[WIP] Saved messages

submodules/Postbox/Sources/MessageHistorySavedMessagesStatsView.swift

@@ -0,0 +1,55 @@
+import Foundation
+
+final class MutableMessageHistorySavedMessagesStatsView: MutablePostboxView {
+    fileprivate let peerId: PeerId
+    fileprivate var count: Int = 0
+    fileprivate var isLoading: Bool = false
+    
+    init(postbox: PostboxImpl, peerId: PeerId) {
+        self.peerId = peerId
+        
+        self.reload(postbox: postbox)
+    }
+    
+    private func reload(postbox: PostboxImpl) {
+        let validIndexBoundary = postbox.peerThreadCombinedStateTable.get(peerId: peerId)?.validIndexBoundary
+        self.isLoading = validIndexBoundary == nil
+        
+        if !self.isLoading {
+            self.count = postbox.messageHistoryThreadIndexTable.getCount(peerId: self.peerId)
+        } else {
+            self.count = 0
+        }
+    }
+    
+    func replay(postbox: PostboxImpl, transaction: PostboxTransaction) -> Bool {
+        var updated = false
+        
+        if transaction.updatedMessageThreadPeerIds.contains(self.peerId) {
+            self.reload(postbox: postbox)
+            updated = true
+        }
+        
+        return updated
+    }
+
+    func refreshDueToExternalTransaction(postbox: PostboxImpl) -> Bool {
+        self.reload(postbox: postbox)
+        
+        return true
+    }
+    
+    func immutableView() -> PostboxView {
+        return MessageHistorySavedMessagesStatsView(self)
+    }
+}
+
+public final class MessageHistorySavedMessagesStatsView: PostboxView {
+    public let isLoading: Bool
+    public let count: Int
+    
+    init(_ view: MutableMessageHistorySavedMessagesStatsView) {
+        self.isLoading = view.isLoading
+        self.count = view.count
+    }
+}