Implement basic multi device message sending

SignalServiceKit/src/Loki/API/LokiAPI.swift

@@ -60,15 +60,8 @@ public final class LokiAPI : NSObject {
         let timeout: TimeInterval? = useLongPolling ? longPollingTimeout : nil
         return invoke(.getMessages, on: target, associatedWith: userHexEncodedPublicKey, parameters: parameters, headers: headers, timeout: timeout)
     }
-    
-    // MARK: Public API
-    public static func getMessages() -> Promise<Set<MessageListPromise>> {
-        return getTargetSnodes(for: userHexEncodedPublicKey).mapValues { targetSnode in
-            return getRawMessages(from: targetSnode, usingLongPolling: false).map { parseRawMessagesResponse($0, from: targetSnode) }
-        }.map { Set($0) }.retryingIfNeeded(maxRetryCount: maxRetryCount)
-    }
-    
-    public static func sendSignalMessage(_ signalMessage: SignalMessage, onP2PSuccess: @escaping () -> Void) -> Promise<Set<RawResponsePromise>> {
+
+    internal static func internalSendSignalMessage(_ signalMessage: SignalMessage, onP2PSuccess: @escaping () -> Void) -> Promise<Set<RawResponsePromise>> {
         guard let lokiMessage = LokiMessage.from(signalMessage: signalMessage) else { return Promise(error: Error.messageConversionFailed) }
         let destination = lokiMessage.destination
         func sendLokiMessage(_ lokiMessage: LokiMessage, to target: LokiAPITarget) -> RawResponsePromise {
@@ -116,6 +109,24 @@ public final class LokiAPI : NSObject {
         }
     }
     
+    // MARK: Public API
+    public static func getMessages() -> Promise<Set<MessageListPromise>> {
+        return getTargetSnodes(for: userHexEncodedPublicKey).mapValues { targetSnode in
+            return getRawMessages(from: targetSnode, usingLongPolling: false).map { parseRawMessagesResponse($0, from: targetSnode) }
+        }.map { Set($0) }.retryingIfNeeded(maxRetryCount: maxRetryCount)
+    }
+    
+    public static func sendSignalMessage(_ signalMessage: SignalMessage, onP2PSuccess: @escaping () -> Void) -> Promise<Set<RawResponsePromise>> {
+        let result = internalSendSignalMessage(signalMessage, onP2PSuccess: onP2PSuccess)
+        // Use a best attempt approach for multi device for now
+        LokiDeviceLinkingAPI.getOtherAccounts(for: signalMessage.recipientID).done { hexEncodedPublicKeyList in
+            hexEncodedPublicKeyList.forEach { hexEncodedPublicKey in
+                internalSendSignalMessage(signalMessage.copy(with: hexEncodedPublicKey)) { }
+            }
+        }
+        return result
+    }
+    
     // MARK: Public API (Obj-C)
     @objc(sendSignalMessage:onP2PSuccess:)
     public static func objc_sendSignalMessage(_ signalMessage: SignalMessage, onP2PSuccess: @escaping () -> Void) -> AnyPromise {

SignalServiceKit/src/Loki/API/LokiDeviceLinkingAPI.swift

@@ -6,12 +6,6 @@ final class LokiDeviceLinkingAPI : NSObject {
     // MARK: Settings
     private static let listeningTimeout = 60
 
-    // MARK: Types
-    public struct Account {
-        public let hexEncodedPublicKey: String
-        public let isMaster: Bool
-    }
-
     // MARK: Lifecycle
     override private init() { }
 
@@ -34,7 +28,7 @@ final class LokiDeviceLinkingAPI : NSObject {
         notImplemented()
     }
 
-    public static func getAccounts(for hexEncodedPublicKey: String) -> Promise<[Account]> {
+    public static func getOtherAccounts(for hexEncodedPublicKey: String) -> Promise<[String]> {
         // Gets the accounts associated with the given hex encoded public key from the server
         notImplemented()
     }

SignalServiceKit/src/Loki/API/SignalMessage.swift

@@ -25,4 +25,10 @@ public final class SignalMessage : NSObject {
         self.isPing = isPing
         super.init()
     }
+
+    public func copy(with recipientID: String) -> SignalMessage {
+        return SignalMessage(type: type, timestamp: timestamp, senderID: senderID, senderDeviceID: senderDeviceID, content: content,
+            recipientID: recipientID, ttl: objc_ttl, isPing: isPing)
+
+    }
 }