fixed payment methods serialization deserialization

api/pkg/model/payment.go

@@ -1,6 +1,7 @@
 package model
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 
@@ -71,3 +72,73 @@ type PaymentMethod struct {
 	Data         bson.Raw           `bson:"data" json:"data"`
 	IsMain       bool               `bson:"isMain" json:"isMain"`
 }
+
+type paymentMethodJSON struct {
+	PermissionBound `json:",inline"`
+	Describable     `json:",inline"`
+
+	RecipientRef primitive.ObjectID `json:"recipientRef"`
+	Type         PaymentType        `json:"type"`
+	Data         json.RawMessage    `json:"data"`
+	IsMain       bool               `json:"isMain"`
+}
+
+func (m PaymentMethod) MarshalJSON() ([]byte, error) {
+	var marshaledData json.RawMessage
+
+	if len(m.Data) > 0 {
+		var data bson.M
+		if err := bson.Unmarshal(m.Data, &data); err != nil {
+			return nil, err
+		}
+		if data != nil {
+			b, err := json.Marshal(data)
+			if err != nil {
+				return nil, err
+			}
+			marshaledData = b
+		}
+	}
+
+	payload := paymentMethodJSON{
+		PermissionBound: m.PermissionBound,
+		Describable:     m.Describable,
+		RecipientRef:    m.RecipientRef,
+		Type:            m.Type,
+		Data:            marshaledData,
+		IsMain:          m.IsMain,
+	}
+
+	return json.Marshal(payload)
+}
+
+func (m *PaymentMethod) UnmarshalJSON(data []byte) error {
+	var payload paymentMethodJSON
+	if err := json.Unmarshal(data, &payload); err != nil {
+		return err
+	}
+
+	m.PermissionBound = payload.PermissionBound
+	m.Describable = payload.Describable
+	m.RecipientRef = payload.RecipientRef
+	m.Type = payload.Type
+	m.IsMain = payload.IsMain
+
+	if len(payload.Data) == 0 || bytes.Equal(payload.Data, []byte("null")) {
+		m.Data = nil
+		return nil
+	}
+
+	var rawData map[string]any
+	if err := json.Unmarshal(payload.Data, &rawData); err != nil {
+		return err
+	}
+
+	raw, err := bson.Marshal(rawData)
+	if err != nil {
+		return err
+	}
+
+	m.Data = raw
+	return nil
+}