"""Transaction service"""

from typing import Optional, List
from datetime import datetime, timedelta
from sqlalchemy.orm import Session
from app.db.repositories import TransactionRepository, AccountRepository, BudgetRepository
from app.db.models import Transaction, TransactionType
from app.schemas import TransactionCreateSchema


class TransactionService:
    """Service for transaction operations"""

    def __init__(self, session: Session):
        self.session = session
        self.transaction_repo = TransactionRepository(session)
        self.account_repo = AccountRepository(session)
        self.budget_repo = BudgetRepository(session)

    def create_transaction(
        self,
        family_id: int,
        user_id: int,
        account_id: int,
        data: TransactionCreateSchema,
    ) -> Transaction:
        """Create new transaction and update account balance"""
        # Create transaction
        transaction = self.transaction_repo.create(
            family_id=family_id,
            user_id=user_id,
            account_id=account_id,
            amount=data.amount,
            transaction_type=data.transaction_type,
            description=data.description,
            notes=data.notes,
            tags=data.tags,
            category_id=data.category_id,
            receipt_photo_url=data.receipt_photo_url,
            transaction_date=data.transaction_date,
        )

        # Update account balance
        if data.transaction_type == TransactionType.EXPENSE:
            self.account_repo.update_balance(account_id, -data.amount)
        elif data.transaction_type == TransactionType.INCOME:
            self.account_repo.update_balance(account_id, data.amount)

        # Update budget if expense
        if (
            data.transaction_type == TransactionType.EXPENSE
            and data.category_id
        ):
            budget = self.budget_repo.get_category_budget(family_id, data.category_id)
            if budget:
                self.budget_repo.update_spent_amount(budget.id, data.amount)

        return transaction

    def get_family_summary(self, family_id: int, days: int = 30) -> dict:
        """Get financial summary for family"""
        end_date = datetime.utcnow()
        start_date = end_date - timedelta(days=days)

        transactions = self.transaction_repo.get_transactions_by_period(
            family_id, start_date, end_date
        )

        income = sum(t.amount for t in transactions if t.transaction_type == TransactionType.INCOME)
        expenses = sum(t.amount for t in transactions if t.transaction_type == TransactionType.EXPENSE)
        net = income - expenses

        return {
            "period_days": days,
            "income": income,
            "expenses": expenses,
            "net": net,
            "average_daily_expense": expenses / days if days > 0 else 0,
            "transaction_count": len(transactions),
        }

    def delete_transaction(self, transaction_id: int) -> bool:
        """Delete transaction and rollback balance"""
        transaction = self.transaction_repo.get_by_id(transaction_id)
        if transaction:
            # Rollback balance
            if transaction.transaction_type == TransactionType.EXPENSE:
                self.account_repo.update_balance(transaction.account_id, transaction.amount)
            elif transaction.transaction_type == TransactionType.INCOME:
                self.account_repo.update_balance(transaction.account_id, -transaction.amount)

            # Delete transaction
            return self.transaction_repo.delete(transaction_id)
        return False