extracted struct-handling helpers into their own file; move sql_type_conversion_test to the parent module

Signed-off-by: Dmitri Dolguikh <dmitri.external@netbird.io>

management/internals/network_map_db/struct_helpers.go

@@ -0,0 +1,133 @@
+package networkmapdb
+
+import (
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"reflect"
+	"strings"
+
+	"github.com/rs/xid"
+)
+
+type fieldTag struct {
+	Key   string
+	Value string
+}
+
+func tagFromString(t string) fieldTag {
+	kv := strings.Split(t, ":")
+	if len(kv) == 1 {
+		return fieldTag{Key: strings.TrimSpace(kv[0])}
+	}
+	return fieldTag{Key: strings.TrimSpace(kv[0]), Value: strings.TrimSpace(kv[1])}
+}
+
+func FromSqlTypesToSharedTypes(src reflect.Value, dst reflect.Value) error {
+	typ := src.Elem().Type()
+
+	for i := 0; i < typ.NumField(); i++ {
+		f := typ.Field(i)
+
+		fieldTags := make(map[string]string)
+		if v := f.Tag.Get(NMAP_STRUCT_TAG); v != "" {
+			for _, t := range strings.Split(v, ",") {
+				kv := tagFromString(t)
+				fieldTags[kv.Key] = kv.Value
+			}
+		}
+		if _, ok := fieldTags[NMAP_SKIP]; ok {
+			continue
+		}
+		if f.PkgPath != "" { // skip unexported fields
+			continue
+		}
+		dstFieldName := f.Name
+		if override, ok := fieldTags[NMAP_MAP_TO]; ok {
+			dstFieldName = override
+		}
+
+		dstField := dst.Elem().FieldByName(dstFieldName)
+		if !dstField.IsValid() {
+			return errors.New("unsupported type in destination field: " + dstFieldName)
+		}
+
+		srcField := src.Elem().Field(i)
+		srcFieldType := srcField.Type().String()
+		switch srcFieldType {
+		case "string":
+			s := srcField.Interface().(string)
+			dstField.SetString(s)
+		case "sql.NullString":
+			s := srcField.Interface().(sql.NullString)
+			if s.Valid {
+				dstField.SetString(s.String)
+			}
+			if (dstFieldName == "PublicId" || dstFieldName == "PublicID") && s.String == "" {
+				dstField.SetString(xid.New().String()) // TODO (dmitri) this needs to be removed to support delta updates
+			}
+		case "sql.NullTime":
+			s := srcField.Interface().(sql.NullTime)
+			if s.Valid {
+				if dstField.Kind() == reflect.Ptr {
+					t := reflect.ValueOf(&s.Time).Elem()
+					dstField.Set(t.Addr())
+				} else {
+					dstField.Set(reflect.ValueOf(s.Time))
+				}
+			}
+		case "sql.NullBool":
+			s := srcField.Interface().(sql.NullBool)
+			if s.Valid {
+				dstField.SetBool(s.Bool)
+			}
+		case "sql.NullInt64":
+			s := srcField.Interface().(sql.NullInt64)
+			if s.Valid {
+				dstField.SetInt(s.Int64)
+			}
+		case "json.RawMessage":
+			s := srcField.Interface().(json.RawMessage)
+			if len(s) == 0 {
+				continue
+			}
+			if err := json.Unmarshal(s, dstField.Addr().Interface()); err != nil {
+				return err
+			}
+		case "[]byte", "[]uint8":
+			s := srcField.Interface().([]byte)
+			if _, ok := fieldTags[NMAP_JSON]; !ok || len(s) == 0 {
+				continue
+			}
+			if err := json.Unmarshal(s, dstField.Addr().Interface()); err != nil {
+				return err
+			}
+		case "[]string":
+			if srcField.IsNil() {
+				continue
+			}
+			dstv := reflect.MakeSlice(dstField.Type(), srcField.Len(), srcField.Cap())
+			reflect.Copy(dstv, srcField)
+			dstField.Set(dstv)
+		}
+	}
+
+	return nil
+}
+
+func StructFields(src reflect.Value) []any {
+	toret := make([]any, 0)
+	typ := src.Elem().Type()
+
+	for i := 0; i < typ.NumField(); i++ {
+		f := typ.Field(i)
+		if f.PkgPath != "" { // skip unexported fields
+			continue
+		}
+
+		srcField := src.Elem().Field(i)
+		toret = append(toret, srcField.Addr().Interface())
+	}
+
+	return toret
+}