new endpoint to return product list

app/utils/reflect/reflect.go

@@ -0,0 +1,90 @@
+package reflect
+
+import (
+	"fmt"
+	"reflect"
+	"regexp"
+	"strings"
+
+	"git.ma-al.com/goc_daniel/b2b/app/db"
+)
+
+// TODO: instead of matching with string.Contains use something less error-prone
+func checkIfContainsJSON(i int, t reflect.Type, name string) string {
+	if wholeTag, ok := t.Field(i).Tag.Lookup("json"); ok {
+		tags := strings.Split(wholeTag, ",")
+		for _, tag := range tags {
+			if name == strings.TrimSpace(tag) {
+				return db.DB.NamingStrategy.ColumnName(t.Name(), t.Field(i).Name)
+			}
+		}
+	}
+	return ""
+}
+
+// Not tail recursive but should do fine. Goes only as deep as the hierarchy of
+// inlined structs.
+// TODO: improve used internally checkIfContainsJSON
+func GetGormColumnFromJsonField(jsonName string, t reflect.Type) (string, error) {
+	var res string
+	for i := range make([]bool, t.NumField()) {
+		if tag, ok := t.Field(i).Tag.Lookup("json"); ok && strings.Contains(tag, "inline") {
+			var err error
+			res, err = GetGormColumnFromJsonField(jsonName, t.Field(i).Type)
+			if err != nil {
+				return "", fmt.Errorf("no field of struct %q has a name %q in its json form", t.Name(), jsonName)
+			}
+
+		} else {
+			res = checkIfContainsJSON(i, t, jsonName)
+		}
+		if res != "" {
+			return res, nil
+		}
+	}
+	return "", fmt.Errorf("no field of struct %q has a name %q in its json form", t.Name(), jsonName)
+}
+
+func GetTableName[T any]() string {
+	var model T
+	typ := reflect.TypeOf(model).Name()
+	return db.DB.NamingStrategy.TableName(typ)
+}
+
+func GetParamFromFieldTag[T any](object T, fieldname string, tagname string, paramname string) string {
+	if table, ok := reflect.TypeOf(object).FieldByName(fieldname); ok {
+		if t, ok := table.Tag.Lookup(tagname); ok {
+			if paramname == "" {
+				return t
+			}
+			re := regexp.MustCompile(`(?m)` + paramname + `:(\w*)`)
+			f := re.FindAllStringSubmatch(t, -1)
+			if len(re.FindAllStringSubmatch(t, -1)) > 0 {
+				return f[0][1]
+			}
+		}
+	}
+	return ""
+}
+
+func GetPrimaryKey[T any](item T) string {
+	var search func(T) string = func(item T) string {
+		val := reflect.ValueOf(item)
+		typ := reflect.TypeOf(item)
+		for i := 0; i < val.NumField(); i++ {
+			if gg, ok := typ.Field(i).Tag.Lookup("gorm"); ok {
+				xx := strings.Split(gg, ";")
+				for _, t := range xx {
+					if strings.HasPrefix(strings.ToLower(t), "primarykey") {
+						return db.DB.NamingStrategy.TableName(typ.Field(i).Name)
+					}
+				}
+			}
+			if val.Field(i).Type().String() == "db.Model" {
+				return db.DB.NamingStrategy.TableName("ID")
+			}
+		}
+		return ""
+	}
+	return search(item)
+}