add my_role in transaction serializer

apps/wallet/serializers.py

@@ -11,6 +11,7 @@ from ..users.models import User
 class TransactionSerializer(serializers.ModelSerializer):
     payee_id = serializers.UUIDField(read_only=True)
     payee_type = serializers.UUIDField(read_only=True)
+    role = serializers.SerializerMethodField()
 
     class Meta:
         model = Transaction
@@ -27,7 +28,20 @@ class TransactionSerializer(serializers.ModelSerializer):
                   'details',
                   )
 
-        read_only_fields = ['uuid', 'updated_at', 'state', 'created_at', 'details']
+        read_only_fields = ['uuid', 'updated_at', 'state', 'created_at', 'details', 'role']
+
+    def get_role(self, obj: Transaction) -> int:
+        request = self.context.get('request')
+        user = request.user
+
+        if obj.payer_id == user.id:
+            return 1
+        elif obj.payee_id == user.id:
+            return 2
+        else:
+            return 0
+
+
 
     # def create(self, validated_data):
     #     transaction = Transaction.objects.create_transaction(**validated_data)