Retry private messages after Noise session replacement

bitchatTests/Services/MessageRouterTests.swift

@@ -79,18 +79,179 @@ struct MessageRouterTests {
     }
 
     @Test @MainActor
-    func sendPrivate_connectedSendIsNotRetained() async {
+    func peerBoundDeliveryAckCannotClearAnotherPeersRetainedMessage() async {
+        let intendedPeer = PeerID(str: "0000000000000023")
+        let otherPeer = PeerID(str: "0000000000000024")
+        let transport = MockTransport()
+        transport.reachablePeers = [intendedPeer, otherPeer]
+
+        let router = MessageRouter(transports: [transport])
+        router.sendPrivate(
+            "Secret",
+            to: intendedPeer,
+            recipientNickname: "Intended",
+            messageID: "peer-bound-ack"
+        )
+        #expect(transport.sentPrivateMessages.count == 1)
+
+        // Even a receipt arriving over another authenticated conversation
+        // must not terminalize the intended peer's retained retry.
+        router.markDelivered("peer-bound-ack", from: [otherPeer])
+        router.flushOutbox(for: intendedPeer)
+        #expect(transport.sentPrivateMessages.count == 2)
+
+        router.markDelivered("peer-bound-ack", from: [intendedPeer])
+        router.flushOutbox(for: intendedPeer)
+        #expect(transport.sentPrivateMessages.count == 2)
+    }
+
+    @Test @MainActor
+    func sendPrivate_connectedSecureSendRetainsUntilDeliveryAck() async {
         let peerID = PeerID(str: "0000000000000007")
         let transport = MockTransport()
         transport.connectedPeers.insert(peerID)
         transport.reachablePeers.insert(peerID)
+        transport.securePeers = [peerID]
 
         let router = MessageRouter(transports: [transport])
         router.sendPrivate("Hello", to: peerID, recipientNickname: "Peer", messageID: "m7")
         #expect(transport.sentPrivateMessages.count == 1)
 
-        router.flushOutbox(for: peerID)
+        // A newly authenticated/replacement session retries the retained
+        // message instead of losing the first ciphertext to a stale session.
+        router.retrySecurePrivateMessagesAfterAuthentication(for: [peerID])
+        #expect(transport.sentPrivateMessages.count == 2)
+
+        router.markDelivered("m7")
+        router.retrySecurePrivateMessagesAfterAuthentication(for: [peerID])
+        #expect(transport.sentPrivateMessages.count == 2)
+    }
+
+    @Test @MainActor
+    func authenticationRetry_matchesStableOutboxAliasWithoutDoubleSending() async {
+        let shortPeerID = PeerID(str: "0000000000000019")
+        let stablePeerID = PeerID(hexData: Data(repeating: 0x19, count: 32))
+        let transport = MockTransport()
+        transport.connectedPeers.insert(stablePeerID)
+        transport.securePeers = [stablePeerID]
+
+        let router = MessageRouter(transports: [transport])
+        router.sendPrivate("Hello", to: stablePeerID, recipientNickname: "Peer", messageID: "alias-retry")
+
+        router.retrySecurePrivateMessagesAfterAuthentication(for: [shortPeerID, stablePeerID, stablePeerID])
+
+        #expect(transport.sentPrivateMessages.map(\.messageID) == ["alias-retry", "alias-retry"])
+        #expect(transport.sentPrivateMessages.allSatisfy { $0.peerID == stablePeerID })
+    }
+
+    @Test @MainActor
+    func authenticationRetry_preservesFIFOAcrossSplitAliases() async {
+        let shortPeerID = PeerID(str: "0000000000000022")
+        let stablePeerID = PeerID(hexData: Data(repeating: 0x22, count: 32))
+        let transport = MockTransport()
+        transport.connectedPeers = [shortPeerID, stablePeerID]
+        transport.securePeers = [shortPeerID, stablePeerID]
+        let clock = MutableTestClock()
+        let router = MessageRouter(transports: [transport], now: { clock.now })
+
+        // The older message lives under the stable key, even though the auth
+        // callback supplies the ephemeral alias first.
+        router.sendPrivate("Older", to: stablePeerID, recipientNickname: "Peer", messageID: "fifo-old")
+        clock.now = clock.now.addingTimeInterval(1)
+        router.sendPrivate("Newer", to: shortPeerID, recipientNickname: "Peer", messageID: "fifo-new")
+        transport.resetRecordings()
+
+        router.retrySecurePrivateMessagesAfterAuthentication(for: [shortPeerID, stablePeerID])
+
+        #expect(transport.sentPrivateMessages.map(\.messageID) == ["fifo-old", "fifo-new"])
+        #expect(transport.sentPrivateMessages.map(\.peerID) == [stablePeerID, shortPeerID])
+    }
+
+    @Test @MainActor
+    func authenticationRetry_doesNotDuplicateNormalPendingHandshakeSend() async {
+        let peerID = PeerID(str: "0000000000000020")
+        let transport = MockTransport()
+        transport.connectedPeers.insert(peerID)
+        transport.securePeers = []
+
+        let router = MessageRouter(transports: [transport])
+        router.sendPrivate("Hello", to: peerID, recipientNickname: "Peer", messageID: "normal-handshake")
         #expect(transport.sentPrivateMessages.count == 1)
+
+        // BLE owns this pending send and drains it after authentication. Once
+        // the session becomes secure, the router's targeted auth retry must
+        // stay silent instead of producing a second copy.
+        transport.securePeers = [peerID]
+        router.retrySecurePrivateMessagesAfterAuthentication(for: [peerID])
+        #expect(transport.sentPrivateMessages.count == 1)
+
+        router.markDelivered("normal-handshake")
+    }
+
+    @Test @MainActor
+    func authenticationRetry_doesNotDuplicateMessageRequeuedByBLEForHandshake() async {
+        let peerID = PeerID(str: "0000000000000021")
+        let transport = MockTransport()
+        transport.connectedPeers.insert(peerID)
+        transport.securePeers = [peerID]
+
+        let router = MessageRouter(transports: [transport])
+        router.sendPrivate("Hello", to: peerID, recipientNickname: "Peer", messageID: "session-lost")
+        #expect(transport.sentPrivateMessages.count == 1)
+
+        // The session disappears before a normal outbox flush. That send is
+        // now owned by BLE's pending-handshake queue, so it clears the
+        // router's secure-auth retry marker.
+        transport.securePeers = []
+        router.flushOutbox(for: peerID)
+        #expect(transport.sentPrivateMessages.count == 2)
+
+        transport.securePeers = [peerID]
+        router.retrySecurePrivateMessagesAfterAuthentication(for: [peerID])
+        #expect(transport.sentPrivateMessages.count == 2)
+
+        router.markDelivered("session-lost")
+    }
+
+    @Test @MainActor
+    func sendPrivate_fastDeliveryAckCannotRaceAheadOfRetention() async {
+        let peerID = PeerID(str: "0000000000000017")
+        let transport = MockTransport()
+        transport.connectedPeers.insert(peerID)
+        transport.securePeers = [peerID]
+
+        let router = MessageRouter(transports: [transport])
+        transport.onSendPrivateMessage = { messageID in
+            router.markDelivered(messageID)
+        }
+
+        router.sendPrivate("Hello", to: peerID, recipientNickname: "Peer", messageID: "fast-ack")
+        #expect(transport.sentPrivateMessages.map(\.messageID) == ["fast-ack"])
+
+        transport.onSendPrivateMessage = nil
+        router.flushOutbox(for: peerID)
+        #expect(transport.sentPrivateMessages.map(\.messageID) == ["fast-ack"])
+    }
+
+    @Test @MainActor
+    func flushOutbox_synchronousAckDoesNotResurrectSnapshotEntry() async {
+        let peerID = PeerID(str: "0000000000000018")
+        let transport = MockTransport()
+        transport.connectedPeers.insert(peerID)
+        transport.securePeers = [peerID]
+
+        let router = MessageRouter(transports: [transport])
+        router.sendPrivate("Hello", to: peerID, recipientNickname: "Peer", messageID: "flush-fast-ack")
+        transport.onSendPrivateMessage = { messageID in
+            router.markDelivered(messageID)
+        }
+
+        router.flushOutbox(for: peerID)
+        #expect(transport.sentPrivateMessages.count == 2)
+
+        transport.onSendPrivateMessage = nil
+        router.flushOutbox(for: peerID)
+        #expect(transport.sentPrivateMessages.count == 2)
     }
 
     @Test @MainActor
@@ -392,10 +553,31 @@ struct MessageRouterTests {
         #expect(transport.sentPrivateMessages.count == 11)
     }
 
-    /// With an established secure session the connected fast-path stays
-    /// exactly as before: trusted outright, no retained copy, no courier.
     @Test @MainActor
-    func sendPrivate_connectedWithSecureSessionIsTrustedOutright() async {
+    func authenticationRetry_capsActualSecureTransmissions() async {
+        let peerID = PeerID(str: "00000000000000ad")
+        let transport = MockTransport()
+        transport.connectedPeers.insert(peerID)
+        transport.securePeers = [peerID]
+
+        let router = MessageRouter(transports: [transport])
+        var dropped: [String] = []
+        router.onMessageDropped = { messageID, _ in dropped.append(messageID) }
+
+        router.sendPrivate("Hello", to: peerID, recipientNickname: "Peer", messageID: "secure-retry")
+        for _ in 0..<10 {
+            router.retrySecurePrivateMessagesAfterAuthentication(for: [peerID])
+        }
+
+        #expect(dropped == ["secure-retry"])
+        #expect(transport.sentPrivateMessages.count == 8)
+    }
+
+    /// With an established secure session the connected fast-path sends
+    /// immediately and never leaks to couriers, but retains a local encrypted
+    /// outbox copy until the peer confirms receipt.
+    @Test @MainActor
+    func sendPrivate_connectedWithSecureSessionRetainsLocallyWithoutCourier() async {
         let peerID = PeerID(str: "00000000000000ab")
         let peerKey = Data(repeating: 0xAB, count: 32)
         let courier = PeerID(str: "00000000000000cc")
@@ -415,7 +597,11 @@ struct MessageRouterTests {
         #expect(transport.sentPrivateMessages.map(\.messageID) == ["cs2"])
         #expect(transport.sentCourierMessages.isEmpty)
         router.flushOutbox(for: peerID)
-        #expect(transport.sentPrivateMessages.count == 1)
+        #expect(transport.sentPrivateMessages.count == 2)
+        #expect(transport.sentCourierMessages.isEmpty)
+        router.markDelivered("cs2")
+        router.flushOutbox(for: peerID)
+        #expect(transport.sentPrivateMessages.count == 2)
     }
 
     @Test @MainActor
@@ -853,12 +1039,14 @@ struct MessageRouterTests {
         protectedDataUnavailable = false
         restoredStore.retryDeferredLoad() // captures unseen durable + known wake
 
-        // Secure direct flush removes the wake message before recovery's
-        // MainActor merge. It must remain removed, while the unseen durable
-        // message still arrives through the pending recovery claim.
+        // A secure direct retry followed by its delivery ack removes the wake
+        // message before recovery's MainActor merge. It must remain removed,
+        // while the unseen durable message still arrives through the pending
+        // recovery claim.
         transport.connectedPeers.insert(peerID)
         transport.securePeers = [peerID]
         router.flushOutbox(for: peerID)
+        router.markDelivered("recovery-gap-known")
         await Task.yield()
         await Task.yield()
 
@@ -929,7 +1117,8 @@ struct MessageRouterTests {
         restoredStore.retryDeferredLoad() // persists D+W and queues recovery
         transport.connectedPeers.insert(peerID)
         transport.securePeers = [peerID]
-        router.flushOutbox(for: peerID) // removes W before queued callback
+        router.flushOutbox(for: peerID)
+        router.markDelivered("recovery-write-failure-known") // removes W before queued callback
 
         // The gap save may remove W, but it must leave unseen D durable until
         // MessageRouter receives the pending recovery callback.