datamodel done without validators

wagfarm-api/logs/fertilizing/model.go

@@ -0,0 +1,34 @@
+package fertilizing
+
+import (
+	"wagfarm-api/assets/fertilizer"
+	"wagfarm-api/database"
+	"wagfarm-api/logs/base"
+
+	"github.com/shopspring/decimal"
+	"gorm.io/gorm"
+)
+
+type FertilizingLog struct {
+	base.ExtendedLog
+	FertilizerID uint                  `gorm:"not null"`
+	Fertilizer   fertilizer.Fertilizer `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;not null"`
+	Amount       float64               `gorm:"not null"` // in units of the fertilizer
+}
+
+func (l *FertilizingLog) AfterSave(db *gorm.DB) (err error) {
+	// Example: compute cost as Amount * UnitPrice
+	if l.FertilizerID == 0 {
+		if err := db.First(&l.Fertilizer, l.FertilizerID).Error; err != nil {
+			return err
+		}
+	}
+
+	unitPrice := l.Fertilizer.Cost
+	totalCost := unitPrice.Mul(decimal.NewFromFloat(l.Amount))
+	l.UpdateCost(db, totalCost)
+
+	return
+}
+
+func RegisterModels() { database.RegisterModel(&FertilizingLog{}) }