"use client";

import { Suspense, useState } from "react";
import Link from "next/link";
import { useSearchParams } from "next/navigation";
import { signIn } from "next-auth/react";
import { Loader2, Lock, Mail, ShieldCheck, Sparkles } from "lucide-react";
import { cn } from "@/lib/utils";

function SignInForm() {
  const searchParams = useSearchParams();
  const callbackUrl = searchParams.get("callbackUrl") ?? "/";
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  async function onSubmit(e: React.FormEvent) {
    e.preventDefault();
    setError(null);
    setLoading(true);
    try {
      const result = await signIn("credentials", {
        email,
        password,
        redirect: false,
        callbackUrl,
      });
      if (result?.error) {
        setError("Invalid email or password.");
        return;
      }
      window.location.href = callbackUrl;
    } finally {
      setLoading(false);
    }
  }

  return (
    <div
      className={cn(
        "rounded-2xl border border-border/60 bg-card/80 p-8 shadow-xl shadow-[hsl(var(--primary)/0.08)] backdrop-blur-md",
        "ring-1 ring-[hsl(var(--primary)/0.12)]",
      )}
    >
      <div className="mb-8 text-center">
        <div className="mx-auto mb-4 flex h-12 w-12 items-center justify-center rounded-xl bg-gradient-to-br from-[hsl(var(--primary))] to-[hsl(var(--teal))] text-primary-foreground shadow-lg">
          <Sparkles className="h-6 w-6" aria-hidden />
        </div>
        <h1 className="text-2xl font-semibold tracking-tight text-foreground">Welcome to Tasks</h1>
        <p className="mt-2 text-sm text-muted-foreground">Sign in to organize your work with clarity.</p>
      </div>

      <form onSubmit={onSubmit} className="space-y-5">
        {error ? (
          <div
            role="alert"
            className="rounded-lg border border-destructive/30 bg-destructive/10 px-3 py-2 text-sm text-destructive"
          >
            {error}
          </div>
        ) : null}

        <div className="space-y-2">
          <label htmlFor="email" className="text-sm font-medium text-foreground">
            Email
          </label>
          <div className="relative">
            <Mail className="pointer-events-none absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-muted-foreground" />
            <input
              id="email"
              name="email"
              type="email"
              autoComplete="email"
              required
              value={email}
              onChange={(e) => setEmail(e.target.value)}
              className={cn(
                "w-full rounded-lg border border-input bg-background py-2.5 pl-10 pr-3 text-sm outline-none transition",
                "placeholder:text-muted-foreground focus:border-[hsl(var(--primary))] focus:ring-2 focus:ring-[hsl(var(--primary)/0.25)]",
              )}
              placeholder="you@example.com"
            />
          </div>
        </div>

        <div className="space-y-2">
          <label htmlFor="password" className="text-sm font-medium text-foreground">
            Password
          </label>
          <div className="relative">
            <Lock className="pointer-events-none absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-muted-foreground" />
            <input
              id="password"
              name="password"
              type="password"
              autoComplete="current-password"
              required
              value={password}
              onChange={(e) => setPassword(e.target.value)}
              className={cn(
                "w-full rounded-lg border border-input bg-background py-2.5 pl-10 pr-3 text-sm outline-none transition",
                "placeholder:text-muted-foreground focus:border-[hsl(var(--primary))] focus:ring-2 focus:ring-[hsl(var(--primary)/0.25)]",
              )}
              placeholder="••••••••"
            />
          </div>
        </div>

        <button
          type="submit"
          disabled={loading}
          className={cn(
            "flex w-full items-center justify-center gap-2 rounded-lg py-2.5 text-sm font-medium text-primary-foreground transition",
            "bg-[hsl(var(--primary))] hover:bg-[hsl(var(--primary)/0.92)] focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-[hsl(var(--primary))]",
            "disabled:pointer-events-none disabled:opacity-60",
          )}
        >
          {loading ? <Loader2 className="h-4 w-4 animate-spin" /> : null}
          Sign in
        </button>
      </form>

      <div className="relative my-8">
        <div className="absolute inset-0 flex items-center">
          <span className="w-full border-t border-border" />
        </div>
        <div className="relative flex justify-center text-xs uppercase tracking-wide">
          <span className="bg-card/90 px-2 text-muted-foreground">Or continue with</span>
        </div>
      </div>

      <div className="space-y-3">
        <div className="grid grid-cols-2 gap-3">
          <button
            type="button"
            onClick={() => void signIn("github", { callbackUrl })}
            className={cn(
              "flex items-center justify-center gap-2 rounded-lg border border-border bg-background py-2.5 text-sm font-medium transition",
              "hover:border-[hsl(var(--primary)/0.4)] hover:bg-muted/50",
            )}
          >
            <svg className="h-4 w-4" viewBox="0 0 24 24" fill="currentColor" aria-hidden>
              <path d="M12 0c-6.626 0-12 5.373-12 12 0 5.302 3.438 9.8 8.207 11.387.599.111.793-.261.793-.577v-2.234c-3.338.726-4.033-1.416-4.033-1.416-.546-1.387-1.333-1.756-1.333-1.756-1.089-.745.083-.729.083-.729 1.205.084 1.839 1.237 1.839 1.237 1.07 1.834 2.807 1.304 3.492.997.107-.775.418-1.305.762-1.604-2.665-.305-5.467-1.334-5.467-5.931 0-1.311.469-2.381 1.236-3.221-.124-.303-.535-1.524.117-3.176 0 0 1.008-.322 3.301 1.23.957-.266 1.983-.399 3.003-.404 1.02.005 2.047.138 3.006.404 2.291-1.552 3.297-1.23 3.297-1.23.653 1.653.242 2.874.118 3.176.77.84 1.235 1.911 1.235 3.221 0 4.609-2.807 5.624-5.479 5.921.43.372.823 1.102.823 2.222v3.293c0 .319.192.694.801.576 4.765-1.589 8.199-6.086 8.199-11.386 0-6.627-5.373-12-12-12z" />
            </svg>
            GitHub
          </button>
          <button
            type="button"
            onClick={() => void signIn("google", { callbackUrl })}
            className={cn(
              "flex items-center justify-center gap-2 rounded-lg border border-border bg-background py-2.5 text-sm font-medium transition",
              "hover:border-[hsl(var(--teal)/0.45)] hover:bg-muted/50",
            )}
          >
            <svg className="h-4 w-4" viewBox="0 0 24 24" aria-hidden>
              <path
                fill="#4285F4"
                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"
              />
              <path
                fill="#34A853"
                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"
              />
              <path
                fill="#FBBC05"
                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 4.93l2.85-2.22.81-.62z"
              />
              <path
                fill="#EA4335"
                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"
              />
            </svg>
            Google
          </button>
        </div>
        <button
          type="button"
          onClick={() => void signIn("authentik", { callbackUrl })}
          className={cn(
            "flex w-full items-center justify-center gap-2 rounded-lg border border-border bg-background py-2.5 text-sm font-medium transition",
            "hover:border-[hsl(var(--primary)/0.4)] hover:bg-muted/50",
          )}
        >
          <ShieldCheck className="h-4 w-4 text-[hsl(var(--primary))]" aria-hidden />
          Authentik SSO
        </button>
      </div>

      <p className="mt-8 text-center text-sm text-muted-foreground">
        New to Tasks?{" "}
        <Link
          href="/sign-up"
          className="font-medium text-[hsl(var(--primary))] underline-offset-4 hover:underline"
        >
          Create an account
        </Link>
      </p>
    </div>
  );
}

export default function SignInPage() {
  return (
    <Suspense
      fallback={
        <div className="flex min-h-[320px] items-center justify-center rounded-2xl border border-border/60 bg-card/80 p-8">
          <Loader2 className="h-8 w-8 animate-spin text-[hsl(var(--primary))]" aria-label="Loading" />
        </div>
      }
    >
      <SignInForm />
    </Suspense>
  );
}