import React, { useState } from 'react';
import { Link, useNavigate, useLocation } from 'react-router-dom';
import { Shield, Mail, Lock, Sparkles, ArrowRight, Server } from 'lucide-react';
import { useAuth } from '../context/AuthContext';
import { Button } from '../components/common/Button';
import { Input } from '../components/common/Input';
import { Toast } from '../components/common/Toast';
import { ThemeToggle } from '../components/layout/ThemeToggle';
import { DEMO_USER } from '../services/mockData';
import '../styles/auth.css';

export function Login() {
  const navigate = useNavigate();
  const location = useLocation();
  const { login } = useAuth();

  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const [rememberMe, setRememberMe] = useState(true);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState(null);

  // If redirected with registered email
  React.useEffect(() => {
    if (location.state?.registeredEmail) {
      setEmail(location.state.registeredEmail);
    }
  }, [location.state]);

  const handleSubmit = async (e) => {
    e.preventDefault();
    if (!email.trim() || !password.trim()) {
      setError('Please provide both email and password.');
      return;
    }

    try {
      setLoading(true);
      setError(null);
      await login(email, password);
      navigate('/dashboard');
    } catch (err) {
      console.error('Login error:', err);
      setError(err.message || 'Failed to authenticate. Please check your credentials.');
    } finally {
      setLoading(false);
    }
  };

  const handleQuickDemo = async () => {
    setEmail(DEMO_USER.email);
    setPassword('admin123');
    try {
      setLoading(true);
      setError(null);
      await login(DEMO_USER.email, 'admin123', true);
      navigate('/dashboard');
    } catch (err) {
      setError(err.message);
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="auth-container">
      {/* Background Orbs */}
      <div className="auth-bg-decorations">
        <div className="auth-orb auth-orb-1" />
        <div className="auth-orb auth-orb-2" />
        <div className="auth-orb auth-orb-3" />
      </div>

      <div className="auth-card animate-fade-in">
        {/* Top bar with Brand and Theme Toggle */}
        <div className="auth-top-bar">
          <div className="auth-brand">
            <div className="auth-brand-icon">
              <Shield size={22} />
            </div>
            <span className="auth-brand-name">AuthSec</span>
          </div>
          <ThemeToggle />
        </div>

        {/* Header */}
        <div className="auth-header">
          <h1 className="auth-title">Welcome back</h1>
          <p className="auth-subtitle">Sign in to your enterprise security console</p>
        </div>

        {/* Demo Credentials Quick-Fill Banner */}
        <div className="demo-quick-bar">
          <div className="demo-quick-info">
            <Sparkles size={16} />
            <span>Demo: <strong>{DEMO_USER.email}</strong></span>
          </div>
          <button
            type="button"
            className="demo-quick-btn"
            onClick={handleQuickDemo}
            disabled={loading}
          >
            One-Click Login
          </button>
        </div>

        {/* Error Toast */}
        {error && <Toast type="error" message={error} onClose={() => setError(null)} />}

        {/* Login Form */}
        <form onSubmit={handleSubmit} className="auth-form" noValidate>
          <Input
            label="Email Address"
            type="email"
            placeholder="admin@authsec.com"
            value={email}
            onChange={(e) => setEmail(e.target.value)}
            icon={Mail}
            required
            autoComplete="email"
          />

          <Input
            label="Password"
            type="password"
            placeholder="••••••••"
            value={password}
            onChange={(e) => setPassword(e.target.value)}
            icon={Lock}
            required
            autoComplete="current-password"
          />

          <div className="auth-options">
            <label className="auth-remember">
              <input
                type="checkbox"
                className="auth-checkbox"
                checked={rememberMe}
                onChange={(e) => setRememberMe(e.target.checked)}
              />
              <span>Remember this session</span>
            </label>
            <a href="#trouble" className="auth-link" onClick={(e) => { e.preventDefault(); setError('Contact security administrator to reset credential tokens.'); }}>
              Forgot password?
            </a>
          </div>

          <Button
            type="submit"
            variant="primary"
            size="lg"
            fullWidth
            isLoading={loading}
            icon={ArrowRight}
          >
            Sign In to AuthSec
          </Button>
        </form>

        {/* Bottom Switch to Register */}
        <div className="auth-footer">
          Don't have an enterprise account?{' '}
          <Link to="/register" className="auth-link">
            Register here
          </Link>
        </div>
      </div>
    </div>
  );
}