(() => {
  const makeStorageKey = (sceneId) => `physilinks-highscore-${sceneId}`;
  const makeChainKey = (sceneId) => `physilinks-longestchain-${sceneId}`;

  const loadHighScore = (sceneId) => {
    try {
      const raw = localStorage.getItem(makeStorageKey(sceneId));
      const parsed = parseInt(raw, 10);
      return Number.isFinite(parsed) ? parsed : 0;
    } catch (err) {
      console.error("Failed to load high score", { sceneId, err });
      return 0;
    }
  };

  const loadLongestChain = (sceneId) => {
    try {
      const raw = localStorage.getItem(makeChainKey(sceneId));
      const parsed = parseInt(raw, 10);
      return Number.isFinite(parsed) ? parsed : 0;
    } catch (err) {
      console.error("Failed to load longest chain", { sceneId, err });
      return 0;
    }
  };

  const saveHighScore = (sceneId, highScore) => {
    try {
      localStorage.setItem(makeStorageKey(sceneId), String(highScore));
    } catch (err) {
      console.error("Failed to save high score", { sceneId, err });
    }
  };

  const saveLongestChain = (sceneId, longestChain) => {
    try {
      localStorage.setItem(makeChainKey(sceneId), String(longestChain));
    } catch (err) {
      console.error("Failed to save longest chain", { sceneId, err });
    }
  };

  window.PhysilinksStorage = {
    makeStorageKey,
    makeChainKey,
    loadHighScore,
    loadLongestChain,
    saveHighScore,
    saveLongestChain,
  };
})();