'use client';

import { useState } from 'react';
import { motion, AnimatePresence } from 'framer-motion';
import toast, { Toaster } from 'react-hot-toast';
import Link from 'next/link';
import { useRouter } from 'next/navigation';
import {
  Mail,
  Lock,
  Eye,
  EyeOff,
  ArrowLeft,
  LogIn,
  CheckCircle,
  Loader2,
  Home,
  Shield,
  Phone,
  KeyRound,
} from 'lucide-react';
import {
  loginWithEmail,
  loginWithPhone,
  sendEmailOTP,
  sendPhoneOTP,
  verifyEmail,
  verifyPhone,
  isEmail,
  isPhoneNumber,
} from '../utils/api';
import AuthService from '../services/AuthService';

export default function LoginPage() {
  const router = useRouter();

  // Step: 'login' | 'otp'
  const [step, setStep] = useState('login');
  const [loginMethod, setLoginMethod] = useState('email'); // 'email' | 'phone'
  const [showPassword, setShowPassword] = useState(false);
  const [isLoading, setIsLoading] = useState(false);
  const [isSuccess, setIsSuccess] = useState(false);

  const [formData, setFormData] = useState({
    credential: '',
    password: '',
    rememberMe: false,
  });

  const [otpCode, setOtpCode] = useState('');
  const [otpError, setOtpError] = useState('');
  const [errors, setErrors] = useState({});

  const validateForm = () => {
    const newErrors = {};

    if (!formData.credential) {
      newErrors.credential = loginMethod === 'email'
        ? 'البريد الإلكتروني مطلوب'
        : 'رقم الهاتف مطلوب';
    } else if (loginMethod === 'email' && !isEmail(formData.credential)) {
      newErrors.credential = 'البريد الإلكتروني غير صالح';
    } else if (loginMethod === 'phone' && !isPhoneNumber(formData.credential)) {
      newErrors.credential = 'رقم الهاتف غير صالح';
    }

    if (!formData.password) {
      newErrors.password = 'كلمة المرور مطلوبة';
    }

    setErrors(newErrors);
    return Object.keys(newErrors).length === 0;
  };

  const handleLogin = async (e) => {
    e.preventDefault();
    if (!validateForm()) return;

    setIsLoading(true);
    setErrors({});

    try {
      const loginFn = loginMethod === 'email' ? loginWithEmail : loginWithPhone;
      console.log('[Login] Attempting login via', loginMethod, ':', formData.credential);

      const result = await loginFn(formData.credential, formData.password);

      console.log('[Login] Response:', result);

      if (result.status === 200) {
        // Login success — store token via AuthService
        const token = typeof result.data === 'string' ? result.data : result.data?.token || result.data;
        AuthService.addToken(token);
        console.log('[Login] Token stored via AuthService');

        // Decode token to get user info (basic JWT decode)
        try {
          const payload = JSON.parse(atob(token.split('.')[1]));
          const user = {
            name: payload.name || payload.unique_name || formData.credential,
            email: payload.email || (loginMethod === 'email' ? formData.credential : ''),
            phone: payload.phone || (loginMethod === 'phone' ? formData.credential : ''),
            role: payload.role || payload.Role || 'customer',
          };
          localStorage.setItem('user', JSON.stringify(user));
          console.log('[Login] User stored:', user);
        } catch (decodeErr) {
          console.warn('[Login] Could not decode JWT, storing credential as user');
          localStorage.setItem('user', JSON.stringify({
            name: formData.credential,
            role: 'customer',
          }));
        }

        setIsSuccess(true);
        toast.success('تم تسجيل الدخول بنجاح!', {
          style: { background: '#dcfce7', color: '#166534' },
        });

        setTimeout(() => {
          const user = JSON.parse(localStorage.getItem('user') || '{}');
          console.log('[Login] Redirecting user:', user);
          if (user.role === 'admin') {
            router.push('/admin');
          } else {
            router.push('/');
          }
        }, 1500);

      } else if (result.status === 206) {
        // Needs OTP verification
        console.log('[Login] 206 — OTP required, sending OTP...');
        toast('يرجى إدخال رمز التحقق', {
          icon: '🔐',
          style: { background: '#fef3c7', color: '#92400e' },
        });

        // Send OTP
        try {
          if (loginMethod === 'email') {
            await sendEmailOTP();
          } else {
            await sendPhoneOTP();
          }
          console.log('[Login] OTP sent successfully');
        } catch (otpErr) {
          console.warn('[Login] OTP send failed, proceeding anyway:', otpErr);
        }

        setStep('otp');
      } else {
        // Other error
        console.error('[Login] Unexpected status:', result.status, result.data);
        toast.error(result.data?.message || result.data || 'بيانات الدخول غير صحيحة', {
          style: { background: '#fee2e2', color: '#991b1b' },
        });
      }
    } catch (err) {
      console.error('[Login] Error:', err);
      toast.error(err.message || 'حدث خطأ في الاتصال', {
        style: { background: '#fee2e2', color: '#991b1b' },
      });
    } finally {
      setIsLoading(false);
    }
  };

  const handleVerifyOTP = async (e) => {
    e.preventDefault();
    if (!otpCode || otpCode.length < 4) {
      setOtpError('يرجى إدخال رمز التحقق');
      return;
    }

    setIsLoading(true);
    setOtpError('');

    try {
      const verifyFn = loginMethod === 'email' ? verifyEmail : verifyPhone;
      console.log('[OTP] Verifying code:', otpCode);

      const result = await verifyFn(otpCode);
      console.log('[OTP] Verify response:', result);

      if (result.ok) {
        // Verified — store token if returned via AuthService
        const token = typeof result.data === 'string' ? result.data : result.data?.token || result.data;
        if (token && typeof token === 'string' && token.includes('.')) {
          AuthService.addToken(token);
          console.log('[OTP] Token stored via AuthService');
        }

        localStorage.setItem('user', JSON.stringify({
          name: formData.credential,
          role: 'customer',
        }));

        setIsSuccess(true);
        toast.success('تم التحقق بنجاح!', {
          style: { background: '#dcfce7', color: '#166534' },
        });

        setTimeout(() => {
          console.log('[OTP] Redirecting to home');
          router.push('/');
        }, 1500);
      } else {
        console.error('[OTP] Verification failed:', result.data);
        setOtpError(result.data?.message || 'رمز التحقق غير صحيح');
      }
    } catch (err) {
      console.error('[OTP] Error:', err);
      setOtpError(err.message || 'حدث خطأ في التحقق');
    } finally {
      setIsLoading(false);
    }
  };

  const resendOTP = async () => {
    try {
      console.log('[OTP] Resending OTP via', loginMethod);
      if (loginMethod === 'email') {
        await sendEmailOTP();
      } else {
        await sendPhoneOTP();
      }
      toast.success('تم إرسال رمز التحقق مجدداً', {
        style: { background: '#dcfce7', color: '#166534' },
      });
    } catch (err) {
      console.error('[OTP] Resend failed:', err);
      toast.error('فشل إرسال الرمز');
    }
  };

  // Auto-detect login method from input
  const handleCredentialChange = (value) => {
    setFormData({ ...formData, credential: value });
    if (errors.credential) setErrors({ ...errors, credential: null });

    // Auto-switch method
    if (isEmail(value)) {
      setLoginMethod('email');
    } else if (isPhoneNumber(value)) {
      setLoginMethod('phone');
    }
  };

  const particles = Array.from({ length: 20 }, (_, i) => ({
    id: i,
    x: Math.random() * 100,
    y: Math.random() * 100,
    size: Math.random() * 3 + 1,
    duration: Math.random() * 15 + 10,
    delay: Math.random() * 5,
  }));

  const containerVariants = {
    hidden: { opacity: 0 },
    visible: {
      opacity: 1,
      transition: { staggerChildren: 0.1, delayChildren: 0.2 },
    },
  };

  const itemVariants = {
    hidden: { y: 20, opacity: 0 },
    visible: {
      y: 0,
      opacity: 1,
      transition: { type: 'spring', stiffness: 100 },
    },
  };

  return (
    <div className="min-h-screen bg-gradient-to-br from-gray-950 via-gray-900 to-gray-950 flex items-center justify-center p-4 relative overflow-hidden">
      <Toaster position="top-center" reverseOrder={false} />

      {/* Particles */}
      <div className="absolute inset-0 overflow-hidden">
        {particles.map((p) => (
          <motion.div
            key={p.id}
            className="absolute rounded-full bg-amber-500/20"
            style={{ left: `${p.x}%`, top: `${p.y}%`, width: p.size, height: p.size }}
            animate={{ y: [0, -20, 0], x: [0, 10, -10, 0], opacity: [0.2, 0.4, 0.2] }}
            transition={{ duration: p.duration, repeat: Infinity, delay: p.delay, ease: 'linear' }}
          />
        ))}
      </div>

      {/* Glow orbs */}
      <motion.div
        className="absolute top-20 left-20 w-64 h-64 bg-amber-500/10 rounded-full blur-3xl"
        animate={{ scale: [1, 1.2, 1], x: [0, 30, 0], y: [0, -20, 0] }}
        transition={{ duration: 12, repeat: Infinity }}
      />
      <motion.div
        className="absolute bottom-20 right-20 w-80 h-80 bg-blue-500/10 rounded-full blur-3xl"
        animate={{ scale: [1, 1.3, 1], x: [0, -30, 0], y: [0, 20, 0] }}
        transition={{ duration: 15, repeat: Infinity }}
      />

      <motion.div
        variants={containerVariants}
        initial="hidden"
        animate="visible"
        className="relative w-full max-w-md z-10"
      >
        {/* Back link */}
        <motion.div variants={itemVariants} className="absolute -top-16 left-0">
          <Link href="/" className="group flex items-center gap-2 text-gray-400 hover:text-white transition-colors">
            <motion.div whileHover={{ x: -5 }} transition={{ type: 'spring', stiffness: 400 }}>
              <ArrowLeft className="w-4 h-4" />
            </motion.div>
            <span>العودة للرئيسية</span>
          </Link>
        </motion.div>

        <motion.div
          variants={itemVariants}
          className="bg-white/10 backdrop-blur-2xl rounded-3xl shadow-2xl border border-white/10 overflow-hidden"
        >
          {/* Header */}
          <div className="bg-gradient-to-r from-amber-500 to-amber-600 p-8 text-center relative overflow-hidden">
            <motion.div
              initial={{ scale: 0 }}
              animate={{ scale: 1 }}
              transition={{ delay: 0.2, type: 'spring' }}
              className="absolute -top-10 -right-10 w-40 h-40 bg-white/10 rounded-full"
            />
            <motion.div
              initial={{ scale: 0 }}
              animate={{ scale: 1 }}
              transition={{ delay: 0.3, type: 'spring' }}
              className="absolute -bottom-10 -left-10 w-40 h-40 bg-white/10 rounded-full"
            />

            <motion.div initial={{ y: 20, opacity: 0 }} animate={{ y: 0, opacity: 1 }} transition={{ delay: 0.2 }} className="relative z-10">
              <motion.div
                animate={{ rotate: [0, 10, -10, 0] }}
                transition={{ duration: 2, repeat: Infinity }}
                className="w-20 h-20 mx-auto mb-4 bg-white/20 rounded-2xl flex items-center justify-center backdrop-blur-sm"
              >
                {step === 'otp' ? (
                  <KeyRound className="w-10 h-10 text-white" />
                ) : (
                  <Home className="w-10 h-10 text-white" />
                )}
              </motion.div>
              <h1 className="text-3xl font-bold text-white mb-2">SweetHome</h1>
              <p className="text-amber-100">
                {step === 'otp' ? 'أدخل رمز التحقق' : 'مرحباً بعودتك!'}
              </p>
            </motion.div>
          </div>

          <div className="p-8">
            <AnimatePresence mode="wait">
              {step === 'login' ? (
                <motion.form
                  key="login"
                  initial={{ opacity: 0, x: -20 }}
                  animate={{ opacity: 1, x: 0 }}
                  exit={{ opacity: 0, x: 20 }}
                  onSubmit={handleLogin}
                  className="space-y-6"
                >
                  {/* Login method tabs */}
                  <div className="flex gap-2 bg-white/5 p-1 rounded-xl">
                    <button
                      type="button"
                      onClick={() => {
                        setLoginMethod('email');
                        setFormData({ ...formData, credential: '' });
                      }}
                      className={`flex-1 py-2.5 rounded-lg text-sm font-medium transition-all flex items-center justify-center gap-2 ${
                        loginMethod === 'email'
                          ? 'bg-amber-500 text-white shadow-lg'
                          : 'text-gray-400 hover:text-white'
                      }`}
                    >
                      <Mail className="w-4 h-4" />
                      بريد إلكتروني
                    </button>
                    <button
                      type="button"
                      onClick={() => {
                        setLoginMethod('phone');
                        setFormData({ ...formData, credential: '' });
                      }}
                      className={`flex-1 py-2.5 rounded-lg text-sm font-medium transition-all flex items-center justify-center gap-2 ${
                        loginMethod === 'phone'
                          ? 'bg-amber-500 text-white shadow-lg'
                          : 'text-gray-400 hover:text-white'
                      }`}
                    >
                      <Phone className="w-4 h-4" />
                      رقم الهاتف
                    </button>
                  </div>

                  {/* Credential input */}
                  <div>
                    <label className="block text-sm font-medium text-gray-300 mb-2">
                      {loginMethod === 'email' ? 'البريد الإلكتروني' : 'رقم الهاتف'}
                    </label>
                    <div className="relative group">
                      <div className="absolute inset-y-0 right-0 pr-3 flex items-center pointer-events-none">
                        {loginMethod === 'email' ? (
                          <Mail className={`w-5 h-5 transition-colors ${errors.credential ? 'text-red-500' : 'text-gray-400 group-focus-within:text-amber-500'}`} />
                        ) : (
                          <Phone className={`w-5 h-5 transition-colors ${errors.credential ? 'text-red-500' : 'text-gray-400 group-focus-within:text-amber-500'}`} />
                        )}
                      </div>
                      <input
                        type={loginMethod === 'email' ? 'email' : 'tel'}
                        value={formData.credential}
                        onChange={(e) => handleCredentialChange(e.target.value)}
                        className={`w-full pr-12 pl-4 py-4 bg-white/5 border rounded-xl focus:outline-none focus:ring-2 focus:ring-amber-500 focus:border-transparent text-white placeholder-gray-500 transition-all ${
                          errors.credential ? 'border-red-500' : 'border-gray-700'
                        }`}
                        placeholder={loginMethod === 'email' ? 'example@email.com' : '+963XXXXXXXXX'}
                        dir="ltr"
                      />
                    </div>
                    {errors.credential && (
                      <motion.p initial={{ opacity: 0, y: -10 }} animate={{ opacity: 1, y: 0 }} className="text-red-500 text-sm mt-1">
                        {errors.credential}
                      </motion.p>
                    )}
                  </div>

                  {/* Password */}
                  <div>
                    <label className="block text-sm font-medium text-gray-300 mb-2">كلمة المرور</label>
                    <div className="relative group">
                      <div className="absolute inset-y-0 right-0 pr-3 flex items-center pointer-events-none">
                        <Lock className={`w-5 h-5 transition-colors ${errors.password ? 'text-red-500' : 'text-gray-400 group-focus-within:text-amber-500'}`} />
                      </div>
                      <input
                        type={showPassword ? 'text' : 'password'}
                        value={formData.password}
                        onChange={(e) => {
                          setFormData({ ...formData, password: e.target.value });
                          if (errors.password) setErrors({ ...errors, password: null });
                        }}
                        className={`w-full pr-12 pl-12 py-4 bg-white/5 border rounded-xl focus:outline-none focus:ring-2 focus:ring-amber-500 focus:border-transparent text-white placeholder-gray-500 transition-all ${
                          errors.password ? 'border-red-500' : 'border-gray-700'
                        }`}
                        placeholder="أدخل كلمة المرور"
                      />
                      <button type="button" onClick={() => setShowPassword(!showPassword)} className="absolute inset-y-0 left-0 pl-3 flex items-center">
                        {showPassword ? (
                          <EyeOff className="w-5 h-5 text-gray-400 hover:text-gray-300 transition-colors" />
                        ) : (
                          <Eye className="w-5 h-5 text-gray-400 hover:text-gray-300 transition-colors" />
                        )}
                      </button>
                    </div>
                    {errors.password && (
                      <motion.p initial={{ opacity: 0, y: -10 }} animate={{ opacity: 1, y: 0 }} className="text-red-500 text-sm mt-1">
                        {errors.password}
                      </motion.p>
                    )}
                  </div>

                  {/* Remember + Forgot */}
                  <div className="flex items-center justify-between">
                    <label className="flex items-center gap-2 cursor-pointer group">
                      <input
                        type="checkbox"
                        checked={formData.rememberMe}
                        onChange={(e) => setFormData({ ...formData, rememberMe: e.target.checked })}
                        className="w-4 h-4 rounded border-gray-600 bg-white/5 text-amber-500 focus:ring-amber-500 focus:ring-offset-0"
                      />
                      <span className="text-sm text-gray-400 group-hover:text-white transition-colors">تذكرني</span>
                    </label>
                    <Link href="/forgot-password" className="text-sm text-amber-400 hover:text-amber-300 transition-colors">
                      نسيت كلمة المرور؟
                    </Link>
                  </div>

                  {/* Submit */}
                  <motion.button
                    type="submit"
                    disabled={isLoading || isSuccess}
                    className="relative w-full bg-gradient-to-r from-amber-500 to-amber-600 text-white py-4 rounded-xl font-bold text-lg overflow-hidden group disabled:opacity-50 disabled:cursor-not-allowed"
                    whileHover={{ scale: 1.02 }}
                    whileTap={{ scale: 0.98 }}
                  >
                    <span className="relative z-10 flex items-center justify-center gap-2">
                      {isLoading ? (
                        <>
                          <Loader2 className="w-5 h-5 animate-spin" />
                          جاري تسجيل الدخول...
                        </>
                      ) : isSuccess ? (
                        <>
                          <CheckCircle className="w-5 h-5" />
                          تم بنجاح!
                        </>
                      ) : (
                        <>
                          <LogIn className="w-5 h-5" />
                          تسجيل الدخول
                        </>
                      )}
                    </span>
                  </motion.button>
                </motion.form>
              ) : (
                /* OTP Verification Step */
                <motion.form
                  key="otp"
                  initial={{ opacity: 0, x: 20 }}
                  animate={{ opacity: 1, x: 0 }}
                  exit={{ opacity: 0, x: -20 }}
                  onSubmit={handleVerifyOTP}
                  className="space-y-6"
                >
                  <div className="text-center mb-4">
                    <Shield className="w-12 h-12 text-amber-500 mx-auto mb-3" />
                    <p className="text-gray-300 text-sm">
                      تم إرسال رمز التحقق إلى{' '}
                      <span className="text-white font-medium" dir="ltr">
                        {formData.credential}
                      </span>
                    </p>
                  </div>

                  <div>
                    <label className="block text-sm font-medium text-gray-300 mb-2">رمز التحقق</label>
                    <input
                      type="text"
                      value={otpCode}
                      onChange={(e) => {
                        setOtpCode(e.target.value);
                        if (otpError) setOtpError('');
                      }}
                      className={`w-full px-4 py-4 bg-white/5 border rounded-xl focus:outline-none focus:ring-2 focus:ring-amber-500 focus:border-transparent text-white text-center text-2xl tracking-[0.5em] placeholder-gray-500 transition-all ${
                        otpError ? 'border-red-500' : 'border-gray-700'
                      }`}
                      placeholder="______"
                      maxLength={6}
                      dir="ltr"
                    />
                    {otpError && (
                      <motion.p initial={{ opacity: 0, y: -10 }} animate={{ opacity: 1, y: 0 }} className="text-red-500 text-sm mt-1 text-center">
                        {otpError}
                      </motion.p>
                    )}
                  </div>

                  <motion.button
                    type="submit"
                    disabled={isLoading || isSuccess}
                    className="relative w-full bg-gradient-to-r from-amber-500 to-amber-600 text-white py-4 rounded-xl font-bold text-lg disabled:opacity-50 disabled:cursor-not-allowed"
                    whileHover={{ scale: 1.02 }}
                    whileTap={{ scale: 0.98 }}
                  >
                    <span className="flex items-center justify-center gap-2">
                      {isLoading ? (
                        <>
                          <Loader2 className="w-5 h-5 animate-spin" />
                          جاري التحقق...
                        </>
                      ) : isSuccess ? (
                        <>
                          <CheckCircle className="w-5 h-5" />
                          تم بنجاح!
                        </>
                      ) : (
                        <>
                          <KeyRound className="w-5 h-5" />
                          تحقق
                        </>
                      )}
                    </span>
                  </motion.button>

                  <div className="flex items-center justify-between text-sm">
                    <button
                      type="button"
                      onClick={() => {
                        setStep('login');
                        setOtpCode('');
                        setOtpError('');
                        console.log('[OTP] Going back to login');
                      }}
                      className="text-gray-400 hover:text-white transition-colors"
                    >
                      ← العودة
                    </button>
                    <button
                      type="button"
                      onClick={resendOTP}
                      className="text-amber-400 hover:text-amber-300 transition-colors"
                    >
                      إعادة إرسال الرمز
                    </button>
                  </div>
                </motion.form>
              )}
            </AnimatePresence>

            <motion.p variants={itemVariants} className="text-center text-gray-400 mt-6">
              ليس لديك حساب؟{' '}
              <Link href="/auth/choose-role" className="text-amber-400 hover:text-amber-300 font-medium transition-colors">
                إنشاء حساب جديد
              </Link>
            </motion.p>
          </div>
        </motion.div>

        <motion.p variants={itemVariants} className="text-center text-gray-500 text-xs mt-4">
          بتسجيل الدخول، أنت توافق على{' '}
          <Link href="/terms" className="text-amber-400 hover:text-amber-300 transition-colors">شروط الاستخدام</Link>
          {' '}و{' '}
          <Link href="/privacy" className="text-amber-400 hover:text-amber-300 transition-colors">سياسة الخصوصية</Link>
        </motion.p>
      </motion.div>
    </div>
  );
}