import React, { useState, useCallback, useRef } from 'react';
import { View, Text } from '@tarojs/components';
import Taro, { useDidShow, useReachBottom, usePullDownRefresh } from '@tarojs/taro';
import { listMyTransactions } from '../../../services/points';
import type { PointsTransaction } from '../../../services/points';
import { usePointsStore } from '../../../stores/points';
import EmptyState from '../../../components/EmptyState';
import Loading from '../../../components/Loading';
import './index.scss';

const TYPE_TABS = [
  { key: '', label: '全部' },
  { key: 'earn', label: '收入' },
  { key: 'spend', label: '支出' },
];

export default function PointsDetail() {
  const { account, refresh: refreshPoints } = usePointsStore();
  const [transactions, setTransactions] = useState<PointsTransaction[]>([]);
  const [activeTab, setActiveTab] = useState('');
  const [page, setPage] = useState(1);
  const [total, setTotal] = useState(0);
  const [loading, setLoading] = useState(false);
  const loadingRef = useRef(false);

  const fetchTransactions = useCallback(
    async (pageNum: number, type: string, isRefresh = false) => {
      if (loadingRef.current) return;
      loadingRef.current = true;
      setLoading(true);
      try {
        const res = await listMyTransactions({
          page: pageNum,
          page_size: 10,
        });
        let list = res.data || [];
        if (type) {
          list = list.filter((t) => t.type === type);
        }
        if (isRefresh) {
          setTransactions(list);
        } else {
          setTransactions((prev) => [...prev, ...list]);
        }
        setTotal(res.total);
        setPage(pageNum);
      } catch {
        Taro.showToast({ title: '加载失败', icon: 'none' });
      } finally {
        loadingRef.current = false;
        setLoading(false);
      }
    },
    [],
  );

  const loadAll = useCallback(
    async (type?: string) => {
      const t = type !== undefined ? type : activeTab;
      await Promise.all([refreshPoints(), fetchTransactions(1, t, true)]);
    },
    [refreshPoints, fetchTransactions, activeTab],
  );

  useDidShow(() => {
    Taro.setNavigationBarTitle({ title: '积分明细' });
    loadAll();
  });

  usePullDownRefresh(() => {
    loadAll().finally(() => {
      Taro.stopPullDownRefresh();
    });
  });

  useReachBottom(() => {
    if (!loading && transactions.length < total) {
      fetchTransactions(page + 1, activeTab);
    }
  });

  const handleTabChange = (key: string) => {
    setActiveTab(key);
    fetchTransactions(1, key, true);
  };

  const getTypeLabel = (type: string) => {
    if (type === 'earn') return '收';
    if (type === 'spend') return '支';
    return '过';
  };

  const getTypeClass = (type: string) => {
    if (type === 'earn') return 'earn';
    if (type === 'spend') return 'spend';
    return 'expired';
  };

  const formatAmount = (tx: PointsTransaction) => {
    const amt = tx.amount;
    if (tx.type === 'earn') return `+${amt.toLocaleString()}`;
    if (tx.type === 'spend') return `-${amt.toLocaleString()}`;
    return `-${amt.toLocaleString()}`;
  };

  const formatDate = (dateStr: string) => {
    if (!dateStr) return '';
    const d = new Date(dateStr);
    return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')} ${String(d.getHours()).padStart(2, '0')}:${String(d.getMinutes()).padStart(2, '0')}`;
  };

  const balance = account?.balance ?? 0;

  return (
    <View className='detail-page'>
      {/* 余额卡片 */}
      <View className='balance-card'>
        <Text className='balance-label'>当前积分</Text>
        <Text className='balance-value'>{balance.toLocaleString()}</Text>
        <View className='balance-stats'>
          <View className='stat-item'>
            <Text className='stat-value stat-earn'>{(account?.total_earned ?? 0).toLocaleString()}</Text>
            <Text className='stat-label'>累计获得</Text>
          </View>
          <View className='stat-divider' />
          <View className='stat-item'>
            <Text className='stat-value stat-spend'>{(account?.total_spent ?? 0).toLocaleString()}</Text>
            <Text className='stat-label'>累计消费</Text>
          </View>
          <View className='stat-divider' />
          <View className='stat-item'>
            <Text className='stat-value stat-expired'>{(account?.total_expired ?? 0).toLocaleString()}</Text>
            <Text className='stat-label'>已过期</Text>
          </View>
        </View>
      </View>

      {/* 类型筛选标签 */}
      <View className='type-tabs'>
        {TYPE_TABS.map((tab) => (
          <View
            key={tab.key}
            className={`type-tab ${activeTab === tab.key ? 'active' : ''}`}
            onClick={() => handleTabChange(tab.key)}
          >
            <Text className='type-tab-text'>{tab.label}</Text>
          </View>
        ))}
      </View>

      {/* 交易列表 */}
      {transactions.length === 0 && !loading ? (
        <EmptyState icon='' text='暂无积分记录' hint='签到或兑换后将显示记录' />
      ) : (
        <View className='transaction-list'>
          {transactions.map((tx) => {
            return (
              <View className='transaction-item' key={tx.id}>
                <View className={`tx-badge tx-badge-${getTypeClass(tx.type)}`}>
                  <Text className='tx-badge-text'>{getTypeLabel(tx.type)}</Text>
                </View>
                <View className='tx-info'>
                  <Text className='tx-desc'>
                    {tx.description || (tx.type === 'earn' ? '积分收入' : tx.type === 'spend' ? '积分消费' : '积分过期')}
                  </Text>
                  <Text className='tx-date'>{formatDate(tx.created_at)}</Text>
                </View>
                <View className='tx-amount-col'>
                  <Text className={`tx-amount tx-amount-${tx.type === 'earn' ? 'positive' : 'negative'}`}>
                    {formatAmount(tx)}
                  </Text>
                  <Text className='tx-remaining'>余额 {tx.balance_after.toLocaleString()}</Text>
                </View>
              </View>
            );
          })}
          {loading && <Loading />}
          {!loading && transactions.length >= total && total > 0 && (
            <Loading text='没有更多了' />
          )}
        </View>
      )}
    </View>
  );
}