order validation

orders/order.go

@@ -0,0 +1,74 @@
+package orders
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"math"
+	"net/http"
+	"piekarnikgosipl/data"
+	"strconv"
+)
+
+type listItem struct {
+	id    string
+	count int // count multiplied by 100 to allow for half item purchases
+}
+
+type order struct {
+	name  string
+	phone string
+	items []listItem
+}
+
+func parseFloat(input string) (int, error) {
+	val, err := strconv.ParseFloat(input, 64)
+	if err != nil {
+		return 0, fmt.Errorf("Invalid float format")
+	}
+
+	if val < 0 || val > 100 {
+		return 0, fmt.Errorf("Value must be between 0 and 100")
+	}
+
+	doubled := val * 2
+	if math.Abs(doubled-math.Round(doubled)) > 1e-9 {
+		return 0, fmt.Errorf("Value must be a multiple of 0.5")
+	}
+
+	return int(math.Round(val * 100)), nil
+
+}
+
+func parseOrder(r *http.Request) (order, error) {
+	var o order
+	var err error
+	var errorList []error
+	o.name = r.PostFormValue("name")
+	if o.name == "" {
+		errorList = append(errorList, fmt.Errorf("Invalid name"))
+	}
+	o.phone, err = parseAndValidatePolishMobile(r.PostFormValue("phone"))
+	if err != nil {
+		errorList = append(errorList, err)
+	}
+	for _, item := range data.Swieta {
+		count, err := parseFloat(r.PostFormValue(item.Id))
+		if err != nil {
+			errorList = append(errorList, fmt.Errorf("Can't parse the count for %v: %e", item.Name, err))
+			continue
+		}
+		if count%10 == 5 && !item.Halveable {
+			errorList = append(errorList, fmt.Errorf("This item can't be bought in fractions %v", item.Name))
+			continue
+		}
+		o.items = append(o.items, listItem{item.Id, count})
+	}
+	return o, errors.Join(errorList...)
+}
+
+func OrderHandler(w http.ResponseWriter, r *http.Request) {
+	o, err := parseOrder(r)
+	log.Println(o, err)
+	fmt.Fprintf(w, "%v, %v", o, err)
+}