package handler

import (
	"net/http"

	"bj_power_wms/ent"
	"bj_power_wms/ent/inventory"
	"bj_power_wms/ent/ordermaterialledger"
	"bj_power_wms/ent/outbounddetail"
	"bj_power_wms/ent/outboundorder"
	"bj_power_wms/internal/svc"

	"github.com/google/uuid"
	"github.com/zeromicro/go-zero/core/logx"
)

// deductStockRequest 出库扣减请求
// createOutboundHandler 创建出库单（等价于扣减库存，走同一套约束）
func createOutboundHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return deductStockHandler(ctx)
}

type deductStockRequest struct {
	OrderNo      string   `json:"orderNo"`
	MaterialCode string   `json:"materialCode"`
	BatchNo      string   `json:"batchNo"`
	SnList       []string `json:"snList"`
	Qty          int      `json:"qty"`
	Operator     string   `json:"operator"`
	Reviewer     string   `json:"reviewer"`
	TargetDock   string   `json:"targetDock"`
	ZoneCode     string   `json:"zoneCode"`
	Remark       string   `json:"remark"`
}

// deductStockHandler 出库扣减
// body: { orderNo, materialCode, batchNo?, snList?[], qty, operator, targetDock? }
// 强约束：累计出库 ≤ 工单 BOM 需求量；等于时领料完结。
//
// 事务保证：出库单 + 库存行扣减(inventory) + 出库明细 + 工单台账 原子提交，
// 任一环节失败整体回滚，杜绝"出库单生成了但库存没扣"或"台账没更新"的中间态。
// 扣减本身用条件原子更新（AddQuantity(-qty) WHERE quantity>=qty），即使并发也不会出现负库存。
func deductStockHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req deductStockRequest
		if err := parseJSON(r, &req); err != nil {
			fail(w, http.StatusBadRequest, "参数错误: "+err.Error())
			return
		}
		if req.OrderNo == "" || req.MaterialCode == "" {
			fail(w, http.StatusBadRequest, "orderNo 和 materialCode 必填")
			return
		}

		// 1. 工单台账强约束：累计出库 ≤ 总需求
		ledger, err := ctx.EntClient.OrderMaterialLedger.Query().
			Where(
				ordermaterialledger.OrderNoEQ(req.OrderNo),
				ordermaterialledger.MaterialCodeEQ(req.MaterialCode),
			).
			Only(ctx0())
		if err != nil {
			fail(w, http.StatusBadRequest, "工单物料台账不存在，请先同步工单 BOM: "+req.OrderNo+"/"+req.MaterialCode)
			return
		}
		if ledger.Status == "领料完结" {
			fail(w, http.StatusConflict, "工单领料已完结，禁止再出库")
			return
		}

		// 实际扣减数量
		actualQty := req.Qty
		if req.BatchNo == "" && len(req.SnList) == 0 {
			fail(w, http.StatusBadRequest, "batchNo 或 snList 至少提供一个")
			return
		}

		outboundNo := "OB" + uuid.NewString()[:12]

		// 开启事务：出库单 + 库存扣减 + 明细 + 台账 原子提交
		tx, err := ctx.EntClient.Tx(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, "开启事务失败: "+err.Error())
			return
		}
		committed := false
		defer func() {
			if !committed {
				_ = tx.Rollback()
			}
		}()

		// 2. 创建出库单
		ob, err := tx.OutboundOrder.Create().
			SetOutboundNo(outboundNo).
			SetOutboundType("workorder").
			SetNillableOrderNo(strPtr(req.OrderNo)).
			SetMaterialCode(req.MaterialCode).
			SetManageMode(1).
			SetNillableBatchNo(strPtr(req.BatchNo)).
			SetNillableZoneCode(strPtr(req.ZoneCode)).
			SetQuantity(0).
			SetNillableOperator(strPtr(req.Operator)).
			SetNillableReviewer(strPtr(req.Reviewer)).
			SetNillableTargetDock(strPtr(req.TargetDock)).
			SetNillableRemark(strPtr(req.Remark)).
			Save(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, "创建出库单失败: "+err.Error())
			return
		}

		// 3. 扣减批次（原子：quantity>=qty 才减，避免超扣/负数；locked_qty 同步回收）
		if req.BatchNo != "" {
			b, err := tx.Inventory.Query().
				Where(inventory.ManageModeEQ(1), inventory.BatchNoEQ(req.BatchNo)).
				Only(ctx0())
			if err != nil {
				fail(w, http.StatusBadRequest, "批次不存在: "+req.BatchNo)
				return
			}
			avail := b.Quantity - b.LockedQty
			if avail < req.Qty {
				fail(w, http.StatusConflict, "批次库存不足: "+req.BatchNo+" 可用 "+itoa(avail))
				return
			}
			aff, err := tx.Inventory.Update().
				Where(inventory.ID(b.ID), inventory.QuantityGTE(req.Qty)).
				AddQuantity(-req.Qty).
				AddLockedQty(-min(req.Qty, b.LockedQty)).
				Save(ctx0())
			if err != nil || aff == 0 {
				fail(w, http.StatusConflict, "批次扣减失败(库存不足或并发冲突): "+req.BatchNo)
				return
			}
			if _, err = tx.OutboundDetail.Create().
				SetOutboundNo(outboundNo).
				SetBatchNo(req.BatchNo).
				SetMaterialCode(req.MaterialCode).
				SetQuantity(req.Qty).
				SetNillableOrderNo(strPtr(req.OrderNo)).
				Save(ctx0()); err != nil {
				fail(w, http.StatusInternalServerError, "创建出库明细失败: "+err.Error())
				return
			}
			actualQty = req.Qty
		}

		// 4. 扣减 SN（原子：仅 在库/锁定 的 SN 可出库 → 置出库）
		if len(req.SnList) > 0 {
			for _, sn := range req.SnList {
				aff, err := tx.Inventory.Update().
					Where(inventory.ManageModeEQ(2), inventory.SnCodeEQ(sn), inventory.StatusIn("在库", "锁定")).
					SetStatus("出库").
					SetNillableZoneCode(strPtr(req.ZoneCode)).
					Save(ctx0())
				if err != nil {
					fail(w, http.StatusInternalServerError, "SN 出库失败: "+sn+" "+err.Error())
					return
				}
				if aff == 0 {
					fail(w, http.StatusBadRequest, "SN 不可出库(不存在或非在库/锁定): "+sn)
					return
				}
				if _, err = tx.OutboundDetail.Create().
					SetOutboundNo(outboundNo).
					SetSnCode(sn).
					SetMaterialCode(req.MaterialCode).
					SetQuantity(1).
					SetNillableOrderNo(strPtr(req.OrderNo)).
					Save(ctx0()); err != nil {
					fail(w, http.StatusInternalServerError, "创建出库明细失败: "+err.Error())
					return
				}
			}
			actualQty = len(req.SnList)
		}

		// 5. 更新出库单实际数量
		if _, err = tx.OutboundOrder.UpdateOneID(ob.ID).
			SetQuantity(actualQty).Save(ctx0()); err != nil {
			fail(w, http.StatusInternalServerError, "更新出库单失败: "+err.Error())
			return
		}

		// 6. 更新工单台账：累计出库（在事务内重读台账，避免并发重复累计）
		ledgerNow, err := tx.OrderMaterialLedger.Query().
			Where(
				ordermaterialledger.OrderNoEQ(req.OrderNo),
				ordermaterialledger.MaterialCodeEQ(req.MaterialCode),
			).Only(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, "重读台账失败: "+err.Error())
			return
		}
		newOutQty := ledgerNow.OutQty + actualQty
		if newOutQty > ledgerNow.TotalQty {
			fail(w, http.StatusConflict, "出库数量超过工单 BOM 需求: 累计 "+itoa(ledgerNow.OutQty)+" + "+itoa(actualQty)+" > 需求 "+itoa(ledgerNow.TotalQty))
			return
		}
		status := ledgerNow.Status
		if newOutQty >= ledgerNow.TotalQty {
			status = "领料完结"
		}
		if _, err = tx.OrderMaterialLedger.UpdateOneID(ledgerNow.ID).
			SetOutQty(newOutQty).
			SetStatus(status).
			Save(ctx0()); err != nil {
			fail(w, http.StatusInternalServerError, "更新台账失败: "+err.Error())
			return
		}

		// 7. 提交事务
		if err = tx.Commit(); err != nil {
			fail(w, http.StatusInternalServerError, "提交事务失败: "+err.Error())
			return
		}
		committed = true

		logx.Infof("deduct stock: order=%s material=%s qty=%d", req.OrderNo, req.MaterialCode, actualQty)
		ok(w, map[string]any{
			"outboundNo":  outboundNo,
			"qty":         actualQty,
			"orderNo":     req.OrderNo,
			"ledgerOut":   newOutQty,
			"ledgerTotal": ledgerNow.TotalQty,
			"status":      status,
		})
	}
}

// queryOutboundHandler 出库单查询
func queryOutboundHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		page := atoi(r.URL.Query().Get("page"), 1)
		pageSize := atoi(r.URL.Query().Get("pageSize"), 20)
		orderNo := r.URL.Query().Get("orderNo")
		materialCode := r.URL.Query().Get("materialCode")
		outboundNo := r.URL.Query().Get("outboundNo")

		q := ctx.EntClient.OutboundOrder.Query()
		if orderNo != "" {
			q = q.Where(outboundorder.OrderNoEQ(orderNo))
		}
		if materialCode != "" {
			q = q.Where(outboundorder.MaterialCodeEQ(materialCode))
		}
		if outboundNo != "" {
			q = q.Where(outboundorder.OutboundNoEQ(outboundNo))
		}

		total, err := q.Count(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, err.Error())
			return
		}
		list, err := q.Order(ent.Desc("id")).
			Offset((page - 1) * pageSize).Limit(pageSize).All(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, err.Error())
			return
		}

		// 附带明细
		type row struct {
			*ent.OutboundOrder
			Details []*ent.OutboundDetail `json:"details"`
		}
		rows := make([]row, 0, len(list))
		for _, ob := range list {
			details, _ := ctx.EntClient.OutboundDetail.Query().
				Where(outbounddetail.OutboundNoEQ(ob.OutboundNo)).
				All(ctx0())
			rows = append(rows, row{ob, details})
		}

		ok(w, map[string]any{
			"total":    total,
			"list":     rows,
			"page":     page,
			"pageSize": pageSize,
		})
	}
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}