import { useRef, useState, useEffect } from 'react';
import { Button } from '../ui/button';
import { Card, CardContent } from '../ui/card';
import { Input } from '../ui/input';
import { Label } from '../ui/label';
import { signIn, sendVerificationEmail } from '../../lib/auth-client';
import {
  Package,
  FileCheck,
  MessageSquare,
  Camera,
  AlertTriangle,
  ChevronDown,
} from 'lucide-react';

const logo = '/logo.png';

interface Props {
  onSignUp: () => void;
  onForgotPassword: () => void;
}

const features = [
  {
    icon: Package,
    title: 'Smart Chemical Inventory',
    description:
      'Track every chemical in your lab with detailed records — storage locations, CAS numbers, container counts, and expiration dates. Get instant alerts before stock runs low or chemicals expire.',
  },
  {
    icon: FileCheck,
    title: 'AI Protocol Checker',
    description:
      'Paste or upload any lab protocol and receive instant AI-powered safety feedback with citations to OSHA standards. Catch PPE gaps, ventilation requirements, and hazard oversights before they become incidents.',
  },
  {
    icon: MessageSquare,
    title: 'Lab Safety Assistant',
    description:
      'Ask anything about chemical handling, disposal, compatibility, or regulatory compliance. Get sourced answers drawn from OSHA, EPA, and lab safety literature — available the moment you need them.',
  },
  {
    icon: Camera,
    title: 'Photo Label Scanning',
    description:
      'Point your camera at any chemical label and LabWise auto-fills the inventory entry for you. Reduce manual entry errors and get new chemicals logged in seconds.',
  },
];

export function LoginForm({ onSignUp, onForgotPassword }: Props) {
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const [error, setError] = useState('');
  const [loading, setLoading] = useState(false);
  const [resendCooldown, setResendCooldown] = useState(0);
  const [resendLoading, setResendLoading] = useState(false);
  const aboutRef = useRef<HTMLElement>(null);
  const heroRef = useRef<HTMLElement>(null);

  useEffect(() => {
    if (resendCooldown <= 0) return;
    const t = setTimeout(() => setResendCooldown(c => c - 1), 1000);
    return () => clearTimeout(t);
  }, [resendCooldown]);

  async function handleResend() {
    setResendLoading(true);
    await sendVerificationEmail({ email, callbackURL: window.location.origin });
    setResendLoading(false);
    setResendCooldown(60);
  }

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault();
    setError('');
    setLoading(true);
    const res = await signIn.email({
      email,
      password,
      callbackURL: window.location.origin,
    });
    setLoading(false);
    if (res.error) {
      setError(res.error.message || 'Invalid email or password');
    }
  }

  async function handleGoogle() {
    await signIn.social({ provider: 'google', callbackURL: window.location.origin, errorCallbackURL: window.location.origin });
  }

  function scrollToAbout() {
    aboutRef.current?.scrollIntoView({ behavior: 'smooth' });
  }

  function scrollToLogin() {
    heroRef.current?.scrollIntoView({ behavior: 'smooth' });
  }

  return (
    <div className="min-h-screen bg-secondary">
      {/* Sticky Navbar */}
      <nav className="sticky top-0 z-50 bg-card border-b border-border">
        <div className="max-w-6xl mx-auto px-6 h-14 flex items-center justify-between">
          <img src={logo} alt="LabWise" className="h-7" />
          <div className="flex items-center gap-2">
            <Button variant="ghost" size="sm" onClick={scrollToAbout}>
              About
            </Button>
            <Button variant="outline" size="sm" onClick={scrollToLogin}>
              Login
            </Button>
          </div>
        </div>
      </nav>

      {/* Hero — login card */}
      <section
        ref={heroRef}
        className="min-h-[calc(100vh-3.5rem)] flex flex-col items-center justify-center px-4 py-16"
      >
        <div className="text-center mb-8">
          <p className="text-muted-foreground text-sm tracking-wide uppercase font-medium">
            AI-powered lab management
          </p>
          <h1 className="text-3xl font-bold text-foreground mt-1">
            Your lab, under control.
          </h1>
        </div>

        <Card className="w-full max-w-sm">
          <CardContent className="p-8 space-y-6">
            <div className="flex justify-center">
              <img src={logo} alt="LabWise" className="h-12" />
            </div>
            <p className="text-center text-muted-foreground text-sm">
              Sign in to access your lab inventory and protocols.
            </p>

            <form onSubmit={handleSubmit} className="space-y-4">
              <div className="space-y-1">
                <Label htmlFor="email">Email</Label>
                <Input
                  id="email"
                  type="email"
                  value={email}
                  onChange={e => setEmail(e.target.value)}
                  required
                  autoComplete="email"
                />
              </div>
              <div className="space-y-1">
                <Label htmlFor="password">Password</Label>
                <Input
                  id="password"
                  type="password"
                  value={password}
                  onChange={e => setPassword(e.target.value)}
                  required
                  autoComplete="current-password"
                />
              </div>
              {error && (
                <div className="space-y-1">
                  <p className="text-sm text-red-600">{error}</p>
                  {error === 'Email not verified' && (
                    <button
                      type="button"
                      onClick={handleResend}
                      disabled={resendLoading || resendCooldown > 0}
                      className="text-sm text-primary hover:underline disabled:opacity-50 disabled:no-underline"
                    >
                      {resendLoading
                        ? 'Sending…'
                        : resendCooldown > 0
                        ? `Resend verification email (${resendCooldown}s)`
                        : 'Resend verification email'}
                    </button>
                  )}
                </div>
              )}
              <Button type="submit" className="w-full" disabled={loading}>
                {loading ? 'Signing in…' : 'Sign in'}
              </Button>
            </form>

            <div className="flex items-center gap-3">
              <div className="flex-1 border-t border-border" />
              <span className="text-xs text-muted-foreground">or</span>
              <div className="flex-1 border-t border-border" />
            </div>

            <Button
              variant="outline"
              className="w-full flex items-center gap-3"
              onClick={handleGoogle}
            >
              <svg viewBox="0 0 24 24" className="h-4 w-4" xmlns="http://www.w3.org/2000/svg">
                <path d="M22.56 12.25c0-.78-.07-1.53-.2-2.25H12v4.26h5.92c-.26 1.37-1.04 2.53-2.21 3.31v2.77h3.57c2.08-1.92 3.28-4.74 3.28-8.09z" fill="#4285F4"/>
                <path d="M12 23c2.97 0 5.46-.98 7.28-2.66l-3.57-2.77c-.98.66-2.23 1.06-3.71 1.06-2.86 0-5.29-1.93-6.16-4.53H2.18v2.84C3.99 20.53 7.7 23 12 23z" fill="#34A853"/>
                <path d="M5.84 14.09c-.22-.66-.35-1.36-.35-2.09s.13-1.43.35-2.09V7.07H2.18C1.43 8.55 1 10.22 1 12s.43 3.45 1.18 4.93l3.66-2.84z" fill="#FBBC05"/>
                <path d="M12 5.38c1.62 0 3.06.56 4.21 1.64l3.15-3.15C17.45 2.09 14.97 1 12 1 7.7 1 3.99 3.47 2.18 7.07l3.66 2.84c.87-2.6 3.3-4.53 6.16-4.53z" fill="#EA4335"/>
              </svg>
              Sign in with Google
            </Button>

            <div className="flex justify-between text-sm">
              <button
                onClick={onForgotPassword}
                className="text-muted-foreground hover:text-foreground transition-colors"
              >
                Forgot password?
              </button>
              <button
                onClick={onSignUp}
                className="text-primary hover:underline font-medium"
              >
                Create account
              </button>
            </div>
          </CardContent>
        </Card>

        {/* Scroll hint */}
        <button
          onClick={scrollToAbout}
          className="mt-12 flex flex-col items-center gap-1 text-muted-foreground hover:text-foreground transition-colors group"
        >
          <span className="text-xs tracking-wide">Learn more</span>
          <ChevronDown className="h-4 w-4 animate-bounce group-hover:text-primary" />
        </button>
      </section>

      {/* About Section */}
      <section ref={aboutRef} id="about" className="bg-card border-t border-border">
        <div className="max-w-5xl mx-auto px-6 py-20">
          {/* Intro */}
          <div className="text-center mb-16">
            <div className="inline-flex items-center gap-2 bg-accent text-primary text-xs font-medium px-3 py-1 rounded-full mb-4">
              <AlertTriangle className="h-3 w-3" />
              Built for research labs
            </div>
            <h2 className="text-3xl font-bold text-foreground mb-4">
              Lab management, made easy.
            </h2>
            <p className="text-muted-foreground max-w-2xl mx-auto leading-relaxed">
              LabWise brings together chemical inventory tracking, AI-powered protocol review, and real-time
              safety alerts in one place — so your team spends less time on paperwork and more time on research.
              Whether you're managing a single lab or multiple rooms across a department, LabWise keeps
              everything organized, compliant, and accessible.
            </p>
          </div>

          {/* Feature grid */}
          <div className="grid grid-cols-1 md:grid-cols-2 gap-6 mb-16">
            {features.map(({ icon: Icon, title, description }) => (
              <div
                key={title}
                className="flex gap-4 p-6 rounded-xl border border-border bg-secondary hover:shadow-md transition-shadow"
              >
                <div className="shrink-0 p-3 bg-accent rounded-lg h-fit">
                  <Icon className="h-5 w-5 text-primary" />
                </div>
                <div>
                  <h3 className="font-semibold text-foreground mb-1">{title}</h3>
                  <p className="text-sm text-muted-foreground leading-relaxed">{description}</p>
                </div>
              </div>
            ))}
          </div>

          {/* CTA */}
          <div className="text-center space-y-4">
            <h3 className="text-xl font-semibold text-foreground">Ready to get started?</h3>
            <div className="flex items-center justify-center gap-3">
              <Button onClick={scrollToLogin}>Sign in</Button>
              <Button variant="outline" onClick={onSignUp}>
                Create account
              </Button>
            </div>
          </div>
        </div>

        {/* Footer */}
        <div className="border-t border-border">
          <div className="max-w-5xl mx-auto px-6 py-6 flex items-center justify-between text-xs text-muted-foreground">
            <span>© {new Date().getFullYear()} LabWise</span>
            <span>Built for research labs</span>
          </div>
        </div>
      </section>
    </div>
  );
}