export interface NanoVDBDeviceLossReplayPlanIR {
  schemaVersion: 1;
  visiblePageIds: readonly number[];
  replayedPageIds: readonly number[];
  skippedPageIds: readonly number[];
  pageCount: number;
  residentPageCapacity: number;
}

function invalid(message: string): never {
  throw new Error(`NANOVDB_INVALID_ARGUMENT: ${message}`);
}

export function planNanoVDBDeviceLossReplay(
  visiblePageIds: readonly number[],
  pageCount: number,
  residentPageCapacity: number,
): NanoVDBDeviceLossReplayPlanIR {
  if (!Array.isArray(visiblePageIds)) invalid("visible page IDs must be an array");
  if (!Number.isSafeInteger(pageCount) || pageCount < 1 || pageCount > 8192) invalid("page count is outside the manifest limit");
  if (!Number.isSafeInteger(residentPageCapacity) || residentPageCapacity < 1 || residentPageCapacity > pageCount) {
    invalid("resident page capacity is outside the virtual grid");
  }
  const visible = [...new Set(visiblePageIds.map((pageId) => {
    if (!Number.isSafeInteger(pageId) || pageId < 0 || pageId >= pageCount) invalid("visible page ID is outside the virtual grid");
    return pageId;
  }))].sort((left, right) => left - right);
  return {
    schemaVersion: 1,
    visiblePageIds: visible,
    replayedPageIds: visible.slice(0, residentPageCapacity),
    skippedPageIds: visible.slice(residentPageCapacity),
    pageCount,
    residentPageCapacity,
  };
}