Send failure verified user : add some comments and logs.

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/crypto/sendfailure/resolve/ResolveVerifiedUserSendFailureView.kt

@@ -118,7 +118,7 @@ private fun VerifiedUserSendFailure.title(): String {
             id = CommonStrings.screen_resolve_send_failure_changed_identity_title,
             userDisplayName
         )
-        VerifiedUserSendFailure.None -> ""
+        VerifiedUserSendFailure.None -> error("This method should never be called for this state")
     }
 }
 
@@ -134,7 +134,7 @@ private fun VerifiedUserSendFailure.subtitle(): String {
             id = CommonStrings.screen_resolve_send_failure_changed_identity_subtitle,
             userDisplayName
         )
-        VerifiedUserSendFailure.None -> ""
+        VerifiedUserSendFailure.None -> error("This method should never be called for this state")
     }
 }
 
@@ -143,7 +143,7 @@ private fun VerifiedUserSendFailure.resolveAction(): String {
     return when (this) {
         is VerifiedUserSendFailure.UnsignedDevice -> stringResource(id = CommonStrings.screen_resolve_send_failure_unsigned_device_primary_button_title)
         is VerifiedUserSendFailure.ChangedIdentity -> stringResource(id = CommonStrings.screen_resolve_send_failure_changed_identity_primary_button_title)
-        VerifiedUserSendFailure.None -> ""
+        VerifiedUserSendFailure.None -> error("This method should never be called for this state")
     }
 }
 

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/crypto/sendfailure/resolve/VerifiedUserSendFailureIterator.kt

@@ -8,6 +8,7 @@
 package io.element.android.features.messages.impl.crypto.sendfailure.resolve
 
 import io.element.android.libraries.matrix.api.timeline.item.event.LocalEventSendState
+import timber.log.Timber
 
 /**
  * Iterator for [LocalEventSendState.Failed.VerifiedUser]
@@ -30,6 +31,12 @@ class UnsignedDeviceSendFailureIterator(
 ) : VerifiedUserSendFailureIterator {
     private val iterator = failure.devices.iterator()
 
+    init {
+        if (!hasNext()) {
+            Timber.w("Got $failure without any devices, shouldn't happen.")
+        }
+    }
+
     override fun hasNext(): Boolean {
         return iterator.hasNext()
     }
@@ -47,6 +54,12 @@ class ChangedIdentitySendFailureIterator(
 ) : VerifiedUserSendFailureIterator {
     private val iterator = failure.users.iterator()
 
+    init {
+        if (!hasNext()) {
+            Timber.w("Got $failure without any users, shouldn't happen.")
+        }
+    }
+
     override fun hasNext(): Boolean {
         return iterator.hasNext()
     }

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/crypto/sendfailure/resolve/VerifiedUserSendFailureResolver.kt

@@ -13,6 +13,12 @@ import io.element.android.libraries.matrix.api.room.MatrixRoom
 import io.element.android.libraries.matrix.api.timeline.item.event.LocalEventSendState
 import timber.log.Timber
 
+/**
+ * This class is responsible for resolving and resending a failed message sent to a verified user.
+ * It also allow to resend the message without resolving the failure, for example if the user has in the meantime verified their device again.
+ * It's using the [VerifiedUserSendFailureIterator] to iterate over the different failures (ie. the different users concerned by the failure).
+ * This way, the user can resolve and resend the message for each user concerned, one by one.
+ */
 class VerifiedUserSendFailureResolver(
     private val room: MatrixRoom,
     private val transactionId: TransactionId,

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/MatrixRoom.kt

@@ -350,7 +350,23 @@ interface MatrixRoom : Closeable {
      */
     suspend fun clearComposerDraft(): Result<Unit>
 
+    /**
+     * Ignore the local trust for the given devices and resend messages that failed to send because said devices are unverified.
+     *
+     * @param devices The map of users identifiers to device identifiers received in the error
+     * @param transactionId The send queue transaction identifier of the local echo the send error applies to.
+     *
+     */
     suspend fun ignoreDeviceTrustAndResend(devices: Map<UserId, List<DeviceId>>, transactionId: TransactionId): Result<Unit>
+
+    /**
+     * Remove verification requirements for the given users and
+     * resend messages that failed to send because their identities were no longer verified.
+     *
+     * @param userIds The list of users identifiers received in the error.
+     * @param transactionId The send queue transaction identifier of the local echo the send error applies to.
+     *
+     */
     suspend fun withdrawVerificationAndResend(userIds: List<UserId>, transactionId: TransactionId): Result<Unit>
 
     override fun close() = destroy()