import { useCallback, useEffect, useState } from 'react';
import { Link, useNavigate, useSearchParams } from 'react-router-dom';
import { useStoreSession } from '../contexts/StoreSessionContext';
import { request } from '../lib/api';
import { parseRedeemTokenFromScan } from '../lib/redeem-scan';
import {
  authorizeShopWechat,
  checkNeedsWechatAuth,
  fetchShopAccount,
  handleShopWechatCallback,
  handleShopWechatLoginResult,
} from '../lib/wechat-auth';
import { isWechatEnv, weixinSdk } from '../lib/weixin';
import { stripOAuthParamsFromLocation } from '@dukang/weixin-sdk';
import WechatScanAuthModal from '../components/WechatScanAuthModal';

const PENDING_SCAN_KEY = 'shop_pending_scan';

function formatMoney(n: number) {
  return n.toLocaleString('zh-CN', { minimumFractionDigits: 0, maximumFractionDigits: 2 });
}

function formatScanError(e: unknown): string {
  const msg = e instanceof Error ? e.message : '扫码失败，请重试';
  if (/invalid signature/i.test(msg)) {
    return '微信 JSSDK 签名校验失败：请确认公众号已配置 JS 接口安全域名为 user.runxian.top，并刷新页面后重试';
  }
  if (/offline verifying|权限验证中|接口未就绪/i.test(msg)) {
    return `${msg}（可在 URL 后加 ?wxdebug=1 开启 JSSDK 调试查看详情）`;
  }
  return msg;
}

export default function HomePage() {
  const navigate = useNavigate();
  const { applySession } = useStoreSession();
  const [searchParams, setSearchParams] = useSearchParams();
  const [dash, setDash] = useState<Record<string, unknown> | null>(null);
  const [open, setOpen] = useState(true);
  const [scanMsg, setScanMsg] = useState('');
  const [scanning, setScanning] = useState(false);
  const [authModalOpen, setAuthModalOpen] = useState(false);
  const [authLoading, setAuthLoading] = useState(false);
  const [authError, setAuthError] = useState('');

  const loadDashboard = useCallback(() => {
    return request<Record<string, unknown>>('SHOP_H5', '/shop/dashboard')
      .then((d) => {
        setDash(d);
        setOpen(String((d.store as Record<string, unknown>)?.status) === 'OPEN');
      })
      .catch(() => {});
  }, []);

  useEffect(() => {
    void loadDashboard();
  }, [loadDashboard]);

  useEffect(() => {
    function onResume() {
      setScanning(false);
      void loadDashboard();
    }
    function onVisibility() {
      if (document.visibilityState === 'visible') onResume();
    }
    document.addEventListener('visibilitychange', onVisibility);
    window.addEventListener('pageshow', onResume);
    window.addEventListener('focus', onResume);
    return () => {
      document.removeEventListener('visibilitychange', onVisibility);
      window.removeEventListener('pageshow', onResume);
      window.removeEventListener('focus', onResume);
    };
  }, [loadDashboard]);

  useEffect(() => {
    if (!isWechatEnv() || !searchParams.get('code')) return;
    void handleShopWechatCallback()
      .then((result) => {
        if (!result) return;
        const session = handleShopWechatLoginResult(result);
        if (session) {
          applySession(session);
        }
        setAuthModalOpen(false);
        setAuthError('');
        stripOAuthParamsFromLocation();
        setSearchParams({}, { replace: true });
        const shouldScan = sessionStorage.getItem(PENDING_SCAN_KEY) === '1';
        sessionStorage.removeItem(PENDING_SCAN_KEY);
        if (shouldScan) {
          window.setTimeout(() => void runScan(), 0);
        }
      })
      .catch((e) => {
        setAuthError(e instanceof Error ? e.message : '微信授权失败');
      });
  }, [searchParams, applySession, setSearchParams]);

  async function runScan() {
    if (!isWechatEnv()) {
      setScanMsg('请在微信内打开门店端进行扫码核销');
      return;
    }
    setScanning(true);
    setScanMsg('');
    try {
      await weixinSdk.init();
      const raw = await weixinSdk.scanQrCode();
      if (!raw) {
        void loadDashboard();
        return;
      }
      const token = parseRedeemTokenFromScan(raw);
      if (!token) {
        setScanMsg('无法识别核销码，请扫描用户出示的核销二维码');
        return;
      }
      navigate(`/redeem?token=${encodeURIComponent(token)}`);
    } catch (e) {
      setScanMsg(formatScanError(e));
    } finally {
      setScanning(false);
    }
  }

  async function handleScan() {
    setScanMsg('');
    if (!isWechatEnv()) {
      setScanMsg('请在微信内打开门店端进行扫码核销');
      return;
    }
    try {
      const profile = await fetchShopAccount();
      if (await checkNeedsWechatAuth(profile)) {
        setAuthModalOpen(true);
        return;
      }
      await runScan();
    } catch (e) {
      setScanMsg(e instanceof Error ? e.message : '无法发起扫码');
    }
  }

  async function startWechatAuth() {
    setAuthLoading(true);
    setAuthError('');
    try {
      sessionStorage.setItem(PENDING_SCAN_KEY, '1');
      await authorizeShopWechat();
    } catch (e) {
      sessionStorage.removeItem(PENDING_SCAN_KEY);
      setAuthError(e instanceof Error ? e.message : '微信授权失败');
      setAuthLoading(false);
    }
  }

  const store = dash?.store as Record<string, unknown> | undefined;
  const recent = (dash?.recentRecords as Array<Record<string, unknown>>) || [];
  const openTime = String(store?.openTime || '10:00');
  const closeTime = String(store?.closeTime || '22:00');

  return (
    <div className="shop-home-page">
      <header className="shop-home-header">
        <h1 className="app-page-title">门店管理中心</h1>
      </header>

      <div className="shop-home-content">
        <section className="shop-home-hero">
          <div className="shop-home-hero-store">
            <span className="material-symbols-outlined shop-fill-icon">store</span>
            <h2>{String(store?.name || '门店')}</h2>
          </div>
          <div className="shop-home-stats">
            <div className="shop-home-stat">
              <p className="shop-home-stat-label">今日核销笔数</p>
              <p className="shop-home-stat-value">{Number(dash?.todayCount || 0)}</p>
            </div>
            <div className="shop-home-stat">
              <p className="shop-home-stat-label">今日到账金额</p>
              <p className="shop-home-stat-value">
                <span style={{ fontSize: 18 }}>¥</span>
                {formatMoney(Number(dash?.todayAmount || 0))}
              </p>
            </div>
          </div>
        </section>

        <section className="shop-home-scan">
          <button
            type="button"
            className="shop-home-scan-btn"
            disabled={scanning}
            onClick={() => void handleScan()}
          >
            <span className="material-symbols-outlined">qr_code_scanner</span>
          </button>
          <p className="shop-home-scan-label">{scanning ? '正在打开相机…' : '扫码核销'}</p>
          {scanMsg && <p className="shop-home-scan-msg" role="alert">{scanMsg}</p>}
          <Link to="/redeem/phone" className="shop-home-phone-link">
            <span className="material-symbols-outlined">smartphone</span>
            手机号核销
          </Link>
        </section>

        <section className="shop-home-status">
          <div className="shop-home-status-left">
            <div className={`shop-home-status-icon${open ? '' : ' closed'}`}>
              <span className="material-symbols-outlined shop-fill-icon">schedule</span>
            </div>
            <div>
              <p className="shop-home-status-title">营业状态</p>
              <p className="shop-home-status-sub">{open ? '当前正在营业中' : '当前已停止营业'}</p>
              <p className="shop-home-status-sub">营业时间: {openTime} - {closeTime}</p>
            </div>
          </div>
          <label className="shop-home-switch" onClick={() => navigate('/status')}>
            <input type="checkbox" checked={open} readOnly tabIndex={-1} />
            <span className="shop-home-switch-track" />
          </label>
        </section>

        <section>
          <div className="shop-home-records-head">
            <h3 className="shop-home-records-title">核销记录</h3>
            <Link to="/records" className="shop-home-records-link">
              查看全部
              <span className="material-symbols-outlined" style={{ fontSize: 16 }}>chevron_right</span>
            </Link>
          </div>
          <div className="shop-home-record-list">
            {recent.length === 0 && (
              <p className="shop-home-status-sub" style={{ textAlign: 'center', padding: '16px 0' }}>暂无核销记录</p>
            )}
            {recent.map((r) => (
              <div key={String(r.id)} className="shop-home-record-item">
                <div>
                  <p className="shop-home-record-time">核销时间</p>
                  <p className="shop-home-record-value">
                    {new Date(String(r.createdAt)).toLocaleString('zh-CN')}
                  </p>
                </div>
                <p className="shop-home-record-amount">¥{formatMoney(Number(r.amount))}</p>
              </div>
            ))}
          </div>
        </section>
      </div>

      <WechatScanAuthModal
        open={authModalOpen}
        loading={authLoading}
        error={authError}
        onAuthorize={() => void startWechatAuth()}
        onCancel={() => {
          setAuthModalOpen(false);
          setAuthError('');
          sessionStorage.removeItem(PENDING_SCAN_KEY);
        }}
      />
    </div>
  );
}