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)
    cumulative_amount = serializers.CharField()
    current_balance = serializers.CharField()
    arrears_amount = serializers.CharField()
    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