import { useState, useEffect } from 'react';
import { Transaction } from '@/components/TransactionCard';
import { useAuth } from '@/contexts/auth/AuthProvider';
import { toast } from '@/hooks/useToast.wrapper';
import { isSyncEnabled } from '@/utils/syncUtils';
import { MONTHS_KR, getCurrentMonth, getPrevMonth, getNextMonth } from '@/utils/dateUtils';
import { 
  loadTransactionsFromStorage, 
  saveTransactionsToStorage, 
  loadBudgetFromStorage 
} from '@/utils/storageUtils';
import { 
  filterTransactionsByMonth, 
  filterTransactionsByQuery, 
  calculateTotalExpenses
} from '@/utils/transactionUtils';
import { 
  syncTransactionsWithSupabase, 
  updateTransactionInSupabase, 
  deleteTransactionFromSupabase 
} from '@/utils/supabaseTransactionUtils';
import { EXPENSE_CATEGORIES } from '@/constants/categoryIcons';

// 월 이름 재노출
export { MONTHS_KR };

export const useTransactions = () => {
  const [transactions, setTransactions] = useState<Transaction[]>([]);
  const [filteredTransactions, setFilteredTransactions] = useState<Transaction[]>([]);
  const [selectedMonth, setSelectedMonth] = useState(getCurrentMonth());
  const [searchQuery, setSearchQuery] = useState('');
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [totalBudget, setTotalBudget] = useState(1000000); // 기본 예산
  const { user } = useAuth();

  // 월 변경 처리
  const handlePrevMonth = () => {
    setSelectedMonth(getPrevMonth(selectedMonth));
  };

  const handleNextMonth = () => {
    setSelectedMonth(getNextMonth(selectedMonth));
  };

  // 트랜잭션 로드
  const loadTransactions = () => {
    setIsLoading(true);
    setError(null);
    
    try {
      // 로컬 스토리지에서 트랜잭션 데이터 가져오기
      const localData = loadTransactionsFromStorage();
      
      // 지원되는 카테고리로 필터링
      const filteredData = localData.map(transaction => {
        // 트랜잭션의 카테고리가 현재 지원되는 카테고리가 아니면 '기타'로 변경
        if (transaction.type === 'expense' && !EXPENSE_CATEGORIES.includes(transaction.category)) {
          return {
            ...transaction,
            category: '생활비' // 기본값으로 '생활비' 사용
          };
        }
        return transaction;
      });
      
      // 로컬 데이터가 있으면 사용
      setTransactions(filteredData);
      
      // 예산 가져오기
      const budget = loadBudgetFromStorage();
      setTotalBudget(budget);
    } catch (err) {
      console.error('트랜잭션 로드 중 오류:', err);
      setError('데이터를 불러오는 중 문제가 발생했습니다.');
      toast({
        title: "데이터 로드 실패",
        description: "지출 내역을 불러오는데 실패했습니다.",
        variant: "destructive"
      });
    } finally {
      setIsLoading(false);
    }
  };
  
  // 필터 적용
  useEffect(() => {
    // 1. 월별 필터링
    let filtered = filterTransactionsByMonth(transactions, selectedMonth);
    
    // 2. 검색어 필터링
    if (searchQuery.trim()) {
      filtered = filterTransactionsByQuery(filtered, searchQuery);
    }
    
    setFilteredTransactions(filtered);
  }, [transactions, selectedMonth, searchQuery]);

  // 초기 데이터 로드
  useEffect(() => {
    loadTransactions();
    
    // Supabase 동기화 (로그인 상태인 경우)
    const syncWithSupabase = async () => {
      if (user) {
        const syncedTransactions = await syncTransactionsWithSupabase(user, transactions);
        if (syncedTransactions !== transactions) {
          setTransactions(syncedTransactions);
          saveTransactionsToStorage(syncedTransactions);
        }
      }
    };
    
    syncWithSupabase();
  }, [user]);

  // 트랜잭션 업데이트
  const updateTransaction = (updatedTransaction: Transaction) => {
    const updatedTransactions = transactions.map(transaction =>
      transaction.id === updatedTransaction.id ? updatedTransaction : transaction
    );
    
    setTransactions(updatedTransactions);
    saveTransactionsToStorage(updatedTransactions);
    
    // Supabase에도 업데이트
    updateTransactionInSupabase(user, updatedTransaction);
    
    toast({
      title: "지출이 수정되었습니다",
      description: `${updatedTransaction.title} 항목이 업데이트되었습니다.`,
    });
  };

  // 트랜잭션 삭제
  const deleteTransaction = (id: string) => {
    const updatedTransactions = transactions.filter(transaction => transaction.id !== id);
    
    setTransactions(updatedTransactions);
    saveTransactionsToStorage(updatedTransactions);
    
    // Supabase에서도 삭제
    deleteTransactionFromSupabase(user, id);
    
    toast({
      title: "지출이 삭제되었습니다",
      description: "선택한 지출 항목이 삭제되었습니다.",
    });
  };

  return {
    transactions: filteredTransactions,
    isLoading,
    error,
    totalBudget,
    selectedMonth,
    searchQuery,
    setSearchQuery,
    handlePrevMonth,
    handleNextMonth,
    updateTransaction,
    deleteTransaction,
    totalExpenses: calculateTotalExpenses(filteredTransactions),
    refreshTransactions: loadTransactions
  };
};