import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common';
import { Reflector } from '@nestjs/core';
import { Role, satisfiesRole } from '@fiberops/shared';
import { ROLES_KEY } from '../decorators/roles.decorator';

@Injectable()
export class RolesGuard implements CanActivate {
  constructor(private reflector: Reflector) {}

  canActivate(context: ExecutionContext): boolean {
    const requiredRoles = this.reflector.getAllAndOverride<Role[]>(ROLES_KEY, [
      context.getHandler(),
      context.getClass(),
    ]);

    if (!requiredRoles || requiredRoles.length === 0) {
      return true;
    }

    const { user } = context.switchToHttp().getRequest();
    if (!user || !user.roles) {
      return false;
    }

    // Hierarchy-aware check: user with 'manager' satisfies 'technician' requirement
    return requiredRoles.some((role) => satisfiesRole(user.roles, role));
  }
}