import { Inject, Provide } from '@midwayjs/core';
import {
  InjectSaasCrud,
  SaasAction,
  SaasActionContext,
  SaasBusinessReject,
  SaasCrudCaller,
  SaasCrudService,
  SaasCrudServiceBase,
} from '@cool-midway/module-runtime';
import {
  Actions,
  Crud,
  Events,
  type GoodsBatchInfoInput,
  type GoodsBatchInfoOutput,
  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> {
  @InjectSaasCrud(Crud.Goods)
  private readonly goods!: SaasCrudCaller<typeof Crud.Goods>;

  @Inject()
  private readonly saasActionContext!: SaasActionContext;

  @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 goods = await this.requireGoods(input.goodsId);
    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 goods = await this.requireGoods(input.goodsId);
    const currentStock = goods.stock + input.quantity;

    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): Promise<GoodsInfoOutput> {
    const goods = 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`
      );
    }
  }
}