zellyy-finance/src/contexts/budget/useBudgetState.ts

import { useState, useEffect } from 'react';
import { Transaction, BudgetData, BudgetPeriod, BudgetContextType } from './types';
import { loadTransactionsFromStorage, saveTransactionsToStorage } from './storage/transactionStorage';
import { v4 as uuidv4 } from 'uuid';

export const useBudgetState = () => {
  // 로컬 스토리지에서 초기 트랜잭션 데이터 로드
  const [transactions, setTransactions] = useState<Transaction[]>([]);
  const [categoryBudgets, setCategoryBudgets] = useState<Record<string, number>>({});
  const [budgetData, setBudgetData] = useState<BudgetData>({
    daily: { targetAmount: 0, spentAmount: 0, remainingAmount: 0 },
    weekly: { targetAmount: 0, spentAmount: 0, remainingAmount: 0 },
    monthly: { targetAmount: 0, spentAmount: 0, remainingAmount: 0 },
  });
  const [selectedTab, setSelectedTab] = useState<BudgetPeriod>('monthly');

  useEffect(() => {
    const storedTransactions = loadTransactionsFromStorage();
    setTransactions(storedTransactions);
  }, []);

  useEffect(() => {
    // 트랜잭션 변경 시 로컬 스토리지에 저장
    saveTransactionsToStorage(transactions);
  }, [transactions]);

  // 트랜잭션 추가
  const addTransaction = (transaction: Transaction) => {
    const newTransaction = { ...transaction, id: uuidv4() };
    setTransactions(prevTransactions => [...prevTransactions, newTransaction]);
  };

  // 트랜잭션 업데이트
  const updateTransaction = (updatedTransaction: Transaction) => {
    setTransactions(prevTransactions =>
      prevTransactions.map(transaction =>
        transaction.id === updatedTransaction.id ? updatedTransaction : transaction
      )
    );
  };

  // 트랜잭션 삭제
  const deleteTransaction = (id: string) => {
    setTransactions(prevTransactions =>
      prevTransactions.filter(transaction => transaction.id !== id)
    );
  };

  // 예산 목표 업데이트
  const handleBudgetGoalUpdate = (type: BudgetPeriod, amount: number, newCategoryBudgets?: Record<string, number>) => {
    setBudgetData(prev => ({
      ...prev,
      [type]: {
        ...prev[type],
        targetAmount: amount,
      },
    }));
    if (newCategoryBudgets) {
      setCategoryBudgets(newCategoryBudgets);
    }
  };

  // 카테고리별 지출 계산
  const getCategorySpending = () => {
    const categorySpending: { [key: string]: { total: number; current: number } } = {};

    // 초기화
    ['음식', '쇼핑', '교통', '기타'].forEach(category => {
      categorySpending[category] = { total: categoryBudgets[category] || 0, current: 0 };
    });

    // 지출 합산
    transactions.filter(tx => tx.type === 'expense').forEach(tx => {
      if (categorySpending[tx.category]) {
        categorySpending[tx.category].current += tx.amount;
      } else {
        // 새 카테고리인 경우 초기화
        categorySpending[tx.category] = { total: 0, current: tx.amount };
      }
    });

    // 배열로 변환
    return Object.entries(categorySpending).map(([title, { total, current }]) => ({
      title,
      total,
      current,
    }));
  };

  // 결제 방법 통계 계산 함수
  const getPaymentMethodStats = () => {
    // 지출 트랜잭션 필터링
    const expenseTransactions = transactions.filter(t => t.type === 'expense');
    
    // 총 지출 계산
    const totalExpense = expenseTransactions.reduce((acc, curr) => acc + curr.amount, 0);
    
    // 결제 방법별 금액 계산
    const cardExpense = expenseTransactions
      .filter(t => t.paymentMethod === '신용카드' || !t.paymentMethod) // paymentMethod가 없으면 신용카드로 간주
      .reduce((acc, curr) => acc + curr.amount, 0);
      
    const cashExpense = expenseTransactions
      .filter(t => t.paymentMethod === '현금')
      .reduce((acc, curr) => acc + curr.amount, 0);
    
    // 결과 배열 생성 - 금액이 큰 순서대로 정렬
    const result = [
      { 
        method: '신용카드', 
        amount: cardExpense,
        percentage: totalExpense > 0 ? (cardExpense / totalExpense) * 100 : 0
      },
      { 
        method: '현금', 
        amount: cashExpense,
        percentage: totalExpense > 0 ? (cashExpense / totalExpense) * 100 : 0
      }
    ].sort((a, b) => b.amount - a.amount);
    
    return result;
  };
  
  // 예산 데이터 재설정 함수
  const resetBudgetData = () => {
    setBudgetData({
      daily: { targetAmount: 0, spentAmount: 0, remainingAmount: 0 },
      weekly: { targetAmount: 0, spentAmount: 0, remainingAmount: 0 },
      monthly: { targetAmount: 0, spentAmount: 0, remainingAmount: 0 },
    });
    setCategoryBudgets({});
  };

  return {
    transactions,
    categoryBudgets,
    budgetData,
    selectedTab,
    setSelectedTab,
    addTransaction,
    updateTransaction,
    deleteTransaction,
    handleBudgetGoalUpdate,
    getCategorySpending,
    getPaymentMethodStats,
    resetBudgetData,
  };
};