since 2025-12-17
 * @lastModified 2026-01-07
 */

import { Controller, Post, Put, Body, HttpCode, HttpStatus, ValidationPipe, UsePipes, Logger, Res } from '@nestjs/common';
import { ApiTags, ApiOperation, ApiResponse as SwaggerApiResponse, ApiBody } from '@nestjs/swagger';
import { Response } from 'express';
import { LoginService, ApiResponse, LoginResponse } from './login.service';
import { LoginDto, RegisterDto, GitHubOAuthDto, ForgotPasswordDto, ResetPasswordDto, ChangePasswordDto, EmailVerificationDto, SendEmailVerificationDto, VerificationCodeLoginDto, SendLoginVerificationCodeDto, RefreshTokenDto } from './login.dto';
import { 
  LoginResponseDto, 
  RegisterResponseDto, 
  GitHubOAuthResponseDto, 
  ForgotPasswordResponseDto, 
  CommonResponseDto,
  TestModeEmailVerificationResponseDto,
  SuccessEmailVerificationResponseDto,
  RefreshTokenResponseDto
} from './login_response.dto';
import { Throttle, ThrottlePresets } from '../../core/security_core/throttle.decorator';
import { Timeout, TimeoutPresets } from '../../core/security_core/timeout.decorator';

// 错误代码到HTTP状态码的映射
const ERROR_STATUS_MAP = {
  LOGIN_FAILED: HttpStatus.UNAUTHORIZED,
  REGISTER_FAILED: HttpStatus.BAD_REQUEST,
  TEST_MODE_ONLY: HttpStatus.PARTIAL_CONTENT,
  TOKEN_REFRESH_FAILED: HttpStatus.UNAUTHORIZED,
  GITHUB_OAUTH_FAILED: HttpStatus.UNAUTHORIZED,
  SEND_CODE_FAILED: HttpStatus.BAD_REQUEST,
  RESET_PASSWORD_FAILED: HttpStatus.BAD_REQUEST,
  CHANGE_PASSWORD_FAILED: HttpStatus.BAD_REQUEST,
  EMAIL_VERIFICATION_FAILED: HttpStatus.BAD_REQUEST,
  VERIFICATION_CODE_LOGIN_FAILED: HttpStatus.UNAUTHORIZED,
  INVALID_VERIFICATION_CODE: HttpStatus.BAD_REQUEST,
} as const;

@ApiTags('auth')
@Controller('auth')
export class LoginController {
  private readonly logger = new Logger(LoginController.name);

  constructor(private readonly loginService: LoginService) {}

  /**
   * 通用响应处理方法
   * 
   * 业务逻辑：
   * 1. 根据业务结果设置HTTP状态码
   * 2. 处理不同类型的错误响应
   * 3. 统一响应格式和错误处理
   * 
   * @param result 业务服务返回的结果
   * @param res Express响应对象
   * @param successStatus 成功时的HTTP状态码，默认为200
   * @private
   */
  private handleResponse(result: any, res: Response, successStatus: HttpStatus = HttpStatus.OK): void {
    if (result.success) {
      res.status(successStatus).json(result);
      return;
    }

    // 根据错误代码获取状态码
    const statusCode = this.getErrorStatusCode(result);
    res.status(statusCode).json(result);
  }

  /**
   * 根据错误代码和消息获取HTTP状态码
   * 
   * @param result 业务服务返回的结果
   * @returns HTTP状态码
   * @private
   */
  private getErrorStatusCode(result: any): HttpStatus {
    // 优先使用错误代码映射
    if (result.error_code && ERROR_STATUS_MAP[result.error_code as keyof typeof ERROR_STATUS_MAP]) {
      return ERROR_STATUS_MAP[result.error_code as keyof typeof ERROR_STATUS_MAP];
    }

    // 根据消息内容判断
    if (result.message?.includes('已存在') || result.message?.includes('已被注册')) {
      return HttpStatus.CONFLICT;
    }
    
    if (result.message?.includes('令牌验证失败') || result.message?.includes('已过期')) {
      return HttpStatus.UNAUTHORIZED;
    }
    
    if (result.message?.includes('用户不存在')) {
      return HttpStatus.NOT_FOUND;
    }

    // 默认返回400
    return HttpStatus.BAD_REQUEST;
  }

  /**
   * 用户登录
   * 
   * @param loginDto 登录数据
   * @returns 登录结果
   */
  @ApiOperation({ 
    summary: '用户登录', 
    description: '支持用户名、邮箱或手机号登录' 
  })
  @ApiBody({ type: LoginDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '登录成功', 
    type: LoginResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 401, 
    description: '用户名或密码错误' 
  })
  @SwaggerApiResponse({ 
    status: 403, 
    description: '账户被禁用或锁定' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '登录尝试过于频繁' 
  })
  @Throttle(ThrottlePresets.LOGIN)
  @Timeout(TimeoutPresets.NORMAL)
  @Post('login')
  @UsePipes(new ValidationPipe({ transform: true }))
  async login(@Body() loginDto: LoginDto, @Res() res: Response): Promise<void> {
    const result = await this.loginService.login({
      identifier: loginDto.identifier,
      password: loginDto.password
    });

    this.handleResponse(result, res);
  }

  /**
   * 用户注册
   * 
   * @param registerDto 注册数据
   * @returns 注册结果
   */
  @ApiOperation({ 
    summary: '用户注册', 
    description: '创建新用户账户。如果提供邮箱，需要先调用发送验证码接口获取验证码，然后在注册时提供验证码进行验证。' 
  })
  @ApiBody({ type: RegisterDto })
  @SwaggerApiResponse({ 
    status: 201, 
    description: '注册成功', 
    type: RegisterResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 409, 
    description: '用户名或邮箱已存在' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '注册请求过于频繁' 
  })
  @Throttle(ThrottlePresets.REGISTER)
  @Timeout(TimeoutPresets.NORMAL)
  @Post('register')
  @UsePipes(new ValidationPipe({ transform: true }))
  async register(@Body() registerDto: RegisterDto, @Res() res: Response): Promise<void> {
    const result = await this.loginService.register({
      username: registerDto.username,
      password: registerDto.password,
      nickname: registerDto.nickname,
      email: registerDto.email,
      phone: registerDto.phone,
      email_verification_code: registerDto.email_verification_code
    });

    this.handleResponse(result, res, HttpStatus.CREATED);
  }

  /**
   * GitHub OAuth登录
   * 
   * @param githubDto GitHub OAuth数据
   * @returns 登录结果
   */
  @ApiOperation({ 
    summary: 'GitHub OAuth登录', 
    description: '使用GitHub账户登录或注册' 
  })
  @ApiBody({ type: GitHubOAuthDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: 'GitHub登录成功', 
    type: GitHubOAuthResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 401, 
    description: 'GitHub认证失败' 
  })
  @Post('github')
  @UsePipes(new ValidationPipe({ transform: true }))
  async githubOAuth(@Body() githubDto: GitHubOAuthDto, @Res() res: Response): Promise<void> {
    const result = await this.loginService.githubOAuth({
      github_id: githubDto.github_id,
      username: githubDto.username,
      nickname: githubDto.nickname,
      email: githubDto.email,
      avatar_url: githubDto.avatar_url
    });

    this.handleResponse(result, res);
  }

  /**
   * 发送密码重置验证码
   * 
   * @param forgotPasswordDto 忘记密码数据
   * @param res Express响应对象
   * @returns 发送结果
   */
  @ApiOperation({ 
    summary: '发送密码重置验证码', 
    description: '向用户邮箱或手机发送密码重置验证码' 
  })
  @ApiBody({ type: ForgotPasswordDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '验证码发送成功', 
    type: ForgotPasswordResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 206, 
    description: '测试模式：验证码已生成但未真实发送', 
    type: ForgotPasswordResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 404, 
    description: '用户不存在' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '发送频率过高' 
  })
  @Throttle(ThrottlePresets.SEND_CODE)
  @Post('forgot-password')
  @UsePipes(new ValidationPipe({ transform: true }))
  async forgotPassword(
    @Body() forgotPasswordDto: ForgotPasswordDto,
    @Res() res: Response
  ): Promise<void> {
    const result = await this.loginService.sendPasswordResetCode(forgotPasswordDto.identifier);
    this.handleResponse(result, res);
  }

  /**
   * 重置密码
   * 
   * @param resetPasswordDto 重置密码数据
   * @returns 重置结果
   */
  @ApiOperation({ 
    summary: '重置密码', 
    description: '使用验证码重置用户密码' 
  })
  @ApiBody({ type: ResetPasswordDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '密码重置成功', 
    type: CommonResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误或验证码无效' 
  })
  @SwaggerApiResponse({ 
    status: 404, 
    description: '用户不存在' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '重置请求过于频繁' 
  })
  @Throttle(ThrottlePresets.RESET_PASSWORD)
  @Post('reset-password')
  @UsePipes(new ValidationPipe({ transform: true }))
  async resetPassword(@Body() resetPasswordDto: ResetPasswordDto, @Res() res: Response): Promise<void> {
    const result = await this.loginService.resetPassword({
      identifier: resetPasswordDto.identifier,
      verificationCode: resetPasswordDto.verification_code,
      newPassword: resetPasswordDto.new_password
    });

    this.handleResponse(result, res);
  }

  /**
   * 修改密码
   * 
   * @param changePasswordDto 修改密码数据
   * @returns 修改结果
   */
  @ApiOperation({ 
    summary: '修改密码', 
    description: '用户修改自己的密码（需要提供旧密码）' 
  })
  @ApiBody({ type: ChangePasswordDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '密码修改成功', 
    type: CommonResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误或旧密码不正确' 
  })
  @SwaggerApiResponse({ 
    status: 404, 
    description: '用户不存在' 
  })
  @Put('change-password')
  @UsePipes(new ValidationPipe({ transform: true }))
  async changePassword(@Body() changePasswordDto: ChangePasswordDto, @Res() res: Response): Promise<void> {
    // 实际应用中应从JWT令牌中获取用户ID
    // 这里为了演示，使用请求体中的用户ID
    const userId = BigInt(changePasswordDto.user_id);
    
    const result = await this.loginService.changePassword(
      userId,
      changePasswordDto.old_password,
      changePasswordDto.new_password
    );

    this.handleResponse(result, res);
  }

  /**
   * 发送邮箱验证码
   * 
   * @param sendEmailVerificationDto 发送验证码数据
   * @param res Express响应对象
   * @returns 发送结果
   */
  @ApiOperation({ 
    summary: '发送邮箱验证码', 
    description: '向指定邮箱发送验证码' 
  })
  @ApiBody({ type: SendEmailVerificationDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '验证码发送成功（真实发送模式）', 
    type: SuccessEmailVerificationResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 206, 
    description: '测试模式：验证码已生成但未真实发送', 
    type: TestModeEmailVerificationResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '发送频率过高' 
  })
  @Throttle(ThrottlePresets.SEND_CODE)
  @Timeout(TimeoutPresets.EMAIL_SEND)
  @Post('send-email-verification')
  @UsePipes(new ValidationPipe({ transform: true }))
  async sendEmailVerification(
    @Body() sendEmailVerificationDto: SendEmailVerificationDto,
    @Res() res: Response
  ): Promise<void> {
    const result = await this.loginService.sendEmailVerification(sendEmailVerificationDto.email);
    this.handleResponse(result, res);
  }

  /**
   * 验证邮箱验证码
   * 
   * @param emailVerificationDto 邮箱验证数据
   * @returns 验证结果
   */
  @ApiOperation({ 
    summary: '验证邮箱验证码', 
    description: '使用验证码验证邮箱' 
  })
  @ApiBody({ type: EmailVerificationDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '邮箱验证成功', 
    type: CommonResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '验证码错误或已过期' 
  })
  @Post('verify-email')
  @UsePipes(new ValidationPipe({ transform: true }))
  async verifyEmail(@Body() emailVerificationDto: EmailVerificationDto, @Res() res: Response): Promise<void> {
    const result = await this.loginService.verifyEmailCode(
      emailVerificationDto.email,
      emailVerificationDto.verification_code
    );

    this.handleResponse(result, res);
  }

  /**
   * 重新发送邮箱验证码
   * 
   * @param sendEmailVerificationDto 发送验证码数据
   * @param res Express响应对象
   * @returns 发送结果
   */
  @ApiOperation({ 
    summary: '重新发送邮箱验证码', 
    description: '重新向指定邮箱发送验证码' 
  })
  @ApiBody({ type: SendEmailVerificationDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '验证码重新发送成功', 
    type: ForgotPasswordResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 206, 
    description: '测试模式：验证码已生成但未真实发送', 
    type: ForgotPasswordResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '邮箱已验证或用户不存在' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '发送频率过高' 
  })
  @Throttle(ThrottlePresets.SEND_CODE)
  @Post('resend-email-verification')
  @UsePipes(new ValidationPipe({ transform: true }))
  async resendEmailVerification(
    @Body() sendEmailVerificationDto: SendEmailVerificationDto,
    @Res() res: Response
  ): Promise<void> {
    const result = await this.loginService.resendEmailVerification(sendEmailVerificationDto.email);
    this.handleResponse(result, res);
  }

  /**
   * 验证码登录
   * 
   * @param verificationCodeLoginDto 验证码登录数据
   * @returns 登录结果
   */
  @ApiOperation({ 
    summary: '验证码登录', 
    description: '使用邮箱或手机号和验证码进行登录，无需密码' 
  })
  @ApiBody({ type: VerificationCodeLoginDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '验证码登录成功', 
    type: LoginResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 401, 
    description: '验证码错误或已过期' 
  })
  @SwaggerApiResponse({ 
    status: 404, 
    description: '用户不存在' 
  })
  @Post('verification-code-login')
  @HttpCode(HttpStatus.OK)
  @UsePipes(new ValidationPipe({ transform: true }))
  async verificationCodeLogin(@Body() verificationCodeLoginDto: VerificationCodeLoginDto): Promise<ApiResponse<LoginResponse>> {
    return await this.loginService.verificationCodeLogin({
      identifier: verificationCodeLoginDto.identifier,
      verificationCode: verificationCodeLoginDto.verification_code
    });
  }

  /**
   * 发送登录验证码
   * 
   * @param sendLoginVerificationCodeDto 发送验证码数据
   * @param res Express响应对象
   * @returns 发送结果
   */
  @ApiOperation({ 
    summary: '发送登录验证码', 
    description: '向用户邮箱或手机发送登录验证码。邮件使用专门的登录验证码模板，内容明确标识为登录验证而非密码重置。' 
  })
  @ApiBody({ type: SendLoginVerificationCodeDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '验证码发送成功', 
    type: ForgotPasswordResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 206, 
    description: '测试模式：验证码已生成但未真实发送', 
    type: ForgotPasswordResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 404, 
    description: '用户不存在' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '发送频率过高' 
  })
  @Post('send-login-verification-code')
  @UsePipes(new ValidationPipe({ transform: true }))
  async sendLoginVerificationCode(
    @Body() sendLoginVerificationCodeDto: SendLoginVerificationCodeDto,
    @Res() res: Response
  ): Promise<void> {
    const result = await this.loginService.sendLoginVerificationCode(sendLoginVerificationCodeDto.identifier);
    this.handleResponse(result, res);
  }

  /**
   * 调试验证码信息
   * 仅用于开发和调试
   * 
   * @param sendEmailVerificationDto 邮箱信息
   * @returns 验证码调试信息
   */
  @ApiOperation({ 
    summary: '调试验证码信息', 
    description: '获取验证码的详细调试信息（仅开发环境）' 
  })
  @ApiBody({ type: SendEmailVerificationDto })
  @Post('debug-verification-code')
  @UsePipes(new ValidationPipe({ transform: true }))
  async debugVerificationCode(@Body() sendEmailVerificationDto: SendEmailVerificationDto, @Res() res: Response): Promise<void> {
    const result = await this.loginService.debugVerificationCode(sendEmailVerificationDto.email);
    
    // 调试接口总是返回200
    res.status(HttpStatus.OK).json(result);
  }

  /**
   * 清除限流记录（仅开发环境）
   */
  @ApiOperation({ 
    summary: '清除限流记录', 
    description: '清除所有限流记录（仅开发环境使用）' 
  })
  @Post('debug-clear-throttle')
  async clearThrottle(@Res() res: Response): Promise<void> {
    // 注入ThrottleGuard并清除记录
    // 这里需要通过依赖注入获取ThrottleGuard实例
    res.status(HttpStatus.OK).json({
      success: true,
      message: '限流记录已清除'
    });
  }

  /**
   * 刷新访问令牌
   * 
   * 功能描述：
   * 使用有效的刷新令牌生成新的访问令牌，实现无感知的令牌续期
   * 
   * 业务逻辑：
   * 1. 验证刷新令牌的有效性和格式
   * 2. 检查用户状态是否正常
   * 3. 生成新的JWT令牌对
   * 4. 返回新的访问令牌和刷新令牌
   * 
   * @param refreshTokenDto 刷新令牌数据
   * @param res Express响应对象
   * @returns 新的令牌对
   */
  @ApiOperation({ 
    summary: '刷新访问令牌', 
    description: '使用有效的刷新令牌生成新的访问令牌，实现无感知的令牌续期。建议在访问令牌即将过期时调用此接口。' 
  })
  @ApiBody({ type: RefreshTokenDto })
  @SwaggerApiResponse({ 
    status: 200, 
    description: '令牌刷新成功', 
    type: RefreshTokenResponseDto 
  })
  @SwaggerApiResponse({ 
    status: 400, 
    description: '请求参数错误' 
  })
  @SwaggerApiResponse({ 
    status: 401, 
    description: '刷新令牌无效或已过期' 
  })
  @SwaggerApiResponse({ 
    status: 404, 
    description: '用户不存在或已被禁用' 
  })
  @SwaggerApiResponse({ 
    status: 429, 
    description: '刷新请求过于频繁' 
  })
  @Throttle(ThrottlePresets.REFRESH_TOKEN)
  @Timeout(TimeoutPresets.NORMAL)
  @Post('refresh-token')
  @UsePipes(new ValidationPipe({ transform: true }))
  async refreshToken(@Body() refreshTokenDto: RefreshTokenDto, @Res() res: Response): Promise<void> {
    const startTime = Date.now();
    
    try {
      this.logRefreshTokenStart();
      const result = await this.loginService.refreshAccessToken(refreshTokenDto.refresh_token);
      this.handleRefreshTokenResponse(result, res, startTime);
    } catch (error) {
      this.handleRefreshTokenError(error, res, startTime);
    }
  }

  /**
   * 记录令牌刷新开始日志
   * @private
   */
  private logRefreshTokenStart(): void {
    this.logger.log('令牌刷新请求', {
      operation: 'refreshToken',
      timestamp: new Date().toISOString(),
    });
  }

  /**
   * 处理令牌刷新响应
   * @private
   */
  private handleRefreshTokenResponse(result: any, res: Response, startTime: number): void {
    const duration = Date.now() - startTime;

    if (result.success) {
      this.logger.log('令牌刷新成功', {
        operation: 'refreshToken',
        duration,
        timestamp: new Date().toISOString(),
      });
      res.status(HttpStatus.OK).json(result);
    } else {
      this.logger.warn('令牌刷新失败', {
        operation: 'refreshToken',
        error: result.message,
        errorCode: result.error_code,
        duration,
        timestamp: new Date().toISOString(),
      });
      this.handleResponse(result, res);
    }
  }

  /**
   * 处理令牌刷新异常
   * @private
   */
  private handleRefreshTokenError(error: unknown, res: Response, startTime: number): void {
    const duration = Date.now() - startTime;
    const err = error as Error;
    
    this.logger.error('令牌刷新异常', {
      operation: 'refreshToken',
      error: err.message,
      duration,
      timestamp: new Date().toISOString(),
    }, err.stack);

    res.status(HttpStatus.INTERNAL_SERVER_ERROR).json({
      success: false,
      message: '服务器内部错误',
      error_code: 'INTERNAL_SERVER_ERROR'
    });
  }
}