backend/src/guards/device.product.guard.ts

import { DeviceRepository } from '@app/common/modules/device/repositories';
import {
  Injectable,
  CanActivate,
  HttpStatus,
  BadRequestException,
  ExecutionContext,
} from '@nestjs/common';

@Injectable()
export class CheckProductUuidForAllDevicesGuard implements CanActivate {
  constructor(private readonly deviceRepository: DeviceRepository) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const req = context.switchToHttp().getRequest();

    try {
      const { deviceUuids } = req.body;

      await this.checkAllDevicesHaveSameProductUuid(deviceUuids);

      return true;
    } catch (error) {
      this.handleGuardError(error, context);
      return false;
    }
  }

  async checkAllDevicesHaveSameProductUuid(deviceUuids: string[]) {
    const firstDevice = await this.deviceRepository.findOne({
      where: { uuid: deviceUuids[0], isActive: true },
      relations: ['productDevice'],
    });

    if (!firstDevice) {
      throw new BadRequestException('First device not found');
    }

    const firstProductType = firstDevice.productDevice.prodType;

    for (let i = 1; i < deviceUuids.length; i++) {
      const device = await this.deviceRepository.findOne({
        where: { uuid: deviceUuids[i], isActive: true },
        relations: ['productDevice'],
      });

      if (!device) {
        throw new BadRequestException(`Device ${deviceUuids[i]} not found`);
      }

      if (device.productDevice.prodType !== firstProductType) {
        throw new BadRequestException(`Devices have different product types`);
      }
    }
  }

  private handleGuardError(error: Error, context: ExecutionContext) {
    const response = context.switchToHttp().getResponse();
    console.error(error);

    if (error instanceof BadRequestException) {
      response
        .status(HttpStatus.BAD_REQUEST)
        .json({ statusCode: HttpStatus.BAD_REQUEST, message: error.message });
    } else {
      response.status(HttpStatus.NOT_FOUND).json({
        statusCode: HttpStatus.NOT_FOUND,
        message: 'Device not found',
      });
    }
  }
}