const lastStand = new Map<string, { stacks: number; expiresAt: number }>();
let boonUntil = 0;

export function applyLastStand(id: string, now: number): number {
  const previous = lastStand.get(id);
  const stacks = Math.min(3, (previous && previous.expiresAt > now ? previous.stacks : 0) + 1);
  lastStand.set(id, { stacks, expiresAt: now + 6_000 });
  return stacks;
}

export function lastStandStacks(id: string, now: number): number {
  const state = lastStand.get(id);
  if (!state || state.expiresAt <= now) { lastStand.delete(id); return 0; }
  return state.stacks;
}
export function activeLastStand(now: number): readonly { id: string; stacks: number }[] {
  return [...lastStand.keys()].flatMap((id) => {
    const stacks = lastStandStacks(id, now);
    return stacks ? [{ id, stacks }] : [];
  });
}

export function raceAffixMobDamageMultiplier(id: string, now: number): number {
  return 1 + lastStandStacks(id, now) * 0.25;
}

export function grantRaceAffixBoon(now: number): void { boonUntil = now + 8_000; }
export function raceAffixHasteMultiplier(now = Date.now()): number { return boonUntil > now ? 1.15 : 1; }
export function raceAffixBoonUntil(): number { return boonUntil; }

export function shiftDungeonRaceAffixBuffs(elapsedMs: number): void {
  if (elapsedMs <= 0) return;
  for (const [id, state] of lastStand) lastStand.set(id, { ...state, expiresAt: state.expiresAt + elapsedMs });
  if (boonUntil > 0) boonUntil += elapsedMs;
}

export function resetDungeonRaceAffixBuffs(): void {
  lastStand.clear();
  boonUntil = 0;
}