import { NextResponse } from 'next/server';
import { getAvailableSlots } from '@/lib/server/booking';

export const dynamic = 'force-dynamic';

/**
 * GET /api/availability?serviceId=&staffId=&date=
 * Server-computed bookable slots (past and taken slots already excluded). All datetimes are UTC
 * ISO strings; `timeZone` tells the client how to display them.
 */
export async function GET(request: Request) {
  const { searchParams } = new URL(request.url);
  const serviceId = searchParams.get('serviceId');
  const staffId = searchParams.get('staffId') || null;
  const date = searchParams.get('date') || undefined;

  if (!serviceId) return NextResponse.json({ error: 'serviceId is required.' }, { status: 400 });

  const result = await getAvailableSlots({ serviceId, staffId, date });
  if (!result) return NextResponse.json({ error: 'Service not found.' }, { status: 404 });

  return NextResponse.json(result);
}