refactor the limit and offset code

backend/utils/database_filters.go

@@ -1,9 +1,39 @@
 package utils
 
 import (
+	"math"
 	"net/url"
+	"strconv"
 )
 
+func GetLimitOffset(queryParams url.Values) (int, int, error) {
+	limit := 50
+
+	if queryParams.Get("limit") != "" {
+		var err error
+		limit, err = strconv.Atoi(queryParams.Get("limit"))
+		if err != nil {
+			return -1, -1, err
+		}
+		limit = int(math.Min(float64(500), float64(limit)))
+		limit = int(math.Max(float64(1), float64(limit)))
+	}
+
+	offset := 0
+
+	if queryParams.Get("offset") != "" {
+		var err error
+		offset, err = strconv.Atoi(queryParams.Get("offset"))
+		if err != nil {
+			return -1, -1, err
+		}
+		offset = int(math.Min(float64(9223372036854775807), float64(offset)))
+		offset = int(math.Max(float64(0), float64(offset)))
+	}
+
+	return limit, offset, nil
+}
+
 func GenerateWhereFilter(filters []string, queryParams url.Values) (map[string]interface{}, error) {
 	whereClause := make(map[string]interface{})