'use client';

import { useSignal } from '@signal-js/nextjs/client';
import { useEffect, useState } from 'react';

function LoginHandler({ userId, userTraits }) {
  const { identify, alias } = useSignal();
  const [anonymousId, setAnonymousId] = useState<string | null>(null);

  useEffect(() => {
    // Store anonymous ID before login
    const stored = localStorage.getItem('anonymous_id');
    if (stored) {
      setAnonymousId(stored);
    }
  }, []);

  const handleLogin = () => {
    // Identify the user
    identify(userId, userTraits);

    // Link anonymous ID if it exists
    if (anonymousId) {
      alias(anonymousId);
      localStorage.removeItem('anonymous_id');
    }
  };

  return <button onClick={handleLogin}>Log in</button>;
}

// app/api/auth/login/route.ts
import { signal, getSessionInfo } from '@/lib/signal-server';
import { NextRequest } from 'next/server';

export async function POST(request: NextRequest) {
  const { sessionId, windowId, distinctId } = getSessionInfo(request);
  const body = await request.json();

  // Identify the user
  signal.identify({
    distinctId: body.userId,
    properties: { email: body.email, name: body.name },
    sessionId,
    windowId,
  });

  // Link anonymous ID if provided
  if (body.anonymousId) {
    signal.alias(body.userId, body.anonymousId, sessionId, windowId);
  }

  return Response.json({ success: true });
}