refactor and cleanup [skip ci]

submodules/Postbox/Sources/PeerChatStateView.swift

@@ -0,0 +1,34 @@
+import Foundation
+
+final class MutablePeerChatStateView: MutablePostboxView {
+    let peerId: PeerId
+    var chatState: PostboxCoding?
+    
+    init(postbox: Postbox, peerId: PeerId) {
+        self.peerId = peerId
+        self.chatState = postbox.peerChatStateTable.get(peerId)
+    }
+    
+    func replay(postbox: Postbox, transaction: PostboxTransaction) -> Bool {
+        if transaction.currentUpdatedPeerChatStates.contains(self.peerId) {
+            self.chatState = postbox.peerChatStateTable.get(self.peerId)
+            return true
+        } else {
+            return false
+        }
+    }
+    
+    func immutableView() -> PostboxView {
+        return PeerChatStateView(self)
+    }
+}
+
+public final class PeerChatStateView: PostboxView {
+    public let peerId: PeerId
+    public let chatState: PostboxCoding?
+    
+    init(_ view: MutablePeerChatStateView) {
+        self.peerId = view.peerId
+        self.chatState = view.chatState
+    }
+}