// In-memory per-game cache. A game the player has opened once is kept here so a
// later re-entry renders instantly from the cache while a fresh fetch updates it in
// the background — removing the blank "loading" flash and the full redraw on every
// lobby <-> game navigation. It is intentionally process-memory only (no persistence):
// stale entries are corrected by the background refresh, and the cache is cleared on
// logout.

import type { MoveRecord, StateView } from './model';

export interface CachedGame {
  view: StateView;
  moves: MoveRecord[];
}

const cache = new Map<string, CachedGame>();

/** getCachedGame returns the last-seen state+history for a game, or undefined. */
export function getCachedGame(id: string): CachedGame | undefined {
  return cache.get(id);
}

/** setCachedGame stores the latest state+history for a game. */
export function setCachedGame(id: string, view: StateView, moves: MoveRecord[]): void {
  cache.set(id, { view, moves });
}

/** clearGameCache drops every cached game (called on logout). */
export function clearGameCache(): void {
  cache.clear();
}