feat[BE-384]: enhance closing reports by introducing calculation context and improving data handling; refactor related functions for better clarity and maintainability

internal/modules/closings/dto/closingMarketing.dto.go

@@ -35,8 +35,7 @@ type PenjualanRealisasiResponseDTO struct {
 
 func ToSalesDTO(e entity.MarketingDeliveryProduct) SalesDTO {
 
-	// todo: usia ayam masih dummy
-	age := 0
+	age := calculateAgeFromChickin(e.MarketingProduct.ProductWarehouse.ProjectFlockKandang, e.DeliveryDate)
 
 	var product *productDTO.ProductRelationDTO
 	if e.MarketingProduct.ProductWarehouse.Product.Id != 0 {
@@ -101,3 +100,20 @@ func extractPeriodFromRealisasi(realisasi []entity.MarketingDeliveryProduct) int
 	}
 	return 0
 }
+
+func calculateAgeFromChickin(projectFlockKandang *entity.ProjectFlockKandang, deliveryDate *time.Time) int {
+	if projectFlockKandang == nil || deliveryDate == nil || len(projectFlockKandang.Chickins) == 0 {
+		return 0
+	}
+
+	earliestChickinDate := projectFlockKandang.Chickins[0].ChickInDate
+	for _, chickin := range projectFlockKandang.Chickins {
+		if chickin.ChickInDate.Before(earliestChickinDate) {
+			earliestChickinDate = chickin.ChickInDate
+		}
+	}
+
+	ageInDays := int(deliveryDate.Sub(earliestChickinDate).Hours() / 24)
+	ageInWeeks := ageInDays / 7
+	return ageInWeeks
+}