fix: Restore ability to cancel an in-progress upload

Author: LouisCAD

app/src/main/java/com/infomaniak/swisstransfer/ui/screen/newtransfer/upload/UploadViewModel.kt

@@ -45,26 +45,27 @@ class UploadViewModel @Inject constructor() : ViewModel() {
     val abandonUploadRequest = CallableState<Unit>()
 
     init {
+        viewModelScope.launch { handleCancellationRequests() }
         viewModelScope.launch {
             UploadForegroundService.uploadStateFlow.collectLatest { uploadState ->
                 if (uploadState is UploadState.Retry) handleRetryRequests()
             }
         }
     }
 
+    private suspend fun handleCancellationRequests(): Nothing = repeatWhileActive {
+        abandonUploadRequest.awaitOneCall()
+        UploadForegroundService.cancelUpload()
+    }
+
     private suspend fun handleRetryRequests(): Nothing = repeatWhileActive {
         val shouldRetry = raceOf(
             { retryRequest.awaitOneCall(); true },
             { editRequest.awaitOneCall(); false },
-            { abandonUploadRequest.awaitOneCall(); null },
         )
         when (shouldRetry) {
             true -> UploadForegroundService.retry()
             false -> UploadForegroundService.giveUp()
-            null -> {
-                UploadForegroundService.removeAllFiles()
-                UploadForegroundService.giveUp()
-            }
         }
     }
 }

app/src/main/java/com/infomaniak/swisstransfer/upload/UploadForegroundService.kt

@@ -40,6 +40,7 @@ import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.*
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.*
+import splitties.coroutines.raceOf
 import splitties.coroutines.repeatWhileActive
 import splitties.experimental.ExperimentalSplittiesApi
 import splitties.init.appCtx
@@ -60,6 +61,7 @@ class UploadForegroundService : ForegroundService(Companion, redeliverIntentIfKi
 
         private val startSignal = Channel<StartUploadRequest>()
 
+        private val cancelTransferSignals = Channel<Unit>()
         private val shouldRetrySignals = Channel<Boolean>()
 
         private val pickedFilesExtractor: PickedFilesExtractor = PickedFilesExtractorImpl().also {
@@ -123,6 +125,10 @@ class UploadForegroundService : ForegroundService(Companion, redeliverIntentIfKi
             shouldRetrySignals.send(false)
         }
 
+        suspend fun cancelUpload() {
+            cancelTransferSignals.send(Unit)
+        }
+
         private fun keepServiceRunningWhileNeeded() {
             val needsToKeepFileUris = isHandlingPickedFilesFlow.transformLatest { isHandlingFiles ->
                 if (isHandlingFiles) emit(true)
@@ -202,21 +208,24 @@ class UploadForegroundService : ForegroundService(Companion, redeliverIntentIfKi
             )
 
             //TODO[UL-retry]: Once we support resuming the upload:
-            // 1. Remove this big `isInternetConnectedFlow` thing and move it to just the uploader part.
+            // 1. Remove `isInternetConnectedFlow.mapLatest` from `tryCompletingWithInternetUnlessCancelled`,
+            //    and move it to just the uploader part.
             // 2. Remove the loop (repeatWhileActive) below.
             // 3. In the uploader, use a function named `uploadAllRemainingWithRetries` or something.
-            val transferUuid = isInternetConnectedFlow.mapLatest { isInternetConnected ->
-                if (isInternetConnected.not()) {
+            val transferUuid = tryCompletingWithInternetUnlessCancelled(
+                valueIfCancelled = null,
+                withoutInternet = {
                     currentState = uploadStateFlow.filterIsInstance<UploadState.Ongoing>().first().copy(
                         status = Status.WaitingForInternet
                     )
                     awaitCancellation()
                 }
+            ) {
                 repeatWhileActive retryLoop@{
                     val result = startUploadSession(
                         startRequest = startRequest,
                         updateState = { currentState = it }
-                    ) ?: return@mapLatest null
+                    ) ?: return@tryCompletingWithInternetUnlessCancelled null
                     val uploader = TransferUploader(
                         uploadManager = uploadManager,
                         fileChunkSizeManager = fileChunkSizeManager,
@@ -242,11 +251,11 @@ class UploadForegroundService : ForegroundService(Companion, redeliverIntentIfKi
                         if (shouldRetry()) {
                             return@retryLoop
                         } else {
-                            return@mapLatest null
+                            return@tryCompletingWithInternetUnlessCancelled null
                         }
-                    }.onSuccess { uuid -> return@mapLatest uuid }
+                    }.onSuccess { uuid -> return@tryCompletingWithInternetUnlessCancelled uuid }
                 }
-            }.first()
+            }
             currentState = if (transferUuid != null) {
                 val url = sharedApiUrlCreator.shareTransferUrl(transferUuid)
                 val transferType = startRequest.info.type
@@ -268,6 +277,19 @@ class UploadForegroundService : ForegroundService(Companion, redeliverIntentIfKi
         }
     }
 
+    private suspend fun <R> tryCompletingWithInternetUnlessCancelled(
+        valueIfCancelled: R,
+        withoutInternet: suspend () -> R,
+        block: suspend () -> R
+    ): R? = raceOf({
+        isInternetConnectedFlow.mapLatest { isInternetConnected ->
+            if (isInternetConnected) block() else withoutInternet()
+        }.first()
+    }, {
+        cancelTransferSignals.receive()
+        valueIfCancelled
+    })
+
     private suspend fun shouldRetry(): Boolean = shouldRetrySignals.receive()
 
     private suspend fun startUploadSession(