'use client';

import { Suspense, useEffect, useState } from 'react';
import { useRouter, useSearchParams } from 'next/navigation';
import { Logo } from '@/components/logo';
import { apiFetch } from '@/lib/api';

function CallbackInner() {
  const router = useRouter();
  const params = useSearchParams();
  const token = params.get('token');
  const [state, setState] = useState<'verifying' | 'ok' | 'error'>('verifying');
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (!token) {
      setState('error');
      setError('Missing token');
      return;
    }
    (async () => {
      try {
        await apiFetch('/v1/auth/verify', {
          method: 'POST',
          body: JSON.stringify({ token }),
        });
        setState('ok');
        setTimeout(() => router.replace('/dashboard'), 200);
      } catch (err) {
        setState('error');
        setError((err as Error).message);
      }
    })();
  }, [token, router]);

  return (
    <div className="flex min-h-screen items-center justify-center px-6">
      <div className="w-full max-w-sm text-center">
        <Logo className="mx-auto mb-8" />
        {state === 'verifying' && (
          <p className="text-[13px] text-[--color-fg-muted]">Verifying your magic link…</p>
        )}
        {state === 'ok' && (
          <p className="text-[13px] text-emerald-300">Signed in. Redirecting…</p>
        )}
        {state === 'error' && (
          <>
            <p className="text-[13px] text-[--color-danger]">Could not verify magic link.</p>
            {error && <p className="mt-2 mono text-[11px] text-[--color-fg-subtle]">{error}</p>}
          </>
        )}
      </div>
    </div>
  );
}

// useSearchParams() requires a Suspense boundary or `next build` cannot
// statically render this route.
export default function CallbackPage() {
  return (
    <Suspense
      fallback={
        <div className="flex min-h-screen items-center justify-center px-6">
          <p className="text-[13px] text-[--color-fg-muted]">Verifying your magic link…</p>
        </div>
      }
    >
      <CallbackInner />
    </Suspense>
  );
}