import React, { useState, FormEvent } from 'react';
import { useAuth } from '../../contexts/AuthContext';
import { useNavigate, Link, Navigate } from 'react-router-dom';
import { LoadingSpinner } from '../../components/ui/LoadingSpinner';
import { Lock, Mail, Eye, EyeOff, ArrowLeft } from 'lucide-react';

export function LoginPage() {
  const { login, isAuthenticated, isLoading } = useAuth();
  const navigate = useNavigate();
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const [error, setError] = useState('');
  const [submitting, setSubmitting] = useState(false);
  const [showPassword, setShowPassword] = useState(false);

  if (isLoading) {
    return (
      <div className="flex min-h-screen items-center justify-center">
        <LoadingSpinner size="lg" />
      </div>
    );
  }

  if (isAuthenticated) {
    return <Navigate to="/app" replace />;
  }

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    setError('');
    setSubmitting(true);

    try {
      await login(email, password);
      navigate('/app');
    } catch (err: any) {
      setError(err.response?.data?.error || 'Login failed. Please check your credentials.');
    } finally {
      setSubmitting(false);
    }
  };

  return (
    <div className="flex min-h-screen bg-surface-50">
       {/* Left: branding */}
       <div className="hidden flex-1 flex-col items-center justify-center bg-brand-600 p-8 sm:flex sm:p-12">
        <Link
          to="/"
          className="self-start flex items-center gap-2 rounded-lg px-3 py-2 text-white/70 hover:text-white hover:bg-white/10 transition-colors mb-8 min-h-[44px]"
        >
          <ArrowLeft size={16} />
          <span className="text-sm font-medium">Back to home</span>
        </Link>
        <div className="max-w-md text-white">
          <div className="mb-8 flex h-12 w-12 items-center justify-center rounded-xl bg-white/10 text-xl font-bold">
            CS
          </div>
          <h1 className="text-4xl font-bold leading-tight">
            Command Center for Home Services Leaders
          </h1>
          <p className="mt-4 text-lg text-brand-200">
            Revenue intelligence and portfolio management for multi-location operators and their partners.
          </p>
          <div className="mt-12 grid grid-cols-2 gap-6">
            {[
              { label: 'Revenue Forecasting', value: 'AI-Powered' },
              { label: 'Portfolio View', value: 'Multi-Market' },
              { label: 'Partner Network', value: 'Commission Tracked' },
              { label: 'Goal Alignment', value: 'Real-Time' },
            ].map((item) => (
              <div key={item.label}>
                <p className="text-sm font-medium text-brand-200">{item.label}</p>
                <p className="text-lg font-semibold">{item.value}</p>
              </div>
            ))}
          </div>
        </div>
      </div>

      {/* Right panel - login form */}
      <div className="flex w-full items-center justify-center bg-white p-8 lg:w-1/2">
        <div className="w-full max-w-md">
          <Link
            to="/"
            className="flex items-center gap-2 rounded-lg px-3 py-2 text-surface-400 hover:text-surface-600 hover:bg-surface-50 transition-colors mb-8 min-h-[44px]"
          >
            <ArrowLeft size={16} />
            <span className="text-sm font-medium">Back to home</span>
          </Link>
          <div className="mb-8">
            <h2 className="text-2xl font-bold text-surface-900">Sign in to Command Center</h2>
            <p className="mt-2 text-surface-500">
              Enter your credentials to access your account
            </p>
          </div>

          {error && (
            <div className="mb-6 rounded-lg bg-error/10 p-4 text-sm text-error">
              {error}
            </div>
          )}

          <form onSubmit={handleSubmit} className="space-y-5">
            <div>
              <label htmlFor="email" className="mb-1.5 block text-sm font-medium text-surface-700">
                Email
              </label>
              <div className="relative">
                <Mail className="absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-surface-500" />
                <input
                  id="email"
                  type="email"
                  value={email}
                  onChange={(e) => setEmail(e.target.value)}
                  className="w-full rounded-lg border border-gray-300 bg-white py-3 pl-10 pr-4 text-sm text-gray-900 outline-none transition-colors placeholder:text-gray-400 focus:border-brand-500 focus:ring-2 focus:ring-brand-100"
                  placeholder="you@company.com"
                  required
                  autoFocus
                />
              </div>
            </div>

            <div>
              <label htmlFor="password" className="mb-1.5 block text-sm font-medium text-surface-700">
                Password
              </label>
              <div className="relative">
                <Lock className="absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-surface-500" />
                <input
                   id="password"
                   type={showPassword ? 'text' : 'password'}
                   value={password}
                   onChange={(e) => setPassword(e.target.value)}
                   className="w-full rounded-lg border border-gray-300 bg-white py-3 pl-10 pr-10 text-sm text-gray-900 outline-none transition-colors placeholder:text-gray-400 focus:border-brand-500 focus:ring-2 focus:ring-brand-100"
                   placeholder="••••••••"
                   required
                 />
                <button
                  type="button"
                  onClick={() => setShowPassword(!showPassword)}
                  className="absolute right-3 top-1/2 -translate-y-1/2 text-surface-400 hover:text-surface-600 p-1.5 rounded min-w-[44px] min-h-[44px] flex items-center justify-center"
                >
                  {showPassword ? <EyeOff className="h-4 w-4" /> : <Eye className="h-4 w-4" />}
                </button>
              </div>
            </div>

            <button
              type="submit"
              disabled={submitting}
              className="w-full rounded-lg bg-brand-600 py-3 text-sm font-semibold text-white transition-colors hover:bg-brand-700 disabled:cursor-not-allowed disabled:opacity-50"
            >
              {submitting ? <LoadingSpinner size="sm" /> : 'Sign In'}
            </button>

            <p className="text-center text-sm">
              <Link to="/auth/forgot-password" className="font-medium text-brand-600 hover:text-brand-700">
                Forgot your password?
              </Link>
            </p>
          </form>

          <p className="mt-6 text-center text-sm text-surface-500">
            Don't have an account?{' '}
            <Link to="/auth/signup" className="font-medium text-brand-600 hover:text-brand-700">
              Create one
            </Link>
          </p>

          <div className="mt-8 rounded-xl border border-surface-200 bg-gradient-to-br from-brand-50 to-surface-50 p-5">
            <p className="text-xs font-semibold text-surface-700 tracking-wide uppercase">Demo Account</p>
            <p className="mt-2 text-sm text-surface-600 font-mono bg-white/60 rounded-lg px-3 py-2 border border-surface-200">
              demo@commandcenter.com / CmdSov-Demo-Xh1F_yVwAhs4
            </p>
          </div>
        </div>
      </div>
    </div>
  );
}