sergey-telpuk / nestjs-rbac

import { IRoleRbac } from './interfaces/role.rbac.interface';

import { IFilterPermission } from '../permissions/interfaces/filter.permission.interface';

import { IParamsFilter } from '../params-filter/interfaces/params.filter.interface';

@Injectable()

export class RoleRbac implements IRoleRbac {

  constructor(

    private readonly role: string,

    private readonly grant: string[],

    private readonly filters: object,

    private readonly paramsFilter?: IParamsFilter,

  ) {

  }

  async canAsync(...permissions: string[]): Promise<boolean> {

    return this.checkPermissions<Promise<boolean>>(permissions, 'canAsync');

  }

  private checkPermissions<T>(permissions, methodName): T {

    if (!permissions.length) {

      return (<any>false);

    }

    // check grant

    for (const permission of permissions) {

      if (!this.grant.includes(permission)) {

        return (<any>false);

      }

    }

    // check custom filter

    for (const permission of permissions) {

      // check particular permission [permission@action]

      if (

        this.grant.includes(permission)

        && permission.includes('@')

      ) {

        const filter: string = permission.split('@')[1];

        const filterService: IFilterPermission = this.filters[filter];

        if (filterService) {

          return filterService?.[methodName]?.(

            this.paramsFilter ? this.paramsFilter.getParam(filter) : null,

          ) ?? true

        }

      }

      // check particular permission [permission]

      if (this.grant.includes(permission)

        && !permission.includes('@')) {

        for (const filter in this.filters) {

          if (

            this.filters.hasOwnProperty(filter) &&

            this.grant.includes(`${permission}@${filter}`)

          ) {

            return this.filters[filter]?.[methodName]?.(

              this.paramsFilter ? this.paramsFilter.getParam(filter) : null,

            ) ?? true

          }

        }

      }

    }

    return (<any>true);

  }

}