backend/src/modules/auth/presentation/auth.controller.ts

import type { Request, Response } from 'express';

import {
  Body,
  Controller,
  Get,
  HttpCode,
  HttpStatus,
  Post,
  Req,
  Res,
  UnauthorizedException,
  UseGuards,
} from '@nestjs/common';
import {
  ApiBearerAuth,
  ApiNoContentResponse,
  ApiOkResponse,
  ApiProperty,
  ApiTags,
} from '@nestjs/swagger';

import { ApiProblemResponses } from '../../../common/decorators/api-safe-error-response.decorator';
import { HttpErrorCode } from '../../../common/error-code';
import { AuthService } from '../application/auth.service';
import { AccessPayload, AuthenticationResult } from '../application/auth.types';
import { LoginDto, RegisterDto } from './auth.dto';
import { JwtAuthGuard } from './jwt-auth.guard';

const REFRESH_COOKIE = 'refresh_token';
const COOKIE_PATH = '/api/v1/auth';

class UserDto {
  @ApiProperty()
  declare id: string;

  @ApiProperty()
  declare email: string;
}

class AuthenticationDto {
  @ApiProperty()
  declare accessToken: string;

  @ApiProperty({ type: UserDto })
  declare user: UserDto;
}

@ApiTags('auth')
@ApiProblemResponses()
@Controller('auth')
export class AuthController {
  constructor(private readonly auth: AuthService) {}

  @Post('register')
  @HttpCode(HttpStatus.OK)
  @ApiOkResponse({ type: AuthenticationDto })
  async register(
    @Body() credentials: RegisterDto,
    @Res({ passthrough: true }) response: Response,
  ) {
    return this.respond(
      response,
      await this.auth.register(credentials.email, credentials.password),
    );
  }

  @Post('login')
  @HttpCode(HttpStatus.OK)
  @ApiOkResponse({ type: AuthenticationDto })
  async login(
    @Body() credentials: LoginDto,
    @Res({ passthrough: true }) response: Response,
  ) {
    return this.respond(
      response,
      await this.auth.login(credentials.email, credentials.password),
    );
  }

  @Post('refresh')
  @HttpCode(HttpStatus.OK)
  @ApiOkResponse({ type: AuthenticationDto })
  async refresh(
    @Req() request: Request,
    @Res({ passthrough: true }) response: Response,
  ) {
    const token = this.refreshToken(request);
    if (!token) throw new UnauthorizedException({ code: HttpErrorCode.Unauthorized });
    return this.respond(response, await this.auth.refresh(token));
  }

  @Post('logout')
  @HttpCode(HttpStatus.NO_CONTENT)
  @ApiNoContentResponse()
  async logout(
    @Req() request: Request,
    @Res({ passthrough: true }) response: Response,
  ): Promise<void> {
    await this.auth.logout(this.refreshToken(request));
    this.clearCookie(response);
  }

  @Get('me')
  @UseGuards(JwtAuthGuard)
  @ApiBearerAuth()
  @ApiOkResponse({ type: UserDto })
  async me(@Req() request: Request & { user: AccessPayload }) {
    const user = await this.auth.userById(request.user.sub);
    return this.auth.toUser(user);
  }

  private respond(
    response: Response,
    result: AuthenticationResult,
  ) {
    response.cookie(REFRESH_COOKIE, result.refreshToken, this.cookieOptions());
    return { user: result.user, accessToken: result.accessToken };
  }

  private clearCookie(response: Response): void {
    response.clearCookie(REFRESH_COOKIE, this.cookieOptions());
  }

  private refreshToken(request: Request): string | undefined {
    // eslint-disable-next-line security/detect-object-injection -- The cookie name is a fixed application constant; its value is narrowed below.
    const token: unknown = request.cookies?.[REFRESH_COOKIE];
    return typeof token === 'string' ? token : undefined;
  }

  private cookieOptions() {
    return {
      httpOnly: true,
      sameSite: 'lax' as const,
      secure: process.env['NODE_ENV'] !== 'development',
      path: COOKIE_PATH,
    };
  }
}