import React, { useState, useEffect } from 'react';
import NavBar from '@/components/NavBar';
import AddTransactionButton from '@/components/AddTransactionButton';
import Header from '@/components/Header';
import BudgetProgressCard from '@/components/BudgetProgressCard';
import BudgetCategoriesSection from '@/components/BudgetCategoriesSection';
import RecentTransactionsSection from '@/components/RecentTransactionsSection';
import { formatCurrency, calculatePercentage } from '@/utils/formatters';
import { toast } from '@/components/ui/use-toast';
import { Transaction } from '@/components/TransactionCard';

const Index = () => {
  const [selectedTab, setSelectedTab] = useState("daily");

  // Sample data - in a real app, this would come from a data source
  const transactions: Transaction[] = [{
    id: '1',
    title: '식료품 구매',
    amount: 25000,
    date: '오늘, 12:30 PM',
    category: '식비',
    type: 'expense'
  }, {
    id: '2',
    title: '주유소',
    amount: 50000,
    date: '어제, 3:45 PM',
    category: '교통비',
    type: 'expense'
  }, {
    id: '3',
    title: '월급',
    amount: 2500000,
    date: '2일전, 9:00 AM',
    category: 'income',
    type: 'income'
  }];

  // 카테고리별 예산
  const [categoryBudgets, setCategoryBudgets] = useState({
    식비: 400000,
    생활비: 600000,
    교통비: 200000
  });

  // 예산 데이터 - 월간 예산을 기반으로 일일, 주간 계산
  const [budgetData, setBudgetData] = useState({
    daily: {
      targetAmount: 0,
      spentAmount: 15000,
      remainingAmount: 0
    },
    weekly: {
      targetAmount: 0,
      spentAmount: 120000,
      remainingAmount: 0
    },
    monthly: {
      targetAmount: 0,
      spentAmount: 750000,
      remainingAmount: 0
    }
  });

  // 초기 로드 및 카테고리 예산 변경 시 전체 예산 업데이트
  useEffect(() => {
    const totalMonthlyBudget = Object.values(categoryBudgets).reduce((sum, value) => sum + value, 0);
    const totalDailyBudget = Math.round(totalMonthlyBudget / 30); // 월간을 일일로 변환
    const totalWeeklyBudget = Math.round(totalMonthlyBudget / 4.3); // 월간을 주간으로 변환

    setBudgetData({
      daily: {
        targetAmount: totalDailyBudget,
        spentAmount: budgetData.daily.spentAmount,
        remainingAmount: totalDailyBudget - budgetData.daily.spentAmount
      },
      weekly: {
        targetAmount: totalWeeklyBudget,
        spentAmount: budgetData.weekly.spentAmount,
        remainingAmount: totalWeeklyBudget - budgetData.weekly.spentAmount
      },
      monthly: {
        targetAmount: totalMonthlyBudget,
        spentAmount: budgetData.monthly.spentAmount,
        remainingAmount: totalMonthlyBudget - budgetData.monthly.spentAmount
      }
    });
  }, [categoryBudgets]);

  // 카테고리 업데이트
  const categories = [
    { title: '식비', current: budgetData.monthly.spentAmount * 0.32, total: categoryBudgets.식비 },
    { title: '생활비', current: budgetData.monthly.spentAmount * 0.47, total: categoryBudgets.생활비 },
    { title: '교통비', current: budgetData.monthly.spentAmount * 0.21, total: categoryBudgets.교통비 },
  ];

  // 예산 목표 업데이트 함수
  const handleBudgetGoalUpdate = (type: 'daily' | 'weekly' | 'monthly', amount: number) => {
    // 월간 예산을 업데이트하고 일일, 주간도 자동 계산
    if (type === 'monthly') {
      const dailyAmount = Math.round(amount / 30);
      const weeklyAmount = Math.round(amount / 4.3);
      
      setBudgetData(prev => ({
        daily: {
          targetAmount: dailyAmount,
          spentAmount: prev.daily.spentAmount,
          remainingAmount: Math.max(0, dailyAmount - prev.daily.spentAmount)
        },
        weekly: {
          targetAmount: weeklyAmount,
          spentAmount: prev.weekly.spentAmount,
          remainingAmount: Math.max(0, weeklyAmount - prev.weekly.spentAmount)
        },
        monthly: {
          targetAmount: amount,
          spentAmount: prev.monthly.spentAmount,
          remainingAmount: Math.max(0, amount - prev.monthly.spentAmount)
        }
      }));
    } else {
      // 일일이나 주간 예산이 직접 업데이트되는 경우
      setBudgetData(prev => {
        const remainingAmount = Math.max(0, amount - prev[type].spentAmount);
        return {
          ...prev,
          [type]: {
            ...prev[type],
            targetAmount: amount,
            remainingAmount: remainingAmount
          }
        };
      });
    }
    
    toast({
      title: "목표 업데이트 완료",
      description: `${type === 'daily' ? '일일' : type === 'weekly' ? '주간' : '월간'} 목표가 ${amount.toLocaleString()}원으로 설정되었습니다.`
    });
  };
  
  return (
    <div className="min-h-screen bg-neuro-background pb-24">
      <div className="max-w-md mx-auto px-6">
        <Header />

        {/* 목표 진행 상황 */}
        <h2 className="text-lg font-semibold mb-3">예산과 지출</h2>
        <BudgetProgressCard 
          budgetData={budgetData}
          selectedTab={selectedTab}
          setSelectedTab={setSelectedTab}
          formatCurrency={formatCurrency}
          calculatePercentage={calculatePercentage}
          onSaveBudget={handleBudgetGoalUpdate}
        />

        {/* 지출 카테고리 */}
        <BudgetCategoriesSection categories={categories} />

        {/* 최근 지출 */}
        <RecentTransactionsSection transactions={transactions} />
      </div>

      <AddTransactionButton />
      <NavBar />
    </div>
  );
};

export default Index;