session-ios/src/Messages/TSMessagesManager.m

//  Created by Frederic Jacobs on 11/11/14.
//  Copyright (c) 2014 Open Whisper Systems. All rights reserved.

#import "TSMessagesManager.h"
#import "ContactsManagerProtocol.h"
#import "ContactsUpdater.h"
#import "MimeTypeUtil.h"
#import "NSData+messagePadding.h"
#import "NSDate+millisecondTimeStamp.h"
#import "OWSAttachmentsProcessor.h"
#import "OWSDisappearingConfigurationUpdateInfoMessage.h"
#import "OWSDisappearingMessagesConfiguration.h"
#import "OWSDisappearingMessagesJob.h"
#import "OWSIncomingSentMessageTranscript.h"
#import "OWSMessageSender.h"
#import "OWSReadReceiptsProcessor.h"
#import "OWSRecordTranscriptJob.h"
#import "OWSSyncContactsMessage.h"
#import "OWSSyncGroupsMessage.h"
#import "TSAccountManager.h"
#import "TSAttachmentStream.h"
#import "TSCall.h"
#import "TSContactThread.h"
#import "TSDatabaseView.h"
#import "TSGroupModel.h"
#import "TSGroupThread.h"
#import "TSInfoMessage.h"
#import "TSInvalidIdentityKeyReceivingErrorMessage.h"
#import "TSNetworkManager.h"
#import "TSStorageHeaders.h"
#import "TextSecureKitEnv.h"
#import <AxolotlKit/AxolotlExceptions.h>
#import <AxolotlKit/SessionCipher.h>

NS_ASSUME_NONNULL_BEGIN

@interface TSMessagesManager ()

@property (nonatomic, readonly) id<ContactsManagerProtocol> contactsManager;
@property (nonatomic, readonly) TSStorageManager *storageManager;
@property (nonatomic, readonly) OWSMessageSender *messageSender;
@property (nonatomic, readonly) OWSDisappearingMessagesJob *disappearingMessagesJob;

@end

@implementation TSMessagesManager

+ (instancetype)sharedManager {
    static TSMessagesManager *sharedMyManager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedMyManager = [[self alloc] initDefault];
    });
    return sharedMyManager;
}

- (instancetype)initDefault
{
    TSNetworkManager *networkManager = [TSNetworkManager sharedManager];
    TSStorageManager *storageManager = [TSStorageManager sharedManager];
    id<ContactsManagerProtocol> contactsManager = [TextSecureKitEnv sharedEnv].contactsManager;
    ContactsUpdater *contactsUpdater = [ContactsUpdater sharedUpdater];
    OWSMessageSender *messageSender = [[OWSMessageSender alloc] initWithNetworkManager:networkManager
                                                                        storageManager:storageManager
                                                                       contactsManager:contactsManager
                                                                       contactsUpdater:contactsUpdater];

    return [self initWithNetworkManager:networkManager
                         storageManager:storageManager
                        contactsManager:contactsManager
                        contactsUpdater:contactsUpdater
                          messageSender:messageSender];
}

- (instancetype)initWithNetworkManager:(TSNetworkManager *)networkManager
                        storageManager:(TSStorageManager *)storageManager
                       contactsManager:(id<ContactsManagerProtocol>)contactsManager
                       contactsUpdater:(ContactsUpdater *)contactsUpdater
                         messageSender:(OWSMessageSender *)messageSender
{
    self = [super init];

    if (!self) {
        return self;
    }

    _storageManager = storageManager;
    _networkManager = networkManager;
    _contactsManager = contactsManager;
    _contactsUpdater = contactsUpdater;
    _messageSender = messageSender;

    _dbConnection = storageManager.newDatabaseConnection;
    _disappearingMessagesJob = [[OWSDisappearingMessagesJob alloc] initWithStorageManager:storageManager];

    return self;
}

#pragma mark - message handling

- (void)handleReceivedEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
{
    @try {
        switch (envelope.type) {
            case OWSSignalServiceProtosEnvelopeTypeCiphertext:
                [self handleSecureMessage:envelope];
                break;
            case OWSSignalServiceProtosEnvelopeTypePrekeyBundle:
                [self handlePreKeyBundle:envelope];
                break;
            case OWSSignalServiceProtosEnvelopeTypeReceipt:
                DDLogInfo(@"Received a delivery receipt");
                [self handleDeliveryReceipt:envelope];
                break;

            // Other messages are just dismissed for now.

            case OWSSignalServiceProtosEnvelopeTypeKeyExchange:
                DDLogWarn(@"Received Key Exchange Message, not supported");
                break;
            case OWSSignalServiceProtosEnvelopeTypeUnknown:
                DDLogWarn(@"Received an unknown message type");
                break;
            default:
                DDLogWarn(@"Received unhandled envelope type: %d", (int)envelope.type);
                break;
        }
    } @catch (NSException *exception) {
        DDLogWarn(@"Received an incorrectly formatted protocol buffer: %@", exception.debugDescription);
    }
}

- (void)handleDeliveryReceipt:(OWSSignalServiceProtosEnvelope *)envelope
{
    [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
        TSInteraction *interaction =
            [TSInteraction interactionForTimestamp:envelope.timestamp withTransaction:transaction];
        if ([interaction isKindOfClass:[TSOutgoingMessage class]]) {
            TSOutgoingMessage *outgoingMessage = (TSOutgoingMessage *)interaction;
            outgoingMessage.messageState = TSOutgoingMessageStateDelivered;

            [outgoingMessage saveWithTransaction:transaction];
        }
    }];
}

- (void)handleSecureMessage:(OWSSignalServiceProtosEnvelope *)messageEnvelope
{
    @synchronized(self) {
        TSStorageManager *storageManager = [TSStorageManager sharedManager];
        NSString *recipientId = messageEnvelope.source;
        int deviceId = messageEnvelope.sourceDevice;

        if (![storageManager containsSession:recipientId deviceId:deviceId]) {
            [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
                TSErrorMessage *errorMessage =
                    [TSErrorMessage missingSessionWithEnvelope:messageEnvelope withTransaction:transaction];
                [errorMessage saveWithTransaction:transaction];
            }];
            return;
        }

        // DEPRECATED - Remove after all clients have been upgraded.
        NSData *encryptedData = messageEnvelope.hasContent ? messageEnvelope.content : messageEnvelope.legacyMessage;
        if (!encryptedData) {
            DDLogError(@"Skipping message envelope which had no encrypted data");
            return;
        }

        NSData *plaintextData;
        @try {
            WhisperMessage *message = [[WhisperMessage alloc] initWithData:encryptedData];
            SessionCipher *cipher = [[SessionCipher alloc] initWithSessionStore:storageManager
                                                                    preKeyStore:storageManager
                                                              signedPreKeyStore:storageManager
                                                               identityKeyStore:storageManager
                                                                    recipientId:recipientId
                                                                       deviceId:deviceId];

            plaintextData = [[cipher decrypt:message] removePadding];
        } @catch (NSException *exception) {
            [self processException:exception envelope:messageEnvelope];
            return;
        }

        if (messageEnvelope.hasContent) {
            OWSSignalServiceProtosContent *content = [OWSSignalServiceProtosContent parseFromData:plaintextData];
            if (content.hasSyncMessage) {
                [self handleIncomingEnvelope:messageEnvelope withSyncMessage:content.syncMessage];
            } else if (content.dataMessage) {
                [self handleIncomingEnvelope:messageEnvelope withDataMessage:content.dataMessage];
            }
        } else if (messageEnvelope.hasLegacyMessage) { // DEPRECATED - Remove after all clients have been upgraded.
            OWSSignalServiceProtosDataMessage *dataMessage =
                [OWSSignalServiceProtosDataMessage parseFromData:plaintextData];
            [self handleIncomingEnvelope:messageEnvelope withDataMessage:dataMessage];
        } else {
            DDLogWarn(@"Ignoring content that has no dataMessage or syncMessage.");
        }
    }
}

- (void)handlePreKeyBundle:(OWSSignalServiceProtosEnvelope *)preKeyEnvelope
{
    @synchronized(self) {
        TSStorageManager *storageManager = [TSStorageManager sharedManager];
        NSString *recipientId = preKeyEnvelope.source;
        int deviceId = preKeyEnvelope.sourceDevice;

        // DEPRECATED - Remove after all clients have been upgraded.
        NSData *encryptedData = preKeyEnvelope.hasContent ? preKeyEnvelope.content : preKeyEnvelope.legacyMessage;
        if (!encryptedData) {
            DDLogError(@"Skipping message envelope which had no encrypted data");
            return;
        }

        NSData *plaintextData;
        @try {
            PreKeyWhisperMessage *message = [[PreKeyWhisperMessage alloc] initWithData:encryptedData];
            SessionCipher *cipher = [[SessionCipher alloc] initWithSessionStore:storageManager
                                                                    preKeyStore:storageManager
                                                              signedPreKeyStore:storageManager
                                                               identityKeyStore:storageManager
                                                                    recipientId:recipientId
                                                                       deviceId:deviceId];

            plaintextData = [[cipher decrypt:message] removePadding];
        } @catch (NSException *exception) {
            [self processException:exception envelope:preKeyEnvelope];
            return;
        }

        if (preKeyEnvelope.hasContent) {
            OWSSignalServiceProtosContent *content = [OWSSignalServiceProtosContent parseFromData:plaintextData];
            if (content.hasSyncMessage) {
                [self handleIncomingEnvelope:preKeyEnvelope withSyncMessage:content.syncMessage];
            } else if (content.dataMessage) {
                [self handleIncomingEnvelope:preKeyEnvelope withDataMessage:content.dataMessage];
            }
        } else if (preKeyEnvelope.hasLegacyMessage) { // DEPRECATED - Remove after all clients have been upgraded.
            OWSSignalServiceProtosDataMessage *dataMessage =
                [OWSSignalServiceProtosDataMessage parseFromData:plaintextData];
            [self handleIncomingEnvelope:preKeyEnvelope withDataMessage:dataMessage];
        } else {
            DDLogWarn(@"Ignoring content that has no dataMessage or syncMessage.");
        }
    }
}

- (void)handleIncomingEnvelope:(OWSSignalServiceProtosEnvelope *)incomingEnvelope
               withDataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    if (dataMessage.hasGroup) {
        __block BOOL ignoreMessage = NO;
        [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
            TSGroupModel *emptyModelToFillOutId =
                [[TSGroupModel alloc] initWithTitle:nil memberIds:nil image:nil groupId:dataMessage.group.id];
            TSGroupThread *gThread = [TSGroupThread threadWithGroupModel:emptyModelToFillOutId transaction:transaction];
            if (gThread == nil && dataMessage.group.type != OWSSignalServiceProtosGroupContextTypeUpdate) {
                ignoreMessage = YES;
            }
        }];
        if (ignoreMessage) {
            // FIXME: https://github.com/WhisperSystems/Signal-iOS/issues/1340
            DDLogDebug(@"%@ Received message from group that I left or don't know about, ignoring", self.tag);
            return;
        }
    }
    if ((dataMessage.flags & OWSSignalServiceProtosDataMessageFlagsEndSession) != 0) {
        DDLogVerbose(@"%@ Received end session message", self.tag);
        [self handleEndSessionMessageWithEnvelope:incomingEnvelope dataMessage:dataMessage];
    } else if ((dataMessage.flags & OWSSignalServiceProtosDataMessageFlagsExpirationTimerUpdate) != 0) {
        DDLogVerbose(@"%@ Received expiration timer update message", self.tag);
        [self handleExpirationTimerUpdateMessageWithEnvelope:incomingEnvelope dataMessage:dataMessage];
    } else if (dataMessage.attachments.count > 0) {
        DDLogVerbose(@"%@ Received media message attachment", self.tag);
        [self handleReceivedMediaWithEnvelope:incomingEnvelope dataMessage:dataMessage];
    } else {
        DDLogVerbose(@"%@ Received data message.", self.tag);
        [self handleReceivedTextMessageWithEnvelope:incomingEnvelope dataMessage:dataMessage];
        if ([self isDataMessageGroupAvatarUpdate:dataMessage]) {
            DDLogVerbose(@"%@ Data message had group avatar attachment", self.tag);
            [self handleReceivedGroupAvatarUpdateWithEnvelope:incomingEnvelope dataMessage:dataMessage];
        }
    }
}

- (void)handleReceivedGroupAvatarUpdateWithEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
                                        dataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    TSGroupThread *groupThread = [TSGroupThread getOrCreateThreadWithGroupIdData:dataMessage.group.id];
    OWSAttachmentsProcessor *attachmentsProcessor =
        [[OWSAttachmentsProcessor alloc] initWithAttachmentProtos:@[ dataMessage.group.avatar ]
                                                        timestamp:envelope.timestamp
                                                            relay:envelope.relay
                                                           thread:groupThread
                                                   networkManager:self.networkManager];

    if (!attachmentsProcessor.hasSupportedAttachments) {
        DDLogWarn(@"%@ received unsupported group avatar envelope", self.tag);
        return;
    }
    [attachmentsProcessor fetchAttachmentsForMessage:nil
        success:^(TSAttachmentStream *_Nonnull attachmentStream) {
            [groupThread updateAvatarWithAttachmentStream:attachmentStream];
        }
        failure:^(NSError *_Nonnull error) {
            DDLogError(@"%@ failed to fetch attachments for group avatar sent at: %llu. with error: %@",
                self.tag,
                envelope.timestamp,
                error);
        }];
}

- (void)handleReceivedMediaWithEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
                            dataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    TSThread *thread = [self threadForEnvelope:envelope dataMessage:dataMessage];
    OWSAttachmentsProcessor *attachmentsProcessor =
        [[OWSAttachmentsProcessor alloc] initWithAttachmentProtos:dataMessage.attachments
                                                        timestamp:envelope.timestamp
                                                            relay:envelope.relay
                                                           thread:thread
                                                   networkManager:self.networkManager];
    if (!attachmentsProcessor.hasSupportedAttachments) {
        DDLogWarn(@"%@ received unsupported media envelope", self.tag);
        return;
    }

    TSIncomingMessage *createdMessage = [self handleReceivedEnvelope:envelope
                                                     withDataMessage:dataMessage
                                                       attachmentIds:attachmentsProcessor.supportedAttachmentIds];

    [attachmentsProcessor fetchAttachmentsForMessage:createdMessage
        success:^(TSAttachmentStream *_Nonnull attachmentStream) {
            DDLogDebug(
                @"%@ successfully fetched attachment: %@ for message: %@", self.tag, attachmentStream, createdMessage);
        }
        failure:^(NSError *_Nonnull error) {
            DDLogError(
                @"%@ failed to fetch attachments for message: %@ with error: %@", self.tag, createdMessage, error);
        }];
}

- (void)handleIncomingEnvelope:(OWSSignalServiceProtosEnvelope *)messageEnvelope
               withSyncMessage:(OWSSignalServiceProtosSyncMessage *)syncMessage
{
    if (syncMessage.hasSent) {
        DDLogInfo(@"%@ Received `sent` syncMessage, recording message transcript.", self.tag);
        OWSIncomingSentMessageTranscript *transcript =
            [[OWSIncomingSentMessageTranscript alloc] initWithProto:syncMessage.sent relay:messageEnvelope.relay];

        OWSRecordTranscriptJob *recordJob =
            [[OWSRecordTranscriptJob alloc] initWithIncomingSentMessageTranscript:transcript
                                                                    messageSender:self.messageSender
                                                                   networkManager:self.networkManager];

        if ([self isDataMessageGroupAvatarUpdate:syncMessage.sent.message]) {
            [recordJob runWithAttachmentHandler:^(TSAttachmentStream *_Nonnull attachmentStream) {
                TSGroupThread *groupThread =
                    [TSGroupThread getOrCreateThreadWithGroupIdData:syncMessage.sent.message.group.id];
                [groupThread updateAvatarWithAttachmentStream:attachmentStream];
            }];
        } else {
            [recordJob runWithAttachmentHandler:^(TSAttachmentStream *_Nonnull attachmentStream) {
                DDLogDebug(@"%@ successfully fetched transcript attachment: %@", self.tag, attachmentStream);
            }];
        }
    } else if (syncMessage.hasRequest) {
        if (syncMessage.request.type == OWSSignalServiceProtosSyncMessageRequestTypeContacts) {
            DDLogInfo(@"%@ Received request `Contacts` syncMessage.", self.tag);

            OWSSyncContactsMessage *syncContactsMessage =
                [[OWSSyncContactsMessage alloc] initWithContactsManager:self.contactsManager];

            [self.messageSender sendTemporaryAttachmentData:[syncContactsMessage buildPlainTextAttachmentData]
                contentType:OWSMimeTypeApplicationOctetStream
                inMessage:syncContactsMessage
                success:^{
                    DDLogInfo(@"%@ Successfully sent Contacts response syncMessage.", self.tag);
                }
                failure:^(NSError *error) {
                    DDLogError(@"%@ Failed to send Contacts response syncMessage with error: %@", self.tag, error);
                }];

        } else if (syncMessage.request.type == OWSSignalServiceProtosSyncMessageRequestTypeGroups) {
            DDLogInfo(@"%@ Received request `groups` syncMessage.", self.tag);

            OWSSyncGroupsMessage *syncGroupsMessage = [[OWSSyncGroupsMessage alloc] init];

            [self.messageSender sendTemporaryAttachmentData:[syncGroupsMessage buildPlainTextAttachmentData]
                contentType:OWSMimeTypeApplicationOctetStream
                inMessage:syncGroupsMessage
                success:^{
                    DDLogInfo(@"%@ Successfully sent Groups response syncMessage.", self.tag);
                }
                failure:^(NSError *error) {
                    DDLogError(@"%@ Failed to send Groups response syncMessage with error: %@", self.tag, error);
                }];
        }
    } else if (syncMessage.read.count > 0) {
        DDLogInfo(@"%@ Received %ld read receipt(s)", self.tag, (u_long)syncMessage.read.count);

        OWSReadReceiptsProcessor *readReceiptsProcessor =
            [[OWSReadReceiptsProcessor alloc] initWithReadReceiptProtos:syncMessage.read
                                                         storageManager:self.storageManager];
        [readReceiptsProcessor process];
    } else {
        DDLogWarn(@"%@ Ignoring unsupported sync message.", self.tag);
    }
}

- (void)handleEndSessionMessageWithEnvelope:(OWSSignalServiceProtosEnvelope *)endSessionEnvelope
                                dataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
        TSContactThread *thread =
            [TSContactThread getOrCreateThreadWithContactId:endSessionEnvelope.source transaction:transaction];
        uint64_t timeStamp = endSessionEnvelope.timestamp;

        if (thread) { // TODO thread should always be nonnull.
            [[[TSInfoMessage alloc] initWithTimestamp:timeStamp
                                             inThread:thread
                                          messageType:TSInfoMessageTypeSessionDidEnd] saveWithTransaction:transaction];
        }
    }];

    [[TSStorageManager sharedManager] deleteAllSessionsForContact:endSessionEnvelope.source];
}

- (void)handleExpirationTimerUpdateMessageWithEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
                                           dataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    TSThread *thread = [self threadForEnvelope:envelope dataMessage:dataMessage];

    OWSDisappearingMessagesConfiguration *disappearingMessagesConfiguration;
    if (dataMessage.hasExpireTimer && dataMessage.expireTimer > 0) {
        DDLogInfo(@"%@ Expiring messages duration turned to %u for thread %@",
            self.tag,
            (unsigned int)dataMessage.expireTimer,
            thread);
        disappearingMessagesConfiguration =
            [[OWSDisappearingMessagesConfiguration alloc] initWithThreadId:thread.uniqueId
                                                                   enabled:YES
                                                           durationSeconds:dataMessage.expireTimer];
    } else {
        DDLogInfo(@"%@ Expiring messages have been turned off for thread %@", self.tag, thread);
        disappearingMessagesConfiguration = [[OWSDisappearingMessagesConfiguration alloc]
            initWithThreadId:thread.uniqueId
                     enabled:NO
             durationSeconds:OWSDisappearingMessagesConfigurationDefaultExpirationDuration];
    }
    [disappearingMessagesConfiguration save];
    NSString *name = [self.contactsManager nameStringForPhoneIdentifier:envelope.source];
    OWSDisappearingConfigurationUpdateInfoMessage *message =
        [[OWSDisappearingConfigurationUpdateInfoMessage alloc] initWithTimestamp:envelope.timestamp
                                                                          thread:thread
                                                                   configuration:disappearingMessagesConfiguration
                                                             createdByRemoteName:name];
    [message save];
}

- (void)handleReceivedTextMessageWithEnvelope:(OWSSignalServiceProtosEnvelope *)textMessageEnvelope
                                  dataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    [self handleReceivedEnvelope:textMessageEnvelope withDataMessage:dataMessage attachmentIds:@[]];
}

- (TSIncomingMessage *)handleReceivedEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
                              withDataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
                                attachmentIds:(NSArray<NSString *> *)attachmentIds
{
    uint64_t timestamp = envelope.timestamp;
    NSString *body = dataMessage.body;
    NSData *groupId = dataMessage.hasGroup ? dataMessage.group.id : nil;

    __block TSIncomingMessage *_Nullable incomingMessage;
    __block TSThread *thread;

    [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
      if (groupId) {
          NSMutableArray *uniqueMemberIds = [[[NSSet setWithArray:dataMessage.group.members] allObjects] mutableCopy];
          TSGroupModel *model = [[TSGroupModel alloc] initWithTitle:dataMessage.group.name
                                                          memberIds:uniqueMemberIds
                                                              image:nil
                                                            groupId:dataMessage.group.id];
          TSGroupThread *gThread = [TSGroupThread getOrCreateThreadWithGroupModel:model transaction:transaction];
          [gThread saveWithTransaction:transaction];

          if (dataMessage.group.type == OWSSignalServiceProtosGroupContextTypeUpdate) {
              NSString *updateGroupInfo = [gThread.groupModel getInfoStringAboutUpdateTo:model contactsManager:self.contactsManager];
              gThread.groupModel        = model;
              [gThread saveWithTransaction:transaction];
              [[[TSInfoMessage alloc] initWithTimestamp:timestamp
                                               inThread:gThread
                                            messageType:TSInfoMessageTypeGroupUpdate
                                          customMessage:updateGroupInfo] saveWithTransaction:transaction];
          } else if (dataMessage.group.type == OWSSignalServiceProtosGroupContextTypeQuit) {
              NSString *nameString = [self.contactsManager nameStringForPhoneIdentifier:envelope.source];

              NSString *updateGroupInfo =
                  [NSString stringWithFormat:NSLocalizedString(@"GROUP_MEMBER_LEFT", @""), nameString];
              NSMutableArray *newGroupMembers = [NSMutableArray arrayWithArray:gThread.groupModel.groupMemberIds];
              [newGroupMembers removeObject:envelope.source];
              gThread.groupModel.groupMemberIds = newGroupMembers;

              [gThread saveWithTransaction:transaction];
              [[[TSInfoMessage alloc] initWithTimestamp:timestamp
                                               inThread:gThread
                                            messageType:TSInfoMessageTypeGroupUpdate
                                          customMessage:updateGroupInfo] saveWithTransaction:transaction];
          } else {
              incomingMessage = [[TSIncomingMessage alloc] initWithTimestamp:timestamp
                                                                    inThread:gThread
                                                                    authorId:envelope.source
                                                                 messageBody:body
                                                               attachmentIds:attachmentIds
                                                            expiresInSeconds:dataMessage.expireTimer];

              [incomingMessage saveWithTransaction:transaction];
          }

          thread = gThread;
      } else {
          TSContactThread *cThread = [TSContactThread getOrCreateThreadWithContactId:envelope.source
                                                                         transaction:transaction
                                                                               relay:envelope.relay];

          incomingMessage = [[TSIncomingMessage alloc] initWithTimestamp:timestamp
                                                                inThread:cThread
                                                                authorId:[cThread contactIdentifier]
                                                             messageBody:body
                                                           attachmentIds:attachmentIds
                                                        expiresInSeconds:dataMessage.expireTimer];
          thread = cThread;
      }

      if (thread && incomingMessage) {
          [incomingMessage saveWithTransaction:transaction];

          // Android allows attachments to be sent with body.
          if ([attachmentIds count] > 0 && body != nil && ![body isEqualToString:@""]) {
              // We want the text to be displayed under the attachment
              uint64_t textMessageTimestamp = timestamp + 1;
              TSIncomingMessage *textMessage;
              if ([thread isGroupThread]) {
                  TSGroupThread *gThread = (TSGroupThread *)thread;
                  textMessage = [[TSIncomingMessage alloc] initWithTimestamp:textMessageTimestamp
                                                                    inThread:gThread
                                                                    authorId:envelope.source
                                                                 messageBody:body];
              } else {
                  TSContactThread *cThread = (TSContactThread *)thread;
                  textMessage = [[TSIncomingMessage alloc] initWithTimestamp:textMessageTimestamp
                                                                    inThread:cThread
                                                                    authorId:[cThread contactIdentifier]
                                                                 messageBody:body];
              }
              textMessage.expiresInSeconds = dataMessage.expireTimer;
              [textMessage saveWithTransaction:transaction];
          }
      }
    }];

    if (incomingMessage && thread) {
        // In case we already have a read receipt for this new message (happens sometimes).
        OWSReadReceiptsProcessor *readReceiptsProcessor =
            [[OWSReadReceiptsProcessor alloc] initWithIncomingMessage:incomingMessage
                                                       storageManager:self.storageManager];
        [readReceiptsProcessor process];

        [self.disappearingMessagesJob becomeConsistentWithConfigurationForMessage:incomingMessage
                                                                  contactsManager:self.contactsManager];

        // Update thread preview in inbox
        [thread touch];

        // TODO Delay notification by 100ms?
        // It's pretty annoying when you're phone keeps buzzing while you're having a conversation on Desktop.
        NSString *name = [thread name];
        [[TextSecureKitEnv sharedEnv].notificationsManager notifyUserForIncomingMessage:incomingMessage
                                                                                   from:name
                                                                               inThread:thread];
    }

    return incomingMessage;
}

- (void)processException:(NSException *)exception envelope:(OWSSignalServiceProtosEnvelope *)envelope
{
    DDLogError(@"%@ Got exception: %@ of type: %@", self.tag, exception.description, exception.name);
    [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
      TSErrorMessage *errorMessage;

      if ([exception.name isEqualToString:NoSessionException]) {
          errorMessage = [TSErrorMessage missingSessionWithEnvelope:envelope withTransaction:transaction];
      } else if ([exception.name isEqualToString:InvalidKeyException]) {
          errorMessage = [TSErrorMessage invalidKeyExceptionWithEnvelope:envelope withTransaction:transaction];
      } else if ([exception.name isEqualToString:InvalidKeyIdException]) {
          errorMessage = [TSErrorMessage invalidKeyExceptionWithEnvelope:envelope withTransaction:transaction];
      } else if ([exception.name isEqualToString:DuplicateMessageException]) {
          // Duplicate messages are dismissed
          return;
      } else if ([exception.name isEqualToString:InvalidVersionException]) {
          errorMessage = [TSErrorMessage invalidVersionWithEnvelope:envelope withTransaction:transaction];
      } else if ([exception.name isEqualToString:UntrustedIdentityKeyException]) {
          errorMessage =
              [TSInvalidIdentityKeyReceivingErrorMessage untrustedKeyWithEnvelope:envelope withTransaction:transaction];
      } else {
          errorMessage = [TSErrorMessage corruptedMessageWithEnvelope:envelope withTransaction:transaction];
      }

      [errorMessage saveWithTransaction:transaction];
    }];
}

#pragma mark - helpers

- (BOOL)isDataMessageGroupAvatarUpdate:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    return dataMessage.hasGroup
        && dataMessage.group.type == OWSSignalServiceProtosGroupContextTypeUpdate
        && dataMessage.group.hasAvatar;
}

- (TSThread *)threadForEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
                    dataMessage:(OWSSignalServiceProtosDataMessage *)dataMessage
{
    if (dataMessage.hasGroup) {
        return [TSGroupThread getOrCreateThreadWithGroupIdData:dataMessage.group.id];
    } else {
        return [TSContactThread getOrCreateThreadWithContactId:envelope.source];
    }
}

- (NSUInteger)unreadMessagesCount {
    __block NSUInteger numberOfItems;
    [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
      numberOfItems = [[transaction ext:TSUnreadDatabaseViewExtensionName] numberOfItemsInAllGroups];
    }];

    return numberOfItems;
}

- (NSUInteger)unreadMessagesCountExcept:(TSThread *)thread {
    __block NSUInteger numberOfItems;
    [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
      numberOfItems = [[transaction ext:TSUnreadDatabaseViewExtensionName] numberOfItemsInAllGroups];
      numberOfItems =
          numberOfItems - [[transaction ext:TSUnreadDatabaseViewExtensionName] numberOfItemsInGroup:thread.uniqueId];
    }];

    return numberOfItems;
}

- (NSUInteger)unreadMessagesInThread:(TSThread *)thread {
    __block NSUInteger numberOfItems;
    [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
      numberOfItems = [[transaction ext:TSUnreadDatabaseViewExtensionName] numberOfItemsInGroup:thread.uniqueId];
    }];
    return numberOfItems;
}

#pragma mark - Logging

+ (NSString *)tag
{
    return [NSString stringWithFormat:@"[%@]", self.class];
}

- (NSString *)tag
{
    return self.class.tag;
}

@end

NS_ASSUME_NONNULL_END