feat: add route order

backend/handlers/cart_handler.go

@@ -10,8 +10,9 @@ import (
 )
 
 func getUserID(c *gin.Context) uint {
-	userID, _ := c.Get("user_id")
-	return userID.(uint)
+	val, _ := c.Get("user_id")
+	userID, _ := val.(uint)
+	return userID
 }
 
 func GetCart(c *gin.Context) {

backend/handlers/order_handler.go

@@ -0,0 +1,85 @@
+package handlers
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+
+	"fishfish/database"
+	"fishfish/models"
+)
+
+func CreateOrder(c *gin.Context) {
+	userID := getUserID(c)
+
+	var req struct {
+		DeliveryAddress string `json:"delivery_address" binding:"required"`
+	}
+
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Не указан адрес доставки"})
+		return
+	}
+
+	var cartItems []models.CartItem
+	if err := database.DB.Preload("Item").Where("user_id = ? ", userID).Find(&cartItems).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Не удалось получить корзину"})
+		return
+	}
+
+	if len(cartItems) == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Корзина пуста"})
+		return
+	}
+
+	var order models.Order
+	err := database.DB.Transaction(func(tx *gorm.DB) error {
+		var total float64
+		var orderItems []models.OrderItem
+
+		for _, cartItem := range cartItems {
+			item := cartItem.Item
+
+			result := tx.Model(&models.Item{}).Where("id = ? AND stock >= ?", item.ID, cartItem.Quantity).Update("stock", gorm.Expr("stock - ? ", cartItem.Quantity))
+
+			if result.RowsAffected == 0 {
+				return fmt.Errorf("Недостаточно товара '%s' на складе", item.Name)
+			}
+
+			itemTotal := float64(item.Price) * cartItem.Quantity
+			total += itemTotal
+
+			orderItems = append(orderItems, models.OrderItem{
+				ItemID:   cartItem.ItemID,
+				Quantity: cartItem.Quantity,
+				Price:    float64(item.Price),
+			})
+		}
+
+		order = models.Order{
+			UserID:          userID,
+			Status:          "new",
+			DeliveryAddress: req.DeliveryAddress,
+			TotalPrice:      total,
+			Items:           orderItems,
+		}
+
+		if err := tx.Create(&order).Error; err != nil {
+			return err
+		}
+
+		if err := tx.Where("user_id = ? ", userID).Delete(&models.CartItem{}).Error; err != nil {
+			return err
+		}
+
+		return nil
+	})
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusCreated, order)
+}