from rest_framework import serializers

from apps.messaging.models import BulkMessage, Channel, MessageRecipient


class SendBulkMessageSerializer(serializers.Serializer):
    group_id = serializers.CharField(required=False, allow_null=True, default=None)
    contact_ids = serializers.ListField(child=serializers.CharField(), required=False, default=list)
    template_id = serializers.CharField(required=False, allow_null=True, default=None)
    body_override = serializers.CharField(required=False, allow_blank=True, default="")
    channels = serializers.ListField(child=serializers.ChoiceField(choices=Channel.choices), min_length=1)

    def validate(self, attrs):
        if not attrs.get("template_id") and not attrs.get("body_override"):
            raise serializers.ValidationError("یا template_id بده یا body_override.")
        return attrs


class MessageRecipientSerializer(serializers.ModelSerializer):
    contact_name = serializers.CharField(source="contact.name", read_only=True)
    contact_phone = serializers.CharField(source="contact.phone", read_only=True)

    class Meta:
        model = MessageRecipient
        fields = [
            "id",
            "contact",
            "contact_name",
            "contact_phone",
            "channel",
            "status",
            "rendered_body",
            "error",
        ]


class BulkMessageSerializer(serializers.ModelSerializer):
    recipients = MessageRecipientSerializer(many=True, read_only=True)
    needs_manual = serializers.SerializerMethodField()

    class Meta:
        model = BulkMessage
        fields = ["id", "group", "template", "channels", "status", "created_at", "recipients", "needs_manual"]

    def get_needs_manual(self, obj: BulkMessage):
        pending = obj.recipients.filter(status=MessageRecipient.Status.NEEDS_MANUAL)
        return MessageRecipientSerializer(pending, many=True).data


class ContactMessageHistorySerializer(serializers.ModelSerializer):
    """یک ردیفِ تاریخچه — متنِ واقعیِ فرستاده‌شده، کانال، وضعیت و زمان."""

    sent_at = serializers.DateTimeField(source="bulk_message.created_at", read_only=True)
    channel_display = serializers.CharField(source="get_channel_display", read_only=True)
    status_display = serializers.CharField(source="get_status_display", read_only=True)

    class Meta:
        model = MessageRecipient
        fields = [
            "id", "channel", "channel_display", "status", "status_display",
            "rendered_body", "error", "sent_at",
        ]