(function exposeSync(root, factory) {
  const api = factory();
  if (typeof module === "object" && module.exports) module.exports = api;
  if (root) root.ValleySync = api;
})(typeof window === "undefined" ? globalThis : window, () => ({
  mergeSnapshot(localChecks, savingIds, currentRevision, snapshot, localPlantings = {}, savingPlantings = new Set()) {
    if (!snapshot || !Number.isInteger(snapshot.revision) || snapshot.revision <= currentRevision) {
      return { applied: false, revision: currentRevision, checks: localChecks, plantings: localPlantings };
    }

    const checks = { ...(snapshot.checks || {}) };
    for (const itemId of savingIds) {
      if (Object.prototype.hasOwnProperty.call(localChecks, itemId)) {
        checks[itemId] = Boolean(localChecks[itemId]);
      }
    }
    const plantings = { ...(snapshot.plantings || {}) };
    for (const itemId of savingPlantings) {
      if (Object.prototype.hasOwnProperty.call(localPlantings, itemId)) plantings[itemId] = localPlantings[itemId];
      else delete plantings[itemId];
    }
    return { applied: true, revision: snapshot.revision, checks, plantings };
  },

  confirmWrite(localChecks, currentRevision, result) {
    return {
      checks: { ...localChecks, [result.itemId]: Boolean(result.checked) },
      revision: Math.max(currentRevision, result.revision)
    };
  },

  confirmPlanting(localPlantings, currentRevision, result) {
    const plantings = { ...localPlantings };
    if (result.planted) plantings[result.itemId] = result.planted;
    else delete plantings[result.itemId];
    return { plantings, revision: Math.max(currentRevision, result.revision) };
  }
}));