import React, { useState, useEffect, useRef } from 'react';
import { useAuth } from '../store/AuthContext';
import { useNavigate } from 'react-router-dom';
import { ShieldCheck, Mail, Lock, Sparkles, ArrowRight, Eye, EyeOff, RefreshCw } from 'lucide-react';

/* ── Floating Particle ─────────────────────────────────────── */
interface Particle {
  id: number;
  x: number;
  y: number;
  size: number;
  opacity: number;
  delay: number;
  duration: number;
}

const generateParticles = (count: number): Particle[] =>
  Array.from({ length: count }, (_, i) => ({
    id: i,
    x: Math.random() * 100,
    y: Math.random() * 100,
    size: Math.random() * 4 + 2,
    opacity: Math.random() * 0.4 + 0.1,
    delay: Math.random() * 6,
    duration: Math.random() * 4 + 5,
  }));

/* ── Animated Background ───────────────────────────────────── */
const AnimatedBackground: React.FC = () => {
  const [particles] = useState(() => generateParticles(25));

  return (
    <div className="absolute inset-0 overflow-hidden pointer-events-none">
      {/* Mesh gradient base */}
      <div className="absolute inset-0 gradient-mesh" />

      {/* Large glowing orbs */}
      <div
        className="orb orb-primary absolute w-[500px] h-[500px] -top-32 -right-32 opacity-60"
        style={{ animationDuration: '9s' }}
      />
      <div
        className="orb orb-secondary absolute w-[400px] h-[400px] -bottom-20 -left-20 opacity-50"
        style={{ animationDuration: '7s', animationDelay: '-4s' }}
      />
      <div
        className="orb orb-accent absolute w-[300px] h-[300px] top-1/2 left-1/3 opacity-40"
        style={{ animationDuration: '11s', animationDelay: '-2s' }}
      />

      {/* Morphing blob */}
      <div
        className="absolute top-1/4 right-1/4 w-64 h-64 opacity-20 animate-morph"
        style={{
          background: 'linear-gradient(135deg, rgba(162,231,113,0.5), rgba(117,191,70,0.3))',
          filter: 'blur(40px)',
        }}
      />

      {/* Grid overlay */}
      <div
        className="absolute inset-0 opacity-[0.025]"
        style={{
          backgroundImage: `linear-gradient(var(--color-ink-800) 1px, transparent 1px),
                            linear-gradient(90deg, var(--color-ink-800) 1px, transparent 1px)`,
          backgroundSize: '60px 60px',
        }}
      />

      {/* Floating particles */}
      {particles.map(p => (
        <div
          key={p.id}
          className="absolute rounded-full animate-float"
          style={{
            left: `${p.x}%`,
            top: `${p.y}%`,
            width: `${p.size}px`,
            height: `${p.size}px`,
            opacity: p.opacity,
            background: `radial-gradient(circle, var(--color-primary-400), var(--color-primary-600))`,
            animationDelay: `${-p.delay}s`,
            animationDuration: `${p.duration}s`,
            filter: 'blur(0.5px)',
          }}
        />
      ))}
    </div>
  );
};

/* ── 3D Orbiting Ring ──────────────────────────────────────── */
const OrbitingRing: React.FC = () => (
  <div className="relative w-28 h-28 mx-auto">
    {/* Center icon */}
    <div className="absolute inset-0 flex items-center justify-center z-10">
      <div
        className="w-16 h-16 rounded-2xl flex items-center justify-center animate-pulse-glow"
        style={{
          background: 'linear-gradient(135deg, var(--color-primary-400), var(--color-primary-600))',
          boxShadow: '0 0 30px rgba(162,231,113,0.5)',
          transform: 'perspective(300px) rotateY(-8deg) rotateX(4deg)',
        }}
      >
        <ShieldCheck className="w-8 h-8" style={{ color: 'var(--color-ink-800)' }} />
      </div>
    </div>

    {/* Orbiting ring 1 */}
    <div
      className="absolute inset-0 rounded-full"
      style={{
        border: '1.5px solid rgba(162,231,113,0.3)',
        animation: 'spin 6s linear infinite',
      }}
    >
      <div
        className="absolute -top-1.5 left-1/2 -translate-x-1/2 w-3 h-3 rounded-full"
        style={{ background: 'var(--color-primary-400)', boxShadow: '0 0 8px rgba(162,231,113,0.8)' }}
      />
    </div>

    {/* Orbiting ring 2 */}
    <div
      className="absolute inset-3 rounded-full"
      style={{
        border: '1px solid rgba(162,231,113,0.2)',
        animation: 'spin 4s linear infinite reverse',
      }}
    >
      <div
        className="absolute -top-1 left-1/2 -translate-x-1/2 w-2 h-2 rounded-full"
        style={{ background: 'var(--color-primary-600)' }}
      />
    </div>
  </div>
);

/* ── Main LoginForm ────────────────────────────────────────── */
export const LoginForm: React.FC = () => {
  const { login, register, verifyMfa, mfaPendingEmail } = useAuth();
  const navigate = useNavigate();

  const [isRegister, setIsRegister] = useState(false);
  const [email, setEmail] = useState('');
  const [showPass, setShowPass] = useState(false);
  const [otp, setOtp] = useState('');
  const [error, setError] = useState('');
  const [loading, setLoading] = useState(false);
  const [mousePos, setMousePos] = useState({ x: 0, y: 0 });
  const cardRef = useRef<HTMLDivElement>(null);

  // Client Profile Registration States
  const [companyName, setCompanyName] = useState('');
  const [website, setWebsite] = useState('');
  const [sector, setSector] = useState('Technology');
  const [companySize, setCompanySize] = useState('1-10');

  /* 3D tilt effect on card */
  const handleMouseMove = (e: React.MouseEvent<HTMLDivElement>) => {
    if (!cardRef.current) return;
    const rect = cardRef.current.getBoundingClientRect();
    const x = (e.clientX - rect.left) / rect.width - 0.5;
    const y = (e.clientY - rect.top) / rect.height - 0.5;
    setMousePos({ x, y });
  };
  const handleMouseLeave = () => setMousePos({ x: 0, y: 0 });

  const cardTransform = `perspective(1200px) rotateY(${mousePos.x * 8}deg) rotateX(${-mousePos.y * 6}deg) translateZ(0)`;

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setError('');
    setLoading(true);
    if (!email) { setError('Email address is required.'); setLoading(false); return; }
    try {
      if (isRegister) {
        if (!companyName.trim() || !website.trim()) {
          setError('Please fill in all company information.');
          setLoading(false);
          return;
        }
        await register(email, { companyName, website, sector, companySize });
      } else {
        await login(email);
      }
    } catch (err: unknown) {
      setError(err instanceof Error ? err.message : 'Authentication failed.');
    } finally {
      setLoading(false);
    }
  };

  const handleMfaSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setError('');
    setLoading(true);
    if (otp.length !== 6) { setError('Enter the 6-digit verification code.'); setLoading(false); return; }
    try {
      const loggedUser = await verifyMfa(otp);
      navigate(loggedUser.role === 'ADMIN' ? '/admin' : '/client');
    } catch (err: unknown) {
      setError(err instanceof Error ? err.message : 'MFA validation failed.');
    } finally {
      setLoading(false);
    }
  };

  const [mounted, setMounted] = useState(false);
  useEffect(() => { setTimeout(() => setMounted(true), 50); }, []);

  return (
    <div className="relative min-h-screen flex items-center justify-center overflow-hidden p-4">
      <AnimatedBackground />

      {/* Card wrapper with 3D tilt */}
      <div
        ref={cardRef}
        onMouseMove={handleMouseMove}
        onMouseLeave={handleMouseLeave}
        className="relative w-full max-w-md z-10"
        style={{
          transform: cardTransform,
          transition: 'transform 0.15s cubic-bezier(0.16,1,0.3,1)',
          transformStyle: 'preserve-3d',
          opacity: mounted ? 1 : 0,
          animation: mounted ? 'scale-up 0.6s cubic-bezier(0.16,1,0.3,1) forwards' : 'none',
        }}
      >
        {/* Glow behind card */}
        <div
          className="absolute -inset-4 rounded-3xl opacity-40 blur-3xl"
          style={{ background: 'linear-gradient(135deg, rgba(162,231,113,0.3), rgba(117,191,70,0.2))' }}
        />

        {/* Main glass card */}
        <div
          className="relative rounded-3xl overflow-hidden"
          style={{
            background: 'rgba(255,255,255,0.85)',
            backdropFilter: 'blur(40px) saturate(200%)',
            WebkitBackdropFilter: 'blur(40px) saturate(200%)',
            border: '1px solid rgba(255,255,255,0.9)',
            boxShadow: `
              0 30px 80px -10px rgba(35,43,33,0.15),
              0 0 0 1px rgba(162,231,113,0.15),
              inset 0 1px 0 rgba(255,255,255,0.9)
            `,
          }}
        >
          {/* Top accent bar */}
          <div
            className="h-1 w-full"
            style={{ background: 'linear-gradient(90deg, var(--color-primary-400), var(--color-primary-600), var(--color-primary-400))' }}
          />

          <div className="p-8 space-y-7">
            {/* Brand Header */}
            <div className="text-center space-y-4 animate-fade-in">
              <OrbitingRing />

              <div>
                <h1 className="text-2xl font-extrabold tracking-tight" style={{ color: 'var(--color-ink-800)' }}>
                  {mfaPendingEmail ? 'Verify Identity' : 'Tech4Biz Portal'}
                </h1>
                <p className="text-sm mt-1.5" style={{ color: 'var(--color-ink-600)' }}>
                  {mfaPendingEmail
                    ? `Code sent to ${mfaPendingEmail}`
                    : 'Enterprise hardware & software asset distribution'}
                </p>
              </div>

              {/* Mode toggle */}
              {!mfaPendingEmail && (
                <div
                  className="inline-flex rounded-xl p-1 gap-1"
                  style={{ background: 'var(--color-ink-100)' }}
                >
                  {(['Login', 'Sign Up'] as const).map(label => {
                    const active = label === 'Login' ? !isRegister : isRegister;
                    return (
                      <button
                        key={label}
                        type="button"
                        onClick={() => { setIsRegister(label === 'Sign Up'); setError(''); }}
                        className="px-5 py-1.5 rounded-lg text-xs font-bold transition-all duration-300"
                        style={{
                          background: active ? 'white' : 'transparent',
                          color: active ? 'var(--color-ink-800)' : 'var(--color-ink-500)',
                          boxShadow: active ? '0 1px 4px rgba(35,43,33,0.08)' : 'none',
                        }}
                      >
                        {label}
                      </button>
                    );
                  })}
                </div>
              )}
            </div>

            {/* Error message */}
            {error && (
              <div
                className="flex items-center gap-2.5 rounded-xl px-4 py-3 text-sm font-medium animate-slide-up"
                style={{
                  background: 'rgba(229,72,77,0.07)',
                  border: '1px solid rgba(229,72,77,0.2)',
                  color: 'var(--color-danger)',
                }}
              >
                <div className="w-1.5 h-1.5 rounded-full bg-current shrink-0" />
                {error}
              </div>
            )}

            {/* ── Credentials Form ── */}
            {!mfaPendingEmail ? (
              <form onSubmit={handleSubmit} className="space-y-4">
                {/* Email field */}
                <div className="animate-slide-up" style={{ animationDelay: '0.05s' }}>
                  <label
                    className="block text-xs font-bold mb-2 uppercase tracking-widest"
                    style={{ color: 'var(--color-ink-600)' }}
                  >
                    Email Address
                  </label>
                  <div className="relative">
                    <div
                      className="absolute left-3.5 top-1/2 -translate-y-1/2 pointer-events-none"
                      style={{ color: 'var(--color-ink-400)' }}
                    >
                      <Mail className="w-4 h-4" />
                    </div>
                    <input
                      type="email"
                      value={email}
                      onChange={e => setEmail(e.target.value)}
                      placeholder="client@tech4biz.com"
                      className="input-field has-left-icon"
                      required
                    />
                  </div>
                </div>

                {/* Password field (mock) */}
                <div className="animate-slide-up" style={{ animationDelay: '0.1s' }}>
                  <label
                    className="block text-xs font-bold mb-2 uppercase tracking-widest"
                    style={{ color: 'var(--color-ink-600)' }}
                  >
                    Password
                  </label>
                  <div className="relative">
                    <div
                      className="absolute left-3.5 top-1/2 -translate-y-1/2 pointer-events-none"
                      style={{ color: 'var(--color-ink-400)' }}
                    >
                      <Lock className="w-4 h-4" />
                    </div>
                    <input
                      type={showPass ? 'text' : 'password'}
                      defaultValue="password"
                      readOnly
                      className="input-field has-left-icon has-right-icon"
                      style={{ background: 'var(--color-ink-50)', cursor: 'default' }}
                    />
                    <button
                      type="button"
                      onClick={() => setShowPass(v => !v)}
                      className="absolute right-3 top-1/2 -translate-y-1/2 transition-premium"
                      style={{ color: 'var(--color-ink-400)' }}
                    >
                      {showPass ? <EyeOff className="w-4 h-4" /> : <Eye className="w-4 h-4" />}
                    </button>
                  </div>
                  <p className="mt-1.5 text-xs" style={{ color: 'var(--color-ink-500)' }}>
                    Mock password preset:{' '}
                    <code
                      className="px-1.5 py-0.5 rounded font-mono text-xs font-bold"
                      style={{ background: 'var(--color-primary-50)', color: 'var(--color-primary-800)' }}
                    >
                      password
                    </code>
                  </p>
                </div>

                {/* Register Profile Fields */}
                {isRegister && (
                  <>
                    <div className="animate-slide-up" style={{ animationDelay: '0.12s' }}>
                      <label
                        className="block text-xs font-bold mb-2 uppercase tracking-widest"
                        style={{ color: 'var(--color-ink-600)' }}
                      >
                        Company Name
                      </label>
                      <input
                        type="text"
                        value={companyName}
                        onChange={e => setCompanyName(e.target.value)}
                        placeholder="e.g. Acme Corporation"
                        className="input-field"
                        required
                      />
                    </div>
                    
                    <div className="animate-slide-up" style={{ animationDelay: '0.14s' }}>
                      <label
                        className="block text-xs font-bold mb-2 uppercase tracking-widest"
                        style={{ color: 'var(--color-ink-600)' }}
                      >
                        Corporate Website
                      </label>
                      <input
                        type="url"
                        value={website}
                        onChange={e => setWebsite(e.target.value)}
                        placeholder="https://example.com"
                        className="input-field"
                        required
                      />
                    </div>

                    <div className="grid grid-cols-2 gap-4">
                      <div className="animate-slide-up" style={{ animationDelay: '0.16s' }}>
                        <label
                          className="block text-xs font-bold mb-2 uppercase tracking-widest"
                          style={{ color: 'var(--color-ink-600)' }}
                        >
                          Sector
                        </label>
                        <select
                          value={sector}
                          onChange={e => setSector(e.target.value)}
                          className="input-field bg-white"
                        >
                          <option value="Technology">Technology</option>
                          <option value="Automotive">Automotive</option>
                          <option value="Telecommunications">Telecommunications</option>
                          <option value="Defense">Defense</option>
                          <option value="Semiconductors">Semiconductors</option>
                          <option value="Other">Other</option>
                        </select>
                      </div>

                      <div className="animate-slide-up" style={{ animationDelay: '0.16s' }}>
                        <label
                          className="block text-xs font-bold mb-2 uppercase tracking-widest"
                          style={{ color: 'var(--color-ink-600)' }}
                        >
                          Company Size
                        </label>
                        <select
                          value={companySize}
                          onChange={e => setCompanySize(e.target.value)}
                          className="input-field bg-white"
                        >
                          <option value="1-10">1-10</option>
                          <option value="10-50">10-50</option>
                          <option value="50-250">50-250</option>
                          <option value="250-1000">250-1000</option>
                          <option value="1000+">1000+</option>
                        </select>
                      </div>
                    </div>
                  </>
                )}

                {/* Quick fill hints */}
                {!isRegister && (
                  <div
                    className="rounded-xl p-3 animate-slide-up"
                    style={{ background: 'var(--color-ink-50)', border: '1px solid var(--color-ink-100)', animationDelay: '0.15s' }}
                  >
                    <p className="text-xs font-bold mb-2" style={{ color: 'var(--color-ink-600)' }}>
                      Quick Access Accounts
                    </p>
                    <div className="flex flex-wrap gap-2">
                      {[
                        { label: 'Admin', email: 'admin@tech4biz.com' },
                        { label: 'Client', email: 'client@tech4biz.com' },
                      ].map(acc => (
                        <button
                          key={acc.label}
                          type="button"
                          onClick={() => setEmail(acc.email)}
                          className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg text-xs font-semibold transition-premium"
                          style={{
                            background: email === acc.email ? 'var(--color-primary-100)' : 'white',
                            color: email === acc.email ? 'var(--color-primary-800)' : 'var(--color-ink-600)',
                            border: `1px solid ${email === acc.email ? 'var(--color-primary-200)' : 'var(--color-ink-200)'}`,
                          }}
                        >
                          <Sparkles className="w-3 h-3" />
                          {acc.label}
                        </button>
                      ))}
                    </div>
                  </div>
                )}

                {/* Submit */}
                <button
                  type="submit"
                  disabled={loading}
                  className="btn-primary w-full py-3 text-sm flex items-center justify-center gap-2 animate-slide-up"
                  style={{ animationDelay: '0.2s' }}
                >
                  {loading ? (
                    <>
                      <RefreshCw className="w-4 h-4 animate-spin-slow" />
                      Processing…
                    </>
                  ) : (
                    <>
                      {isRegister ? 'Create Account' : 'Authenticate'} <ArrowRight className="w-4 h-4" />
                    </>
                  )}
                </button>
              </form>
            ) : (
              /* ── MFA Form ── */
              <form onSubmit={handleMfaSubmit} className="space-y-5">
                <div
                  className="text-center p-4 rounded-2xl animate-fade-in"
                  style={{ background: 'var(--color-primary-50)', border: '1px solid var(--color-primary-100)' }}
                >
                  <p className="text-xs font-bold mb-1" style={{ color: 'var(--color-primary-700)' }}>
                    Development Mode
                  </p>
                  <p className="text-sm" style={{ color: 'var(--color-ink-700)' }}>
                    Use code{' '}
                    <code
                      className="px-2 py-0.5 rounded font-mono font-bold text-base"
                      style={{ background: 'var(--color-primary-100)', color: 'var(--color-primary-800)' }}
                    >
                      123456
                    </code>
                  </p>
                </div>

                {/* OTP input */}
                <div>
                  <label className="block text-xs font-bold mb-3 text-center uppercase tracking-widest" style={{ color: 'var(--color-ink-600)' }}>
                    Verification Code
                  </label>
                  <input
                    type="text"
                    inputMode="numeric"
                    maxLength={6}
                    value={otp}
                    onChange={e => setOtp(e.target.value.replace(/\D/g, ''))}
                    placeholder="000000"
                    className="input-field text-center font-mono text-2xl tracking-[0.5em] py-4"
                    required
                    autoFocus
                  />
                </div>

                <button
                  type="submit"
                  disabled={loading || otp.length !== 6}
                  className="btn-primary w-full py-3 text-sm flex items-center justify-center gap-2"
                >
                  {loading ? (
                    <>
                      <RefreshCw className="w-4 h-4 animate-spin-slow" />
                      Verifying…
                    </>
                  ) : (
                    <>
                      <ShieldCheck className="w-4 h-4" />
                      Verify Code
                    </>
                  )}
                </button>
              </form>
            )}
          </div>

          {/* Bottom accent */}
          <div
            className="px-8 py-4 text-center"
            style={{ borderTop: '1px solid var(--color-ink-50)', background: 'rgba(247,249,246,0.5)' }}
          >
            <p className="text-xs" style={{ color: 'var(--color-ink-400)' }}>
              © 2026 Tech4Biz Solutions Inc. · Enterprise Security Portal
            </p>
          </div>
        </div>
      </div>
    </div>
  );
};