import { Inject, Provide } from '@midwayjs/core';
import {
  InjectSaasCrud,
  SaasAction,
  SaasActionContext,
  SaasBusinessReject,
  SaasCrudCaller,
  SaasCrudService,
  SaasCrudServiceBase,
  SaasInventoryReservation,
  saasWorkflowBusinessId,
} from '@cool-midway/module-runtime';
import {
  Actions,
  Crud,
  Events,
  type GoodsBatchInfoInput,
  type GoodsBatchInfoOutput,
  type GoodsCrudBeforeChange,
  type GoodsInfoOutput,
  type GoodsReleaseStockInput,
  type GoodsReleaseStockOutput,
  type GoodsReserveStockInput,
  type GoodsReserveStockOutput,
} from '../saas/generated';

@Provide()
@SaasCrudService(Crud.Goods)
export class GoodsService extends SaasCrudServiceBase<typeof Crud.Goods> {
  @Inject() private readonly inventory!: SaasInventoryReservation;
  @InjectSaasCrud(Crud.Goods)
  private readonly goods!: SaasCrudCaller<typeof Crud.Goods>;

  @Inject()
  private readonly saasActionContext!: SaasActionContext;

  protected async modifyBefore(change: GoodsCrudBeforeChange): Promise<void> {
    if (change.operation === 'delete') {
      await this.inventory.assertNoActiveReservations(change.input.id);
    }
    if (change.operation === 'update' && Object.prototype.hasOwnProperty.call(change.input, 'stock')) {
      const caller = this.saasActionContext.managedCrudCaller;
      if (caller?.kind !== 'business' || !['goods.reserveStock','goods.releaseStock'].includes(caller.actionName) || this.saasActionContext.workflow?.coordinatorModule !== 'order') {
        throw new SaasBusinessReject('STOCK_COMMAND_REQUIRED','现有商品库存只能通过受管库存命令变更');
      }
    }
    if (change.operation === 'add' || change.operation === 'update') {
      const input = change.input;
      if (Object.prototype.hasOwnProperty.call(input, 'title') && !input.title.trim()) {
        throw new SaasBusinessReject('GOODS_INPUT_INVALID', '商品名称不能为空');
      }
      if (Object.prototype.hasOwnProperty.call(input, 'price') && !/^(?:0|[1-9][0-9]*)(?:\.[0-9]+)?$/.test(input.price)) {
        throw new SaasBusinessReject('GOODS_INPUT_INVALID', '商品价格必须是非负金额');
      }
      if (Object.prototype.hasOwnProperty.call(input, 'stock') && (!Number.isSafeInteger(input.stock) || input.stock < 0 || input.stock > 2147483647)) {
        throw new SaasBusinessReject('GOODS_INPUT_INVALID', '商品库存必须是有效的非负整数');
      }
      if (Object.prototype.hasOwnProperty.call(input, 'status') && input.status !== 0 && input.status !== 1) {
        throw new SaasBusinessReject('GOODS_INPUT_INVALID', '商品状态仅允许下架或上架');
      }
    }
  }

  @SaasAction(Actions.GoodsBatchInfo)
  async batchInfo(
    input: GoodsBatchInfoInput
  ): Promise<GoodsBatchInfoOutput> {
    const list: GoodsInfoOutput[] = [];
    for (const id of input.ids) {
      const goods = await this.findGoods(id);
      if (goods) list.push(goods);
    }
    return { list };
  }

  @SaasAction(Actions.GoodsReserveStock)
  async reserveStock(
    input: GoodsReserveStockInput
  ): Promise<GoodsReserveStockOutput> {
    const workflow = this.saasActionContext.workflow;
    if (!workflow || workflow.coordinatorModule !== 'order' || workflow.sagaType !== 'order.create@1') throw new SaasBusinessReject('STOCK_RESERVATION_CONFLICT','库存扣减需要订单创建工作流');
    return this.inventory.reserve({reservationId:workflow.sagaId,goodsId:input.goodsId,quantity:input.quantity},async () => {
    const goods = await this.requireGoods(input.goodsId, true);
    if (goods.status !== 1) {
      throw new SaasBusinessReject(
        'GOODS_UNAVAILABLE',
        `商品 ${input.goodsId} 当前不可售`
      );
    }
    if (goods.stock < input.quantity) {
      throw new SaasBusinessReject(
        'INSUFFICIENT_STOCK',
        `商品 ${input.goodsId} 库存不足`,
        { available: goods.stock, requested: input.quantity }
      );
    }

    const remainingStock = goods.stock - input.quantity;
    this.saasActionContext.raise(Events.DemoGoodsStockReserved, {
      goodsId: input.goodsId,
      quantity: input.quantity,
      remainingStock,
    });
    await this.updateStock(input.goodsId, remainingStock);
    return { goodsId: input.goodsId, remainingStock };
    });
  }

  @SaasAction(Actions.GoodsReleaseStock)
  async releaseStock(
    input: GoodsReleaseStockInput
  ): Promise<GoodsReleaseStockOutput> {
    const workflow = this.saasActionContext.workflow;
    const reservationId = saasWorkflowBusinessId('order','order.create@1',input.orderNo);
    if (!workflow || workflow.coordinatorModule !== 'order' || !['order.create@1','order.cancel@1'].includes(workflow.sagaType) || (workflow.sagaType === 'order.create@1' && workflow.sagaId !== reservationId)) throw new SaasBusinessReject('STOCK_RESERVATION_CONFLICT','库存释放需要匹配的订单工作流');
    return this.inventory.release({reservationId,goodsId:input.goodsId,quantity:input.quantity},async () => {
    const goods = await this.requireGoods(input.goodsId, true);
    const currentStock = goods.stock + input.quantity;
    if (!Number.isSafeInteger(currentStock)) throw new SaasBusinessReject('STOCK_RESERVATION_CONFLICT','库存数量溢出');

    this.saasActionContext.raise(Events.DemoGoodsStockReserved, {
      goodsId: input.goodsId,
      quantity: input.quantity,
      remainingStock: currentStock,
    });
    await this.updateStock(input.goodsId, currentStock);
    return { goodsId: input.goodsId, currentStock };
    });
  }

  private async findGoods(goodsId: number): Promise<GoodsInfoOutput | null> {
    const rows = await this.goods.list({
      where: { id: String(goodsId) },
      take: 1,
    });
    return rows[0] || null;
  }

  private async requireGoods(goodsId: number, lock = false): Promise<GoodsInfoOutput> {
    const goods = lock
      ? await this.goods.lock({ id: String(goodsId) })
      : await this.findGoods(goodsId);
    if (!goods) {
      throw new SaasBusinessReject(
        'GOODS_NOT_FOUND',
        `商品 ${goodsId} 不存在`
      );
    }
    return goods;
  }

  private async updateStock(goodsId: number, stock: number): Promise<void> {
    const result = await this.goods.update({ id: String(goodsId), stock });
    if (result.affected !== 1) {
      throw new SaasBusinessReject(
        'GOODS_STOCK_UPDATE_FAILED',
        `商品 ${goodsId} 库存更新失败`
      );
    }
  }
}