Cleanup var -> val

matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/common/CryptoTestHelper.kt

@@ -340,18 +340,14 @@ class CryptoTestHelper(val mTestHelper: CommonTestHelper) {
     fun createFakeMegolmBackupAuthData(): MegolmBackupAuthData {
         return MegolmBackupAuthData(
                 publicKey = "abcdefg",
-                signatures = HashMap<String, Map<String, String>>().apply {
+                signatures = mapOf("something" to mapOf("ed25519:something" to "hijklmnop"))
-                    this["something"] = HashMap<String, String>().apply {
-                        this["ed25519:something"] = "hijklmnop"
-                    }
-                }
         )
     }
 
     fun createFakeMegolmBackupCreationInfo(): MegolmBackupCreationInfo {
-        return MegolmBackupCreationInfo().apply {
+        return MegolmBackupCreationInfo(
-            algorithm = MXCRYPTO_ALGORITHM_MEGOLM_BACKUP
+                algorithm = MXCRYPTO_ALGORITHM_MEGOLM_BACKUP,
-            authData = createFakeMegolmBackupAuthData()
+                authData = createFakeMegolmBackupAuthData()
-        }
+        )
     }
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/auth/data/WellKnown.kt

@@ -46,13 +46,13 @@ import com.squareup.moshi.JsonClass
 @JsonClass(generateAdapter = true)
 data class WellKnown(
         @Json(name = "m.homeserver")
-        var homeServer: WellKnownBaseConfig? = null,
+        val homeServer: WellKnownBaseConfig? = null,
 
         @Json(name = "m.identity_server")
-        var identityServer: WellKnownBaseConfig? = null,
+        val identityServer: WellKnownBaseConfig? = null,
 
         @Json(name = "m.integrations")
-        var integrations: Map<String, @JvmSuppressWildcards Any>? = null
+        val integrations: Map<String, @JvmSuppressWildcards Any>? = null
 ) {
     /**
      * Returns the list of integration managers proposed

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/create/CreateRoomResponse.kt

@@ -24,7 +24,7 @@ internal data class CreateRoomResponse(
         /**
          * Required. The created room's ID.
          */
-        @Json(name = "room_id") var roomId: String
+        @Json(name = "room_id") val roomId: String
 )
 
 internal typealias JoinRoomResponse = CreateRoomResponse

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/roomdirectory/PublicRoomsFilter.kt

@@ -27,5 +27,5 @@ data class PublicRoomsFilter(
          * A string to search for in the room metadata, e.g. name, topic, canonical alias etc. (Optional).
          */
         @Json(name = "generic_search_term")
-        var searchTerm: String? = null
+        val searchTerm: String? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/roomdirectory/PublicRoomsParams.kt

@@ -28,30 +28,30 @@ data class PublicRoomsParams(
          * Limit the number of results returned.
          */
         @Json(name = "limit")
-        var limit: Int? = null,
+        val limit: Int? = null,
 
         /**
          * A pagination token from a previous request, allowing clients to get the next (or previous) batch of rooms.
          * The direction of pagination is specified solely by which token is supplied, rather than via an explicit flag.
          */
         @Json(name = "since")
-        var since: String? = null,
+        val since: String? = null,
 
         /**
          * Filter to apply to the results.
          */
         @Json(name = "filter")
-        var filter: PublicRoomsFilter? = null,
+        val filter: PublicRoomsFilter? = null,
 
         /**
          * Whether or not to include all known networks/protocols from application services on the homeserver. Defaults to false.
          */
         @Json(name = "include_all_networks")
-        var includeAllNetworks: Boolean = false,
+        val includeAllNetworks: Boolean = false,
 
         /**
          * The specific third party network/protocol to request from the homeserver. Can only be used if include_all_networks is false.
          */
         @Json(name = "third_party_instance_id")
-        var thirdPartyInstanceId: String? = null
+        val thirdPartyInstanceId: String? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/thirdparty/ThirdPartyProtocol.kt

@@ -26,7 +26,7 @@ data class ThirdPartyProtocol(
          * where higher groupings are ordered first. For example, the name of a network should be searched before the nickname of a user.
          */
         @Json(name = "user_fields")
-        var userFields: List<String>? = null,
+        val userFields: List<String>? = null,
 
         /**
          * Required. Fields which may be used to identify a third party location. These should be ordered to suggest the way that
@@ -34,15 +34,15 @@ data class ThirdPartyProtocol(
          * searched before the name of a channel.
          */
         @Json(name = "location_fields")
-        var locationFields: List<String>? = null,
+        val locationFields: List<String>? = null,
 
         /**
          * Required. A content URI representing an icon for the third party protocol.
          *
-         * FIXDOC: This field was not present in legacy Riot, and it is sometimes sent by the server (no not Required?)
+         * FIXDOC: This field was not present in legacy Riot, and it is sometimes sent by the server (so not Required?)
          */
         @Json(name = "icon")
-        var icon: String? = null,
+        val icon: String? = null,
 
         /**
          * Required. The type definitions for the fields defined in the user_fields and location_fields. Each entry in those arrays MUST have an entry here.
@@ -51,12 +51,12 @@ data class ThirdPartyProtocol(
          * May be an empty object if no fields are defined.
          */
         @Json(name = "field_types")
-        var fieldTypes: Map<String, FieldType>? = null,
+        val fieldTypes: Map<String, FieldType>? = null,
 
         /**
          * Required. A list of objects representing independent instances of configuration. For example, multiple networks on IRC
          * if multiple are provided by the same application service.
          */
         @Json(name = "instances")
-        var instances: List<ThirdPartyProtocolInstance>? = null
+        val instances: List<ThirdPartyProtocolInstance>? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/thirdparty/ThirdPartyProtocolInstance.kt

@@ -25,35 +25,35 @@ data class ThirdPartyProtocolInstance(
          * Required. A human-readable description for the protocol, such as the name.
          */
         @Json(name = "desc")
-        var desc: String? = null,
+        val desc: String? = null,
 
         /**
          * An optional content URI representing the protocol. Overrides the one provided at the higher level Protocol object.
          */
         @Json(name = "icon")
-        var icon: String? = null,
+        val icon: String? = null,
 
         /**
          * Required. Preset values for fields the client may use to search by.
          */
         @Json(name = "fields")
-        var fields: Map<String, Any>? = null,
+        val fields: Map<String, Any>? = null,
 
         /**
          * Required. A unique identifier across all instances.
          */
         @Json(name = "network_id")
-        var networkId: String? = null,
+        val networkId: String? = null,
 
         /**
          * FIXDOC Not documented on matrix.org doc
          */
         @Json(name = "instance_id")
-        var instanceId: String? = null,
+        val instanceId: String? = null,
 
         /**
          * FIXDOC Not documented on matrix.org doc
          */
         @Json(name = "bot_user_id")
-        var botUserId: String? = null
+        val botUserId: String? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/auth/registration/RegistrationFlowResponse.kt

@@ -32,20 +32,20 @@ data class RegistrationFlowResponse(
          * The list of flows.
          */
         @Json(name = "flows")
-        var flows: List<InteractiveAuthenticationFlow>? = null,
+        val flows: List<InteractiveAuthenticationFlow>? = null,
 
         /**
          * The list of stages the client has completed successfully.
          */
         @Json(name = "completed")
-        var completedStages: List<String>? = null,
+        val completedStages: List<String>? = null,
 
         /**
          * The session identifier that the client must pass back to the home server, if one is provided,
          * in subsequent attempts to authenticate in the same API call.
          */
         @Json(name = "session")
-        var session: String? = null,
+        val session: String? = null,
 
         /**
          * The information that the client will need to know in order to use a given type of authentication.
@@ -53,7 +53,7 @@ data class RegistrationFlowResponse(
          * For example, the public key of reCAPTCHA stage could be given here.
          */
         @Json(name = "params")
-        var params: JsonDict? = null
+        val params: JsonDict? = null
 
         /**
          * WARNING,

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/DefaultCryptoService.kt

@@ -1021,12 +1021,12 @@ internal class DefaultCryptoService @Inject constructor(
             return
         }
 
-        val requestBody = RoomKeyRequestBody()
+        val requestBody = RoomKeyRequestBody(
-
+                algorithm = wireContent["algorithm"]?.toString(),
-        requestBody.roomId = event.roomId
+                roomId = event.roomId,
-        requestBody.algorithm = wireContent["algorithm"]?.toString()
+                senderKey = wireContent["sender_key"]?.toString(),
-        requestBody.senderKey = wireContent["sender_key"]?.toString()
+                sessionId = wireContent["session_id"]?.toString()
-        requestBody.sessionId = wireContent["session_id"]?.toString()
+        )
 
         outgoingRoomKeyRequestManager.resendRoomKeyRequest(requestBody)
     }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/IncomingRoomKeyRequest.kt

@@ -25,54 +25,54 @@ import im.vector.matrix.android.internal.crypto.model.rest.RoomKeyShareRequest
 /**
  * IncomingRoomKeyRequest class defines the incoming room keys request.
  */
-open class IncomingRoomKeyRequest {
+data class IncomingRoomKeyRequest(
-    /**
+        /**
-     * The user id
+         * The user id
-     */
+         */
-    var userId: String? = null
+        override val userId: String? = null,
 
-    /**
+        /**
-     * The device id
+         * The device id
-     */
+         */
-    var deviceId: String? = null
+        override val deviceId: String? = null,
 
-    /**
+        /**
-     * The request id
+         * The request id
-     */
+         */
-    var requestId: String? = null
+        override val requestId: String? = null,
 
-    /**
+        /**
-     * The request body
+         * The request body
-     */
+         */
-    var requestBody: RoomKeyRequestBody? = null
+        val requestBody: RoomKeyRequestBody? = null,
 
-    /**
+        /**
-     * The runnable to call to accept to share the keys
+         * The runnable to call to accept to share the keys
-     */
+         */
-    @Transient
+        @Transient
-    var share: Runnable? = null
+        var share: Runnable? = null,
 
-    /**
+        /**
-     * The runnable to call to ignore the key share request.
+         * The runnable to call to ignore the key share request.
-     */
+         */
-    @Transient
+        @Transient
-    var ignore: Runnable? = null
+        var ignore: Runnable? = null
+) : IncomingRoomKeyRequestCommon {
+    companion object {
+        /**
+         * Factory
+         *
+         * @param event the event
+         */
+        fun fromEvent(event: Event): IncomingRoomKeyRequest {
+            val roomKeyShareRequest = event.getClearContent().toModel<RoomKeyShareRequest>()!!
 
-    /**
+            return IncomingRoomKeyRequest(
-     * Constructor
+                    userId = event.senderId,
-     *
+                    deviceId = roomKeyShareRequest.requestingDeviceId,
-     * @param event the event
+                    requestId = roomKeyShareRequest.requestId,
-     */
+                    requestBody = roomKeyShareRequest.body ?: RoomKeyRequestBody()
-    constructor(event: Event) {
+            )
-        userId = event.senderId
+        }
-        val roomKeyShareRequest = event.getClearContent().toModel<RoomKeyShareRequest>()!!
-        deviceId = roomKeyShareRequest.requestingDeviceId
-        requestId = roomKeyShareRequest.requestId
-        requestBody = if (null != roomKeyShareRequest.body) roomKeyShareRequest.body else RoomKeyRequestBody()
     }
-
-    /**
-     * Constructor for object creation from crypto store
-     */
-    constructor()
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/IncomingRoomKeyRequestCancellation.kt

@@ -17,13 +17,43 @@
 package im.vector.matrix.android.internal.crypto
 
 import im.vector.matrix.android.api.session.events.model.Event
+import im.vector.matrix.android.api.session.events.model.toModel
+import im.vector.matrix.android.internal.crypto.model.rest.RoomKeyShareCancellation
 
 /**
  * IncomingRoomKeyRequestCancellation describes the incoming room key cancellation.
  */
-class IncomingRoomKeyRequestCancellation(event: Event) : IncomingRoomKeyRequest(event) {
+data class IncomingRoomKeyRequestCancellation(
+        /**
+         * The user id
+         */
+        override val userId: String? = null,
 
-    init {
+        /**
-        requestBody = null
+         * The device id
+         */
+        override val deviceId: String? = null,
+
+        /**
+         * The request id
+         */
+        override val requestId: String? = null
+) : IncomingRoomKeyRequestCommon {
+    companion object {
+
+        /**
+         * Factory
+         *
+         * @param event the event
+         */
+        fun fromEvent(event: Event): IncomingRoomKeyRequestCancellation {
+            val roomKeyShareRequestCancellation = event.getClearContent().toModel<RoomKeyShareCancellation>()!!
+
+            return IncomingRoomKeyRequestCancellation(
+                    userId = event.senderId,
+                    deviceId = roomKeyShareRequestCancellation.requestingDeviceId,
+                    requestId = roomKeyShareRequestCancellation.requestId
+            )
+        }
     }
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/IncomingRoomKeyRequestCommon.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2020 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package im.vector.matrix.android.internal.crypto
+
+interface IncomingRoomKeyRequestCommon {
+    /**
+     * The user id
+     */
+    val userId: String?
+
+    /**
+     * The device id
+     */
+    val deviceId: String?
+
+    /**
+     * The request id
+     */
+    val requestId: String?
+}

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/IncomingRoomKeyRequestManager.kt

@@ -53,8 +53,8 @@ internal class IncomingRoomKeyRequestManager @Inject constructor(
     fun onRoomKeyRequestEvent(event: Event) {
         val roomKeyShare = event.getClearContent().toModel<RoomKeyShare>()
         when (roomKeyShare?.action) {
-            RoomKeyShare.ACTION_SHARE_REQUEST      -> receivedRoomKeyRequests.add(IncomingRoomKeyRequest(event))
+            RoomKeyShare.ACTION_SHARE_REQUEST      -> receivedRoomKeyRequests.add(IncomingRoomKeyRequest.fromEvent(event))
-            RoomKeyShare.ACTION_SHARE_CANCELLATION -> receivedRoomKeyRequestCancellations.add(IncomingRoomKeyRequestCancellation(event))
+            RoomKeyShare.ACTION_SHARE_CANCELLATION -> receivedRoomKeyRequestCancellations.add(IncomingRoomKeyRequestCancellation.fromEvent(event))
             else                                   -> Timber.e("## onRoomKeyRequestEvent() : unsupported action ${roomKeyShare?.action}")
         }
     }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/MegolmSessionData.kt

@@ -28,46 +28,46 @@ data class MegolmSessionData(
          * The algorithm used.
          */
         @Json(name = "algorithm")
-        var algorithm: String? = null,
+        val algorithm: String? = null,
 
         /**
          * Unique id for the session.
          */
         @Json(name = "session_id")
-        var sessionId: String? = null,
+        val sessionId: String? = null,
 
         /**
          * Sender's Curve25519 device key.
          */
         @Json(name = "sender_key")
-        var senderKey: String? = null,
+        val senderKey: String? = null,
 
         /**
          * Room this session is used in.
          */
         @Json(name = "room_id")
-        var roomId: String? = null,
+        val roomId: String? = null,
 
         /**
          * Base64'ed key data.
          */
         @Json(name = "session_key")
-        var sessionKey: String? = null,
+        val sessionKey: String? = null,
 
         /**
          * Other keys the sender claims.
          */
         @Json(name = "sender_claimed_keys")
-        var senderClaimedKeys: Map<String, String>? = null,
+        val senderClaimedKeys: Map<String, String>? = null,
 
         // This is a shortcut for sender_claimed_keys.get("ed25519")
         // Keep it for compatibility reason.
         @Json(name = "sender_claimed_ed25519_key")
-        var senderClaimedEd25519Key: String? = null,
+        val senderClaimedEd25519Key: String? = null,
 
         /**
          * Devices which forwarded this session to us (normally empty).
          */
         @Json(name = "forwarding_curve25519_key_chain")
-        var forwardingCurve25519KeyChain: List<String>? = null
+        val forwardingCurve25519KeyChain: List<String>? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/OutgoingRoomKeyRequestManager.kt

@@ -213,10 +213,11 @@ internal class OutgoingRoomKeyRequestManager @Inject constructor(
         Timber.v("## sendOutgoingRoomKeyRequest() : Requesting keys " + request.requestBody
                 + " from " + request.recipients + " id " + request.requestId)
 
-        val requestMessage = RoomKeyShareRequest()
+        val requestMessage = RoomKeyShareRequest(
-        requestMessage.requestingDeviceId = cryptoStore.getDeviceId()
+                requestingDeviceId = cryptoStore.getDeviceId(),
-        requestMessage.requestId = request.requestId
+                requestId = request.requestId,
-        requestMessage.body = request.requestBody
+                body = request.requestBody
+        )
 
         sendMessageToDevices(requestMessage, request.recipients, request.requestId, object : MatrixCallback<Unit> {
             private fun onDone(state: OutgoingRoomKeyRequest.RequestState) {
@@ -253,9 +254,10 @@ internal class OutgoingRoomKeyRequestManager @Inject constructor(
                 + " to " + request.recipients
                 + " cancellation id  " + request.cancellationTxnId)
 
-        val roomKeyShareCancellation = RoomKeyShareCancellation()
+        val roomKeyShareCancellation = RoomKeyShareCancellation(
-        roomKeyShareCancellation.requestingDeviceId = cryptoStore.getDeviceId()
+                requestingDeviceId = cryptoStore.getDeviceId(),
-        roomKeyShareCancellation.requestId = request.cancellationTxnId
+                requestId = request.cancellationTxnId
+        )
 
         sendMessageToDevices(roomKeyShareCancellation, request.recipients, request.cancellationTxnId, object : MatrixCallback<Unit> {
             private fun onDone() {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/actions/MegolmSessionDataImporter.kt

@@ -66,12 +66,12 @@ internal class MegolmSessionDataImporter @Inject constructor(private val olmDevi
                     totalNumbersOfImportedKeys++
 
                     // cancel any outstanding room key requests for this session
-                    val roomKeyRequestBody = RoomKeyRequestBody()
+                    val roomKeyRequestBody = RoomKeyRequestBody(
-
+                            algorithm = megolmSessionData.algorithm,
-                    roomKeyRequestBody.algorithm = megolmSessionData.algorithm
+                            roomId = megolmSessionData.roomId,
-                    roomKeyRequestBody.roomId = megolmSessionData.roomId
+                            senderKey = megolmSessionData.senderKey,
-                    roomKeyRequestBody.senderKey = megolmSessionData.senderKey
+                            sessionId = megolmSessionData.sessionId
-                    roomKeyRequestBody.sessionId = megolmSessionData.sessionId
+                    )
 
                     outgoingRoomKeyRequestManager.cancelRoomKeyRequest(roomKeyRequestBody)
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/megolm/MXMegolmDecryption.kt

@@ -163,12 +163,12 @@ internal class MXMegolmDecryption(private val userId: String,
             recipients.add(senderMap)
         }
 
-        val requestBody = RoomKeyRequestBody()
+        val requestBody = RoomKeyRequestBody(
-
+                roomId = event.roomId,
-        requestBody.roomId = event.roomId
+                algorithm = encryptedEventContent.algorithm,
-        requestBody.algorithm = encryptedEventContent.algorithm
+                senderKey = encryptedEventContent.senderKey,
-        requestBody.senderKey = encryptedEventContent.senderKey
+                sessionId = encryptedEventContent.sessionId
-        requestBody.sessionId = encryptedEventContent.sessionId
+        )
 
         outgoingRoomKeyRequestManager.sendRoomKeyRequest(requestBody, recipients)
     }
@@ -264,12 +264,12 @@ internal class MXMegolmDecryption(private val userId: String,
         if (added) {
             defaultKeysBackupService.maybeBackupKeys()
 
-            val content = RoomKeyRequestBody()
+            val content = RoomKeyRequestBody(
-
+                    algorithm = roomKeyContent.algorithm,
-            content.algorithm = roomKeyContent.algorithm
+                    roomId = roomKeyContent.roomId,
-            content.roomId = roomKeyContent.roomId
+                    sessionId = roomKeyContent.sessionId,
-            content.sessionId = roomKeyContent.sessionId
+                    senderKey = senderKey
-            content.senderKey = senderKey
+            )
 
             outgoingRoomKeyRequestManager.cancelRoomKeyRequest(content)
 
@@ -290,8 +290,8 @@ internal class MXMegolmDecryption(private val userId: String,
 
     override fun hasKeysForKeyRequest(request: IncomingRoomKeyRequest): Boolean {
         val roomId = request.requestBody?.roomId ?: return false
-        val senderKey = request.requestBody?.senderKey ?: return false
+        val senderKey = request.requestBody.senderKey ?: return false
-        val sessionId = request.requestBody?.sessionId ?: return false
+        val sessionId = request.requestBody.sessionId ?: return false
         return olmDevice.hasInboundSessionKeys(roomId, senderKey, sessionId)
     }
 
@@ -319,15 +319,14 @@ internal class MXMegolmDecryption(private val userId: String,
                                 return@mapCatching
                             }
                             Timber.v("## shareKeysWithDevice() : sharing keys for session" +
-                                    " ${body?.senderKey}|${body?.sessionId} with device $userId:$deviceId")
+                                    " ${body.senderKey}|${body.sessionId} with device $userId:$deviceId")
 
                             val payloadJson = mutableMapOf<String, Any>("type" to EventType.FORWARDED_ROOM_KEY)
-                            runCatching { olmDevice.getInboundGroupSession(body?.sessionId, body?.senderKey, body?.roomId) }
+                            runCatching { olmDevice.getInboundGroupSession(body.sessionId, body.senderKey, body.roomId) }
                                     .fold(
                                             {
                                                 // TODO
-                                                payloadJson["content"] = it.exportKeys()
+                                                payloadJson["content"] = it.exportKeys() ?: ""
-                                                        ?: ""
                                             },
                                             {
                                                 // TODO

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/DefaultKeysBackupService.kt

@@ -167,9 +167,7 @@ internal class DefaultKeysBackupService @Inject constructor(
             runCatching {
                 withContext(coroutineDispatchers.crypto) {
                     val olmPkDecryption = OlmPkDecryption()
-                    val megolmBackupAuthData = MegolmBackupAuthData()
+                    val megolmBackupAuthData = if (password != null) {
-
-                    if (password != null) {
                         // Generate a private key from the password
                         val backgroundProgressListener = if (progressListener == null) {
                             null
@@ -188,25 +186,30 @@ internal class DefaultKeysBackupService @Inject constructor(
                         }
 
                         val generatePrivateKeyResult = generatePrivateKeyWithPassword(password, backgroundProgressListener)
-                        megolmBackupAuthData.publicKey = olmPkDecryption.setPrivateKey(generatePrivateKeyResult.privateKey)
+                        MegolmBackupAuthData(
-                        megolmBackupAuthData.privateKeySalt = generatePrivateKeyResult.salt
+                                publicKey = olmPkDecryption.setPrivateKey(generatePrivateKeyResult.privateKey),
-                        megolmBackupAuthData.privateKeyIterations = generatePrivateKeyResult.iterations
+                                privateKeySalt = generatePrivateKeyResult.salt,
+                                privateKeyIterations = generatePrivateKeyResult.iterations
+                        )
                     } else {
                         val publicKey = olmPkDecryption.generateKey()
 
-                        megolmBackupAuthData.publicKey = publicKey
+                        MegolmBackupAuthData(
+                                publicKey = publicKey
+                        )
                     }
 
                     val canonicalJson = JsonCanonicalizer.getCanonicalJson(Map::class.java, megolmBackupAuthData.signalableJSONDictionary())
 
-                    megolmBackupAuthData.signatures = objectSigner.signObject(canonicalJson)
+                    val signedMegolmBackupAuthData = megolmBackupAuthData.copy(
+                            signatures = objectSigner.signObject(canonicalJson)
+                    )
 
-                    val megolmBackupCreationInfo = MegolmBackupCreationInfo()
+                    MegolmBackupCreationInfo(
-                    megolmBackupCreationInfo.algorithm = MXCRYPTO_ALGORITHM_MEGOLM_BACKUP
+                            algorithm = MXCRYPTO_ALGORITHM_MEGOLM_BACKUP,
-                    megolmBackupCreationInfo.authData = megolmBackupAuthData
+                            authData = signedMegolmBackupAuthData,
-                    megolmBackupCreationInfo.recoveryKey = computeRecoveryKey(olmPkDecryption.privateKey())
+                            recoveryKey = computeRecoveryKey(olmPkDecryption.privateKey())
-
+                    )
-                    megolmBackupCreationInfo
                 }
             }.foldToCallback(callback)
         }
@@ -214,11 +217,12 @@ internal class DefaultKeysBackupService @Inject constructor(
 
     override fun createKeysBackupVersion(keysBackupCreationInfo: MegolmBackupCreationInfo,
                                          callback: MatrixCallback<KeysVersion>) {
-        val createKeysBackupVersionBody = CreateKeysBackupVersionBody()
-        createKeysBackupVersionBody.algorithm = keysBackupCreationInfo.algorithm
         @Suppress("UNCHECKED_CAST")
-        createKeysBackupVersionBody.authData = MoshiProvider.providesMoshi().adapter(Map::class.java)
+        val createKeysBackupVersionBody = CreateKeysBackupVersionBody(
-                .fromJson(keysBackupCreationInfo.authData?.toJsonString() ?: "") as JsonDict?
+                algorithm = keysBackupCreationInfo.algorithm,
+                authData = MoshiProvider.providesMoshi().adapter(Map::class.java)
+                        .fromJson(keysBackupCreationInfo.authData?.toJsonString() ?: "") as JsonDict?
+        )
 
         keysBackupStateManager.state = KeysBackupState.Enabling
 
@@ -229,14 +233,14 @@ internal class DefaultKeysBackupService @Inject constructor(
                             // Reset backup markers.
                             cryptoStore.resetBackupMarkers()
 
-                            val keyBackupVersion = KeysVersionResult()
+                            val keyBackupVersion = KeysVersionResult(
-                            keyBackupVersion.algorithm = createKeysBackupVersionBody.algorithm
+                                    algorithm = createKeysBackupVersionBody.algorithm,
-                            keyBackupVersion.authData = createKeysBackupVersionBody.authData
+                                    authData = createKeysBackupVersionBody.authData,
-                            keyBackupVersion.version = data.version
+                                    version = data.version,
-
+                                    // We can consider that the server does not have keys yet
-                            // We can consider that the server does not have keys yet
+                                    count = 0,
-                            keyBackupVersion.count = 0
+                                    hash = null
-                            keyBackupVersion.hash = null
+                            )
 
                             enableKeysBackup(keyBackupVersion)
 
@@ -406,7 +410,7 @@ internal class DefaultKeysBackupService @Inject constructor(
             return keysBackupVersionTrust
         }
 
-        val mySigs = authData.signatures?.get(userId)
+        val mySigs = authData.signatures[userId]
         if (mySigs.isNullOrEmpty()) {
             Timber.v("getKeysBackupTrust: Ignoring key backup because it lacks any signatures from this user")
             return keysBackupVersionTrust
@@ -469,8 +473,7 @@ internal class DefaultKeysBackupService @Inject constructor(
             cryptoCoroutineScope.launch(coroutineDispatchers.main) {
                 val updateKeysBackupVersionBody = withContext(coroutineDispatchers.crypto) {
                     // Get current signatures, or create an empty set
-                    val myUserSignatures = authData.signatures?.get(userId)?.toMutableMap()
+                    val myUserSignatures = authData.signatures?.get(userId)?.toMutableMap() ?: HashMap()
-                            ?: HashMap()
 
                     if (trust) {
                         // Add current device signature
@@ -487,24 +490,23 @@ internal class DefaultKeysBackupService @Inject constructor(
                     }
 
                     // Create an updated version of KeysVersionResult
-                    val updateKeysBackupVersionBody = UpdateKeysBackupVersionBody(keysBackupVersion.version!!)
-
-                    updateKeysBackupVersionBody.algorithm = keysBackupVersion.algorithm
-
                     val newMegolmBackupAuthData = authData.copy()
 
                     val newSignatures = newMegolmBackupAuthData.signatures!!.toMutableMap()
                     newSignatures[userId] = myUserSignatures
 
-                    newMegolmBackupAuthData.signatures = newSignatures
+                    val newMegolmBackupAuthDataWithNewSignature = newMegolmBackupAuthData.copy(
+                            signatures = newSignatures
+                    )
 
                     val moshi = MoshiProvider.providesMoshi()
                     val adapter = moshi.adapter(Map::class.java)
 
                     @Suppress("UNCHECKED_CAST")
-                    updateKeysBackupVersionBody.authData = adapter.fromJson(newMegolmBackupAuthData.toJsonString()) as Map<String, Any>?
+                    UpdateKeysBackupVersionBody(
-
+                            algorithm = keysBackupVersion.algorithm,
-                    updateKeysBackupVersionBody
+                            authData = adapter.fromJson(newMegolmBackupAuthDataWithNewSignature.toJsonString()) as Map<String, Any>?,
+                            version = keysBackupVersion.version!!)
                 }
 
                 // And send it to the homeserver
@@ -513,13 +515,13 @@ internal class DefaultKeysBackupService @Inject constructor(
                             this.callback = object : MatrixCallback<Unit> {
                                 override fun onSuccess(data: Unit) {
                                     // Relaunch the state machine on this updated backup version
-                                    val newKeysBackupVersion = KeysVersionResult()
+                                    val newKeysBackupVersion = KeysVersionResult(
-
+                                            algorithm = keysBackupVersion.algorithm,
-                                    newKeysBackupVersion.version = keysBackupVersion.version
+                                            authData = updateKeysBackupVersionBody.authData,
-                                    newKeysBackupVersion.algorithm = keysBackupVersion.algorithm
+                                            version = keysBackupVersion.version,
-                                    newKeysBackupVersion.count = keysBackupVersion.count
+                                            hash = keysBackupVersion.hash,
-                                    newKeysBackupVersion.hash = keysBackupVersion.hash
+                                            count = keysBackupVersion.count
-                                    newKeysBackupVersion.authData = updateKeysBackupVersionBody.authData
+                                    )
 
                                     checkAndStartWithKeysBackupVersion(newKeysBackupVersion)
 
@@ -1024,7 +1026,7 @@ internal class DefaultKeysBackupService @Inject constructor(
         }
 
         // Extract the recovery key from the passphrase
-        val data = retrievePrivateKeyWithPassword(password, authData.privateKeySalt!!, authData.privateKeyIterations!!, progressListener)
+        val data = retrievePrivateKeyWithPassword(password, authData.privateKeySalt, authData.privateKeyIterations, progressListener)
 
         return computeRecoveryKey(data)
     }
@@ -1178,14 +1180,16 @@ internal class DefaultKeysBackupService @Inject constructor(
 
                 // Gather data to send to the homeserver
                 // roomId -> sessionId -> MXKeyBackupData
-                val keysBackupData = KeysBackupData()
+                val keysBackupData = KeysBackupData(
-                keysBackupData.roomIdToRoomKeysBackupData = HashMap()
+                        roomIdToRoomKeysBackupData = HashMap()
+                )
 
                 for (olmInboundGroupSessionWrapper in olmInboundGroupSessionWrappers) {
                     val keyBackupData = encryptGroupSession(olmInboundGroupSessionWrapper)
                     if (keysBackupData.roomIdToRoomKeysBackupData[olmInboundGroupSessionWrapper.roomId] == null) {
-                        val roomKeysBackupData = RoomKeysBackupData()
+                        val roomKeysBackupData = RoomKeysBackupData(
-                        roomKeysBackupData.sessionIdToKeyBackupData = HashMap()
+                                sessionIdToKeyBackupData = HashMap()
+                        )
                         keysBackupData.roomIdToRoomKeysBackupData[olmInboundGroupSessionWrapper.roomId!!] = roomKeysBackupData
                     }
 
@@ -1301,24 +1305,21 @@ internal class DefaultKeysBackupService @Inject constructor(
         }
 
         // Build backup data for that key
-        val keyBackupData = KeyBackupData()
+        return KeyBackupData(
-        try {
+                firstMessageIndex = try {
-            keyBackupData.firstMessageIndex = olmInboundGroupSessionWrapper.olmInboundGroupSession!!.firstKnownIndex
+                    olmInboundGroupSessionWrapper.olmInboundGroupSession!!.firstKnownIndex
-        } catch (e: OlmException) {
+                } catch (e: OlmException) {
-            Timber.e(e, "OlmException")
+                    Timber.e(e, "OlmException")
-        }
+                    0L
+                },
+                forwardedCount = olmInboundGroupSessionWrapper.forwardingCurve25519KeyChain!!.size,
+                isVerified = device?.isVerified == true,
 
-        keyBackupData.forwardedCount = olmInboundGroupSessionWrapper.forwardingCurve25519KeyChain!!.size
+                sessionData = mapOf(
-        keyBackupData.isVerified = device?.isVerified == true
+                        "ciphertext" to encryptedSessionBackupData!!.mCipherText,
-
+                        "mac" to encryptedSessionBackupData.mMac,
-        val data = mapOf(
+                        "ephemeral" to encryptedSessionBackupData.mEphemeralKey)
-                "ciphertext" to encryptedSessionBackupData!!.mCipherText,
+        )
-                "mac" to encryptedSessionBackupData.mMac,
-                "ephemeral" to encryptedSessionBackupData.mEphemeralKey)
-
-        keyBackupData.sessionData = data
-
-        return keyBackupData
     }
 
     @VisibleForTesting
@@ -1350,8 +1351,10 @@ internal class DefaultKeysBackupService @Inject constructor(
             }
 
             if (sessionBackupData != null) {
-                sessionBackupData.sessionId = sessionId
+                sessionBackupData = sessionBackupData.copy(
-                sessionBackupData.roomId = roomId
+                        sessionId = sessionId,
+                        roomId = roomId
+                )
             }
         }
 
@@ -1370,11 +1373,12 @@ internal class DefaultKeysBackupService @Inject constructor(
     @VisibleForTesting
     fun createFakeKeysBackupVersion(keysBackupCreationInfo: MegolmBackupCreationInfo,
                                     callback: MatrixCallback<KeysVersion>) {
-        val createKeysBackupVersionBody = CreateKeysBackupVersionBody()
-        createKeysBackupVersionBody.algorithm = keysBackupCreationInfo.algorithm
         @Suppress("UNCHECKED_CAST")
-        createKeysBackupVersionBody.authData = MoshiProvider.providesMoshi().adapter(Map::class.java)
+        val createKeysBackupVersionBody = CreateKeysBackupVersionBody(
-                .fromJson(keysBackupCreationInfo.authData?.toJsonString() ?: "") as JsonDict?
+                algorithm = keysBackupCreationInfo.algorithm,
+                authData = MoshiProvider.providesMoshi().adapter(Map::class.java)
+                        .fromJson(keysBackupCreationInfo.authData?.toJsonString() ?: "") as JsonDict?
+        )
 
         createKeysBackupVersionTask
                 .configureWith(createKeysBackupVersionBody) {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/MegolmBackupAuthData.kt

@@ -30,26 +30,27 @@ data class MegolmBackupAuthData(
          * The curve25519 public key used to encrypt the backups.
          */
         @Json(name = "public_key")
-        var publicKey: String = "",
+        val publicKey: String = "",
 
         /**
          * In case of a backup created from a password, the salt associated with the backup
          * private key.
          */
         @Json(name = "private_key_salt")
-        var privateKeySalt: String? = null,
+        val privateKeySalt: String? = null,
 
         /**
          * In case of a backup created from a password, the number of key derivations.
          */
         @Json(name = "private_key_iterations")
-        var privateKeyIterations: Int? = null,
+        val privateKeyIterations: Int? = null,
 
         /**
          * Signatures of the public key.
          * userId -> (deviceSignKeyId -> signature)
          */
-        var signatures: Map<String, Map<String, String>>? = null
+        @Json(name = "signatures")
+        val signatures: Map<String, Map<String, String>>? = null
 ) {
 
     fun toJsonString(): String {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/MegolmBackupCreationInfo.kt

@@ -19,20 +19,19 @@ package im.vector.matrix.android.internal.crypto.keysbackup.model
 /**
  * Data retrieved from Olm library. algorithm and authData will be send to the homeserver, and recoveryKey will be displayed to the user
  */
-class MegolmBackupCreationInfo {
+data class MegolmBackupCreationInfo(
+        /**
+         * The algorithm used for storing backups [org.matrix.androidsdk.crypto.MXCRYPTO_ALGORITHM_MEGOLM_BACKUP].
+         */
+        val algorithm: String = "",
 
-    /**
+        /**
-     * The algorithm used for storing backups [org.matrix.androidsdk.crypto.MXCRYPTO_ALGORITHM_MEGOLM_BACKUP].
+         * Authentication data.
-     */
+         */
-    var algorithm: String = ""
+        val authData: MegolmBackupAuthData? = null,
 
-    /**
+        /**
-     * Authentication data.
+         * The Base58 recovery key.
-     */
+         */
-    var authData: MegolmBackupAuthData? = null
+        val recoveryKey: String = ""
-
+)
-    /**
-     * The Base58 recovery key.
-     */
-    var recoveryKey: String = ""
-}

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/rest/CreateKeysBackupVersionBody.kt

@@ -16,7 +16,21 @@
 
 package im.vector.matrix.android.internal.crypto.keysbackup.model.rest
 
+import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.util.JsonDict
 
 @JsonClass(generateAdapter = true)
-class CreateKeysBackupVersionBody : KeysAlgorithmAndData()
+data class CreateKeysBackupVersionBody(
+        /**
+         * The algorithm used for storing backups. Currently, only "m.megolm_backup.v1.curve25519-aes-sha2" is defined
+         */
+        @Json(name = "algorithm")
+        override val algorithm: String? = null,
+
+        /**
+         * algorithm-dependent data, for "m.megolm_backup.v1.curve25519-aes-sha2" see [im.vector.matrix.android.internal.crypto.keysbackup.MegolmBackupAuthData]
+         */
+        @Json(name = "auth_data")
+        override val authData: JsonDict? = null
+) : KeysAlgorithmAndData

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/rest/KeyBackupData.kt

@@ -29,25 +29,25 @@ data class KeyBackupData(
          * Required. The index of the first message in the session that the key can decrypt.
          */
         @Json(name = "first_message_index")
-        var firstMessageIndex: Long = 0,
+        val firstMessageIndex: Long = 0,
 
         /**
          * Required. The number of times this key has been forwarded.
          */
         @Json(name = "forwarded_count")
-        var forwardedCount: Int = 0,
+        val forwardedCount: Int = 0,
 
         /**
          * Whether the device backing up the key has verified the device that the key is from.
          */
         @Json(name = "is_verified")
-        var isVerified: Boolean = false,
+        val isVerified: Boolean = false,
 
         /**
          * Algorithm-dependent data.
          */
         @Json(name = "session_data")
-        var sessionData: Map<String, Any>? = null
+        val sessionData: Map<String, Any>? = null
 ) {
 
     fun toJsonString(): String {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/rest/KeysAlgorithmAndData.kt

@@ -16,7 +16,6 @@
 
 package im.vector.matrix.android.internal.crypto.keysbackup.model.rest
 
-import com.squareup.moshi.Json
 import im.vector.matrix.android.api.util.JsonDict
 import im.vector.matrix.android.internal.crypto.keysbackup.model.MegolmBackupAuthData
 import im.vector.matrix.android.internal.di.MoshiProvider
@@ -38,19 +37,17 @@ import im.vector.matrix.android.internal.di.MoshiProvider
  *     }
  * </pre>
  */
-open class KeysAlgorithmAndData {
+interface KeysAlgorithmAndData {
 
     /**
      * The algorithm used for storing backups. Currently, only "m.megolm_backup.v1.curve25519-aes-sha2" is defined
      */
-    @Json(name = "algorithm")
+    val algorithm: String?
-    var algorithm: String? = null
 
     /**
      * algorithm-dependent data, for "m.megolm_backup.v1.curve25519-aes-sha2" see [im.vector.matrix.android.internal.crypto.keysbackup.MegolmBackupAuthData]
      */
-    @Json(name = "auth_data")
+    val authData: JsonDict?
-    var authData: JsonDict? = null
 
     /**
      * Facility method to convert authData to a MegolmBackupAuthData object

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/rest/KeysBackupData.kt

@@ -24,9 +24,7 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 data class KeysBackupData(
-
         // the keys are the room IDs, and the values are RoomKeysBackupData
         @Json(name = "rooms")
-        var roomIdToRoomKeysBackupData: MutableMap<String, RoomKeysBackupData> = HashMap()
+        val roomIdToRoomKeysBackupData: MutableMap<String, RoomKeysBackupData> = HashMap()
-
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/rest/KeysVersionResult.kt

@@ -16,16 +16,33 @@
 
 package im.vector.matrix.android.internal.crypto.keysbackup.model.rest
 
+import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.util.JsonDict
 
 @JsonClass(generateAdapter = true)
 data class KeysVersionResult(
+        /**
+         * The algorithm used for storing backups. Currently, only "m.megolm_backup.v1.curve25519-aes-sha2" is defined
+         */
+        @Json(name = "algorithm")
+        override val algorithm: String? = null,
+
+        /**
+         * algorithm-dependent data, for "m.megolm_backup.v1.curve25519-aes-sha2" see [im.vector.matrix.android.internal.crypto.keysbackup.MegolmBackupAuthData]
+         */
+        @Json(name = "auth_data")
+        override val authData: JsonDict? = null,
+
         // the backup version
-        var version: String? = null,
+        @Json(name = "version")
+        val version: String? = null,
 
         // The hash value which is an opaque string representing stored keys in the backup
-        var hash: String? = null,
+        @Json(name = "hash")
+        val hash: String? = null,
 
         // The number of keys stored in the backup.
-        var count: Int? = null
+        @Json(name = "count")
-) : KeysAlgorithmAndData()
+        val count: Int? = null
+) : KeysAlgorithmAndData

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/rest/RoomKeysBackupData.kt

@@ -24,8 +24,7 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 data class RoomKeysBackupData(
-
         // the keys are the session IDs, and the values are KeyBackupData
         @Json(name = "sessions")
-        var sessionIdToKeyBackupData: MutableMap<String, KeyBackupData> = HashMap()
+        val sessionIdToKeyBackupData: MutableMap<String, KeyBackupData> = HashMap()
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/model/rest/UpdateKeysBackupVersionBody.kt

@@ -16,10 +16,25 @@
 
 package im.vector.matrix.android.internal.crypto.keysbackup.model.rest
 
+import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.util.JsonDict
 
 @JsonClass(generateAdapter = true)
 data class UpdateKeysBackupVersionBody(
+        /**
+         * The algorithm used for storing backups. Currently, only "m.megolm_backup.v1.curve25519-aes-sha2" is defined
+         */
+        @Json(name = "algorithm")
+        override val algorithm: String? = null,
+
+        /**
+         * algorithm-dependent data, for "m.megolm_backup.v1.curve25519-aes-sha2" see [im.vector.matrix.android.internal.crypto.keysbackup.MegolmBackupAuthData]
+         */
+        @Json(name = "auth_data")
+        override val authData: JsonDict? = null,
+
         // the backup version, mandatory
+        @Json(name = "version")
         val version: String
-) : KeysAlgorithmAndData()
+) : KeysAlgorithmAndData

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXDeviceInfo.kt

@@ -26,48 +26,47 @@ import java.io.Serializable
 
 @JsonClass(generateAdapter = true)
 data class MXDeviceInfo(
-
         /**
          * The id of this device.
          */
         @Json(name = "device_id")
-        var deviceId: String,
+        val deviceId: String,
 
         /**
          * the user id
          */
         @Json(name = "user_id")
-        var userId: String,
+        val userId: String,
 
         /**
          * The list of algorithms supported by this device.
          */
         @Json(name = "algorithms")
-        var algorithms: List<String>? = null,
+        val algorithms: List<String>? = null,
 
         /**
          * A map from "<key type>:<deviceId>" to "<base64-encoded key>".
          */
         @Json(name = "keys")
-        var keys: Map<String, String>? = null,
+        val keys: Map<String, String>? = null,
 
         /**
          * The signature of this MXDeviceInfo.
          * A map from "<userId>" to a map from "<key type>:<deviceId>" to "<signature>"
          */
         @Json(name = "signatures")
-        var signatures: Map<String, Map<String, String>>? = null,
+        val signatures: Map<String, Map<String, String>>? = null,
 
         /*
          * Additional data from the home server.
          */
         @Json(name = "unsigned")
-        var unsigned: JsonDict? = null,
+        val unsigned: JsonDict? = null,
 
         /**
          * Verification state of this device.
          */
-        var verified: Int = DEVICE_VERIFICATION_UNKNOWN
+        val verified: Int = DEVICE_VERIFICATION_UNKNOWN
 ) : Serializable {
     /**
      * Tells if the device is unknown
@@ -137,11 +136,11 @@ data class MXDeviceInfo(
         map["user_id"] = userId
 
         if (null != algorithms) {
-            map["algorithms"] = algorithms!!
+            map["algorithms"] = algorithms
         }
 
         if (null != keys) {
-            map["keys"] = keys!!
+            map["keys"] = keys
         }
 
         return map

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/OlmInboundGroupSessionWrapper.kt

@@ -116,16 +116,16 @@ class OlmInboundGroupSessionWrapper : Serializable {
                 return null
             }
 
-            MegolmSessionData().also {
+            MegolmSessionData(
-                it.senderClaimedEd25519Key = keysClaimed?.get("ed25519")
+                    senderClaimedEd25519Key = keysClaimed?.get("ed25519"),
-                it.forwardingCurve25519KeyChain = ArrayList(forwardingCurve25519KeyChain!!)
+                    forwardingCurve25519KeyChain = ArrayList(forwardingCurve25519KeyChain!!),
-                it.senderKey = senderKey
+                    senderKey = senderKey,
-                it.senderClaimedKeys = keysClaimed
+                    senderClaimedKeys = keysClaimed,
-                it.roomId = roomId
+                    roomId = roomId,
-                it.sessionId = olmInboundGroupSession!!.sessionIdentifier()
+                    sessionId = olmInboundGroupSession!!.sessionIdentifier(),
-                it.sessionKey = olmInboundGroupSession!!.export(olmInboundGroupSession!!.firstKnownIndex)
+                    sessionKey = olmInboundGroupSession!!.export(olmInboundGroupSession!!.firstKnownIndex),
-                it.algorithm = MXCRYPTO_ALGORITHM_MEGOLM
+                    algorithm = MXCRYPTO_ALGORITHM_MEGOLM
-            }
+            )
         } catch (e: Exception) {
             Timber.e(e, "## export() : senderKey $senderKey failed")
             null

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/event/EncryptionEventContent.kt

@@ -23,22 +23,21 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 data class EncryptionEventContent(
-
         /**
          * Required. The encryption algorithm to be used to encrypt messages sent in this room. Must be 'm.megolm.v1.aes-sha2'.
          */
         @Json(name = "algorithm")
-        var algorithm: String,
+        val algorithm: String,
 
         /**
          * How long the session should be used before changing it. 604800000 (a week) is the recommended default.
          */
         @Json(name = "rotation_period_ms")
-        var rotationPeriodMs: Long? = null,
+        val rotationPeriodMs: Long? = null,
 
         /**
          * How many messages should be sent before changing the session. 100 is the recommended default.
          */
         @Json(name = "rotation_period_msgs")
-        var rotationPeriodMsgs: Long? = null
+        val rotationPeriodMsgs: Long? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/event/NewDeviceContent.kt

@@ -20,12 +20,11 @@ import com.squareup.moshi.JsonClass
 
 @JsonClass(generateAdapter = true)
 data class NewDeviceContent(
-
         // the device id
         @Json(name = "device_id")
-        var deviceId: String? = null,
+        val deviceId: String? = null,
 
         // the room ids list
         @Json(name = "rooms")
-        var rooms: List<String>? = null
+        val rooms: List<String>? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/event/OlmEventContent.kt

@@ -27,11 +27,11 @@ data class OlmEventContent(
          *
          */
         @Json(name = "ciphertext")
-        var ciphertext: Map<String, Any>? = null,
+        val ciphertext: Map<String, Any>? = null,
 
         /**
          * the sender key
          */
         @Json(name = "sender_key")
-        var senderKey: String? = null
+        val senderKey: String? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/DeviceInfo.kt

@@ -30,31 +30,31 @@ data class DeviceInfo(
          * The owner user id (not documented and useless but the homeserver sent it. You should not need it)
          */
         @Json(name = "user_id")
-        var user_id: String? = null,
+        val user_id: String? = null,
 
         /**
          * The device id
          */
         @Json(name = "device_id")
-        var deviceId: String? = null,
+        val deviceId: String? = null,
 
         /**
          * The device display name
          */
         @Json(name = "display_name")
-        var displayName: String? = null,
+        val displayName: String? = null,
 
         /**
          * The last time this device has been seen.
          */
         @Json(name = "last_seen_ts")
-        var lastSeenTs: Long? = null,
+        val lastSeenTs: Long? = null,
 
         /**
          * The last ip address
          */
         @Json(name = "last_seen_ip")
-        var lastSeenIp: String? = null
+        val lastSeenIp: String? = null
 ) : DatedObject {
 
     override val date: Long

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/DevicesListResponse.kt

@@ -24,5 +24,5 @@ import com.squareup.moshi.JsonClass
 @JsonClass(generateAdapter = true)
 data class DevicesListResponse(
         @Json(name = "devices")
-        var devices: List<DeviceInfo>? = null
+        val devices: List<DeviceInfo>? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/EncryptedFileInfo.kt

@@ -27,38 +27,38 @@ data class EncryptedFileInfo(
          * Required. The URL to the file.
          */
         @Json(name = "url")
-        var url: String? = null,
+        val url: String? = null,
 
         /**
          * Not documented
          */
         @Json(name = "mimetype")
-        var mimetype: String? = null,
+        val mimetype: String? = null,
 
         /**
          * Required. A JSON Web Key object.
          */
         @Json(name = "key")
-        var key: EncryptedFileKey? = null,
+        val key: EncryptedFileKey? = null,
 
         /**
          * Required. The Initialisation Vector used by AES-CTR, encoded as unpadded base64.
          */
         @Json(name = "iv")
-        var iv: String? = null,
+        val iv: String? = null,
 
         /**
          * Required. A map from an algorithm name to a hash of the ciphertext, encoded as unpadded base64.
          * Clients should support the SHA-256 hash, which uses the key "sha256".
          */
         @Json(name = "hashes")
-        var hashes: Map<String, String>? = null,
+        val hashes: Map<String, String>? = null,
 
         /**
          * Required. Version of the encrypted attachments protocol. Must be "v2".
          */
         @Json(name = "v")
-        var v: String? = null
+        val v: String? = null
 ) {
     /**
      * Check what the spec tells us

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/EncryptedFileKey.kt

@@ -24,31 +24,31 @@ data class EncryptedFileKey(
          * Required. Algorithm. Must be "A256CTR".
          */
         @Json(name = "alg")
-        var alg: String? = null,
+        val alg: String? = null,
 
         /**
          * Required. Extractable. Must be true. This is a W3C extension.
          */
         @Json(name = "ext")
-        var ext: Boolean? = null,
+        val ext: Boolean? = null,
 
         /**
          * Required. Key operations. Must at least contain "encrypt" and "decrypt".
          */
         @Json(name = "key_ops")
-        var key_ops: List<String>? = null,
+        val key_ops: List<String>? = null,
 
         /**
          * Required. Key type. Must be "oct".
          */
         @Json(name = "kty")
-        var kty: String? = null,
+        val kty: String? = null,
 
         /**
          * Required. The key, encoded as urlsafe unpadded base64.
          */
         @Json(name = "k")
-        var k: String? = null
+        val k: String? = null
 ) {
     /**
      * Check what the spec tells us
@@ -62,7 +62,7 @@ data class EncryptedFileKey(
             return false
         }
 
-        if (key_ops?.contains("encrypt") != true || key_ops?.contains("decrypt") != true) {
+        if (key_ops?.contains("encrypt") != true || !key_ops.contains("decrypt")) {
             return false
         }
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/EncryptedMessage.kt

@@ -21,11 +21,12 @@ import com.squareup.moshi.JsonClass
 
 @JsonClass(generateAdapter = true)
 data class EncryptedMessage(
-        var algorithm: String? = null,
+        @Json(name = "algorithm")
+        val algorithm: String? = null,
 
         @Json(name = "sender_key")
-        var senderKey: String? = null,
+        val senderKey: String? = null,
 
         @Json(name = "ciphertext")
-        var cipherText: Map<String, Any>? = null
+        val cipherText: Map<String, Any>? = null
 ) : SendToDeviceObject

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyChangesResponse.kt

@@ -25,9 +25,9 @@ import com.squareup.moshi.JsonClass
 internal data class KeyChangesResponse(
         // list of user ids which have new devices
         @Json(name = "changed")
-        var changed: List<String>? = null,
+        val changed: List<String>? = null,
 
         //  List of user ids who are no more tracked.
         @Json(name = "left")
-        var left: List<String>? = null
+        val left: List<String>? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationDone.kt

@@ -24,7 +24,7 @@ import im.vector.matrix.android.internal.crypto.verification.VerificationInfoDon
  */
 @JsonClass(generateAdapter = true)
 internal data class KeyVerificationDone(
-        @Json(name = "transaction_id") override var transactionID: String? = null
+        @Json(name = "transaction_id") override val transactionID: String? = null
 ) : SendToDeviceObject, VerificationInfoDone {
 
     override fun toSendToDeviceObject() = this

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationRequest.kt

@@ -27,7 +27,7 @@ internal data class KeyVerificationRequest(
         @Json(name = "from_device") override val fromDevice: String?,
         @Json(name = "methods") override val methods: List<String>,
         @Json(name = "timestamp") override val timestamp: Long?,
-        @Json(name = "transaction_id") override var transactionID: String? = null
+        @Json(name = "transaction_id") override val transactionID: String? = null
 
 ) : SendToDeviceObject, VerificationInfoRequest {
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeysClaimBody.kt

@@ -24,16 +24,15 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 internal data class KeysClaimBody(
-
         /**
          * The time (in milliseconds) to wait when downloading keys from remote servers. 10 seconds is the recommended default.
          */
         @Json(name = "timeout")
-        var timeout: Int? = null,
+        val timeout: Int? = null,
 
         /**
          * Required. The keys to be claimed. A map from user ID, to a map from device ID to algorithm name.
          */
         @Json(name = "one_time_keys")
-        var oneTimeKeys: Map<String, Map<String, String>>
+        val oneTimeKeys: Map<String, Map<String, String>>
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeysClaimResponse.kt

@@ -24,11 +24,10 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 internal data class KeysClaimResponse(
-
         /**
          * The requested keys ordered by device by user.
          * TODO Type does not match spec, should be Map<String, JsonDict>
          */
         @Json(name = "one_time_keys")
-        var oneTimeKeys: Map<String, Map<String, Map<String, Map<String, Any>>>>? = null
+        val oneTimeKeys: Map<String, Map<String, Map<String, Map<String, Any>>>>? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeysQueryBody.kt

@@ -25,12 +25,11 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 internal data class KeysQueryBody(
-
         /**
          * The time (in milliseconds) to wait when downloading keys from remote servers. 10 seconds is the recommended default.
          */
         @Json(name = "timeout")
-        var timeout: Int? = null,
+        val timeout: Int? = null,
 
         /**
          * Required. The keys to be downloaded.
@@ -45,6 +44,5 @@ internal data class KeysQueryBody(
          * by the notification in that sync.
          */
         @Json(name = "token")
-        var token: String? = null
+        val token: String? = null
-
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeysUploadResponse.kt

@@ -23,13 +23,11 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 internal data class KeysUploadResponse(
-
         /**
          * The count per algorithm as returned by the home server: a map (algorithm to count).
          */
         @Json(name = "one_time_key_counts")
-        var oneTimeKeyCounts: Map<String, Int>? = null
+        val oneTimeKeyCounts: Map<String, Int>? = null
-
 ) {
     /**
      * Helper methods to extract information from 'oneTimeKeyCounts'

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/RoomKeyRequestBody.kt

@@ -25,14 +25,14 @@ import com.squareup.moshi.JsonClass
 @JsonClass(generateAdapter = true)
 data class RoomKeyRequestBody(
         @Json(name = "algorithm")
-        var algorithm: String? = null,
+        val algorithm: String? = null,
 
         @Json(name = "room_id")
-        var roomId: String? = null,
+        val roomId: String? = null,
 
         @Json(name = "sender_key")
-        var senderKey: String? = null,
+        val senderKey: String? = null,
 
         @Json(name = "session_id")
-        var sessionId: String? = null
+        val sessionId: String? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/RoomKeyShare.kt

@@ -15,21 +15,17 @@
  */
 package im.vector.matrix.android.internal.crypto.model.rest
 
-import com.squareup.moshi.Json
-
 /**
- * Parent class representing an room key action request
+ * Interface representing an room key action request
  * Note: this class cannot be abstract because of [org.matrix.androidsdk.core.JsonUtils.toRoomKeyShare]
  */
-internal open class RoomKeyShare : SendToDeviceObject {
+internal interface RoomKeyShare : SendToDeviceObject {
 
-    var action: String? = null
+    val action: String?
 
-    @Json(name = "requesting_device_id")
+    val requestingDeviceId: String?
-    var requestingDeviceId: String? = null
 
-    @Json(name = "request_id")
+    val requestId: String?
-    var requestId: String? = null
 
     companion object {
         const val ACTION_SHARE_REQUEST = "request"

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/RoomKeyShareCancellation.kt

@@ -15,14 +15,21 @@
  */
 package im.vector.matrix.android.internal.crypto.model.rest
 
+import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.internal.crypto.model.rest.RoomKeyShare.Companion.ACTION_SHARE_CANCELLATION
 
 /**
- * Class representing an room key request cancellation content
+ * Class representing a room key request cancellation content
  */
 @JsonClass(generateAdapter = true)
-internal class RoomKeyShareCancellation : RoomKeyShare() {
+internal data class RoomKeyShareCancellation(
-    init {
+        @Json(name = "action")
-        action = ACTION_SHARE_CANCELLATION
+        override val action: String? = ACTION_SHARE_CANCELLATION,
-    }
+
-}
+        @Json(name = "requesting_device_id")
+        override val requestingDeviceId: String? = null,
+
+        @Json(name = "request_id")
+        override val requestId: String? = null
+) : RoomKeyShare

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/RoomKeyShareRequest.kt

@@ -16,16 +16,23 @@
  */
 package im.vector.matrix.android.internal.crypto.model.rest
 
+import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
 
 /**
- * Class representing an room key request content
+ * Class representing a room key request content
  */
 @JsonClass(generateAdapter = true)
-internal class RoomKeyShareRequest : RoomKeyShare() {
+internal data class RoomKeyShareRequest(
-    var body: RoomKeyRequestBody? = null
+        @Json(name = "action")
+        override val action: String? = RoomKeyShare.ACTION_SHARE_REQUEST,
 
-    init {
+        @Json(name = "requesting_device_id")
-        action = ACTION_SHARE_REQUEST
+        override val requestingDeviceId: String? = null,
-    }
+
-}
+        @Json(name = "request_id")
+        override val requestId: String? = null,
+
+        @Json(name = "body")
+        val body: RoomKeyRequestBody? = null
+) : RoomKeyShare

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/UpdateDeviceInfoBody.kt

@@ -25,5 +25,5 @@ internal data class UpdateDeviceInfoBody(
          * The new display name for this device. If not given, the display name is unchanged.
          */
         @Json(name = "display_name")
-        var displayName: String? = null
+        val displayName: String? = null
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/IMXCryptoStore.kt

@@ -20,6 +20,7 @@ package im.vector.matrix.android.internal.crypto.store
 import androidx.lifecycle.LiveData
 import im.vector.matrix.android.api.session.crypto.crosssigning.MXCrossSigningInfo
 import im.vector.matrix.android.api.util.Optional
+import im.vector.matrix.android.internal.crypto.IncomingRoomKeyRequestCommon
 import im.vector.matrix.android.internal.crypto.IncomingRoomKeyRequest
 import im.vector.matrix.android.internal.crypto.NewSessionListener
 import im.vector.matrix.android.internal.crypto.OutgoingRoomKeyRequest
@@ -382,7 +383,7 @@ internal interface IMXCryptoStore {
      *
      * @param incomingRoomKeyRequest the incoming key request
      */
-    fun deleteIncomingRoomKeyRequest(incomingRoomKeyRequest: IncomingRoomKeyRequest)
+    fun deleteIncomingRoomKeyRequest(incomingRoomKeyRequest: IncomingRoomKeyRequestCommon)
 
     /**
      * Search an IncomingRoomKeyRequest

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/RealmCryptoStore.kt

@@ -23,6 +23,7 @@ import im.vector.matrix.android.api.auth.data.Credentials
 import im.vector.matrix.android.api.session.crypto.crosssigning.MXCrossSigningInfo
 import im.vector.matrix.android.api.util.Optional
 import im.vector.matrix.android.api.util.toOptional
+import im.vector.matrix.android.internal.crypto.IncomingRoomKeyRequestCommon
 import im.vector.matrix.android.internal.crypto.IncomingRoomKeyRequest
 import im.vector.matrix.android.internal.crypto.NewSessionListener
 import im.vector.matrix.android.internal.crypto.OutgoingRoomKeyRequest
@@ -888,7 +889,7 @@ internal class RealmCryptoStore @Inject constructor(
         }
     }
 
-    override fun deleteIncomingRoomKeyRequest(incomingRoomKeyRequest: IncomingRoomKeyRequest) {
+    override fun deleteIncomingRoomKeyRequest(incomingRoomKeyRequest: IncomingRoomKeyRequestCommon) {
         doRealmTransaction(realmConfiguration) {
             it.where<IncomingRoomKeyRequestEntity>()
                     .equalTo(IncomingRoomKeyRequestEntityFields.USER_ID, incomingRoomKeyRequest.userId)

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/model/IncomingRoomKeyRequestEntity.kt

@@ -32,17 +32,17 @@ internal open class IncomingRoomKeyRequestEntity(
 ) : RealmObject() {
 
     fun toIncomingRoomKeyRequest(): IncomingRoomKeyRequest {
-        return IncomingRoomKeyRequest().also {
+        return IncomingRoomKeyRequest(
-            it.requestId = requestId
+                requestId = requestId,
-            it.userId = userId
+                userId = userId,
-            it.deviceId = deviceId
+                deviceId = deviceId,
-            it.requestBody = RoomKeyRequestBody().apply {
+                requestBody = RoomKeyRequestBody(
-                algorithm = requestBodyAlgorithm
+                        algorithm = requestBodyAlgorithm,
-                roomId = requestBodyRoomId
+                        roomId = requestBodyRoomId,
-                senderKey = requestBodySenderKey
+                        senderKey = requestBodySenderKey,
-                sessionId = requestBodySessionId
+                        sessionId = requestBodySessionId
-            }
+                )
-        }
+        )
     }
 
     fun putRequestBody(requestBody: RoomKeyRequestBody?) {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/model/OutgoingRoomKeyRequestEntity.kt

@@ -43,12 +43,12 @@ internal open class OutgoingRoomKeyRequestEntity(
     fun toOutgoingRoomKeyRequest(): OutgoingRoomKeyRequest {
         val cancellationTxnId = this.cancellationTxnId
         return OutgoingRoomKeyRequest(
-                RoomKeyRequestBody().apply {
+                RoomKeyRequestBody(
-                    algorithm = requestBodyAlgorithm
+                        algorithm = requestBodyAlgorithm,
-                    roomId = requestBodyRoomId
+                        roomId = requestBodyRoomId,
-                    senderKey = requestBodySenderKey
+                        senderKey = requestBodySenderKey,
-                    sessionId = requestBodySessionId
+                        sessionId = requestBodySessionId
-                },
+                ),
                 getRecipients()!!,
                 requestId!!,
                 OutgoingRoomKeyRequest.RequestState.from(state)

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/DownloadKeysForUsersTask.kt

@@ -29,7 +29,8 @@ internal interface DownloadKeysForUsersTask : Task<DownloadKeysForUsersTask.Para
             // the list of users to get keys for.
             val userIds: List<String>?,
             // the up-to token
-            val token: String?)
+            val token: String?
+    )
 }
 
 internal class DefaultDownloadKeysForUsers @Inject constructor(
@@ -41,13 +42,10 @@ internal class DefaultDownloadKeysForUsers @Inject constructor(
         val downloadQuery = params.userIds?.associateWith { emptyMap<String, Any>() }.orEmpty()
 
         val body = KeysQueryBody(
-                deviceKeys = downloadQuery
+                deviceKeys = downloadQuery,
+                token = params.token?.takeIf { it.isNotEmpty() }
         )
 
-        if (!params.token.isNullOrEmpty()) {
-            body.token = params.token
-        }
-
         return executeRequest(eventBus) {
             apiCall = cryptoApi.downloadKeysForUsers(body)
         }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/filter/Filter.kt

@@ -24,13 +24,13 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 data class Filter(
-        @Json(name = "limit") var limit: Int? = null,
+        @Json(name = "limit") val limit: Int? = null,
-        @Json(name = "senders") var senders: MutableList<String>? = null,
+        @Json(name = "senders") val senders: List<String>? = null,
-        @Json(name = "not_senders") var notSenders: MutableList<String>? = null,
+        @Json(name = "not_senders") val notSenders: List<String>? = null,
-        @Json(name = "types") var types: MutableList<String>? = null,
+        @Json(name = "types") val types: List<String>? = null,
-        @Json(name = "not_types") var notTypes: MutableList<String>? = null,
+        @Json(name = "not_types") val notTypes: List<String>? = null,
-        @Json(name = "rooms") var rooms: MutableList<String>? = null,
+        @Json(name = "rooms") val rooms: List<String>? = null,
-        @Json(name = "not_rooms") var notRooms: MutableList<String>? = null
+        @Json(name = "not_rooms") val notRooms: List<String>? = null
 ) {
     fun hasData(): Boolean {
         return (limit != null

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/filter/FilterBody.kt

@@ -26,11 +26,11 @@ import im.vector.matrix.android.internal.di.MoshiProvider
  */
 @JsonClass(generateAdapter = true)
 internal data class FilterBody(
-        @Json(name = "event_fields") var eventFields: List<String>? = null,
+        @Json(name = "event_fields") val eventFields: List<String>? = null,
-        @Json(name = "event_format") var eventFormat: String? = null,
+        @Json(name = "event_format") val eventFormat: String? = null,
-        @Json(name = "presence") var presence: Filter? = null,
+        @Json(name = "presence") val presence: Filter? = null,
-        @Json(name = "account_data") var accountData: Filter? = null,
+        @Json(name = "account_data") val accountData: Filter? = null,
-        @Json(name = "room") var room: RoomFilter? = null
+        @Json(name = "room") val room: RoomFilter? = null
 ) {
 
     fun toJSONString(): String {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/filter/FilterFactory.kt

@@ -21,32 +21,30 @@ import im.vector.matrix.android.api.session.events.model.EventType
 internal object FilterFactory {
 
     fun createDefaultFilterBody(): FilterBody {
-        val filterBody = FilterBody()
+        return FilterUtil.enableLazyLoading(FilterBody(), true)
-        FilterUtil.enableLazyLoading(filterBody, true)
-        return filterBody
     }
 
     fun createRiotFilterBody(): FilterBody {
-        val filterBody = FilterBody()
+        return FilterBody(
-        filterBody.room = RoomFilter().apply {
+                room = RoomFilter(
-            timeline = createRiotTimelineFilter()
+                        timeline = createRiotTimelineFilter(),
-            state = createRiotStateFilter()
+                        state = createRiotStateFilter()
-        }
+                )
-        return filterBody
+        )
     }
 
     fun createDefaultRoomFilter(): RoomEventFilter {
-        return RoomEventFilter().apply {
+        return RoomEventFilter(
-            lazyLoadMembers = true
+                lazyLoadMembers = true
-        }
+        )
     }
 
     fun createRiotRoomFilter(): RoomEventFilter {
-        return RoomEventFilter().apply {
+        return RoomEventFilter(
-            lazyLoadMembers = true
+                lazyLoadMembers = true
-            // TODO Enable this for optimization
+                // TODO Enable this for optimization
-            // types = (listOfSupportedEventTypes + listOfSupportedStateEventTypes).toMutableList()
+                // types = (listOfSupportedEventTypes + listOfSupportedStateEventTypes).toMutableList()
-        }
+        )
     }
 
     private fun createRiotTimelineFilter(): RoomEventFilter {
@@ -57,9 +55,9 @@ internal object FilterFactory {
     }
 
     private fun createRiotStateFilter(): RoomEventFilter {
-        return RoomEventFilter().apply {
+        return RoomEventFilter(
-            lazyLoadMembers = true
+                lazyLoadMembers = true
-        }
+        )
     }
 
     // Get only managed types by Riot

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/filter/FilterResponse.kt

@@ -24,5 +24,5 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 data class FilterResponse(
-        @Json(name = "filter_id") var filterId: String
+        @Json(name = "filter_id") val filterId: String
 )

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/filter/FilterUtil.kt

@@ -21,7 +21,6 @@ internal object FilterUtil {
     /**
      * Patch the filterBody to enable or disable the data save mode
      *
-     *
      * If data save mode is on, FilterBody will contains
      * FIXME New expected filter:
      * "{\"room\": {\"ephemeral\": {\"notTypes\": [\"m.typing\"]}}, \"presence\":{\"notTypes\": [\"*\"]}}"
@@ -29,6 +28,7 @@ internal object FilterUtil {
      * @param filterBody      filterBody to patch
      * @param useDataSaveMode true to enable data save mode
      */
+    /*
     fun enableDataSaveMode(filterBody: FilterBody, useDataSaveMode: Boolean) {
         if (useDataSaveMode) {
             // Enable data save mode
@@ -79,9 +79,10 @@ internal object FilterUtil {
             }
         }
     }
+    */
 
     /**
-     * Patch the filterBody to enable or disable the lazy loading
+     * Compute a new filterBody to enable or disable the lazy loading
      *
      *
      * If lazy loading is on, the filterBody will looks like
@@ -90,29 +91,23 @@ internal object FilterUtil {
      * @param filterBody     filterBody to patch
      * @param useLazyLoading true to enable lazy loading
      */
-    fun enableLazyLoading(filterBody: FilterBody, useLazyLoading: Boolean) {
+    fun enableLazyLoading(filterBody: FilterBody, useLazyLoading: Boolean): FilterBody {
         if (useLazyLoading) {
             // Enable lazy loading
-            if (filterBody.room == null) {
+            return filterBody.copy(
-                filterBody.room = RoomFilter()
+                    room = filterBody.room?.copy(
-            }
+                            state = filterBody.room.state?.copy(lazyLoadMembers = true)
-            if (filterBody.room!!.state == null) {
+                                    ?: RoomEventFilter(lazyLoadMembers = true)
-                filterBody.room!!.state = RoomEventFilter()
+                    )
-            }
+                            ?: RoomFilter(state = RoomEventFilter(lazyLoadMembers = true))
-
+            )
-            filterBody.room!!.state!!.lazyLoadMembers = true
         } else {
-            if (filterBody.room != null && filterBody.room!!.state != null) {
+            val newRoomEventFilter = filterBody.room?.state?.copy(lazyLoadMembers = null)?.takeIf { it.hasData() }
-                filterBody.room!!.state!!.lazyLoadMembers = null
+            val newRoomFilter = filterBody.room?.copy(state = newRoomEventFilter)?.takeIf { it.hasData() }
 
-                if (!filterBody.room!!.state!!.hasData()) {
+            return filterBody.copy(
-                    filterBody.room!!.state = null
+                    room = newRoomFilter
-                }
+            )
-
-                if (!filterBody.room!!.hasData()) {
-                    filterBody.room = null
-                }
-            }
         }
     }
 }

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/filter/RoomEventFilter.kt

@@ -26,14 +26,14 @@ import im.vector.matrix.android.internal.di.MoshiProvider
 @JsonClass(generateAdapter = true)
 data class RoomEventFilter(
         @Json(name = "limit") var limit: Int? = null,
-        @Json(name = "not_senders") var notSenders: MutableList<String>? = null,
+        @Json(name = "not_senders") val notSenders: List<String>? = null,
-        @Json(name = "not_types") var notTypes: MutableList<String>? = null,
+        @Json(name = "not_types") val notTypes: List<String>? = null,
-        @Json(name = "senders") var senders: MutableList<String>? = null,
+        @Json(name = "senders") val senders: List<String>? = null,
-        @Json(name = "types") var types: MutableList<String>? = null,
+        @Json(name = "types") val types: List<String>? = null,
-        @Json(name = "rooms") var rooms: MutableList<String>? = null,
+        @Json(name = "rooms") val rooms: List<String>? = null,
-        @Json(name = "not_rooms") var notRooms: List<String>? = null,
+        @Json(name = "not_rooms") val notRooms: List<String>? = null,
-        @Json(name = "contains_url") var containsUrl: Boolean? = null,
+        @Json(name = "contains_url") val containsUrl: Boolean? = null,
-        @Json(name = "lazy_load_members") var lazyLoadMembers: Boolean? = null
+        @Json(name = "lazy_load_members") val lazyLoadMembers: Boolean? = null
 ) {
 
     fun toJSONString(): String {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/filter/RoomFilter.kt

@@ -24,13 +24,13 @@ import com.squareup.moshi.JsonClass
  */
 @JsonClass(generateAdapter = true)
 data class RoomFilter(
-        @Json(name = "not_rooms") var notRooms: List<String>? = null,
+        @Json(name = "not_rooms") val notRooms: List<String>? = null,
-        @Json(name = "rooms") var rooms: List<String>? = null,
+        @Json(name = "rooms") val rooms: List<String>? = null,
-        @Json(name = "ephemeral") var ephemeral: RoomEventFilter? = null,
+        @Json(name = "ephemeral") val ephemeral: RoomEventFilter? = null,
-        @Json(name = "include_leave") var includeLeave: Boolean? = null,
+        @Json(name = "include_leave") val includeLeave: Boolean? = null,
-        @Json(name = "state") var state: RoomEventFilter? = null,
+        @Json(name = "state") val state: RoomEventFilter? = null,
-        @Json(name = "timeline") var timeline: RoomEventFilter? = null,
+        @Json(name = "timeline") val timeline: RoomEventFilter? = null,
-        @Json(name = "account_data") var accountData: RoomEventFilter? = null
+        @Json(name = "account_data") val accountData: RoomEventFilter? = null
 ) {
 
     fun hasData(): Boolean {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/model/GroupSyncProfile.kt

@@ -24,10 +24,10 @@ internal data class GroupSyncProfile(
         /**
          * The name of the group, if any. May be nil.
          */
-        @Json(name = "name") var name: String? = null,
+        @Json(name = "name") val name: String? = null,
 
         /**
          * The URL for the group's avatar. May be nil.
          */
-        @Json(name = "avatar_url") var avatarUrl: String? = null
+        @Json(name = "avatar_url") val avatarUrl: String? = null
 )