import {
  CanActivate,
  ExecutionContext,
  Injectable,
  UnauthorizedException,
} from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { AdministradorService } from 'src/administrador/administrador.service';

@Injectable()
export class JwtValidationGuard implements CanActivate {
  constructor(
    private jwtService: JwtService,
    private administradorService: AdministradorService,
  ) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const request = context.switchToHttp().getRequest();
    const authHeader = request.headers.authorization;

    if (!authHeader) {
      throw new UnauthorizedException('Token no proporcionado');
    }

    const token = authHeader.split(' ')[1];

    try {
      const decodedToken = this.jwtService.verify(token, {
        secret: process.env.JWT_SECRET,
      });

      const administrador = await this.administradorService.getAdminById(
        decodedToken.sub,
      );

      if (!administrador) {
        throw new UnauthorizedException('Usuario no encontrado');
      }

      request.user = administrador;
    } catch (error) {
      if (error.name === 'TokenExpiredError') {
        throw new UnauthorizedException(
          `La sesión ha expirado, inicia sesión nuevamente.`,
        );
      }
      throw new UnauthorizedException('Token inválido');
    }

    return true;
  }
}