更新

2026-10-19 01:13:17 +08:00
1 parent 5718a00e31
commit 1850ac640e
@@ -0,0 +1,189 @@
+package erp
+
+import (
+	"fmt"
+	"math"
+	"time"
+
+	"server/models"
+
+	"github.com/beego/beego/v2/client/orm"
+)
+
+// Movement 一次库存变动的入参。库存结存只能由本引擎经流水驱动。
+type Movement struct {
+	TenantID     string
+	ProductID    uint64
+	WarehouseID  uint64
+	BatchNo      string
+	Direction    int8 // models.ErpStockIn / ErpStockOut
+	Qty          float64
+	UnitCost     float64 // 入库=进价/成本；出库传 0 表示按当前加权成本
+	DocType      string
+	DocID        uint64
+	DocNo        string
+	DocItemID    uint64
+	OperatorID   string
+	OperatorName string
+	Remark       string
+	// 批次效期随入库流水落地，出库/调拨沿用同批次快照
+	ProductionDate *time.Time
+	ExpireDate     *time.Time
+}
+
+// StockError 库存不足等业务错误（调用方可据 ErrInsufficientStock 区分文案）。
+type StockError struct {
+	ProductName  string
+	Requested    float64
+	Available    float64
+	Insufficient bool
+}
+
+func (e *StockError) Error() string {
+	if e.Insufficient {
+		return fmt.Sprintf("商品「%s」库存不足：可用 %.4f，本次需要 %.4f", e.ProductName, e.Available, e.Requested)
+	}
+	return fmt.Sprintf("商品「%s」库存异常", e.ProductName)
+}
+
+// ApplyMovement 在事务内执行一条库存变动：
+//  1. 定位/创建结存行（tenant+product+warehouse+batch 唯一）；
+//  2. 出库时校验可用量（负库存开关取自基础设置）；
+//  3. 入库按移动加权平均重算单位成本；出库成本=出库时加权成本（记入流水，毛利口径）；
+//  4. 写库存流水 + 更新结存。
+//
+// 返回出库时点的单位成本（销售成本/退货回冲依据）。
+func ApplyMovement(o orm.QueryExecutor, mv *Movement) (float64, error) {
+	if mv.Qty <= 0 {
+		return 0, fmt.Errorf("库存变动数量必须大于0")
+	}
+	if mv.WarehouseID == 0 || mv.ProductID == 0 {
+		return 0, fmt.Errorf("库存变动缺少商品或仓库")
+	}
+
+	settings := GetSettings(mv.TenantID)
+
+	var product models.ErpProduct
+	if err := o.QueryTable(new(models.ErpProduct)).
+		Filter("id", mv.ProductID).Filter("tenant_id", mv.TenantID).One(&product); err != nil {
+		return 0, fmt.Errorf("商品不存在(id=%d)", mv.ProductID)
+	}
+
+	var stock models.ErpStock
+	err := o.QueryTable(new(models.ErpStock)).
+		Filter("tenant_id", mv.TenantID).
+		Filter("product_id", mv.ProductID).
+		Filter("warehouse_id", mv.WarehouseID).
+		Filter("batch_no", mv.BatchNo).
+		ForUpdate().One(&stock)
+	if err == orm.ErrNoRows {
+		stock = models.ErpStock{
+			TenantID: mv.TenantID, ProductID: mv.ProductID,
+			WarehouseID: mv.WarehouseID, BatchNo: mv.BatchNo,
+			Quantity: 0, CostPrice: product.PurchasePrice,
+			UpdateTime: time.Now(),
+		}
+		id, ierr := o.Insert(&stock)
+		if ierr != nil {
+			return 0, fmt.Errorf("初始化库存结存失败: %v", ierr)
+		}
+		stock.ID = uint64(id)
+	} else if err != nil {
+		return 0, fmt.Errorf("查询库存失败: %v", err)
+	}
+
+	before := stock.Quantity
+	dir := mv.Direction
+	unitCost := mv.UnitCost
+	outCost := stock.CostPrice // 出库成本口径：当前加权成本
+
+	if dir == models.ErpStockOut {
+		if !settings.NegativeAllowed && before-mv.Qty < -0.000001 {
+			return 0, &StockError{
+				ProductName:  product.ProductName,
+				Requested:    mv.Qty,
+				Available:    before,
+				Insufficient: true,
+			}
+		}
+		after := before - mv.Qty
+		if unitCost <= 0 {
+			unitCost = outCost
+		}
+		if err := writeLedger(o, mv, dir, before, after, unitCost); err != nil {
+			return 0, err
+		}
+		if _, err := o.QueryTable(new(models.ErpStock)).Filter("id", stock.ID).
+			Update(orm.Params{"quantity": after, "update_time": time.Now()}); err != nil {
+			return 0, fmt.Errorf("更新库存结存失败: %v", err)
+		}
+		return unitCost, nil
+	}
+
+	// 入库：移动加权平均
+	if unitCost <= 0 {
+		unitCost = product.PurchasePrice
+	}
+	after := before + mv.Qty
+	newCost := unitCost
+	if after > 0.000001 {
+		newCost = (before*stock.CostPrice + mv.Qty*unitCost) / after
+	}
+	if err := writeLedger(o, mv, dir, before, after, unitCost); err != nil {
+		return 0, err
+	}
+	if _, err := o.QueryTable(new(models.ErpStock)).Filter("id", stock.ID).
+		Update(orm.Params{"quantity": after, "cost_price": newCost, "update_time": time.Now()}); err != nil {
+		return 0, fmt.Errorf("更新库存结存失败: %v", err)
+	}
+	return unitCost, nil
+}
+
+func writeLedger(o orm.QueryExecutor, mv *Movement, dir int8, before, after, unitCost float64) error {
+	now := time.Now()
+	ledger := models.ErpStockLedger{
+		TenantID: mv.TenantID, ProductID: mv.ProductID, WarehouseID: mv.WarehouseID,
+		BatchNo: mv.BatchNo, Direction: dir, Quantity: mv.Qty,
+		BeforeQty: before, AfterQty: after,
+		UnitCost: unitCost, TotalCost: round2(unitCost * mv.Qty),
+		DocType: mv.DocType, DocID: mv.DocID, DocNo: mv.DocNo, DocItemID: mv.DocItemID,
+		ProductionDate: mv.ProductionDate, ExpireDate: mv.ExpireDate,
+		OperatorID: mv.OperatorID, OperatorName: mv.OperatorName,
+		Remark: mv.Remark, CreateTime: now,
+	}
+	if _, err := o.Insert(&ledger); err != nil {
+		return fmt.Errorf("写入库存流水失败: %v", err)
+	}
+	return nil
+}
+
+// RefOutboundCost 取某条出库流水记录的出库成本（销售退货回冲入库成本用）。
+func RefOutboundCost(o orm.QueryExecutor, tenantID string, docItemID uint64) float64 {
+	if docItemID == 0 {
+		return 0
+	}
+	var led models.ErpStockLedger
+	if err := o.QueryTable(new(models.ErpStockLedger)).
+		Filter("tenant_id", tenantID).
+		Filter("doc_item_id", docItemID).
+		Filter("direction", models.ErpStockOut).
+		OrderBy("-id").One(&led); err != nil {
+		return 0
+	}
+	return led.UnitCost
+}
+
+func round2(v float64) float64 {
+	return math.Round(v*100) / 100
+}
+
+func round4(v float64) float64 {
+	return math.Round(v*10000) / 10000
+}
+
+func absf(v float64) float64 {
+	if v < 0 {
+		return -v
+	}
+	return v
+}