Check that you have enough money

api/purchase.go

@@ -12,7 +12,7 @@ import (
 )
 
 type Purchase struct {
-	gorm.Model `json:"-"`
+	gorm.Model
 	MemberNum int                `json:"member" gorm:"column:member"`
 	Member    Member             `json:"-" gorm:"foreignKey:MemberNum;references:Num"`
 	Date      time.Time          `json:"date"`
@@ -56,9 +56,6 @@ func (a *api) AddPurchase(num int, w http.ResponseWriter, req *http.Request) {
 	}
 	total := 0
 	for i, p := range products {
-		if p.ProductCode == 0 {
-			continue
-		}
 		var product Product
 		err = a.db.Where("code = ?", p.ProductCode).First(&product).Error
 		if err != nil {
@@ -71,6 +68,18 @@ func (a *api) AddPurchase(num int, w http.ResponseWriter, req *http.Request) {
 		products[i].Price = product.Price
 	}
 
+	var member Member
+	err = a.db.Where("num = ?", num).Find(&member).Error
+	if err != nil {
+		log.Printf("Can't find member %d: %v", num, err)
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+	if member.Balance < total {
+		log.Printf("Member %d don't have enough money (%d-%d): %v", num, member.Balance, total, err)
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
 	err = a.db.Model(&Member{}).
 		Where("num = ?", num).
 		Update("balance", gorm.Expr("balance - ?", total)).Error
@@ -79,6 +88,7 @@ func (a *api) AddPurchase(num int, w http.ResponseWriter, req *http.Request) {
 		w.WriteHeader(http.StatusBadRequest)
 		return
 	}
+
 	purchase := Purchase{
 		MemberNum: num,
 		Date:      time.Now(),
@@ -114,7 +124,9 @@ func (a *api) AddPurchase(num int, w http.ResponseWriter, req *http.Request) {
 func (a *api) GetPurchase(w http.ResponseWriter, req *http.Request) {
 	vars := mux.Vars(req)
 	var purchase Purchase
-	err := a.db.Where("id = ?", vars["id"]).First(&purchase).Error
+	err := a.db.Where("id = ?", vars["id"]).
+		Preload("Products.Product").
+		First(&purchase).Error
 	if err != nil {
 		if err.Error() == "record not found" {
 			w.WriteHeader(http.StatusNotFound)