from rest_framework import serializers

from core.apps.chat.models import ChatmessageModel
from core.apps.chat.tasks.message import send_message_to_chat

class BaseChatmessageSerializer(serializers.ModelSerializer):
    sender = serializers.SerializerMethodField()
    file_url = serializers.SerializerMethodField()

    def get_sender(self, obj):
        if obj.sender is None:
            return None
        full_name = obj.sender.get_full_name().strip()
        if not full_name:
            full_name = str(obj.sender.phone)
        request = self.context.get("request")
        return {
            "id": obj.sender.id,
            "full_name": full_name,
            "role": obj.sender.role,
            "phone": obj.sender.phone,
            "avatar": request.build_absolute_uri(obj.sender.avatar.url) if obj.sender.avatar else None,
        }

    def get_file_url(self, obj):
        if not obj.file:
            return None
        request = self.context.get("request")
        if request:
            return request.build_absolute_uri(obj.file.url)
        return obj.file.url

    class Meta:
        model = ChatmessageModel
        fields = [
            "id",
            "room",
            "sender",
            "message_type",
            "text",
            "file_url",
            "is_read",
            "created_at",
        ]


class ListChatmessageSerializer(BaseChatmessageSerializer):
    class Meta(BaseChatmessageSerializer.Meta): ...


class RetrieveChatmessageSerializer(BaseChatmessageSerializer):
    class Meta(BaseChatmessageSerializer.Meta): ...


class CreateChatmessageSerializer(serializers.ModelSerializer):
    class Meta:
        model = ChatmessageModel
        fields = [
            "room",
            "message_type",
            "text",
            "file",
        ]

    def validate(self, attrs):
        message_type = attrs.get("message_type", "text")
        text = attrs.get("text", "").strip() if attrs.get("text") else ""
        file = attrs.get("file")

        if message_type == "text" and not text:
            raise serializers.ValidationError({"text": "Matn xabari uchun text majburiy."})
        if message_type != "text" and not file:
            raise serializers.ValidationError({"file": f"{message_type} xabari uchun fayl majburiy."})
        return attrs

    def create(self, validated_data):
        validated_data["sender"] = self.context["request"].user
        request = self.context["request"]
        message = super().create(validated_data)
        file_url = request.build_absolute_uri(message.file.url) if message.file else None
        avatar_url = request.build_absolute_uri(self.context['request'].user.avatar.url) if self.context['request'].user.avatar else None
        send_message_to_chat.delay(message.id, file_url, avatar_url)
        return message