feat: statement for supplier and customer

api_v1/views/business/statements/serializers.py

@@ -0,0 +1,37 @@
+from rest_framework import serializers
+
+
+class StatementRecordSerializer(serializers.Serializer):
+    source_type = serializers.CharField()
+    source_label = serializers.CharField()
+    source_id = serializers.IntegerField()
+    occurred_at = serializers.DateField()
+    recorded_at = serializers.DateTimeField()
+    status = serializers.IntegerField()
+    status_label = serializers.CharField()
+    counterparty = serializers.IntegerField()
+    counterparty_name = serializers.CharField()
+    positive_amount = serializers.DecimalField(max_digits=15, decimal_places=2)
+    negative_amount = serializers.DecimalField(max_digits=15, decimal_places=2)
+    extra = serializers.DictField(required=False)
+
+
+class StatementResponseSerializer(serializers.Serializer):
+    counterparty = serializers.IntegerField()
+    counterparty_name = serializers.CharField()
+    records = StatementRecordSerializer(many=True)
+    summary = serializers.SerializerMethodField()
+
+    def get_summary(self, obj):
+        summary_builder = self.context.get('summary_builder')
+        if callable(summary_builder):
+            return summary_builder(obj)
+        return self.context.get('summary')
+
+    def to_representation(self, instance):
+        data = super().to_representation(instance)
+        if data.get('summary') is None:
+            data.pop('summary', None)
+        return data
+
+