Moved the rest of the presence code into presence object.

I've split presence `onAttached:` into two parts, because:

with this variance:

```
[_attachedEventEmitter emit:nil with:nil];
[self.presence onAttached:message fromState:state];
```

the test "test__105__Presence__get..." fails because it needs sync to begin (within `presence onAttached:`) before attach event emitted, otherwise the logic inside `channel.presence.get { ... }` takes another path and calls callback without an error.

with opposite order:

```
[self.presence onAttached:message fromState:state];
[_attachedEventEmitter emit:nil with:nil];
```
the test "test__020__Presence__Channel..." fails because it sends pending presence messages before the `detach` call has an oportunity to fail those messages.

So those tests are kinda mutually exclusive.

Source/ARTRealtimeChannel.m

@@ -654,7 +654,8 @@ - (void)onChannelMessage:(ARTProtocolMessage *)message {
 }
 
 - (void)setAttached:(ARTProtocolMessage *)message {
-    switch (self.state_nosync) {
+    ARTRealtimeChannelState state = self.state_nosync;
+    switch (state) {
         case ARTRealtimeChannelDetaching:
         case ARTRealtimeChannelFailed:
             // Ignore
@@ -673,24 +674,15 @@ - (void)setAttached:(ARTProtocolMessage *)message {
         self.serial = message.channelSerial;
     }
 
-    if (message.hasPresence) {
-        [self.presence startSync];
-    }
-    else {
-        // RTP1 - when an ATTACHED message is received without a HAS_PRESENCE flag, reset PresenceMap
-        [self.presence startSync];
-        [self.presence endSync];
-        ARTLogDebug(self.logger, @"R:%p C:%p (%@) PresenceMap has been reset", _realtime, self, self.name);
-    }
-
-    if (self.state_nosync == ARTRealtimeChannelAttached) {
+    [self.presence beforeAttached:message];
+
+    if (state == ARTRealtimeChannelAttached) {
         if (!message.resumed) { // RTL12
             if (message.error != nil) {
                 _errorReason = message.error;
             }
-            ARTChannelStateChange *stateChange = [[ARTChannelStateChange alloc] initWithCurrent:self.state_nosync previous:self.state_nosync event:ARTChannelEventUpdate reason:message.error resumed:message.resumed];
+            ARTChannelStateChange *stateChange = [[ARTChannelStateChange alloc] initWithCurrent:state previous:state event:ARTChannelEventUpdate reason:message.error resumed:message.resumed];
             [self emit:stateChange.event with:stateChange];
-            [self reenterLocalMembers]; // RTP17i
         }
         return;
     }
@@ -704,8 +696,7 @@ - (void)setAttached:(ARTProtocolMessage *)message {
     [self performTransitionToState:ARTRealtimeChannelAttached withParams:params];
     [_attachedEventEmitter emit:nil with:nil];
 
-    [self.presence sendPendingPresence];
-    [self reenterLocalMembers]; // RTP17i
+    [self.presence afterAttached:message fromState:state];
 }
 
 - (void)setDetached:(ARTProtocolMessage *)message {
@@ -1084,23 +1075,6 @@ - (void)startDecodeFailureRecoveryWithErrorInfo:(ARTErrorInfo *)error {
     } withParams:params];
 }
 
-- (void)reenterLocalMembers {
-    [self.presence reenterLocalMembersWithMemberCallback:^(ARTPresenceMessage *member, ARTErrorInfo *error) {
-        if (error != nil) {
-            NSString *message = [NSString stringWithFormat:@"Re-entering member \"%@\" is failed with code %ld (%@)", member.memberKey, (long)error.code, error.message];
-            ARTErrorInfo *reenterError = [ARTErrorInfo createWithCode:ARTErrorUnableToAutomaticallyReEnterPresenceChannel message:message];
-            ARTChannelStateChange *stateChange = [[ARTChannelStateChange alloc] initWithCurrent:self.state_nosync previous:self.state_nosync event:ARTChannelEventUpdate reason:reenterError resumed:true]; // RTP17e
-
-            [self emit:stateChange.event with:stateChange];
-
-            ARTLogWarn(self.logger, @"RT:%p C:%p (%@) Re-entering member \"%@\" is failed with code %ld (%@)", self->_realtime, self, self.name, member.memberKey, (long)error.code, error.message);
-        }
-        else {
-            ARTLogDebug(self.logger, @"RT:%p C:%p (%@) re-entered local member \"%@\"", self->_realtime, self, self.name, member.memberKey);
-        }
-    }];
-}
-
 - (NSString *)connectionId {
     return _realtime.connection.id_nosync;
 }

Source/ARTRealtimePresence.m

@@ -13,6 +13,8 @@
 #import "ARTEventEmitter+Private.h"
 #import "ARTDataEncoder.h"
 #import "ARTBaseMessage+Private.h"
+#import "ARTProtocolMessage+Private.h"
+#import "ARTEventEmitter+Private.h"
 
 #pragma mark - ARTRealtimePresenceQuery
 
@@ -662,17 +664,6 @@ - (void)broadcast:(ARTPresenceMessage *)pm {
     [_eventEmitter emit:[ARTEvent newWithPresenceAction:pm.action] with:pm];
 }
 
-- (void)reenterLocalMembersWithMemberCallback:(ARTPresenceMessageErrorCallback)callback {
-    ARTLogDebug(self.logger, @"%p reentering local members", self);
-    for (ARTPresenceMessage *member in [self.localMembers allValues]) {
-        [self enterWithPresenceMessageId:member.id clientId:member.clientId data:member.data callback:^(ARTErrorInfo *error) {
-            callback(member, error);
-        }];
-        ARTLogDebug(self.logger, @"RT:%p C:%p (%@) re-entering local member \"%@\"", _realtime, _channel, _channel.name, member.memberKey);
-    }
-    [self cleanUpAbsentMembers];
-}
-
 - (void)sync {
     [self sync:nil];
 }
@@ -722,6 +713,30 @@ - (void)sync:(ARTCallback)callback {
     } ackCallback:nil];
 }
 
+- (void)beforeAttached:(ARTProtocolMessage *)message {
+    if (message.hasPresence) {
+        [self startSync];
+    }
+    else {
+        // RTP1 - when an ATTACHED message is received without a HAS_PRESENCE flag, reset PresenceMap
+        [self startSync];
+        [self endSync];
+        ARTLogDebug(self.logger, @"R:%p C:%p (%@) PresenceMap has been reset", _realtime, self, _channel.name);
+    }
+}
+
+- (void)afterAttached:(ARTProtocolMessage *)message fromState:(ARTRealtimeChannelState)state {
+    if (state == ARTRealtimeChannelAttached) {
+        if (!message.resumed) { // RTL12
+            [self reenterLocalMembers]; // RTP17i
+        }
+    }
+    else {
+        [self sendPendingPresence];
+        [self reenterLocalMembers]; // RTP17i
+    }
+}
+
 - (void)onMessage:(ARTProtocolMessage *)message {
     int i = 0;
     for (ARTPresenceMessage *p in message.presence) {
@@ -762,12 +777,7 @@ - (void)onSync:(ARTProtocolMessage *)message {
         ARTLogDebug(self.logger, @"RT:%p C:%p (%@) PresenceMap sync is in progress", _realtime, _channel, _channel.name);
     }
 
-    for (int i = 0; i < [message.presence count]; i++) {
-        ARTPresenceMessage *presence = [message.presence objectAtIndex:i];
-        if ([self add:presence]) {
-            [self broadcast:presence];
-        }
-    }
+    [self onMessage:message];
 
     if ([_channel isLastChannelSerial:message.channelSerial]) {
         [self endSync];
@@ -788,6 +798,28 @@ - (void)didRemovedMemberNoLongerPresent:(ARTPresenceMessage *)pm {
     ARTLogDebug(self.logger, @"RT:%p C:%p (%@) member \"%@\" no longer present", _realtime, _channel, _channel.name, pm.memberKey);
 }
 
+- (void)reenterLocalMembers {
+    ARTLogDebug(self.logger, @"%p reentering local members", self);
+    for (ARTPresenceMessage *member in [self.localMembers allValues]) {
+        [self enterWithPresenceMessageId:member.id clientId:member.clientId data:member.data callback:^(ARTErrorInfo *error) {
+            if (error != nil) {
+                NSString *message = [NSString stringWithFormat:@"Re-entering member \"%@\" is failed with code %ld (%@)", member.memberKey, (long)error.code, error.message];
+                ARTErrorInfo *reenterError = [ARTErrorInfo createWithCode:ARTErrorUnableToAutomaticallyReEnterPresenceChannel message:message];
+                ARTChannelStateChange *stateChange = [[ARTChannelStateChange alloc] initWithCurrent:self->_channel.state_nosync previous:self->_channel.state_nosync event:ARTChannelEventUpdate reason:reenterError resumed:true]; // RTP17e
+
+                [self->_channel emit:stateChange.event with:stateChange];
+
+                ARTLogWarn(self.logger, @"RT:%p C:%p (%@) Re-entering member \"%@\" is failed with code %ld (%@)", self->_realtime, self->_channel, self->_channel.name, member.memberKey, (long)error.code, error.message);
+            }
+            else {
+                ARTLogDebug(self.logger, @"RT:%p C:%p (%@) re-entered local member \"%@\"", self->_realtime, self->_channel, self->_channel.name, member.memberKey);
+            }
+        }];
+        ARTLogDebug(self.logger, @"RT:%p C:%p (%@) re-entering local member \"%@\"", _realtime, _channel, _channel.name, member.memberKey);
+    }
+    [self cleanUpAbsentMembers];
+}
+
 #pragma mark - Presence Map
 
 - (NSDictionary<NSString *, ARTPresenceMessage *> *)members {

Source/PrivateHeaders/Ably/ARTRealtimeChannel+Private.h

@@ -82,6 +82,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)detachChannel:(ARTChannelStateChangeParams *)params;
 
+- (void)emit:(ARTChannelEvent)event with:(ARTChannelStateChange *)data;
+
 @end
 
 @interface ARTRealtimeChannel ()

Source/PrivateHeaders/Ably/ARTRealtimePresence+Private.h

@@ -12,18 +12,18 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)_unsubscribe;
 - (BOOL)syncComplete_nosync;
 
-- (void)sendPendingPresence;
 - (void)failPendingPresence:(ARTStatus *)status;
-
 - (void)broadcast:(ARTPresenceMessage *)pm;
-- (void)reenterLocalMembersWithMemberCallback:(ARTPresenceMessageErrorCallback)callback;
 
 - (void)sync;
 - (void)sync:(nullable ARTCallback)callback;
 
 - (void)onMessage:(ARTProtocolMessage *)message;
 - (void)onSync:(ARTProtocolMessage *)message;
 
+- (void)beforeAttached:(ARTProtocolMessage *)message;
+- (void)afterAttached:(ARTProtocolMessage *)message fromState:(ARTRealtimeChannelState)state;
+
 @property (nonatomic) dispatch_queue_t queue;
 @property (readwrite, nonatomic) ARTPresenceAction lastPresenceAction;
 @property (readonly, nonatomic) NSMutableArray<ARTQueuedMessage *> *pendingPresence;