[hw-1] implement cart service

cart/internal/app/server/delete_item_handler.go

@@ -0,0 +1,55 @@
+package server
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"strconv"
+
+	"route256/cart/internal/domain/entity"
+	"route256/cart/internal/domain/model"
+
+	"github.com/rs/zerolog/log"
+)
+
+func (s *Server) DeleteItemHandler(w http.ResponseWriter, r *http.Request) {
+	strUserID := r.PathValue("user_id")
+	userID, err := strconv.ParseInt(strUserID, 10, 64)
+	if err != nil || userID <= 0 {
+		if err == nil {
+			err = fmt.Errorf("user_id must be greater than 0")
+		}
+
+		makeErrorResponse(w, err, http.StatusBadRequest)
+
+		log.Trace().Err(err).Msgf("user_id=`%s`", strUserID)
+
+		return
+	}
+
+	strSku := r.PathValue("sku_id")
+	sku, err := strconv.ParseInt(strSku, 10, 64)
+	if err != nil || sku <= 0 {
+		if err == nil {
+			err = fmt.Errorf("sku_id must be greater than 0")
+		}
+
+		makeErrorResponse(w, err, http.StatusBadRequest)
+
+		log.Trace().Err(err).Msgf("sku_id=`%s`", strUserID)
+
+		return
+	}
+
+	err = s.cartService.DeleteItem(r.Context(), entity.UID(userID), entity.Sku(sku))
+	switch {
+	case errors.Is(err, model.ErrCartNotFound), errors.Is(err, model.ErrItemNotFoundInCart), err == nil:
+		w.WriteHeader(http.StatusNoContent)
+	default:
+		makeErrorResponse(w, err, http.StatusBadRequest)
+
+		log.Trace().Err(err).Msgf("cartService.DeleteItemFromCart failed for uid=%d sku=%d: %d", userID, sku, http.StatusBadRequest)
+
+		return
+	}
+}