auth.guard.ts

auth.guard.ts

import {
  CanActivate,
  ExecutionContext,
  Injectable,
  UnauthorizedException,
} from '@nestjs/common';
import { JwtService, TokenExpiredError } from '@nestjs/jwt';
import { jwtConstants } from './constants';
import { Request } from 'express';

@Injectable()
export class AuthGuard implements CanActivate {
  constructor(private jwtService: JwtService) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const request = context.switchToHttp().getRequest();
    const token = this.extractTokenFromHeader(request);

    if (!token) {
      throw new UnauthorizedException('Token no proporcionado');
    }
    try {
      const payload = await this.jwtService.verifyAsync(token, {
        secret: jwtConstants.secret,
      });
      // 💡 We're assigning the payload to the request object here
      // so that we can access it in our route handlers
      request['user'] = payload;
    } catch (error) {
      console.log(error);
      if (error instanceof TokenExpiredError) {
        throw new UnauthorizedException(
          'La sesión ya expiró, inicie sesión nuevamente',
        );
      }
      throw new UnauthorizedException(
        'No tienes acceso a esto, consulta a un administrador o de rol más alto',
      );
    }

    return true;
  }

  private extractTokenFromHeader(request: Request): string | undefined {
    const [type, token] = request.headers.authorization?.split(' ') ?? [];
    return type === 'Bearer' ? token : undefined;
  }
}