from django.db import transaction
from rest_framework import serializers

from core.apps.finance.models import Income


class IncomeListSerializer(serializers.ModelSerializer):
    cash_transaction = serializers.SerializerMethodField(
        method_name="get_cash_transaction"
    )
    payment_type = serializers.SerializerMethodField(method_name="get_payment_type")
    project_folder = serializers.SerializerMethodField(method_name="get_project_folder")
    project = serializers.SerializerMethodField(method_name="get_project")
    counterparty = serializers.SerializerMethodField(method_name="get_counterparty")
    type_income = serializers.SerializerMethodField(method_name="get_type_income")
    user = serializers.SerializerMethodField(method_name="get_user")

    class Meta:
        model = Income
        fields = [
            "id",
            "cash_transaction",
            "payment_type",
            "project_folder",
            "project",
            "counterparty",
            "type_income",
            "currency",
            "price",
            "exchange_rate",
            "date",
            "comment",
            "file",
            "audit",
            "user",
            "income_chat",
            "created_at",
        ]

    def get_cash_transaction(self, obj):
        return {"id": obj.cash_transaction.id, "name": obj.cash_transaction.name}

    def get_payment_type(self, obj):
        return {"id": obj.payment_type.id, "name": obj.payment_type.name}

    def get_project_folder(self, obj):
        return (
            {"id": obj.project_folder.id, "name": obj.project_folder.name}
            if obj.project_folder
            else None
        )

    def get_project(self, obj):
        return {"id": obj.project.id, "name": obj.project.name} if obj.project else None

    def get_counterparty(self, obj):
        return (
            {"id": obj.counterparty.id, "name": obj.counterparty.name}
            if obj.counterparty
            else None
        )

    def get_type_income(self, obj):
        return (
            {"id": obj.type_income.id, "name": obj.type_income.name}
            if obj.type_income
            else None
        )

    def get_user(self, obj):
        return (
            {
                "id": obj.user.id,
                "full_name": obj.user.full_name,
            }
            if obj.user
            else None
        )


class IncomeCreateSerializer(serializers.ModelSerializer):
    class Meta:
        model = Income
        fields = [
            "cash_transaction",
            "payment_type",
            "project_folder",
            "project",
            "counterparty",
            "type_income",
            "currency",
            "price",
            "exchange_rate",
            "date",
            "comment",
            "file",
            "audit",
        ]

    def validate(self, data):
        """Validasiya qilish"""
        price = data.get('price')
        exchange_rate = data.get('exchange_rate')
        
        if price and price < 0:
            raise serializers.ValidationError("Narxi manfiy bo'lishi mumkin emas")
        
        if exchange_rate and exchange_rate < 0:
            raise serializers.ValidationError("Kurs manfiy bo'lishi mumkin emas")
        
        return data

    def create(self, validated_data):
        with transaction.atomic():
            # Exchange rate va final price hisoblash
            exchange_rate = validated_data.get("exchange_rate") or 1
            final_price = validated_data.get("price")
            
            income = Income.objects.create(
                user=self.context.get("user"),
                cash_transaction=validated_data["cash_transaction"],
                payment_type=validated_data["payment_type"],
                project_folder=validated_data.get("project_folder"),
                project=validated_data.get("project"),
                counterparty=validated_data.get("counterparty"),
                type_income=validated_data.get("type_income"),
                currency=validated_data.get("currency"),
                price=final_price,
                exchange_rate=exchange_rate,
                date=validated_data.get("date"),
                comment=validated_data.get("comment"),
                file=validated_data.get("file"),
                audit=validated_data.get("audit"),
            )
            
            cash_transaction = income.cash_transaction
            payment_type = income.payment_type
            currency = validated_data.get("currency", "uzs").lower()

            if currency == "uzs":
                # Cash transaction balansini yangilash
                cash_transaction.income_balance_uzs += income.price
                cash_transaction.total_balance_uzs = (
                    cash_transaction.income_balance_uzs
                    - cash_transaction.expence_balance_uzs
                )
                
                # Payment type balansini yangilash
                payment_type.total_uzs += income.price

                # Kontrapartiya hisobini yangilash
                if income.counterparty:
                    if income.counterparty.debit_uzs > 0:
                        # Debit bo'lsa, uni qisqartirish
                        income.counterparty.debit_uzs -= income.price
                        income.counterparty.total_debit -= income.price
                        
                        # Kredit oshirish
                        income.counterparty.kredit_uzs += income.price  # ✅ TUZATILDI
                        income.counterparty.total_kredit += income.price
                    else:
                        # Debit yo'q bo'lsa, to'g'ridan-to'g'ri kredit oshirish
                        income.counterparty.kredit_uzs += income.price
                        income.counterparty.total_kredit += income.price
                    
                    income.counterparty.save()

            elif currency == "usd":
                # Cash transaction balansini yangilash
                cash_transaction.income_balance_usd += income.price
                cash_transaction.total_balance_usd = (
                    cash_transaction.income_balance_usd
                    - cash_transaction.expence_balance_usd
                )
                
                # Payment type balansini yangilash
                payment_type.total_usd += income.price
                
                # Kontrapartiya hisobini yangilash
                if income.counterparty:
                    if income.counterparty.debit_usd > 0:
                        # Debit bo'lsa, uni qisqartirish
                        income.counterparty.debit_usd -= income.price  # ✅ TUZATILDI
                        income.counterparty.total_debit -= income.price

                        # Kredit oshirish
                        income.counterparty.kredit_usd += income.price  # ✅ TUZATILDI
                        income.counterparty.total_kredit += income.price
                    else:
                        # Debit yo'q bo'lsa, to'g'ridan-to'g'ri kredit oshirish
                        income.counterparty.kredit_usd += income.price  # ✅ TUZATILDI
                        income.counterparty.total_kredit += income.price
                    
                    income.counterparty.save()

            cash_transaction.save()
            payment_type.save()
            return income


class IncomeDeleteSerializer(serializers.Serializer):
    comment = serializers.CharField()


class IncomeUpdateSerializer(serializers.ModelSerializer):
    class Meta:
        model = Income
        fields = [
            "project_folder",
            "project",
            "price",
            "type_income",
            "counterparty",
            "date",
            "comment",
            "audit",
            "file",
        ]
        extra_kwargs = {
            "price": {"required": False},
        }

    def validate_price(self, value):
        """Narxi manfiy bo'lmasligi tekshiruvi"""
        if value and value < 0:
            raise serializers.ValidationError("Narxi manfiy bo'lishi mumkin emas")
        return value

    def update(self, instance, validated_data):
        with transaction.atomic():
            old_price = instance.price
            old_counterparty = instance.counterparty
            new_price = validated_data.get("price", instance.price)
            new_counterparty = validated_data.get("counterparty", instance.counterparty)
            currency = instance.currency.lower()
            
            # Asosiy ma'lumotlarni yangilash
            instance.project_folder = validated_data.get(
                "project_folder", instance.project_folder
            )
            instance.project = validated_data.get("project", instance.project)
            instance.price = new_price
            instance.type_income = validated_data.get("type_income", instance.type_income)
            instance.counterparty = new_counterparty
            instance.date = validated_data.get("date", instance.date)
            instance.comment = validated_data.get("comment", instance.comment)
            instance.audit = validated_data.get("audit", instance.audit)
            instance.file = validated_data.get("file", instance.file)
            
            # Agar narxi o'zgarsa, balanslarni yangilash
            if validated_data.get("price") and old_price != new_price:
                price_difference = new_price - old_price  # ✅ To'g'ri farq
                cash_transaction = instance.cash_transaction
                payment_type = instance.payment_type
                
                if currency == "uzs":
                    # Cash transaction balansini yangilash
                    cash_transaction.income_balance_uzs += price_difference
                    cash_transaction.total_balance_uzs = (
                        cash_transaction.income_balance_uzs
                        - cash_transaction.expence_balance_uzs
                    )
                    
                    # Payment type balansini yangilash
                    payment_type.total_uzs += price_difference  # ✅ Narx oshsa, balans oshadi
                    
                elif currency == "usd":
                    # Cash transaction balansini yangilash
                    cash_transaction.income_balance_usd += price_difference
                    cash_transaction.total_balance_usd = (
                        cash_transaction.income_balance_usd
                        - cash_transaction.expence_balance_usd
                    )
                    
                    # Payment type balansini yangilash
                    payment_type.total_usd += price_difference  # ✅ Narx oshsa, balans oshadi
                
                cash_transaction.save()
                payment_type.save()
            
            # Agar kontrapartiya o'zgarsa, uning hisobini yangilash
            if new_counterparty != old_counterparty:
                # Eski kontrapartyani qaytarish
                if old_counterparty:
                    if currency == "uzs":
                        if old_counterparty.kredit_uzs > 0:
                            old_counterparty.kredit_uzs -= old_price
                            old_counterparty.total_kredit -= old_price
                        else:
                            old_counterparty.debit_uzs += old_price
                            old_counterparty.total_debit += old_price
                    else:
                        if old_counterparty.kredit_usd > 0:
                            old_counterparty.kredit_usd -= old_price
                            old_counterparty.total_kredit -= old_price
                        else:
                            old_counterparty.debit_usd += old_price
                            old_counterparty.total_debit += old_price
                    
                    old_counterparty.save()
                
                # Yangi kontrapartyani yangilash
                if new_counterparty:
                    if currency == "uzs":
                        if new_counterparty.debit_uzs > 0:
                            new_counterparty.debit_uzs -= new_price
                            new_counterparty.total_debit -= new_price
                            new_counterparty.kredit_uzs += new_price
                            new_counterparty.total_kredit += new_price
                        else:
                            new_counterparty.kredit_uzs += new_price
                            new_counterparty.total_kredit += new_price
                    else:
                        if new_counterparty.debit_usd > 0:
                            new_counterparty.debit_usd -= new_price
                            new_counterparty.total_debit -= new_price
                            new_counterparty.kredit_usd += new_price
                            new_counterparty.total_kredit += new_price
                        else:
                            new_counterparty.kredit_usd += new_price
                            new_counterparty.total_kredit += new_price
                    
                    new_counterparty.save()
            
            instance.save()
            return instance