import { Injectable } from '@nestjs/common';
import { AppLogger } from '../../../logger';
import { AclData } from '../../authorization/interfaces/acl-data.interface';
import { AclResourceIdLocation } from '../enums';

@Injectable()
export class AclGuardService {
  private readonly TAG: string = `${this.constructor.name}`;

  constructor() {
    AppLogger.log('Init', this.TAG);
  }

  public canActivate(request, aclData: AclData): boolean {
    try {
      let resourceName: string = null;
      let resourceId: string = null;
      if (aclData) {
        resourceName = this.extractResourceName(aclData.resourceName);
        if (!resourceName) {
          return null;
        }
        if (aclData.resourceId) {
          resourceId = this.extractResourceId(request, aclData.resourceId.location, aclData.resourceId.name);
          if (!resourceId) {
            return null;
          }
        }
      }
      request.resourceName = resourceName;
      request.resourceId = resourceId;
      return true;

    } catch (e) {
      AppLogger.error(e, this.TAG);
      return null;
    }
  }

  private extractResourceName(resourceName: string): string {
    if (resourceName) {
      AppLogger.debug(`Set ACL Resource Name on request - '${resourceName}'`, this.TAG);
      return resourceName;
    } else {
      AppLogger.error(`No resource name received`, this.TAG);
      return null;
    }
  }

  private extractResourceId(request, resourceIdLocation: AclResourceIdLocation, resourceIdNameInLocation: string): string {
    if (resourceIdLocation && resourceIdNameInLocation && request[resourceIdLocation][resourceIdNameInLocation]) {
      const resourceId: string = request[resourceIdLocation][resourceIdNameInLocation];
      AppLogger.debug(`Set ACL Resource ID on request - '${resourceId}'`, this.TAG);
      return resourceId;
    } else {
      AppLogger.error(`No resource id found on location - '${resourceIdLocation}', by name - '${resourceIdNameInLocation}'`, this.TAG);
      AppLogger.error(`location - '${resourceIdLocation}' data received from request - ${JSON.stringify(request[resourceIdLocation])}`, this.TAG);
      return null;
    }
  }

}