From 9a328ae1e44d914ad0774f8c91278f80fa39dded Mon Sep 17 00:00:00 2001
From: aguhh18 <teguh180902@gmail.com>
Date: Tue, 3 Feb 2026 08:06:52 +0700
Subject: [PATCH] FEAT[BE] :implement proportional distribution with rounding
 for stock allocation in transfer laying approval process

---
 .../services/deliveryorder.service.go         |  1 +
 .../services/transfer_laying.service.go       | 85 ++++++++++++-------
 2 files changed, 55 insertions(+), 31 deletions(-)

diff --git a/internal/modules/marketing/services/deliveryorder.service.go b/internal/modules/marketing/services/deliveryorder.service.go
index 1d0a9481..6d9392a6 100644
--- a/internal/modules/marketing/services/deliveryorder.service.go
+++ b/internal/modules/marketing/services/deliveryorder.service.go
@@ -520,6 +520,7 @@ func (s deliveryOrdersService) consumeDeliveryStock(ctx context.Context, tx *gor
 			CreatedBy:          actorID,
 			Notes:              fmt.Sprintf("FIFO consume (%.2f)", result.UsageQuantity),
 		}
+
 		stockLogs, err := s.StockLogRepo.GetByProductWarehouse(ctx, marketingProduct.ProductWarehouseId, 1)
 		if err != nil {
 			return fiber.NewError(fiber.StatusInternalServerError, "Failed to get stock logs")
diff --git a/internal/modules/production/transfer_layings/services/transfer_laying.service.go b/internal/modules/production/transfer_layings/services/transfer_laying.service.go
index e6e9a862..15351e56 100644
--- a/internal/modules/production/transfer_layings/services/transfer_laying.service.go
+++ b/internal/modules/production/transfer_layings/services/transfer_laying.service.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math"
 	"strings"
 	"time"
 
@@ -743,7 +744,7 @@ func (s transferLayingService) Approval(c *fiber.Ctx, req *validation.Approve) (
 	err = s.Repository.DB().WithContext(c.Context()).Transaction(func(dbTransaction *gorm.DB) error {
 		repoTx := s.Repository.WithTx(dbTransaction)
 		approvalSvcTx := commonSvc.NewApprovalService(commonRepo.NewApprovalRepository(dbTransaction))
-
+		stockAllocationRepo := commonRepo.NewStockAllocationRepository(dbTransaction)
 		sourceRepoTx := repository.NewLayingTransferSourceRepository(dbTransaction)
 		targetRepoTx := repository.NewLayingTransferTargetRepository(dbTransaction)
 		stockLogRepoTx := rStockLogs.NewStockLogRepository(dbTransaction)
@@ -817,6 +818,27 @@ func (s transferLayingService) Approval(c *fiber.Ctx, req *validation.Approve) (
 						return fiber.NewError(fiber.StatusInternalServerError, "Gagal update source usage qty")
 					}
 
+					targetShares := distributeProportionalWithRounding(targets, totalTargetQty, sourceShare)
+
+					for i, target := range targets {
+						roundedQty := math.Round(targetShares[i])
+						if roundedQty <= 0 {
+							continue
+						}
+						mappingAllocation := &entity.StockAllocation{
+							StockableType:      fifo.UsableKeyTransferToLayingOut.String(),
+							StockableId:        source.Id,
+							UsableType:         fifo.StockableKeyTransferToLayingIn.String(),
+							UsableId:           target.Id,
+							ProductWarehouseId: *source.ProductWarehouseId,
+							Qty:                roundedQty,
+							Status:             entity.StockAllocationStatusActive,
+						}
+						if err := stockAllocationRepo.CreateOne(c.Context(), mappingAllocation, nil); err != nil {
+							return fiber.NewError(fiber.StatusInternalServerError, "Gagal create mapping allocation source→target")
+						}
+					}
+
 					stockLogDecrease := &entity.StockLog{
 						ProductWarehouseId: *source.ProductWarehouseId,
 						CreatedBy:          actorID,
@@ -937,36 +959,6 @@ func createApprovalTransferLaying(ctx context.Context, tx *gorm.DB, transferLayi
 	return err
 }
 
-func (s *transferLayingService) getOrCreateProductWarehouse(ctx context.Context, tx *gorm.DB, productID uint, warehouseID uint, quantity float64, actorID uint, projectFlockKandangId *uint) (*entity.ProductWarehouse, error) {
-
-	productWarehouseRepoTx := rInventory.NewProductWarehouseRepository(tx)
-
-	existing, err := productWarehouseRepoTx.GetProductWarehouseByProductAndWarehouseID(ctx, productID, warehouseID)
-	if err == nil && existing != nil {
-
-		if err := productWarehouseRepoTx.PatchOne(ctx, existing.Id, map[string]any{"qty": gorm.Expr("qty + ?", quantity)}, nil); err != nil {
-			return nil, err
-		}
-		return existing, nil
-	}
-	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
-		return nil, err
-	}
-
-	newWarehouse := &entity.ProductWarehouse{
-		ProductId:             productID,
-		WarehouseId:           warehouseID,
-		ProjectFlockKandangId: projectFlockKandangId,
-		Quantity:              quantity,
-	}
-
-	if err := productWarehouseRepoTx.CreateOne(ctx, newWarehouse, nil); err != nil {
-		return nil, err
-	}
-
-	return newWarehouse, nil
-}
-
 func (s transferLayingService) GetAvailableQtyPerKandang(ctx *fiber.Ctx, projectFlockID uint) (*entity.ProjectFlock, map[uint]float64, error) {
 
 	pf, err := s.ProjectFlockRepo.GetByID(ctx.Context(), projectFlockID, func(db *gorm.DB) *gorm.DB {
@@ -1060,3 +1052,34 @@ func (s transferLayingService) GetMaxTargetQtyPerKandang(c *fiber.Ctx, projectFl
 
 	return kandangMaxTargetQty, nil
 }
+
+func distributeProportionalWithRounding(targets []entity.LayingTransferTarget, totalTargetQty, sourceShare float64) []float64 {
+	if len(targets) == 0 {
+		return []float64{}
+	}
+
+	targetShares := make([]float64, len(targets))
+	totalRounded := 0.0
+
+	for i, target := range targets {
+		targetShares[i] = (target.TotalQty / totalTargetQty) * sourceShare
+		totalRounded += math.Round(targetShares[i])
+	}
+
+	diff := sourceShare - totalRounded
+
+	if diff != 0 {
+		maxIdx := 0
+		maxDecimal := 0.0
+		for i, share := range targetShares {
+			decimal := share - math.Round(share)
+			if decimal > maxDecimal {
+				maxDecimal = decimal
+				maxIdx = i
+			}
+		}
+		targetShares[maxIdx] += diff
+	}
+
+	return targetShares
+}