/**
   * This generates a map for use on the recalculation and recovery of pending maps after reloading
   * it
   *
   * @param queues
   * @param pendingNonTXPageCounter
   * @param txRecoverCounter
   * @return
   * @throws Exception
   */
  private Map<SimpleString, Map<Long, Map<Long, List<PageCountPending>>>>
      generateMapsOnPendingCount(
          Map<Long, Queue> queues,
          List<PageCountPending> pendingNonTXPageCounter,
          Transaction txRecoverCounter)
          throws Exception {
    Map<SimpleString, Map<Long, Map<Long, List<PageCountPending>>>> perAddressMap = new HashMap<>();
    for (PageCountPending pgCount : pendingNonTXPageCounter) {
      long queueID = pgCount.getQueueID();
      long pageID = pgCount.getPageID();

      // We first figure what Queue is based on the queue id
      Queue queue = queues.get(queueID);

      if (queue == null) {
        logger.debug(
            "removing pending page counter id = "
                + pgCount.getID()
                + " as queueID="
                + pgCount.getID()
                + " no longer exists");
        // this means the queue doesn't exist any longer, we will remove it from the storage
        storageManager.deletePendingPageCounter(txRecoverCounter.getID(), pgCount.getID());
        txRecoverCounter.setContainsPersistent();
        continue;
      }

      // Level 1 on the structure, per address
      SimpleString address = queue.getAddress();

      Map<Long, Map<Long, List<PageCountPending>>> perPageMap = perAddressMap.get(address);

      if (perPageMap == null) {
        perPageMap = new HashMap<>();
        perAddressMap.put(address, perPageMap);
      }

      Map<Long, List<PageCountPending>> perQueueMap = perPageMap.get(pageID);

      if (perQueueMap == null) {
        perQueueMap = new HashMap<>();
        perPageMap.put(pageID, perQueueMap);
      }

      List<PageCountPending> pendingCounters = perQueueMap.get(queueID);

      if (pendingCounters == null) {
        pendingCounters = new LinkedList<>();
        perQueueMap.put(queueID, pendingCounters);
      }

      pendingCounters.add(pgCount);

      perQueueMap.put(queueID, pendingCounters);
    }
    return perAddressMap;
  }
  /**
   * This method will recover the counters after failures making sure the page counter doesn't get
   * out of sync
   *
   * @param pendingNonTXPageCounter
   * @throws Exception
   */
  @Override
  public void recoverPendingPageCounters(List<PageCountPending> pendingNonTXPageCounter)
      throws Exception {
    // We need a structure of the following
    // Address -> PageID -> QueueID -> List<PageCountPending>
    // The following loop will sort the records according to the hierarchy we need

    Transaction txRecoverCounter = new TransactionImpl(storageManager);

    Map<SimpleString, Map<Long, Map<Long, List<PageCountPending>>>> perAddressMap =
        generateMapsOnPendingCount(queues, pendingNonTXPageCounter, txRecoverCounter);

    for (SimpleString address : perAddressMap.keySet()) {
      PagingStore store = pagingManager.getPageStore(address);
      Map<Long, Map<Long, List<PageCountPending>>> perPageMap = perAddressMap.get(address);

      // We have already generated this before, so it can't be null
      assert (perPageMap != null);

      for (Long pageId : perPageMap.keySet()) {
        Map<Long, List<PageCountPending>> perQueue = perPageMap.get(pageId);

        // This can't be true!
        assert (perQueue != null);

        if (store.checkPageFileExists(pageId.intValue())) {
          // on this case we need to recalculate the records
          Page pg = store.createPage(pageId.intValue());
          pg.open();

          List<PagedMessage> pgMessages = pg.read(storageManager);
          Map<Long, AtomicInteger> countsPerQueueOnPage = new HashMap<>();

          for (PagedMessage pgd : pgMessages) {
            if (pgd.getTransactionID() <= 0) {
              for (long q : pgd.getQueueIDs()) {
                AtomicInteger countQ = countsPerQueueOnPage.get(q);
                if (countQ == null) {
                  countQ = new AtomicInteger(0);
                  countsPerQueueOnPage.put(q, countQ);
                }
                countQ.incrementAndGet();
              }
            }
          }

          for (Map.Entry<Long, List<PageCountPending>> entry : perQueue.entrySet()) {
            for (PageCountPending record : entry.getValue()) {
              logger.debug("Deleting pg tempCount " + record.getID());
              storageManager.deletePendingPageCounter(txRecoverCounter.getID(), record.getID());
            }

            PageSubscriptionCounter counter =
                store.getCursorProvider().getSubscription(entry.getKey()).getCounter();

            AtomicInteger value = countsPerQueueOnPage.get(entry.getKey());

            if (value == null) {
              logger.debug("Page " + entry.getKey() + " wasn't open, so we will just ignore");
            } else {
              logger.debug("Replacing counter " + value.get());
              counter.increment(txRecoverCounter, value.get());
            }
          }
        } else {
          // on this case the page file didn't exist, we just remove all the records since the page
          // is already gone
          logger.debug(
              "Page "
                  + pageId
                  + " didn't exist on address "
                  + address
                  + ", so we are just removing records");
          for (List<PageCountPending> records : perQueue.values()) {
            for (PageCountPending record : records) {
              logger.debug("Removing pending page counter " + record.getID());
              storageManager.deletePendingPageCounter(txRecoverCounter.getID(), record.getID());
              txRecoverCounter.setContainsPersistent();
            }
          }
        }
      }
    }

    txRecoverCounter.commit();
  }