Inconsistent behavior for firebase friendslist - ios

Question

I'm currently trying to setup a friendslist relationship using Firebase and I'm experiencing some issues with the process of adding a friend for a user.
I currently have a schema like this:
users
-----
UID
->Name
->Friendslist
->UID of friend:true
userDisplays
------------
-Users Name:Users UID
addedFriends
------------
-UID of added user
->UID Of user that did the adding
My idea of adding a friend is using the name of the user and looking them up in the userDisplays tree, that lookup seems to work everytime. However, when I then try to read the uid value from the child in userDisplays it will sometimes return NULL, or will skip the adding entirely after it finds the uid value (by this I mean it will not add the uid to the adding user and not create a addedFriends child).
The same issue is when the adding user successfully adds the desired user and a addedFriends child is created linking the two, but again when the added user checks for recent addings and is given the option to 'add back' it will return NULL or skip the removal of the addedFriends child and not add the uid to the users list of friends.
I tried to copy the relationship example found in the docs, but I'm confused on where I am missing things, or if this is expected behavior?
Here is my structure after two users have been created. Before a friends list has been created.
{
"userDisplays" : {
"a" : "fed7738e-7dec-4ff3-9cc9-46dee3c189e6",
"t" : "c3b27833-d56b-40e9-b46f-c99128193f3d"
},
"users" : {
"c3b27833-d56b-40e9-b46f-c99128193f3d" : {
"displayName" : "t",
"email" : "test#test.com",
"provider" : "password"
},
"fed7738e-7dec-4ff3-9cc9-46dee3c189e6" : {
"displayName" : "a",
"email" : "test2#test.com",
"provider" : "password"
}
}
}
This is the swift code I'm using to perform the adding of a friend given a user name:
ref.userDisplayBaseSingleton.childByAppendingPath("/\(userName)").observeSingleEventOfType(.Value, withBlock: { snapshot in
if snapshot.value is NSNull{
print("null")
}else{
print(snapshot.value)
print("found val")
ref.userBaseSingleton.childByAppendingPath(snapshot.value as! String).observeSingleEventOfType(.Value, withBlock: { (snap) in
let friendData = [
snap.key:true
]
ref.userBaseSingleton.childByAppendingPath("\(currentUser!.id!)/friends").updateChildValues(friendData)
let currentAddData = [
snap.key:currentUser!.id!
]
let friendAddRef = ref.addBaseSingleton.childByAutoId()
friendAddRef.setValue(currentAddData)
})
}
})
Basically the issues I'm experiencing from this snippet is that sometimes the look up from userDisplays doesn't return a value, or if it does it doesn't add a addedFriends node. I've experienced a bug when retrying adding the username again, but it will actually generate a new uid of the users and then generate a new addedFriends child.
For example, if I was user t and I tried to add a a few kinds of behavior can happen.
userDisplay for a returns null
userDisplay returns a and returns a's uid but the addedFriends node isn't generated
a is properly added, and an addedFriends node is generated, however when user a is notified of the add and is given the option to add back t it seems to reproduce the same kind of errors.
I've noticed that after a period of time, the actual uid of t will update on the firebase and then the add will be successful. By this I mean that the initial uid that t is assigned will change and then I've noticed the code above will work. I'm also assuming the reason why its updated has to do with the errors thats happening, but I could be wrong.
Heres a snippet of the error happening
}
{
"addedFriends" : {
"-KH6pR5TV7vjVeADc7mc" : {
"22a3c5fa-e578-4ada-b3c1-355add80041e" : "098804cd-1ffa-4508-b353-6f6a4377661f"
}
},
"userDisplays" : {
"test" : "f0bb77a9-8156-4d44-ad74-6d6b01765802",
"test2" : "098804cd-1ffa-4508-b353-6f6a4377661f"
},
"users" : {
"098804cd-1ffa-4508-b353-6f6a4377661f" : {
"displayName" : "test2",
"email" : "test2#test.com",
"friends" : {
"22a3c5fa-e578-4ada-b3c1-355add80041e" : true
},
"provider" : "password"
},
"f0bb77a9-8156-4d44-ad74-6d6b01765802" : {
"displayName" : "test",
"email" : "test#test.com",
"provider" : "password"
}
}
}