Update device link endpoint for batch fetching

SignalServiceKit/src/Loki/API/LokiStorageAPI.swift

@@ -18,24 +18,30 @@ public final class LokiStorageAPI : LokiDotNetAPI {
     /// Gets the device links associated with the given hex encoded public key from the
     /// server and stores and returns the valid ones.
     public static func getDeviceLinks(associatedWith hexEncodedPublicKey: String) -> Promise<Set<DeviceLink>> {
-        print("[Loki] Getting device links for: \(hexEncodedPublicKey).")
+        return getDeviceLinks(associatedWith: [ hexEncodedPublicKey ])
+    }
+    
+    /// Gets the device links associated with the given hex encoded public keys from the
+    /// server and stores and returns the valid ones.
+    public static func getDeviceLinks(associatedWith hexEncodedPublicKeys: [String]) -> Promise<Set<DeviceLink>> {
+        print("[Loki] Getting device links for: \(hexEncodedPublicKeys).")
         return getAuthToken(for: server).then(on: DispatchQueue.global()) { token -> Promise<Set<DeviceLink>> in
-            let queryParameters = "include_user_annotations=1"
-            let url = URL(string: "\(server)/users/@\(hexEncodedPublicKey)?\(queryParameters)")!
+            let queryParameters = "ids=\(hexEncodedPublicKeys.map { "@\($0)" }.joined(separator: ","))&include_user_annotations=1"
+            let url = URL(string: "\(server)/users?\(queryParameters)")!
             let request = TSRequest(url: url)
             return TSNetworkManager.shared().perform(request, withCompletionQueue: DispatchQueue.global()).map { $0.responseObject }.map { rawResponse -> Set<DeviceLink> in
-                guard let json = rawResponse as? JSON, let data = json["data"] as? JSON,
-                    let annotations = data["annotations"] as? [JSON] else {
-                    print("[Loki] Couldn't parse device links for user: \(hexEncodedPublicKey) from: \(rawResponse).")
+                guard let json = rawResponse as? JSON, let data = json["data"] as? [JSON] else {
+                    print("[Loki] Couldn't parse device links for users: \(hexEncodedPublicKeys) from: \(rawResponse).")
                     throw Error.parsingFailed
                 }
-                guard !annotations.isEmpty else { return [] }
+                return Set(data.flatMap { data -> [DeviceLink] in
+                    guard let annotations = data["annotations"] as? [JSON], !annotations.isEmpty, let hexEncodedPublicKey = data["username"] as? String else { return [] }
                     guard let annotation = annotations.first(where: { $0["type"] as? String == deviceLinkType }),
                         let value = annotation["value"] as? JSON, let rawDeviceLinks = value["authorisations"] as? [JSON] else {
                         print("[Loki] Couldn't parse device links for user: \(hexEncodedPublicKey) from: \(rawResponse).")
-                    throw Error.parsingFailed
+                        return []
                     }
-                return Set(rawDeviceLinks.flatMap { rawDeviceLink in
+                    return rawDeviceLinks.compactMap { rawDeviceLink in
                         guard let masterHexEncodedPublicKey = rawDeviceLink["primaryDevicePubKey"] as? String, let slaveHexEncodedPublicKey = rawDeviceLink["secondaryDevicePubKey"] as? String,
                             let base64EncodedSlaveSignature = rawDeviceLink["requestSignature"] as? String else {
                             print("[Loki] Couldn't parse device link for user: \(hexEncodedPublicKey) from: \(rawResponse).")
@@ -62,6 +68,7 @@ public final class LokiStorageAPI : LokiDotNetAPI {
                             return nil
                         }
                         return deviceLink
+                    }
                 })
             }.map { deviceLinks -> Set<DeviceLink> in
                 storage.dbReadWriteConnection.readWrite { transaction in