import type { WorldSpawn } from "./dungeonTypes";

export function derivePartySpawnSlots(spawn: WorldSpawn, partySize = 5): readonly WorldSpawn[] {
  const size = Math.max(1, Math.min(5, Math.trunc(partySize)));
  const offsets = [
    [0, 0],
    [-1.65, -1.8],
    [1.65, -1.8],
    [-3.05, -3.5],
    [3.05, -3.5],
  ] as const;
  const sin = Math.sin(spawn.yaw);
  const cos = Math.cos(spawn.yaw);
  return Object.freeze(offsets.slice(0, size).map(([lateral, forward]) => ({
    footPosition: [
      spawn.footPosition[0] + lateral * cos + forward * sin,
      spawn.footPosition[1],
      spawn.footPosition[2] - lateral * sin + forward * cos,
    ] as const,
    yaw: spawn.yaw,
  })));
}