from rest_framework import serializers
from django.contrib.auth import get_user_model
from .models import Account, Transaction, Budget, Expense, Profile, Deadline

User = get_user_model()


class AccountSerializer(serializers.ModelSerializer):
    class Meta:
        model = Account
        exclude = ['user']


class TransactionSerializer(serializers.ModelSerializer):
    class Meta:
        model = Transaction
        fields = '__all__'

    def validate(self, data):
        request = self.context.get('request')
        if not request:
            return data
        user = request.user
        source = data.get('source_account') or (self.instance.source_account if self.instance else None)
        dest = data.get('destination_account') or (self.instance.destination_account if self.instance else None)
        if source and source.user != user:
            raise serializers.ValidationError('Source account does not belong to you.')
        if dest and dest.user != user:
            raise serializers.ValidationError('Destination account does not belong to you.')
        return data


class BudgetSerializer(serializers.ModelSerializer):
    class Meta:
        model = Budget
        fields = '__all__'


class ExpenseSerializer(serializers.ModelSerializer):
    class Meta:
        model = Expense
        fields = '__all__'


class ProfileSerializer(serializers.ModelSerializer):
    totp_enabled = serializers.BooleanField(read_only=True)

    class Meta:
        model = Profile
        exclude = ['user', 'totp_secret', 'email_verify_token', 'email_verify_token_expires', 'password_reset_token_hash', 'password_reset_token_expires']


class DeadlineSerializer(serializers.ModelSerializer):
    class Meta:
        model = Deadline
        exclude = ['user']


class RegisterSerializer(serializers.Serializer):
    email = serializers.EmailField()
    password = serializers.CharField(min_length=8, write_only=True)

    def validate_email(self, value):
        if User.objects.filter(email=value).exists():
            raise serializers.ValidationError('Email already registered.')
        return value

    def create(self, validated_data):
        email = validated_data['email']
        return User.objects.create_user(
            username=email,
            email=email,
            password=validated_data['password'],
        )