import { useState, useEffect } from 'react';
import { useRouter } from 'next/router';
import { isLoggedIn, searchRecords } from '../lib/api';
import { DEFAULT_CATEGORIES } from '../lib/categories';
import AppShell from '../components/AppShell';
import { Icon } from '../components/icons';
import { useToast } from '../components/ToastProvider';

export default function Search() {
  const router = useRouter();
  const { showToast } = useToast();
  const [keyword, setKeyword] = useState('');
  const [results, setResults] = useState([]);
  const [loading, setLoading] = useState(false);

  useEffect(() => {
    if (!isLoggedIn()) {
      router.push('/login');
    }
  }, [router]);

  const handleSearch = async (e) => {
    e.preventDefault();
    if (!keyword.trim()) {
      showToast('请输入搜索关键词', { tone: 'info' });
      return;
    }

    setLoading(true);
    try {
      const data = await searchRecords(keyword);
      setResults(data);
    } catch (err) {
      console.error(err);
      showToast(err.message, { tone: 'error' });
    } finally {
      setLoading(false);
    }
  };

  const formatMoney = (num) => (num || 0).toFixed(2);

  const groupedResults = results.reduce((groups, record) => {
    const date = record.date.split(' ')[0];
    if (!groups[date]) groups[date] = [];
    groups[date].push(record);
    return groups;
  }, {});

  const sortedDates = Object.keys(groupedResults).sort((a, b) => b.localeCompare(a));
  const totalIncome = results.filter((record) => record.type === 'income').reduce((sum, record) => sum + record.amount, 0);
  const totalExpense = results.filter((record) => record.type === 'expense').reduce((sum, record) => sum + record.amount, 0);
  const totalBalance = totalIncome - totalExpense;

  const actions = (
    <button type="button" className="icon-button" aria-label="设置" onClick={() => router.push('/settings')}>
      <Icon name="settings" size={18} />
    </button>
  );

  return (
    <AppShell title="搜索" subtitle="快速查找分类、备注与金额" actions={actions} compactHeader>
      <section className="card section-card section-card--search section-card--search-panel">
        <form className="search-form search-form--refresh" onSubmit={handleSearch}>
          <div className="search-input-wrap">
            <Icon name="search" size={18} className="search-input-wrap__icon" />
            <input
              type="text"
              value={keyword}
              onChange={(e) => setKeyword(e.target.value)}
              placeholder="搜索分类或备注..."
              autoFocus
              disabled={loading}
            />
          </div>
          <button type="submit" className="btn btn-primary btn-inline" disabled={loading}>
            {loading ? (
              <span className="button-content">
                <Icon name="spinner" size={16} className="is-spinning" />
                搜索中...
              </span>
            ) : '搜索'}
          </button>
        </form>

        {results.length > 0 ? (
          <>
            <div className="search-summary">
              <div className="search-stat">
                <span className="label">收入</span>
                <span className="value income">+{formatMoney(totalIncome)}</span>
              </div>
              <div className="search-stat">
                <span className="label">支出</span>
                <span className="value expense">-{formatMoney(totalExpense)}</span>
              </div>
              <div className="search-stat">
                <span className="label">结余</span>
                <span className="value">{formatMoney(totalBalance)}</span>
              </div>
            </div>
            <div className="results-count">找到 {results.length} 条记录</div>
          </>
        ) : null}
      </section>

      {loading ? (
        <div className="card loading-state">搜索中...</div>
      ) : results.length > 0 ? (
        <section className="card section-card">
          <div className="records-list records-list--flush">
            {sortedDates.map((date) => (
              <div key={date} className="date-group">
                <div className="date-label">
                  {new Date(date).toLocaleDateString('zh-CN', { month: 'short', day: 'numeric', weekday: 'short' })}
                </div>
                {groupedResults[date].map((record) => {
                  const categories = DEFAULT_CATEGORIES[record.type];
                  const cat = categories.find((item) => item.name === record.category) || { icon: '📝' };
                  return (
                    <div key={record.id} className="record-item record-item--static">
                      <div className="record-left">
                        <div className="record-icon">{cat.icon}</div>
                        <div className="record-info">
                          <div className="record-category">{record.category}</div>
                          {record.note && <div className="record-note">{record.note}</div>}
                        </div>
                      </div>
                      <div className={`record-amount ${record.type}`}>
                        {record.type === 'income' ? '+' : '-'}
                        {formatMoney(record.amount)}
                      </div>
                    </div>
                  );
                })}
              </div>
            ))}
          </div>
        </section>
      ) : keyword ? (
        <div className="card empty-state empty-state--card">
          <div className="empty-state__icon"><Icon name="search" size={24} /></div>
          <p>未找到相关记录</p>
        </div>
      ) : (
        <div className="card empty-state empty-state--card">
          <div className="empty-state__icon"><Icon name="search" size={24} /></div>
          <p>输入关键词开始搜索</p>
        </div>
      )}
    </AppShell>
  );
}