export interface SeededRNG {
  random(): number;
  install(): void;
  uninstall(): void;
}

export function createSeededRNG(seed: number): SeededRNG {
  let state = seed | 0;
  const originalRandom = Math.random;

  function random(): number {
    state = (state + 0x6D2B79F5) | 0;
    let t = Math.imul(state ^ (state >>> 15), 1 | state);
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  }

  return {
    random,
    install() { Math.random = random; },
    uninstall() { Math.random = originalRandom; },
  };
}