import {
  Body,
  Controller,
  Get,
  HttpCode,
  HttpStatus,
  Post,
  Req,
  Res,
  UnauthorizedException,
} from '@nestjs/common';
import { ApiBearerAuth, ApiTags } from '@nestjs/swagger';
import { Throttle } from '@nestjs/throttler';
import type { Request, Response } from 'express';
import { Public } from './decorators/public.decorator';
import { CurrentUser } from './decorators/current-user.decorator';
import type { AuthenticatedUser } from './types/authenticated-user';
import { LoginDto } from './dto/login.dto';
import { AccessTokenDto } from './dto/access-token.dto';
import { AuthService, CurrentUserProfile } from './auth.service';
import { parseDurationToMs } from './util/duration';

const REFRESH_TOKEN_COOKIE = 'refreshToken';
const REFRESH_TOKEN_COOKIE_PATH = '/api/v1/auth';
// Stricter than the global default: bounds brute-force/credential-stuffing
// attempts against login and refresh-token guessing specifically.
const AUTH_THROTTLE = { default: { limit: 10, ttl: 60000 } };

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

  private setRefreshTokenCookie(res: Response, refreshToken: string): void {
    res.cookie(REFRESH_TOKEN_COOKIE, refreshToken, {
      httpOnly: true,
      // Explicit opt-out for local HTTP dev only; every real deployment must
      // set COOKIE_SECURE=true so the refresh-token cookie is never sent
      // over plaintext HTTP.
      secure: process.env.COOKIE_SECURE !== 'false',
      sameSite: 'lax',
      path: REFRESH_TOKEN_COOKIE_PATH,
      maxAge: parseDurationToMs(process.env.JWT_REFRESH_EXPIRES_IN ?? '7d'),
    });
  }

  private clearRefreshTokenCookie(res: Response): void {
    res.clearCookie(REFRESH_TOKEN_COOKIE, { path: REFRESH_TOKEN_COOKIE_PATH });
  }

  private extractRefreshToken(req: Request): string {
    const refreshToken = (req.cookies as Record<string, string> | undefined)?.[
      REFRESH_TOKEN_COOKIE
    ];
    if (!refreshToken) {
      throw new UnauthorizedException('Missing refresh token');
    }
    return refreshToken;
  }

  @Public()
  @Throttle(AUTH_THROTTLE)
  @Post('login')
  @HttpCode(HttpStatus.OK)
  async login(
    @Body() dto: LoginDto,
    @Res({ passthrough: true }) res: Response,
  ): Promise<AccessTokenDto> {
    const { accessToken, refreshToken } = await this.authService.login(
      dto.email,
      dto.password,
    );
    this.setRefreshTokenCookie(res, refreshToken);
    return { accessToken };
  }

  @Public()
  @Throttle(AUTH_THROTTLE)
  @Post('refresh')
  @HttpCode(HttpStatus.OK)
  async refresh(
    @Req() req: Request,
    @Res({ passthrough: true }) res: Response,
  ): Promise<AccessTokenDto> {
    const { accessToken, refreshToken } = await this.authService.refresh(
      this.extractRefreshToken(req),
    );
    this.setRefreshTokenCookie(res, refreshToken);
    return { accessToken };
  }

  @Public()
  @Post('logout')
  @HttpCode(HttpStatus.NO_CONTENT)
  async logout(
    @Req() req: Request,
    @Res({ passthrough: true }) res: Response,
  ): Promise<void> {
    await this.authService.logout(this.extractRefreshToken(req));
    this.clearRefreshTokenCookie(res);
  }

  @ApiBearerAuth()
  @Get('me')
  me(@CurrentUser() user: AuthenticatedUser): Promise<CurrentUserProfile> {
    return this.authService.getCurrentUserProfile(user.id);
  }
}