import { useEffect, useState } from 'react';
import { Link, useNavigate, useSearchParams } from 'react-router-dom';
import { isWxAuthorizeEnabled } from '@dukang/shared-types';
import { WECHAT_INAPP_REQUIRED_MSG } from '@dukang/weixin-sdk';
import {
  getLastPhone,
  getPartnerProfile,
  hasPartnerWxSession,
  request,
  saveAuth,
  type PartnerSessionPayload,
} from '../lib/api';
import { usePartnerSession } from '../contexts/PartnerSessionContext';
import { partnerHomePath } from '../lib/partnerAccess';
import {
  bindPartnerWechatAfterSmsLogin,
  canPartnerUseWechatLogin,
  fetchClientConfig,
  loginPartnerWithWechat,
  PARTNER_WECHAT_LOGIN_HINT,
} from '../lib/wechat-auth';
import { isWechatEnv } from '../lib/weixin';

const REMEMBER_PHONE_KEY = 'partner_remember_phone';
const REMEMBER_FLAG_KEY = 'partner_remember_account';

function maskPhone(phone: string) {
  if (phone.length < 7) return phone;
  return `${phone.slice(0, 3)} **** ${phone.slice(-4)}`;
}

function loadRememberedPhone(): { phone: string; remember: boolean } {
  try {
    const remember = localStorage.getItem(REMEMBER_FLAG_KEY) === '1';
    const phone = remember ? localStorage.getItem(REMEMBER_PHONE_KEY) || '' : '';
    return { phone, remember };
  } catch {
    return { phone: '', remember: false };
  }
}

function formatPartnerError(e: unknown): string {
  const text = e instanceof Error ? e.message : '操作失败';
  if (text.includes('合伙人账号不存在') || text.includes('未找到合伙人账号')) {
    return '未找到合伙人账号';
  }
  if (text.includes('合伙人账号已停用')) {
    return '合伙人账号已停用';
  }
  return text;
}

function formatWechatError(e: unknown): string {
  const text = e instanceof Error ? e.message : '微信登录失败';
  if (text.includes('首次登录') || text.includes('手机验证码')) {
    return '该微信尚未绑定合伙人账号，请先使用手机验证码登录，登录后将自动关联微信';
  }
  return text;
}

export default function LoginPage() {
  const navigate = useNavigate();
  const { applySession, refresh, account } = usePartnerSession();
  const [params] = useSearchParams();
  const quick = params.get('quick') === '1';
  const savedProfile = getPartnerProfile();
  const remembered = loadRememberedPhone();
  const [phone, setPhone] = useState(remembered.phone || getLastPhone());
  const [code, setCode] = useState('');
  const [rememberAccount, setRememberAccount] = useState(remembered.remember);
  const [agreed, setAgreed] = useState(false);
  const [loading, setLoading] = useState(false);
  const [wxLoading, setWxLoading] = useState(false);
  const [msg, setMsg] = useState('');
  const [codeCooldown, setCodeCooldown] = useState(0);
  const [wxAuthorize, setWxAuthorize] = useState(false);

  useEffect(() => {
    fetchClientConfig()
      .then((config) => setWxAuthorize(isWxAuthorizeEnabled(config)))
      .catch(() => setWxAuthorize(false));
  }, []);

  const quickName = savedProfile?.name ?? '城市合伙人';
  const quickCompany = savedProfile?.companyName ?? '';
  const quickPhone = savedProfile?.phone || phone;

  function ensureAgreed() {
    if (!agreed) {
      setMsg('请先勾选并同意用户协议');
      return false;
    }
    return true;
  }

  function persistRememberAccount(nextPhone: string) {
    try {
      if (rememberAccount) {
        localStorage.setItem(REMEMBER_FLAG_KEY, '1');
        localStorage.setItem(REMEMBER_PHONE_KEY, nextPhone);
      } else {
        localStorage.removeItem(REMEMBER_FLAG_KEY);
        localStorage.removeItem(REMEMBER_PHONE_KEY);
      }
    } catch {
      /* ignore */
    }
  }

  async function sendCode() {
    if (!ensureAgreed()) return;
    setMsg('');
    try {
      await request('PARTNER_H5', '/partner/auth/sms/send', {
        method: 'POST',
        body: JSON.stringify({ phone, scene: 'PARTNER_LOGIN' }),
        silent: true,
      });
      setMsg('验证码已发送');
      setCodeCooldown(60);
      const timer = setInterval(() => {
        setCodeCooldown((s) => {
          if (s <= 1) {
            clearInterval(timer);
            return 0;
          }
          return s - 1;
        });
      }, 1000);
    } catch (e) {
      setMsg(formatPartnerError(e));
    }
  }

  async function finishLoginNavigate() {
    const me = await refresh();
    navigate(partnerHomePath(me ?? account ?? savedProfile));
  }

  async function login() {
    if (!ensureAgreed()) return;
    setLoading(true);
    setMsg('');
    try {
      const data = await request<PartnerSessionPayload>('PARTNER_H5', '/partner/auth/login/sms', {
        method: 'POST',
        body: JSON.stringify({ phone, code }),
        silent: true,
      });
      saveAuth(data);
      applySession(data);
      persistRememberAccount(phone);
      if (isWechatEnv() && wxAuthorize) {
        setMsg('登录成功，正在关联微信…');
        await bindPartnerWechatAfterSmsLogin();
        return;
      }
      await finishLoginNavigate();
    } catch (e) {
      setMsg(formatPartnerError(e));
    } finally {
      setLoading(false);
    }
  }

  async function wechatLogin() {
    if (!ensureAgreed()) return;
    setMsg('');
    if (!isWechatEnv()) {
      setMsg(WECHAT_INAPP_REQUIRED_MSG);
      return;
    }
    const canUseWechat = await canPartnerUseWechatLogin({
      profile: savedProfile,
      phone,
    });
    if (!canUseWechat) {
      setMsg(PARTNER_WECHAT_LOGIN_HINT);
      return;
    }
    setWxLoading(true);
    try {
      const session = await loginPartnerWithWechat();
      if (session) {
        applySession(session);
        await finishLoginNavigate();
      }
    } catch (e) {
      setMsg(formatWechatError(e));
    } finally {
      setWxLoading(false);
    }
  }

  if (quick) {
    const canWechatQuick =
      wxAuthorize &&
      isWechatEnv() &&
      hasPartnerWxSession() &&
      !!savedProfile &&
      savedProfile.hasWechat === true;

    return (
      <div className="partner-auth-page partner-auth-page--quick">
        <header className="partner-auth-brand">
          <div className="partner-quick-avatar" style={{ width: 120, height: 120, margin: '0 auto 16px' }}>
            <span className="material-symbols-outlined" style={{ fontSize: 48 }}>wine_bar</span>
          </div>
          <h1 className="partner-auth-title" style={{ fontSize: 20 }}>杜康好客</h1>
          <p className="partner-auth-subtitle" style={{ fontSize: 12, letterSpacing: '0.2em', textTransform: 'uppercase' }}>城市合伙人端</p>
        </header>

        <section className="partner-glass-card">
          <div className="partner-quick-badge">已识别账号</div>
          <div className="partner-quick-avatar">
            <span className="material-symbols-outlined">person</span>
          </div>
          <div style={{ textAlign: 'center' }}>
            <h2 className="headline-md">
              {quickName}
              {quickCompany ? (
                <span className="text-muted body-md" style={{ fontWeight: 400 }}> ({quickCompany})</span>
              ) : null}
            </h2>
            <p className="text-muted body-md" style={{ letterSpacing: '0.1em', marginTop: 4 }}>
              {quickPhone ? maskPhone(quickPhone) : '暂无已保存账号'}
            </p>
          </div>
        </section>

        <nav style={{ width: '100%', maxWidth: 384, marginTop: 16 }}>
          {msg && <p className="partner-auth-msg" style={{ color: 'var(--color-error, #d33)', fontSize: 13, textAlign: 'center', marginBottom: 12 }}>{msg}</p>}
          {canWechatQuick ? (
            <button
              type="button"
              className="partner-btn-primary"
              disabled={wxLoading}
              onClick={() => void wechatLogin()}
            >
              <span className="material-symbols-outlined">chat</span>
              <span>{wxLoading ? '登录中...' : '微信一键登录'}</span>
            </button>
          ) : (
            <p className="partner-auth-msg" style={{ textAlign: 'center', marginBottom: 12 }}>
              {wxAuthorize && !isWechatEnv()
                ? '请在微信内打开以使用一键登录'
                : '请使用验证码登录并绑定微信后，即可 7 天内免登录'}
            </p>
          )}
          {!canWechatQuick && (
            <Link to="/login" className="partner-btn-primary" style={{ display: 'block', textAlign: 'center', textDecoration: 'none', marginTop: 12 }}>
              验证码登录
            </Link>
          )}
          <Link to="/login" className="partner-btn-ghost" style={{ display: 'block', marginTop: 12 }}>切换账号</Link>
        </nav>

        <footer className="partner-auth-footer">
          <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
            <span className="material-symbols-outlined">verified_user</span>
            <span className="label-md" style={{ fontSize: 10, letterSpacing: '0.1em', textTransform: 'uppercase' }}>
              {canWechatQuick ? '微信验证 · 7 天内免登录' : 'Secured by Dukang Heritage'}
            </span>
          </div>
        </footer>
      </div>
    );
  }

  return (
    <div className="partner-auth-page">
      <div className="partner-auth-brand">
        <div className="partner-auth-logo-circle">
          <span className="material-symbols-outlined">wine_bar</span>
        </div>
        <h1 className="partner-auth-title">杜康好客</h1>
        <p className="partner-auth-subtitle">城市合伙人端</p>
      </div>

      <main className="partner-auth-card">
        <h2 className="partner-auth-card-title">城市合伙人登录</h2>
        <div style={{ display: 'flex', flexDirection: 'column', gap: 16 }}>
          <div className="partner-input-wrap">
            <span className="material-symbols-outlined partner-input-icon">smartphone</span>
            <input
              className="partner-input"
              type="tel"
              maxLength={11}
              placeholder="请输入手机号"
              value={phone}
              onChange={(e) => {
                setPhone(e.target.value);
                setMsg('');
              }}
            />
          </div>

          <div className="partner-input-row">
            <div className="partner-input-wrap">
              <span className="material-symbols-outlined partner-input-icon">shield</span>
              <input
                className="partner-input"
                type="text"
                maxLength={6}
                placeholder="验证码"
                value={code}
                onChange={(e) => setCode(e.target.value)}
              />
            </div>
            <button type="button" className="partner-code-btn" onClick={sendCode} disabled={codeCooldown > 0}>
              {codeCooldown > 0 ? `${codeCooldown}s` : '获取验证码'}
            </button>
          </div>

          <label className="partner-remember-row">
            <input
              type="checkbox"
              checked={rememberAccount}
              onChange={(e) => setRememberAccount(e.target.checked)}
            />
            <span>记住账号</span>
          </label>

          {msg && <p className="partner-auth-msg" style={{ color: 'var(--color-error, #d33)', fontSize: 13, textAlign: 'center' }}>{msg}</p>}

          <button type="button" className="partner-btn-primary" onClick={() => void login()} disabled={loading}>
            <span>{loading ? '登录中...' : '登录'}</span>
            {!loading && <span className="material-symbols-outlined">arrow_forward</span>}
          </button>

          {wxAuthorize && (
            <>
              <div className="partner-auth-divider"><span>其他登录方式</span></div>
              <button type="button" className="partner-btn-wechat" onClick={() => void wechatLogin()} disabled={wxLoading}>
                <svg viewBox="0 0 24 24" fill="#07C160" aria-hidden>
                  <path d="M8.25 4.5C4.52 4.5 1.5 7.04 1.5 10.17c0 1.78.98 3.37 2.5 4.48l-.63 1.88 2.19-1.09c.84.24 1.74.38 2.69.38.25 0 .5 0 .75-.03-.16-.53-.25-1.09-.25-1.66 0-3.13 3.02-5.67 6.75-5.67.57 0 1.13.06 1.66.17C15.17 6.13 12 4.5 8.25 4.5zm10.5 6.33c-3.11 0-5.62 2.12-5.62 4.73 0 2.61 2.51 4.73 5.62 4.73.79 0 1.54-.14 2.24-.38l1.83.91-.53-1.57c1.27-.92 2.08-2.25 2.08-3.73 0-2.61-2.51-4.73-5.62-4.73z" />
                </svg>
                <span>{wxLoading ? '登录中...' : '微信一键登录'}</span>
              </button>
            </>
          )}

          <label className="partner-checkbox-row">
            <input type="checkbox" checked={agreed} onChange={(e) => setAgreed(e.target.checked)} />
            <span>
              我已阅读并同意{' '}
              <Link to="/legal/user-agreement" className="text-primary" style={{ fontWeight: 600 }} onClick={(e) => e.stopPropagation()}>
                《用户协议》
              </Link>{' '}
              与{' '}
              <Link to="/legal/privacy-policy" className="text-primary" style={{ fontWeight: 600 }} onClick={(e) => e.stopPropagation()}>
                《隐私政策》
              </Link>
            </span>
          </label>
        </div>
      </main>

      {hasPartnerWxSession() && savedProfile?.hasWechat && (
        <Link to="/login?quick=1" className="partner-link">微信快捷登录</Link>
      )}

      <footer className="partner-auth-footer">
        <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
          <span className="material-symbols-outlined">verified_user</span>
          <span className="label-md" style={{ fontSize: 10, letterSpacing: '0.15em', textTransform: 'uppercase' }}>SECURED BY DUKANG HERITAGE</span>
        </div>
      </footer>
    </div>
  );
}