kill pending queries when archiving conversation

1 files changed, 639 insertions, 630 deletions

diff --git a/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java b/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java
index 592a36702..b382022b9 100644
--- a/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java
+++ b/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java
@@ -26,636 +26,645 @@ import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
 
 public class MessageArchiveService implements OnAdvancedStreamFeaturesLoaded {
 
-	private final XmppConnectionService mXmppConnectionService;
-
-	private final HashSet<Query> queries = new HashSet<>();
-	private final ArrayList<Query> pendingQueries = new ArrayList<>();
-
-	public enum Version {
-		MAM_0("urn:xmpp:mam:0", true),
-		MAM_1("urn:xmpp:mam:1", false),
-		MAM_2("urn:xmpp:mam:2", false);
-
-		public final boolean legacy;
-		public final String namespace;
-
-		Version(String namespace, boolean legacy) {
-			this.namespace = namespace;
-			this.legacy = legacy;
-		}
-
-		public static Version get(Account account) {
-			return get(account,null);
-		}
-
-		public static Version get(Account account, Conversation conversation) {
-			if (conversation == null || conversation.getMode() == Conversation.MODE_SINGLE) {
-				return get(account.getXmppConnection().getFeatures().getAccountFeatures());
-			} else {
-				return get(conversation.getMucOptions().getFeatures());
-			}
-		}
-
-		private static Version get(List<String> features) {
-			final Version[] values = values();
-			for(int i = values.length -1; i >= 0; --i) {
-				for(String feature : features) {
-					if (values[i].namespace.equals(feature)) {
-						return values[i];
-					}
-				}
-			}
-			return MAM_0;
-		}
-
-		public static boolean has(List<String> features) {
-			for(String feature : features) {
-				for(Version version : values()) {
-					if (version.namespace.equals(feature)) {
-						return true;
-					}
-				}
-			}
-			return false;
-		}
-
-		public static Element findResult(MessagePacket packet) {
-			for(Version version : values()) {
-				Element result = packet.findChild("result", version.namespace);
-				if (result != null) {
-					return result;
-				}
-			}
-			return null;
-		}
-
-	}
+    private final XmppConnectionService mXmppConnectionService;
+
+    private final HashSet<Query> queries = new HashSet<>();
+    private final ArrayList<Query> pendingQueries = new ArrayList<>();
+
+    public enum Version {
+        MAM_0("urn:xmpp:mam:0", true),
+        MAM_1("urn:xmpp:mam:1", false),
+        MAM_2("urn:xmpp:mam:2", false);
+
+        public final boolean legacy;
+        public final String namespace;
+
+        Version(String namespace, boolean legacy) {
+            this.namespace = namespace;
+            this.legacy = legacy;
+        }
+
+        public static Version get(Account account) {
+            return get(account, null);
+        }
+
+        public static Version get(Account account, Conversation conversation) {
+            if (conversation == null || conversation.getMode() == Conversation.MODE_SINGLE) {
+                return get(account.getXmppConnection().getFeatures().getAccountFeatures());
+            } else {
+                return get(conversation.getMucOptions().getFeatures());
+            }
+        }
+
+        private static Version get(List<String> features) {
+            final Version[] values = values();
+            for (int i = values.length - 1; i >= 0; --i) {
+                for (String feature : features) {
+                    if (values[i].namespace.equals(feature)) {
+                        return values[i];
+                    }
+                }
+            }
+            return MAM_0;
+        }
+
+        public static boolean has(List<String> features) {
+            for (String feature : features) {
+                for (Version version : values()) {
+                    if (version.namespace.equals(feature)) {
+                        return true;
+                    }
+                }
+            }
+            return false;
+        }
+
+        public static Element findResult(MessagePacket packet) {
+            for (Version version : values()) {
+                Element result = packet.findChild("result", version.namespace);
+                if (result != null) {
+                    return result;
+                }
+            }
+            return null;
+        }
+
+    }
 
     MessageArchiveService(final XmppConnectionService service) {
-		this.mXmppConnectionService = service;
-	}
-
-	private void catchup(final Account account) {
-		synchronized (this.queries) {
-			for (Iterator<Query> iterator = this.queries.iterator(); iterator.hasNext(); ) {
-				Query query = iterator.next();
-				if (query.getAccount() == account) {
-					iterator.remove();
-				}
-			}
-		}
-		MamReference mamReference = MamReference.max(
-				mXmppConnectionService.databaseBackend.getLastMessageReceived(account),
-				mXmppConnectionService.databaseBackend.getLastClearDate(account)
-		);
-		mamReference = MamReference.max(mamReference, mXmppConnectionService.getAutomaticMessageDeletionDate());
-		long endCatchup = account.getXmppConnection().getLastSessionEstablished();
-		final Query query;
-		if (mamReference.getTimestamp() == 0) {
-			return;
-		} else if (endCatchup - mamReference.getTimestamp() >= Config.MAM_MAX_CATCHUP) {
-			long startCatchup = endCatchup - Config.MAM_MAX_CATCHUP;
-			List<Conversation> conversations = mXmppConnectionService.getConversations();
-			for (Conversation conversation : conversations) {
-				if (conversation.getMode() == Conversation.MODE_SINGLE && conversation.getAccount() == account && startCatchup > conversation.getLastMessageTransmitted().getTimestamp()) {
-					this.query(conversation, startCatchup, true);
-				}
-			}
-			query = new Query(account, new MamReference(startCatchup), 0);
-		} else {
-			query = new Query(account, mamReference, 0);
-		}
-		synchronized (this.queries) {
-			this.queries.add(query);
-		}
-		this.execute(query);
-	}
-
-	void catchupMUC(final Conversation conversation) {
-		if (conversation.getLastMessageTransmitted().getTimestamp() < 0 && conversation.countMessages() == 0) {
-			query(conversation,
-					new MamReference(0),
-					0,
-					true);
-		} else {
-			query(conversation,
-					conversation.getLastMessageTransmitted(),
-					0,
-					true);
-		}
-	}
-
-	public Query query(final Conversation conversation) {
-		if (conversation.getLastMessageTransmitted().getTimestamp() < 0 && conversation.countMessages() == 0) {
-			return query(conversation,
-					new MamReference(0),
-					System.currentTimeMillis(),
-					false);
-		} else {
-			return query(conversation,
-					conversation.getLastMessageTransmitted(),
-					conversation.getAccount().getXmppConnection().getLastSessionEstablished(),
-					false);
-		}
-	}
-
-	public boolean isCatchingUp(Conversation conversation) {
-		final Account account = conversation.getAccount();
-		if (account.getXmppConnection().isWaitingForSmCatchup()) {
-			return true;
-		} else {
-			synchronized (this.queries) {
-				for (Query query : this.queries) {
-					if (query.getAccount() == account && query.isCatchup() && ((conversation.getMode() == Conversation.MODE_SINGLE && query.getWith() == null) || query.getConversation() == conversation)) {
-						return true;
-					}
-				}
-			}
-			return false;
-		}
-	}
-
-	public Query query(final Conversation conversation, long end, boolean allowCatchup) {
-		return this.query(conversation, conversation.getLastMessageTransmitted(), end, allowCatchup);
-	}
-
-	public Query query(Conversation conversation, MamReference start, long end, boolean allowCatchup) {
-		synchronized (this.queries) {
-			final Query query;
-			final MamReference startActual = MamReference.max(start, mXmppConnectionService.getAutomaticMessageDeletionDate());
-			if (start.getTimestamp() == 0) {
-				query = new Query(conversation, startActual, end, false);
-				query.reference = conversation.getFirstMamReference();
-			} else {
-				if (allowCatchup) {
-					MamReference maxCatchup = MamReference.max(startActual, System.currentTimeMillis() - Config.MAM_MAX_CATCHUP);
-					if (maxCatchup.greaterThan(startActual)) {
-						Query reverseCatchup = new Query(conversation, startActual, maxCatchup.getTimestamp(), false);
-						this.queries.add(reverseCatchup);
-						this.execute(reverseCatchup);
-					}
-					query = new Query(conversation, maxCatchup, end, true);
-				} else {
-					query = new Query(conversation, startActual, end, false);
-				}
-			}
-			if (end != 0 && start.greaterThan(end)) {
-				return null;
-			}
-			this.queries.add(query);
-			this.execute(query);
-			return query;
-		}
-	}
-
-	void executePendingQueries(final Account account) {
-		List<Query> pending = new ArrayList<>();
-		synchronized (this.pendingQueries) {
-			for (Iterator<Query> iterator = this.pendingQueries.iterator(); iterator.hasNext(); ) {
-				Query query = iterator.next();
-				if (query.getAccount() == account) {
-					pending.add(query);
-					iterator.remove();
-				}
-			}
-		}
-		for (Query query : pending) {
-			this.execute(query);
-		}
-	}
-
-	private void execute(final Query query) {
-		final Account account = query.getAccount();
-		if (account.getStatus() == Account.State.ONLINE) {
-			final Conversation conversation = query.getConversation();
-			if (conversation != null && conversation.getStatus() == Conversation.STATUS_ARCHIVED) {
-				throw new IllegalStateException("Attempted to run MAM query for archived conversation");
-			}
-			Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": running mam query " + query.toString());
-			final IqPacket packet = this.mXmppConnectionService.getIqGenerator().queryMessageArchiveManagement(query);
-			this.mXmppConnectionService.sendIqPacket(account, packet, (a, p) -> {
-				final Element fin = p.findChild("fin", query.version.namespace);
-				if (p.getType() == IqPacket.TYPE.TIMEOUT) {
-					synchronized (this.queries) {
-						this.queries.remove(query);
-						if (query.hasCallback()) {
-							query.callback(false);
-						}
-					}
-				} else if (p.getType() == IqPacket.TYPE.RESULT && fin != null) {
-					final boolean running;
-					synchronized (this.queries) {
-						running = this.queries.contains(query);
-					}
-					if (running) {
-						processFin(query, fin);
-					} else {
-						Log.d(Config.LOGTAG,account.getJid().asBareJid()+": ignoring MAM iq result because query had been killed");
-					}
-				} else if (p.getType() == IqPacket.TYPE.RESULT && query.isLegacy()) {
-					//do nothing
-				} else {
-					Log.d(Config.LOGTAG, a.getJid().asBareJid().toString() + ": error executing mam: " + p.toString());
-					finalizeQuery(query, true);
-				}
-			});
-		} else {
-			synchronized (this.pendingQueries) {
-				this.pendingQueries.add(query);
-			}
-		}
-	}
-
-	private void finalizeQuery(final Query query, boolean done) {
-		synchronized (this.queries) {
-			if (!this.queries.remove(query)) {
-				throw new IllegalStateException("Unable to remove query from queries");
-			}
-		}
-		final Conversation conversation = query.getConversation();
-		if (conversation != null) {
-			conversation.sort();
-			conversation.setHasMessagesLeftOnServer(!done);
-		} else {
-			for (Conversation tmp : this.mXmppConnectionService.getConversations()) {
-				if (tmp.getAccount() == query.getAccount()) {
-					tmp.sort();
-				}
-			}
-		}
-		if (query.hasCallback()) {
-			query.callback(done);
-		} else {
-			this.mXmppConnectionService.updateConversationUi();
-		}
-	}
-
-	boolean inCatchup(Account account) {
-		synchronized (this.queries) {
-			for (Query query : queries) {
-				if (query.account == account && query.isCatchup() && query.getWith() == null) {
-					return true;
-				}
-			}
-		}
-		return false;
-	}
-
-	public boolean isCatchupInProgress(Conversation conversation) {
-		synchronized (this.queries) {
-			for(Query query : queries) {
-				if (query.account == conversation.getAccount() && query.isCatchup()) {
-					final Jid with = query.getWith() == null ? null : query.getWith().asBareJid();
-					if ((conversation.getMode() == Conversational.MODE_SINGLE && with == null) || (conversation.getJid().asBareJid().equals(with))) {
-						return true;
-					}
-				}
-			}
-		}
-		return false;
-	}
-
-	boolean queryInProgress(Conversation conversation, XmppConnectionService.OnMoreMessagesLoaded callback) {
-		synchronized (this.queries) {
-			for (Query query : queries) {
-				if (query.conversation == conversation) {
-					if (!query.hasCallback() && callback != null) {
-						query.setCallback(callback);
-					}
-					return true;
-				}
-			}
-			return false;
-		}
-	}
-
-	public boolean queryInProgress(Conversation conversation) {
-		return queryInProgress(conversation, null);
-	}
-
-	public void processFinLegacy(Element fin, Jid from) {
-		Query query = findQuery(fin.getAttribute("queryid"));
-		if (query != null && query.validFrom(from)) {
-			processFin(query, fin);
-		}
-	}
-
-	private void processFin(Query query, Element fin) {
-		boolean complete = fin.getAttributeAsBoolean("complete");
-		Element set = fin.findChild("set", "http://jabber.org/protocol/rsm");
-		Element last = set == null ? null : set.findChild("last");
-		String count = set == null ? null : set.findChildContent("count");
-		Element first = set == null ? null : set.findChild("first");
-		Element relevant = query.getPagingOrder() == PagingOrder.NORMAL ? last : first;
-		boolean abort = (!query.isCatchup() && query.getTotalCount() >= Config.PAGE_SIZE) || query.getTotalCount() >= Config.MAM_MAX_MESSAGES;
-		if (query.getConversation() != null) {
-			query.getConversation().setFirstMamReference(first == null ? null : first.getContent());
-		}
-		if (complete || relevant == null || abort) {
-			//TODO: FIX done logic to look at complete. using count is probably unreliable because it can be ommited and doesn’t work with paging.
-			boolean done;
-			if (query.isCatchup()) {
-				done = false;
-			} else {
-				if (count != null) {
-					try {
-						done = Integer.parseInt(count) <= query.getTotalCount();
-					} catch (NumberFormatException e) {
-						done = false;
-					}
-				} else {
-					done = query.getTotalCount() == 0;
-				}
-			}
-			done = done || (query.getActualMessageCount() == 0 && !query.isCatchup());
-			this.finalizeQuery(query, done);
-
-			Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": finished mam after " + query.getTotalCount() + "(" + query.getActualMessageCount() + ") messages. messages left=" + !done + " count=" + count);
-			if (query.isCatchup() && query.getActualMessageCount() > 0) {
-				mXmppConnectionService.getNotificationService().finishBacklog(true, query.getAccount());
-			}
-			processPostponed(query);
-		} else {
-			final Query nextQuery;
-			if (query.getPagingOrder() == PagingOrder.NORMAL) {
-				nextQuery = query.next(last == null ? null : last.getContent());
-			} else {
-				nextQuery = query.prev(first == null ? null : first.getContent());
-			}
-			this.execute(nextQuery);
-			this.finalizeQuery(query, false);
-			synchronized (this.queries) {
-				this.queries.add(nextQuery);
-			}
-		}
-	}
-
-	void kill(Conversation conversation) {
-		final ArrayList<Query> toBeKilled = new ArrayList<>();
-		synchronized (this.queries) {
-			for (final Query q : queries) {
-				if (q.conversation == conversation) {
-					toBeKilled.add(q);
-				}
-			}
-		}
-		for (Query q : toBeKilled) {
-			kill(q);
-		}
-	}
-
-	private void kill(Query query) {
-		Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": killing mam query prematurely");
-		query.callback = null;
-		this.finalizeQuery(query, false);
-		if (query.isCatchup() && query.getActualMessageCount() > 0) {
-			mXmppConnectionService.getNotificationService().finishBacklog(true, query.getAccount());
-		}
-		this.processPostponed(query);
-	}
-
-	private void processPostponed(Query query) {
-		query.account.getAxolotlService().processPostponed();
-		query.pendingReceiptRequests.removeAll(query.receiptRequests);
-		Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": found " + query.pendingReceiptRequests.size() + " pending receipt requests");
-		Iterator<ReceiptRequest> iterator = query.pendingReceiptRequests.iterator();
-		while (iterator.hasNext()) {
-			ReceiptRequest rr = iterator.next();
-			mXmppConnectionService.sendMessagePacket(query.account, mXmppConnectionService.getMessageGenerator().received(query.account, rr.getJid(), rr.getId()));
-			iterator.remove();
-		}
-	}
-
-	public Query findQuery(String id) {
-		if (id == null) {
-			return null;
-		}
-		synchronized (this.queries) {
-			for (Query query : this.queries) {
-				if (query.getQueryId().equals(id)) {
-					return query;
-				}
-			}
-			return null;
-		}
-	}
-
-	@Override
-	public void onAdvancedStreamFeaturesAvailable(Account account) {
-		if (account.getXmppConnection() != null && account.getXmppConnection().getFeatures().mam()) {
-			this.catchup(account);
-		}
-	}
-
-	public enum PagingOrder {
-		NORMAL,
-		REVERSE
-	}
-
-	public class Query {
-		private HashSet<ReceiptRequest> pendingReceiptRequests = new HashSet<>();
-		private HashSet<ReceiptRequest> receiptRequests = new HashSet<>();
-		private int totalCount = 0;
-		private int actualCount = 0;
-		private int actualInThisQuery = 0;
-		private long start;
-		private final long end;
-		private final String queryId;
-		private String reference = null;
-		private final Account account;
-		private Conversation conversation;
-		private PagingOrder pagingOrder = PagingOrder.NORMAL;
-		private XmppConnectionService.OnMoreMessagesLoaded callback = null;
-		private boolean catchup = true;
-		public final Version version;
-
-
-		Query(Conversation conversation, MamReference start, long end, boolean catchup) {
-			this(conversation.getAccount(), Version.get(conversation.getAccount(), conversation), catchup ? start : start.timeOnly(), end);
-			this.conversation = conversation;
-			this.pagingOrder = catchup ? PagingOrder.NORMAL : PagingOrder.REVERSE;
-			this.catchup = catchup;
-		}
-
-		Query(Account account, MamReference start, long end) {
-			this(account, Version.get(account), start, end);
-		}
-
-		Query(Account account, Version version, MamReference start, long end) {
-			this.account = account;
-			if (start.getReference() != null) {
-				this.reference = start.getReference();
-			} else {
-				this.start = start.getTimestamp();
-			}
-			this.end = end;
-			this.queryId = new BigInteger(50, mXmppConnectionService.getRNG()).toString(32);
-			this.version = version;
-		}
-
-		private Query page(String reference) {
-			Query query = new Query(this.account, this.version, new MamReference(this.start, reference), this.end);
-			query.conversation = conversation;
-			query.totalCount = totalCount;
-			query.actualCount = actualCount;
-			query.pendingReceiptRequests = pendingReceiptRequests;
-			query.receiptRequests = receiptRequests;
-			query.callback = callback;
-			query.catchup = catchup;
-			return query;
-		}
-
-		public void removePendingReceiptRequest(ReceiptRequest receiptRequest) {
-			if (!this.pendingReceiptRequests.remove(receiptRequest)) {
-				this.receiptRequests.add(receiptRequest);
-			}
-		}
-
-		public void addPendingReceiptRequest(ReceiptRequest receiptRequest) {
-			this.pendingReceiptRequests.add(receiptRequest);
-		}
-
-		public boolean isLegacy() {
-			return version.legacy;
-		}
-
-		public boolean safeToExtractTrueCounterpart() {
-			return muc() && !isLegacy();
-		}
-
-		public Query next(String reference) {
-			Query query = page(reference);
-			query.pagingOrder = PagingOrder.NORMAL;
-			return query;
-		}
-
-		Query prev(String reference) {
-			Query query = page(reference);
-			query.pagingOrder = PagingOrder.REVERSE;
-			return query;
-		}
-
-		public String getReference() {
-			return reference;
-		}
-
-		public PagingOrder getPagingOrder() {
-			return this.pagingOrder;
-		}
-
-		public String getQueryId() {
-			return queryId;
-		}
-
-		public Jid getWith() {
-			return conversation == null ? null : conversation.getJid().asBareJid();
-		}
-
-		public boolean muc() {
-			return conversation != null && conversation.getMode() == Conversation.MODE_MULTI;
-		}
-
-		public long getStart() {
-			return start;
-		}
-
-		public boolean isCatchup() {
-			return catchup;
-		}
-
-		public void setCallback(XmppConnectionService.OnMoreMessagesLoaded callback) {
-			this.callback = callback;
-		}
-
-		public void callback(boolean done) {
-			if (this.callback != null) {
-				this.callback.onMoreMessagesLoaded(actualCount, conversation);
-				if (done) {
-					this.callback.informUser(R.string.no_more_history_on_server);
-				}
-			}
-		}
-
-		public long getEnd() {
-			return end;
-		}
-
-		public Conversation getConversation() {
-			return conversation;
-		}
-
-		public Account getAccount() {
-			return this.account;
-		}
-
-		public void incrementMessageCount() {
-			this.totalCount++;
-		}
-
-		public void incrementActualMessageCount() {
-			this.actualInThisQuery++;
-			this.actualCount++;
-		}
-
-		int getTotalCount() {
-			return this.totalCount;
-		}
-
-		int getActualMessageCount() {
-			return this.actualCount;
-		}
-
-		public int getActualInThisQuery() {
-			return this.actualInThisQuery;
-		}
-
-		public boolean validFrom(Jid from) {
-			if (muc()) {
-				return getWith().equals(from);
-			} else {
-				return (from == null) || account.getJid().asBareJid().equals(from.asBareJid());
-			}
-		}
-
-		@NotNull
-		@Override
-		public String toString() {
-			StringBuilder builder = new StringBuilder();
-			if (this.muc()) {
-				builder.append("to=");
-				builder.append(this.getWith().toString());
-			} else {
-				builder.append("with=");
-				if (this.getWith() == null) {
-					builder.append("*");
-				} else {
-					builder.append(getWith().toString());
-				}
-			}
-			if (this.start != 0) {
-				builder.append(", start=");
-				builder.append(AbstractGenerator.getTimestamp(this.start));
-			}
-			if (this.end != 0) {
-				builder.append(", end=");
-				builder.append(AbstractGenerator.getTimestamp(this.end));
-			}
-			builder.append(", order=").append(pagingOrder.toString());
-			if (this.reference != null) {
-				if (this.pagingOrder == PagingOrder.NORMAL) {
-					builder.append(", after=");
-				} else {
-					builder.append(", before=");
-				}
-				builder.append(this.reference);
-			}
-			builder.append(", catchup=").append(catchup);
-			builder.append(", ns=").append(version.namespace);
-			return builder.toString();
-		}
-
-		boolean hasCallback() {
-			return this.callback != null;
-		}
-	}
+        this.mXmppConnectionService = service;
+    }
+
+    private void catchup(final Account account) {
+        synchronized (this.queries) {
+            for (Iterator<Query> iterator = this.queries.iterator(); iterator.hasNext(); ) {
+                Query query = iterator.next();
+                if (query.getAccount() == account) {
+                    iterator.remove();
+                }
+            }
+        }
+        MamReference mamReference = MamReference.max(
+                mXmppConnectionService.databaseBackend.getLastMessageReceived(account),
+                mXmppConnectionService.databaseBackend.getLastClearDate(account)
+        );
+        mamReference = MamReference.max(mamReference, mXmppConnectionService.getAutomaticMessageDeletionDate());
+        long endCatchup = account.getXmppConnection().getLastSessionEstablished();
+        final Query query;
+        if (mamReference.getTimestamp() == 0) {
+            return;
+        } else if (endCatchup - mamReference.getTimestamp() >= Config.MAM_MAX_CATCHUP) {
+            long startCatchup = endCatchup - Config.MAM_MAX_CATCHUP;
+            List<Conversation> conversations = mXmppConnectionService.getConversations();
+            for (Conversation conversation : conversations) {
+                if (conversation.getMode() == Conversation.MODE_SINGLE && conversation.getAccount() == account && startCatchup > conversation.getLastMessageTransmitted().getTimestamp()) {
+                    this.query(conversation, startCatchup, true);
+                }
+            }
+            query = new Query(account, new MamReference(startCatchup), 0);
+        } else {
+            query = new Query(account, mamReference, 0);
+        }
+        synchronized (this.queries) {
+            this.queries.add(query);
+        }
+        this.execute(query);
+    }
+
+    void catchupMUC(final Conversation conversation) {
+        if (conversation.getLastMessageTransmitted().getTimestamp() < 0 && conversation.countMessages() == 0) {
+            query(conversation,
+                    new MamReference(0),
+                    0,
+                    true);
+        } else {
+            query(conversation,
+                    conversation.getLastMessageTransmitted(),
+                    0,
+                    true);
+        }
+    }
+
+    public Query query(final Conversation conversation) {
+        if (conversation.getLastMessageTransmitted().getTimestamp() < 0 && conversation.countMessages() == 0) {
+            return query(conversation,
+                    new MamReference(0),
+                    System.currentTimeMillis(),
+                    false);
+        } else {
+            return query(conversation,
+                    conversation.getLastMessageTransmitted(),
+                    conversation.getAccount().getXmppConnection().getLastSessionEstablished(),
+                    false);
+        }
+    }
+
+    public boolean isCatchingUp(Conversation conversation) {
+        final Account account = conversation.getAccount();
+        if (account.getXmppConnection().isWaitingForSmCatchup()) {
+            return true;
+        } else {
+            synchronized (this.queries) {
+                for (Query query : this.queries) {
+                    if (query.getAccount() == account && query.isCatchup() && ((conversation.getMode() == Conversation.MODE_SINGLE && query.getWith() == null) || query.getConversation() == conversation)) {
+                        return true;
+                    }
+                }
+            }
+            return false;
+        }
+    }
+
+    public Query query(final Conversation conversation, long end, boolean allowCatchup) {
+        return this.query(conversation, conversation.getLastMessageTransmitted(), end, allowCatchup);
+    }
+
+    public Query query(Conversation conversation, MamReference start, long end, boolean allowCatchup) {
+        synchronized (this.queries) {
+            final Query query;
+            final MamReference startActual = MamReference.max(start, mXmppConnectionService.getAutomaticMessageDeletionDate());
+            if (start.getTimestamp() == 0) {
+                query = new Query(conversation, startActual, end, false);
+                query.reference = conversation.getFirstMamReference();
+            } else {
+                if (allowCatchup) {
+                    MamReference maxCatchup = MamReference.max(startActual, System.currentTimeMillis() - Config.MAM_MAX_CATCHUP);
+                    if (maxCatchup.greaterThan(startActual)) {
+                        Query reverseCatchup = new Query(conversation, startActual, maxCatchup.getTimestamp(), false);
+                        this.queries.add(reverseCatchup);
+                        this.execute(reverseCatchup);
+                    }
+                    query = new Query(conversation, maxCatchup, end, true);
+                } else {
+                    query = new Query(conversation, startActual, end, false);
+                }
+            }
+            if (end != 0 && start.greaterThan(end)) {
+                return null;
+            }
+            this.queries.add(query);
+            this.execute(query);
+            return query;
+        }
+    }
+
+    void executePendingQueries(final Account account) {
+        final List<Query> pending = new ArrayList<>();
+        synchronized (this.pendingQueries) {
+            for (Iterator<Query> iterator = this.pendingQueries.iterator(); iterator.hasNext(); ) {
+                Query query = iterator.next();
+                if (query.getAccount() == account) {
+                    pending.add(query);
+                    iterator.remove();
+                }
+            }
+        }
+        for (Query query : pending) {
+            this.execute(query);
+        }
+    }
+
+    private void execute(final Query query) {
+        final Account account = query.getAccount();
+        if (account.getStatus() == Account.State.ONLINE) {
+            final Conversation conversation = query.getConversation();
+            if (conversation != null && conversation.getStatus() == Conversation.STATUS_ARCHIVED) {
+                throw new IllegalStateException("Attempted to run MAM query for archived conversation");
+            }
+            Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": running mam query " + query.toString());
+            final IqPacket packet = this.mXmppConnectionService.getIqGenerator().queryMessageArchiveManagement(query);
+            this.mXmppConnectionService.sendIqPacket(account, packet, (a, p) -> {
+                final Element fin = p.findChild("fin", query.version.namespace);
+                if (p.getType() == IqPacket.TYPE.TIMEOUT) {
+                    synchronized (this.queries) {
+                        this.queries.remove(query);
+                        if (query.hasCallback()) {
+                            query.callback(false);
+                        }
+                    }
+                } else if (p.getType() == IqPacket.TYPE.RESULT && fin != null) {
+                    final boolean running;
+                    synchronized (this.queries) {
+                        running = this.queries.contains(query);
+                    }
+                    if (running) {
+                        processFin(query, fin);
+                    } else {
+                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": ignoring MAM iq result because query had been killed");
+                    }
+                } else if (p.getType() == IqPacket.TYPE.RESULT && query.isLegacy()) {
+                    //do nothing
+                } else {
+                    Log.d(Config.LOGTAG, a.getJid().asBareJid().toString() + ": error executing mam: " + p.toString());
+                    finalizeQuery(query, true);
+                }
+            });
+        } else {
+            synchronized (this.pendingQueries) {
+                this.pendingQueries.add(query);
+            }
+        }
+    }
+
+    private void finalizeQuery(final Query query, boolean done) {
+        synchronized (this.queries) {
+            if (!this.queries.remove(query)) {
+                throw new IllegalStateException("Unable to remove query from queries");
+            }
+        }
+        final Conversation conversation = query.getConversation();
+        if (conversation != null) {
+            conversation.sort();
+            conversation.setHasMessagesLeftOnServer(!done);
+        } else {
+            for (Conversation tmp : this.mXmppConnectionService.getConversations()) {
+                if (tmp.getAccount() == query.getAccount()) {
+                    tmp.sort();
+                }
+            }
+        }
+        if (query.hasCallback()) {
+            query.callback(done);
+        } else {
+            this.mXmppConnectionService.updateConversationUi();
+        }
+    }
+
+    boolean inCatchup(Account account) {
+        synchronized (this.queries) {
+            for (Query query : queries) {
+                if (query.account == account && query.isCatchup() && query.getWith() == null) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    public boolean isCatchupInProgress(Conversation conversation) {
+        synchronized (this.queries) {
+            for (Query query : queries) {
+                if (query.account == conversation.getAccount() && query.isCatchup()) {
+                    final Jid with = query.getWith() == null ? null : query.getWith().asBareJid();
+                    if ((conversation.getMode() == Conversational.MODE_SINGLE && with == null) || (conversation.getJid().asBareJid().equals(with))) {
+                        return true;
+                    }
+                }
+            }
+        }
+        return false;
+    }
+
+    boolean queryInProgress(Conversation conversation, XmppConnectionService.OnMoreMessagesLoaded callback) {
+        synchronized (this.queries) {
+            for (Query query : queries) {
+                if (query.conversation == conversation) {
+                    if (!query.hasCallback() && callback != null) {
+                        query.setCallback(callback);
+                    }
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
+
+    public boolean queryInProgress(Conversation conversation) {
+        return queryInProgress(conversation, null);
+    }
+
+    public void processFinLegacy(Element fin, Jid from) {
+        Query query = findQuery(fin.getAttribute("queryid"));
+        if (query != null && query.validFrom(from)) {
+            processFin(query, fin);
+        }
+    }
+
+    private void processFin(Query query, Element fin) {
+        boolean complete = fin.getAttributeAsBoolean("complete");
+        Element set = fin.findChild("set", "http://jabber.org/protocol/rsm");
+        Element last = set == null ? null : set.findChild("last");
+        String count = set == null ? null : set.findChildContent("count");
+        Element first = set == null ? null : set.findChild("first");
+        Element relevant = query.getPagingOrder() == PagingOrder.NORMAL ? last : first;
+        boolean abort = (!query.isCatchup() && query.getTotalCount() >= Config.PAGE_SIZE) || query.getTotalCount() >= Config.MAM_MAX_MESSAGES;
+        if (query.getConversation() != null) {
+            query.getConversation().setFirstMamReference(first == null ? null : first.getContent());
+        }
+        if (complete || relevant == null || abort) {
+            //TODO: FIX done logic to look at complete. using count is probably unreliable because it can be ommited and doesn’t work with paging.
+            boolean done;
+            if (query.isCatchup()) {
+                done = false;
+            } else {
+                if (count != null) {
+                    try {
+                        done = Integer.parseInt(count) <= query.getTotalCount();
+                    } catch (NumberFormatException e) {
+                        done = false;
+                    }
+                } else {
+                    done = query.getTotalCount() == 0;
+                }
+            }
+            done = done || (query.getActualMessageCount() == 0 && !query.isCatchup());
+            this.finalizeQuery(query, done);
+
+            Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": finished mam after " + query.getTotalCount() + "(" + query.getActualMessageCount() + ") messages. messages left=" + !done + " count=" + count);
+            if (query.isCatchup() && query.getActualMessageCount() > 0) {
+                mXmppConnectionService.getNotificationService().finishBacklog(true, query.getAccount());
+            }
+            processPostponed(query);
+        } else {
+            final Query nextQuery;
+            if (query.getPagingOrder() == PagingOrder.NORMAL) {
+                nextQuery = query.next(last == null ? null : last.getContent());
+            } else {
+                nextQuery = query.prev(first == null ? null : first.getContent());
+            }
+            this.execute(nextQuery);
+            this.finalizeQuery(query, false);
+            synchronized (this.queries) {
+                this.queries.add(nextQuery);
+            }
+        }
+    }
+
+    void kill(final Conversation conversation) {
+        final ArrayList<Query> toBeKilled = new ArrayList<>();
+        synchronized (this.pendingQueries) {
+            for (final Iterator<Query> iterator = this.pendingQueries.iterator(); iterator.hasNext(); ) {
+                final Query query = iterator.next();
+                if (query.getConversation() == conversation) {
+                    iterator.remove();
+                    Log.d(Config.LOGTAG, conversation.getAccount().getJid().asBareJid() + ": killed pending MAM query for archived conversation");
+                }
+            }
+        }
+        synchronized (this.queries) {
+            for (final Query q : queries) {
+                if (q.conversation == conversation) {
+                    toBeKilled.add(q);
+                }
+            }
+        }
+        for (final Query q : toBeKilled) {
+            kill(q);
+        }
+    }
+
+    private void kill(Query query) {
+        Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": killing mam query prematurely");
+        query.callback = null;
+        this.finalizeQuery(query, false);
+        if (query.isCatchup() && query.getActualMessageCount() > 0) {
+            mXmppConnectionService.getNotificationService().finishBacklog(true, query.getAccount());
+        }
+        this.processPostponed(query);
+    }
+
+    private void processPostponed(Query query) {
+        query.account.getAxolotlService().processPostponed();
+        query.pendingReceiptRequests.removeAll(query.receiptRequests);
+        Log.d(Config.LOGTAG, query.getAccount().getJid().asBareJid() + ": found " + query.pendingReceiptRequests.size() + " pending receipt requests");
+        Iterator<ReceiptRequest> iterator = query.pendingReceiptRequests.iterator();
+        while (iterator.hasNext()) {
+            ReceiptRequest rr = iterator.next();
+            mXmppConnectionService.sendMessagePacket(query.account, mXmppConnectionService.getMessageGenerator().received(query.account, rr.getJid(), rr.getId()));
+            iterator.remove();
+        }
+    }
+
+    public Query findQuery(String id) {
+        if (id == null) {
+            return null;
+        }
+        synchronized (this.queries) {
+            for (Query query : this.queries) {
+                if (query.getQueryId().equals(id)) {
+                    return query;
+                }
+            }
+            return null;
+        }
+    }
+
+    @Override
+    public void onAdvancedStreamFeaturesAvailable(Account account) {
+        if (account.getXmppConnection() != null && account.getXmppConnection().getFeatures().mam()) {
+            this.catchup(account);
+        }
+    }
+
+    public enum PagingOrder {
+        NORMAL,
+        REVERSE
+    }
+
+    public class Query {
+        private HashSet<ReceiptRequest> pendingReceiptRequests = new HashSet<>();
+        private HashSet<ReceiptRequest> receiptRequests = new HashSet<>();
+        private int totalCount = 0;
+        private int actualCount = 0;
+        private int actualInThisQuery = 0;
+        private long start;
+        private final long end;
+        private final String queryId;
+        private String reference = null;
+        private final Account account;
+        private Conversation conversation;
+        private PagingOrder pagingOrder = PagingOrder.NORMAL;
+        private XmppConnectionService.OnMoreMessagesLoaded callback = null;
+        private boolean catchup = true;
+        public final Version version;
+
+
+        Query(Conversation conversation, MamReference start, long end, boolean catchup) {
+            this(conversation.getAccount(), Version.get(conversation.getAccount(), conversation), catchup ? start : start.timeOnly(), end);
+            this.conversation = conversation;
+            this.pagingOrder = catchup ? PagingOrder.NORMAL : PagingOrder.REVERSE;
+            this.catchup = catchup;
+        }
+
+        Query(Account account, MamReference start, long end) {
+            this(account, Version.get(account), start, end);
+        }
+
+        Query(Account account, Version version, MamReference start, long end) {
+            this.account = account;
+            if (start.getReference() != null) {
+                this.reference = start.getReference();
+            } else {
+                this.start = start.getTimestamp();
+            }
+            this.end = end;
+            this.queryId = new BigInteger(50, mXmppConnectionService.getRNG()).toString(32);
+            this.version = version;
+        }
+
+        private Query page(String reference) {
+            Query query = new Query(this.account, this.version, new MamReference(this.start, reference), this.end);
+            query.conversation = conversation;
+            query.totalCount = totalCount;
+            query.actualCount = actualCount;
+            query.pendingReceiptRequests = pendingReceiptRequests;
+            query.receiptRequests = receiptRequests;
+            query.callback = callback;
+            query.catchup = catchup;
+            return query;
+        }
+
+        public void removePendingReceiptRequest(ReceiptRequest receiptRequest) {
+            if (!this.pendingReceiptRequests.remove(receiptRequest)) {
+                this.receiptRequests.add(receiptRequest);
+            }
+        }
+
+        public void addPendingReceiptRequest(ReceiptRequest receiptRequest) {
+            this.pendingReceiptRequests.add(receiptRequest);
+        }
+
+        public boolean isLegacy() {
+            return version.legacy;
+        }
+
+        public boolean safeToExtractTrueCounterpart() {
+            return muc() && !isLegacy();
+        }
+
+        public Query next(String reference) {
+            Query query = page(reference);
+            query.pagingOrder = PagingOrder.NORMAL;
+            return query;
+        }
+
+        Query prev(String reference) {
+            Query query = page(reference);
+            query.pagingOrder = PagingOrder.REVERSE;
+            return query;
+        }
+
+        public String getReference() {
+            return reference;
+        }
+
+        public PagingOrder getPagingOrder() {
+            return this.pagingOrder;
+        }
+
+        public String getQueryId() {
+            return queryId;
+        }
+
+        public Jid getWith() {
+            return conversation == null ? null : conversation.getJid().asBareJid();
+        }
+
+        public boolean muc() {
+            return conversation != null && conversation.getMode() == Conversation.MODE_MULTI;
+        }
+
+        public long getStart() {
+            return start;
+        }
+
+        public boolean isCatchup() {
+            return catchup;
+        }
+
+        public void setCallback(XmppConnectionService.OnMoreMessagesLoaded callback) {
+            this.callback = callback;
+        }
+
+        public void callback(boolean done) {
+            if (this.callback != null) {
+                this.callback.onMoreMessagesLoaded(actualCount, conversation);
+                if (done) {
+                    this.callback.informUser(R.string.no_more_history_on_server);
+                }
+            }
+        }
+
+        public long getEnd() {
+            return end;
+        }
+
+        public Conversation getConversation() {
+            return conversation;
+        }
+
+        public Account getAccount() {
+            return this.account;
+        }
+
+        public void incrementMessageCount() {
+            this.totalCount++;
+        }
+
+        public void incrementActualMessageCount() {
+            this.actualInThisQuery++;
+            this.actualCount++;
+        }
+
+        int getTotalCount() {
+            return this.totalCount;
+        }
+
+        int getActualMessageCount() {
+            return this.actualCount;
+        }
+
+        public int getActualInThisQuery() {
+            return this.actualInThisQuery;
+        }
+
+        public boolean validFrom(Jid from) {
+            if (muc()) {
+                return getWith().equals(from);
+            } else {
+                return (from == null) || account.getJid().asBareJid().equals(from.asBareJid());
+            }
+        }
+
+        @NotNull
+        @Override
+        public String toString() {
+            StringBuilder builder = new StringBuilder();
+            if (this.muc()) {
+                builder.append("to=");
+                builder.append(this.getWith().toString());
+            } else {
+                builder.append("with=");
+                if (this.getWith() == null) {
+                    builder.append("*");
+                } else {
+                    builder.append(getWith().toString());
+                }
+            }
+            if (this.start != 0) {
+                builder.append(", start=");
+                builder.append(AbstractGenerator.getTimestamp(this.start));
+            }
+            if (this.end != 0) {
+                builder.append(", end=");
+                builder.append(AbstractGenerator.getTimestamp(this.end));
+            }
+            builder.append(", order=").append(pagingOrder.toString());
+            if (this.reference != null) {
+                if (this.pagingOrder == PagingOrder.NORMAL) {
+                    builder.append(", after=");
+                } else {
+                    builder.append(", before=");
+                }
+                builder.append(this.reference);
+            }
+            builder.append(", catchup=").append(catchup);
+            builder.append(", ns=").append(version.namespace);
+            return builder.toString();
+        }
+
+        boolean hasCallback() {
+            return this.callback != null;
+        }
+    }
 }