init: first steps

pkg/http/extract.go

@@ -0,0 +1,46 @@
+package http
+
+import (
+	"net/http"
+	"strconv"
+)
+
+func ExtractLimitOffset(r *http.Request) (int, int, ResponseErrReadyToSend) {
+	limit, offset := r.URL.Query().Get("limit"), r.URL.Query().Get("offset")
+
+	if limit == "" {
+		limit = "20"
+	}
+
+	if offset == "" {
+		offset = "0"
+	}
+
+	limitInt, err := strconv.Atoi(limit)
+	if err != nil {
+		writeErr := NewResponseErrBuilder().
+			WithMessage("Incorrect limit parameter").
+			WithDetails(map[string]interface{}{
+				"err": err.Error(),
+			}).
+			WithStatusCode(http.StatusBadRequest).
+			Ready()
+
+		return 0, 0, writeErr
+	}
+
+	offsetInt, err := strconv.Atoi(offset)
+	if err != nil {
+		writeErr := NewResponseErrBuilder().
+			WithMessage("Incorrect offset parameter").
+			WithDetails(map[string]interface{}{
+				"err": err.Error(),
+			}).
+			WithStatusCode(http.StatusBadRequest).
+			Ready()
+
+		return 0, 0, writeErr
+	}
+
+	return limitInt, offsetInt, nil
+}