import { encryptPassword } from '../utils/cryptots';
import React, { useState, useEffect } from 'react';
import { useNavigate, Link } from 'react-router-dom';
import { authService, RegisterRequest } from '../services/authService';
import { userApi } from '../services/userApi';
import { Mail, Lock, User, Phone, GraduationCap, AlertCircle, CheckCircle2 } from 'lucide-react';
import { Loader2 } from '../icons/commonIcons';
import PasswordStrengthIndicator from '../components/PasswordStrengthIndicator';
import { BrandingContext } from '../App';

const Register: React.FC = () => {
  const navigate = useNavigate();
  const branding = React.useContext(BrandingContext);
  const [formData, setFormData] = useState<RegisterRequest>({
    username: '',
    password: '',
    email: '',
    phone: '',
    nickname: '',
  });

  // 手机验证码
  const [smsCode, setSmsCode] = useState('');
  const [smsSending, setSmsSending] = useState(false);
  const [smsCountdown, setSmsCountdown] = useState(0);

  // 邮箱验证码
  const [emailCode, setEmailCode] = useState('');
  const [emailSending, setEmailSending] = useState(false);
  const [emailCountdown, setEmailCountdown] = useState(0);
  const [emailVerified, setEmailVerified] = useState(false);

  const [confirmPassword, setConfirmPassword] = useState('');
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [success, setSuccess] = useState(false);
  const [autoLoginLoading, setAutoLoginLoading] = useState(false);
  const [passwordMeetsRequirements, setPasswordMeetsRequirements] = useState(false);

  useEffect(() => {
    if (smsCountdown <= 0) return;
    const timer = setTimeout(() => setSmsCountdown(c => c - 1), 1000);
    return () => clearTimeout(timer);
  }, [smsCountdown]);

  useEffect(() => {
    if (emailCountdown <= 0) return;
    const timer = setTimeout(() => setEmailCountdown(c => c - 1), 1000);
    return () => clearTimeout(timer);
  }, [emailCountdown]);

  // 邮箱变化时重置验证状态
  useEffect(() => {
    setEmailVerified(false);
    setEmailCode('');
  }, [formData.email]);

  const handleInputChange = (field: keyof RegisterRequest, value: string) => {
    setFormData(prev => ({ ...prev, [field]: value }));
    setError(null);
  };

  const handleSendSms = async () => {
    if (!formData.phone || formData.phone.length !== 11) {
      setError('请先填写正确的手机号');
      return;
    }
    setSmsSending(true); setError(null);
    try {
      await userApi.sendSmsCode(formData.phone, 'register');
      setSmsCountdown(60);
    } catch (e: any) {
      setError(e.message || '发送失败');
    } finally { setSmsSending(false); }
  };

  const handleSendEmailCode = async () => {
    if (!formData.email) { setError('请先填写邮箱'); return; }
    const emailRe = /^[^@\s]+@[^@\s]+\.[^@\s]+$/;
    if (!emailRe.test(formData.email)) { setError('邮箱格式不正确'); return; }
    setEmailSending(true); setError(null);
    try {
      await userApi.sendEmailCode(formData.email, 'register');
      setEmailCountdown(60);
    } catch (e: any) {
      setError(e.message || '发送失败');
    } finally { setEmailSending(false); }
  };

  const validateForm = (): boolean => {
    if (!formData.username.trim()) { setError('请输入用户名'); return false; }
    if (formData.username.length < 3) { setError('用户名至少需要3个字符'); return false; }
    if (!formData.password) { setError('请输入密码'); return false; }
    if (formData.password.length < 6) { setError('密码至少需要6个字符'); return false; }
    if (!passwordMeetsRequirements) { setError('密码强度太弱，请至少包含字母和数字两种字符'); return false; }
    if (formData.password !== confirmPassword) { setError('两次输入的密码不一致'); return false; }
    if (!formData.phone) { setError('请输入手机号'); return false; }
    if (formData.phone.length !== 11) { setError('请输入正确的11位手机号'); return false; }
    if (!smsCode) { setError('请输入手机验证码'); return false; }
    // 填了邮箱必须验证
    if (formData.email) {
      if (!emailCode) { setError('请输入邮箱验证码'); return false; }
    }
    return true;
  };

  const handleRegister = async (e: React.FormEvent) => {
    e.preventDefault();
    setError(null);
    if (!validateForm()) return;
    setLoading(true);
    try {
      const encryptedPassword = encryptPassword(formData.password);
      const registerData: RegisterRequest = {
        username: formData.username,
        password: encryptedPassword,
        nickname: formData.nickname || formData.username,
        phone: formData.phone,
        sms_code: smsCode,
        ...(formData.email ? { email: formData.email, email_code: emailCode } : {}),
      };
      const response = await authService.register(registerData);
      if (response.code === 200) {
        setSuccess(true);
      } else {
        setError(response.message || '注册失败，请稍后重试');
      }
    } catch (err) {
      setError(err instanceof Error ? err.message : '注册失败，请稍后重试');
    } finally { setLoading(false); }
  };

  const handleAutoLogin = async () => {
    setAutoLoginLoading(true);
    try {
      const encryptedPassword = encryptPassword(formData.password);
      const loginResponse = await authService.login(formData.username, encryptedPassword);
      if (loginResponse.code === 200) { navigate('/'); } else { navigate('/login'); }
    } catch { navigate('/login'); }
    finally { setAutoLoginLoading(false); }
  };

  if (success) {
    return (
      <div className="min-h-screen flex items-center justify-center bg-gradient-to-br from-blue-50 via-white to-indigo-50 px-4">
        <div className="w-full max-w-md">
          <div className="bg-white rounded-2xl shadow-2xl border border-gray-100 p-8 text-center">
            <CheckCircle2 className="w-16 h-16 text-green-500 mx-auto mb-6" />
            <h1 className="text-2xl font-bold text-gray-900 mb-2">注册成功！</h1>
            <p className="text-sm text-gray-500 mb-6">您的账号已创建成功</p>
            <button onClick={handleAutoLogin} disabled={autoLoginLoading}
              className="inline-block px-6 py-2 bg-blue-600 text-white rounded-lg font-bold hover:bg-blue-700 transition-colors disabled:opacity-50">
              {autoLoginLoading ? <span className="flex items-center gap-2"><Loader2 className="w-4 h-4 animate-spin" />登录中...</span> : '立即登录'}
            </button>
          </div>
        </div>
      </div>
    );
  }

  const showEmailCodeInput = !!formData.email && /^[^@\s]+@[^@\s]+\.[^@\s]+$/.test(formData.email);

  return (
    <div className="min-h-screen flex items-center justify-center bg-gradient-to-br from-blue-50 via-white to-indigo-50 px-4 py-8">
      <div className="w-full max-w-md">
        <div className="bg-white rounded-2xl shadow-2xl border border-gray-100 p-8">
          <div className="text-center mb-8">
            <div className="inline-flex items-center justify-center w-16 h-16 bg-gradient-to-r from-blue-600 to-indigo-600 rounded-2xl mb-4 overflow-hidden">
              {branding.system_logo
                ? <img src={branding.system_logo} alt="logo" className="w-full h-full object-contain" />
                : <GraduationCap className="w-8 h-8 text-white" />}
            </div>
            <h1 className="text-2xl font-bold text-gray-900 mb-2">注册{branding.system_name}</h1>
            <p className="text-sm text-gray-500">创建您的账号</p>
          </div>

          {error && (
            <div className="mb-4 p-3 bg-red-50 border border-red-200 rounded-lg flex items-center gap-2">
              <AlertCircle className="w-4 h-4 text-red-500 flex-shrink-0" />
              <p className="text-sm text-red-600">{error}</p>
            </div>
          )}

          <form onSubmit={handleRegister} className="space-y-4">
            {/* 用户名 */}
            <div>
              <label className="block text-sm font-bold text-gray-700 mb-2">用户名 <span className="text-red-500">*</span></label>
              <div className="relative">
                <User className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-gray-400" />
                <input type="text" value={formData.username} onChange={e => handleInputChange('username', e.target.value)}
                  placeholder="请输入用户名（至少3个字符）"
                  className="w-full pl-10 pr-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" required />
              </div>
            </div>

            {/* 手机号（必填） */}
            <div>
              <label className="block text-sm font-bold text-gray-700 mb-2">手机号 <span className="text-red-500">*</span></label>
              <div className="relative">
                <Phone className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-gray-400" />
                <input type="tel" value={formData.phone} onChange={e => handleInputChange('phone', e.target.value)}
                  placeholder="请输入手机号" maxLength={11}
                  className="w-full pl-10 pr-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" required />
              </div>
            </div>

            {/* 手机验证码 */}
            <div>
              <label className="block text-sm font-bold text-gray-700 mb-2">手机验证码 <span className="text-red-500">*</span></label>
              <div className="flex gap-2">
                <input type="text" value={smsCode} onChange={e => setSmsCode(e.target.value)}
                  placeholder="请输入验证码" maxLength={6}
                  className="flex-1 px-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" required />
                <button type="button" onClick={handleSendSms} disabled={smsSending || smsCountdown > 0}
                  className="px-4 py-3 bg-blue-600 text-white rounded-xl text-sm font-bold hover:bg-blue-700 disabled:opacity-50 whitespace-nowrap">
                  {smsSending ? '发送中...' : smsCountdown > 0 ? `${smsCountdown}s` : '获取验证码'}
                </button>
              </div>
            </div>

            {/* 邮箱（可选） */}
            <div>
              <label className="block text-sm font-bold text-gray-700 mb-2">
                邮箱 <span className="text-gray-400 font-normal text-xs">（可选）</span>
              </label>
              <div className="relative">
                <Mail className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-gray-400" />
                <input type="email" value={formData.email} onChange={e => handleInputChange('email', e.target.value)}
                  placeholder="请输入邮箱（可选）"
                  className="w-full pl-10 pr-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" />
              </div>
              <p className="mt-1.5 text-xs text-gray-400 flex items-center gap-1">
                <Mail className="w-3 h-3 flex-shrink-0" />
                绑定邮箱后可通过邮箱验证码找回密码
              </p>
            </div>

            {/* 邮箱验证码（仅当邮箱格式正确时显示） */}
            {showEmailCodeInput && (
              <div>
                <label className="block text-sm font-bold text-gray-700 mb-2">
                  邮箱验证码 <span className="text-red-500">*</span>
                </label>
                <div className="flex gap-2">
                  <input type="text" value={emailCode} onChange={e => { setEmailCode(e.target.value); setEmailVerified(false); }}
                    placeholder="请输入邮箱验证码" maxLength={6}
                    className="flex-1 px-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" />
                  <button type="button" onClick={handleSendEmailCode} disabled={emailSending || emailCountdown > 0}
                    className="px-4 py-3 bg-blue-600 text-white rounded-xl text-sm font-bold hover:bg-blue-700 disabled:opacity-50 whitespace-nowrap">
                    {emailSending ? '发送中...' : emailCountdown > 0 ? `${emailCountdown}s` : '获取验证码'}
                  </button>
                </div>
                <p className="mt-1 text-xs text-gray-400">验证码已发送至 {formData.email}</p>
              </div>
            )}

            {/* 昵称 */}
            <div>
              <label className="block text-sm font-bold text-gray-700 mb-2">昵称 <span className="text-gray-400 font-normal text-xs">（可选）</span></label>
              <div className="relative">
                <User className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-gray-400" />
                <input type="text" value={formData.nickname} onChange={e => handleInputChange('nickname', e.target.value)}
                  placeholder="请输入昵称（默认为用户名）"
                  className="w-full pl-10 pr-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" />
              </div>
            </div>

            {/* 密码 */}
            <div>
              <label className="block text-sm font-bold text-gray-700 mb-2">密码 <span className="text-red-500">*</span></label>
              <div className="relative">
                <Lock className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-gray-400" />
                <input type="password" value={formData.password} onChange={e => handleInputChange('password', e.target.value)}
                  placeholder="请输入密码（至少6个字符）"
                  className="w-full pl-10 pr-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" required />
              </div>
              {formData.password && (
                <div className="mt-2">
                  <PasswordStrengthIndicator password={formData.password} onStrengthChange={setPasswordMeetsRequirements} />
                </div>
              )}
            </div>

            {/* 确认密码 */}
            <div>
              <label className="block text-sm font-bold text-gray-700 mb-2">确认密码 <span className="text-red-500">*</span></label>
              <div className="relative">
                <Lock className="absolute left-3 top-1/2 -translate-y-1/2 w-5 h-5 text-gray-400" />
                <input type="password" value={confirmPassword} onChange={e => { setConfirmPassword(e.target.value); setError(null); }}
                  placeholder="请再次输入密码"
                  className="w-full pl-10 pr-4 py-3 bg-gray-50 border border-gray-200 rounded-xl text-sm outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500 transition-all" required />
              </div>
            </div>

            <div className="flex items-start gap-2 text-sm">
              <input type="checkbox" className="w-4 h-4 text-blue-600 border-gray-300 rounded focus:ring-blue-500 mt-0.5" required />
              <label className="text-gray-600">
                我已阅读并同意{' '}
                <a href="#/user-agreement" target="_blank" rel="noopener noreferrer" className="text-blue-600 hover:text-blue-700 font-medium">用户协议</a>
                {' '}和{' '}
                <a href="#/privacy-policy" target="_blank" rel="noopener noreferrer" className="text-blue-600 hover:text-blue-700 font-medium">隐私政策</a>
              </label>
            </div>

            <button type="submit" disabled={loading}
              className="w-full py-3 bg-gradient-to-r from-blue-600 to-indigo-600 text-white rounded-xl font-bold shadow-lg hover:shadow-xl hover:from-blue-700 hover:to-indigo-700 transition-all disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2">
              {loading ? <><Loader2 className="w-5 h-5 animate-spin" /><span>注册中...</span></> : <span>立即注册</span>}
            </button>
          </form>

          <div className="mt-6 text-center">
            <p className="text-sm text-gray-600">
              已有账号？{' '}
              <Link to="/login" className="text-blue-600 hover:text-blue-700 font-bold">立即登录</Link>
            </p>
          </div>
        </div>
      </div>
    </div>
  );
};

export default Register;