import React, { useState } from 'react';
import { useAuth } from '../contexts/AuthContext';
import { useLanguage } from '../contexts/LanguageContext';
import { t } from '../i18n/translations';
import HeaderBar from './landing/HeaderBar';

export function LoginPage() {
  const { language } = useLanguage();
  const { login, verifyOTP } = useAuth();
  const [step, setStep] = useState<'login' | 'otp'>('login');
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const [otpCode, setOtpCode] = useState('');
  const [userID, setUserID] = useState('');
  const [error, setError] = useState('');
  const [loading, setLoading] = useState(false);

  const handleLogin = async (e: React.FormEvent) => {
    e.preventDefault();
    setError('');
    setLoading(true);

    const result = await login(email, password);
    
    if (result.success) {
      if (result.requiresOTP && result.userID) {
        setUserID(result.userID);
        setStep('otp');
      }
    } else {
      setError(result.message || t('loginFailed', language));
    }
    
    setLoading(false);
  };

  const handleOTPVerify = async (e: React.FormEvent) => {
    e.preventDefault();
    setError('');
    setLoading(true);

    const result = await verifyOTP(userID, otpCode);
    
    if (!result.success) {
      setError(result.message || t('verificationFailed', language));
    }
    // 成功的话AuthContext会自动处理登录状态
    
    setLoading(false);
  };

  return (
    <div className="min-h-screen" style={{ background: 'var(--brand-black)' }}>
      <HeaderBar 
        onLoginClick={() => {}} 
        isLoggedIn={false} 
        isHomePage={false}
        currentPage="login"
        language={language}
        onLanguageChange={() => {}}
        onPageChange={(page) => {
          console.log('LoginPage onPageChange called with:', page);
          if (page === 'competition') {
            window.location.href = '/competition';
          }
        }}
      />

      <div className="flex items-center justify-center pt-20" style={{ minHeight: 'calc(100vh - 80px)' }}>
        <div className="w-full max-w-md">

          {/* Logo */}
          <div className="text-center mb-8">
            <div className="w-16 h-16 mx-auto mb-4 flex items-center justify-center">
              <img src="/icons/nofx.svg" alt="NoFx Logo" className="w-16 h-16 object-contain" />
            </div>
            <h1 className="text-2xl font-bold" style={{ color: 'var(--brand-light-gray)' }}>
              登录 NOFX
            </h1>
            <p className="text-sm mt-2" style={{ color: 'var(--text-secondary)' }}>
              {step === 'login' ? '请输入您的邮箱和密码' : '请输入两步验证码'}
            </p>
          </div>

        {/* Login Form */}
        <div className="rounded-lg p-6" style={{ background: 'var(--panel-bg)', border: '1px solid var(--panel-border)' }}>
          {step === 'login' ? (
            <form onSubmit={handleLogin} className="space-y-4">
              <div>
                <label className="block text-sm font-semibold mb-2" style={{ color: 'var(--brand-light-gray)' }}>
                  {t('email', language)}
                </label>
                <input
                  type="email"
                  value={email}
                  onChange={(e) => setEmail(e.target.value)}
                  className="w-full px-3 py-2 rounded"
                  style={{ background: 'var(--brand-black)', border: '1px solid var(--panel-border)', color: 'var(--brand-light-gray)' }}
                  placeholder={t('emailPlaceholder', language)}
                  required
                />
              </div>

              <div>
                <label className="block text-sm font-semibold mb-2" style={{ color: 'var(--brand-light-gray)' }}>
                  {t('password', language)}
                </label>
                <input
                  type="password"
                  value={password}
                  onChange={(e) => setPassword(e.target.value)}
                  className="w-full px-3 py-2 rounded"
                  style={{ background: 'var(--brand-black)', border: '1px solid var(--panel-border)', color: 'var(--brand-light-gray)' }}
                  placeholder={t('passwordPlaceholder', language)}
                  required
                />
              </div>

              {error && (
                <div className="text-sm px-3 py-2 rounded" style={{ background: 'var(--binance-red-bg)', color: 'var(--binance-red)' }}>
                  {error}
                </div>
              )}

              <button
                type="submit"
                disabled={loading}
                className="w-full px-4 py-2 rounded text-sm font-semibold transition-all hover:scale-105 disabled:opacity-50"
                style={{ background: 'var(--brand-yellow)', color: 'var(--brand-black)' }}
              >
                {loading ? t('loading', language) : t('loginButton', language)}
              </button>
            </form>
          ) : (
            <form onSubmit={handleOTPVerify} className="space-y-4">
              <div className="text-center mb-4">
                <div className="text-4xl mb-2">📱</div>
                <p className="text-sm" style={{ color: '#848E9C' }}>
                  {t('scanQRCodeInstructions', language)}<br />
                  {t('enterOTPCode', language)}
                </p>
              </div>

              <div>
                <label className="block text-sm font-semibold mb-2" style={{ color: 'var(--brand-light-gray)' }}>
                  {t('otpCode', language)}
                </label>
                <input
                  type="text"
                  value={otpCode}
                  onChange={(e) => setOtpCode(e.target.value.replace(/\D/g, '').slice(0, 6))}
                  className="w-full px-3 py-2 rounded text-center text-2xl font-mono"
                  style={{ background: 'var(--brand-black)', border: '1px solid var(--panel-border)', color: 'var(--brand-light-gray)' }}
                  placeholder={t('otpPlaceholder', language)}
                  maxLength={6}
                  required
                />
              </div>

              {error && (
                <div className="text-sm px-3 py-2 rounded" style={{ background: 'var(--binance-red-bg)', color: 'var(--binance-red)' }}>
                  {error}
                </div>
              )}

              <div className="flex gap-3">
                <button
                  type="button"
                  onClick={() => setStep('login')}
                  className="flex-1 px-4 py-2 rounded text-sm font-semibold"
                  style={{ background: 'var(--panel-bg-hover)', color: 'var(--text-secondary)' }}
                >
                  {t('back', language)}
                </button>
                <button
                  type="submit"
                  disabled={loading || otpCode.length !== 6}
                  className="flex-1 px-4 py-2 rounded text-sm font-semibold transition-all hover:scale-105 disabled:opacity-50"
                  style={{ background: '#F0B90B', color: '#000' }}
                >
                  {loading ? t('loading', language) : t('verifyOTP', language)}
                </button>
              </div>
            </form>
          )}
        </div>

        {/* Register Link */}
        <div className="text-center mt-6">
          <p className="text-sm" style={{ color: 'var(--text-secondary)' }}>
            还没有账户？{' '}
            <button
              onClick={() => {
                window.history.pushState({}, '', '/register');
                window.dispatchEvent(new PopStateEvent('popstate'));
              }}
              className="font-semibold hover:underline transition-colors"
              style={{ color: 'var(--brand-yellow)' }}
            >
              立即注册
            </button>
          </p>
        </div>
      </div>
      </div>
    </div>
  );
}
