LocChat/server/providers/guards/roles.guard.ts

import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common';
import { Reflector } from '@nestjs/core';
import { ROLES_CONTEXT_KEY } from 'server/decorators/roles.decorator';
import { JwtBodyDto } from 'server/dto/jwt_body.dto';
import { RoleKey } from 'server/entities/role.entity';
import { RolesService } from '../services/roles.service';
import { UsersService } from '../services/users.service';
import { some } from 'lodash';

@Injectable()
export class RolesGuard implements CanActivate {
  constructor(private reflector: Reflector, private usersService: UsersService, private rolesService: RolesService) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const requiredRoles = this.reflector.getAllAndOverride<RoleKey[]>(ROLES_CONTEXT_KEY, [
      context.getHandler(),
      context.getClass(),
    ]);
    console.log(requiredRoles);

    if (!requiredRoles) {
      return true;
    }

    const jwtBody: JwtBodyDto = context.switchToHttp().getRequest().jwtBody;

    if (!jwtBody) return false; // unauthenticated users are not authorized

    const user = await this.usersService.find(jwtBody.userId, ['userRoles']);
    const roles = await this.rolesService.findByKey(...requiredRoles);
    const roleMatches = user.userRoles.map((userRole) => {
      return !!roles.find((role) => role.id === userRole.roleId);
    });

    return some(roleMatches);
  }
}