feat: prompt to use Ktor downloader on Android DownloadManager failure

app/src/main/kotlin/com/aliucord/manager/manager/download/AndroidDownloadManager.kt

@@ -110,7 +110,7 @@ class AndroidDownloadManager(application: Application) : IDownloadManager {
      * Error returned by the system [DownloadManager].
      * @param reason The reason code returned by the [DownloadManager.COLUMN_REASON] column.
      */
-    data class Error(private val reason: Int) : Result.Error() {
+    data class Error(val reason: Int) : Result.Error() {
         /**
          * Convert a [DownloadManager.COLUMN_REASON] code into its name.
          */

app/src/main/kotlin/com/aliucord/manager/patcher/StepRunner.kt

@@ -19,9 +19,12 @@ import org.koin.core.component.inject
  * quickly switching the step groups in the UI. (very disorienting)
  * Larger delay leads to a perception that it's doing more work than it actually is.
  */
-const val MINIMUM_STEP_DELAY: Long = 600L
+private const val MINIMUM_STEP_DELAY: Long = 600L
 
-const val ERROR_NOTIF_ID = 200002
+/**
+ * ID used for showing error notifications emanating from this step runner.
+ */
+private const val ERROR_NOTIF_ID = 200002
 
 abstract class StepRunner : KoinComponent {
     private val context: Context by inject()

app/src/main/kotlin/com/aliucord/manager/patcher/steps/base/DownloadStep.kt

@@ -1,13 +1,22 @@
 package com.aliucord.manager.patcher.steps.base
 
+import android.app.DownloadManager
 import android.content.Context
+import android.util.Log
 import android.widget.Toast
+import androidx.annotation.CallSuper
 import androidx.compose.runtime.Stable
+import com.aliucord.manager.BuildConfig
 import com.aliucord.manager.R
 import com.aliucord.manager.di.DownloadManagerProvider
+import com.aliucord.manager.di.DownloaderSetting
+import com.aliucord.manager.manager.OverlayManager
+import com.aliucord.manager.manager.PreferencesManager
+import com.aliucord.manager.manager.download.AndroidDownloadManager
 import com.aliucord.manager.manager.download.IDownloadManager
 import com.aliucord.manager.patcher.StepRunner
 import com.aliucord.manager.patcher.steps.StepGroup
+import com.aliucord.manager.ui.components.dialogs.AlternativeDownloaderDialog
 import com.aliucord.manager.util.showToast
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
@@ -18,6 +27,8 @@ import java.io.File
 @Stable
 abstract class DownloadStep : Step(), KoinComponent {
     private val context: Context by inject()
+    private val overlays: OverlayManager by inject()
+    private val prefs: PreferencesManager by inject()
     private val downloaders: DownloadManagerProvider by inject()
 
     /**
@@ -35,6 +46,7 @@ abstract class DownloadStep : Step(), KoinComponent {
      * Verify that the download completely successfully without errors.
      * @throws Throwable If verification fails.
      */
+    @CallSuper
     open suspend fun verify() {
         if (!targetFile.exists())
             throw Error("Downloaded file is missing!")
@@ -60,6 +72,9 @@ abstract class DownloadStep : Step(), KoinComponent {
         }
 
         when (result) {
+            is IDownloadManager.Result.Cancelled ->
+                state = StepState.Error
+
             is IDownloadManager.Result.Success -> {
                 try {
                     verify()
@@ -80,11 +95,31 @@ abstract class DownloadStep : Step(), KoinComponent {
                     Toast.makeText(context, toastText, Toast.LENGTH_LONG).show()
                 }
 
+                // If this is a specific Android DownloadManager error, then prompt to use a different downloader
+                if (result is AndroidDownloadManager.Error
+                    && result.reason in arrayOf(DownloadManager.ERROR_HTTP_DATA_ERROR, DownloadManager.ERROR_CANNOT_RESUME)
+                    && prefs.downloader != DownloaderSetting.Ktor
+                ) {
+                    state = StepState.Error
+
+                    val confirmed = overlays.startComposableForResult { callback ->
+                        AlternativeDownloaderDialog(
+                            onConfirm = { callback(true) },
+                            onDismiss = { callback(false) },
+                        )
+                    }
+
+                    if (confirmed) {
+                        Log.i(BuildConfig.TAG, "Changing to alternative downloader after failure")
+                        prefs.downloader = DownloaderSetting.Ktor
+                        state = StepState.Running
+
+                        return execute(container)
+                    }
+                }
+
                 throw Error("Failed to download: $result")
             }
-
-            is IDownloadManager.Result.Cancelled ->
-                state = StepState.Error
         }
     }
 }

app/src/main/kotlin/com/aliucord/manager/patcher/steps/download/DownloadDiscordStep.kt

@@ -29,7 +29,7 @@ class DownloadDiscordStep : DownloadStep(), KoinComponent {
 
     private companion object {
         /**
-         * Last version of Discord before the RN transition.
+         * Last version of Discord before the RNA rewrite
          */
         const val DISCORD_KT_VERSION = 126021
 

app/src/main/kotlin/com/aliucord/manager/ui/components/dialogs/AlternativeDownloaderDialog.kt

@@ -0,0 +1,41 @@
+package com.aliucord.manager.ui.components.dialogs
+
+import androidx.compose.material3.*
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import com.aliucord.manager.R
+
+@Composable
+fun AlternativeDownloaderDialog(
+    onConfirm: () -> Unit,
+    onDismiss: () -> Unit,
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        confirmButton = {
+            FilledTonalButton(
+                onClick = onConfirm,
+                colors = ButtonDefaults.filledTonalButtonColors(
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    contentColor = MaterialTheme.colorScheme.onPrimary,
+                ),
+            ) {
+                Text(stringResource(R.string.action_retry))
+            }
+        },
+        dismissButton = {
+            TextButton(
+                onClick = onDismiss,
+                colors = ButtonDefaults.textButtonColors(
+                    contentColor = MaterialTheme.colorScheme.error,
+                ),
+            ) {
+                Text(stringResource(R.string.action_cancel))
+            }
+        },
+        title = { Text(stringResource(R.string.alt_downloader_dialog_title)) },
+        text = { Text(stringResource(R.string.alt_downloader_dialog_desc)) },
+        icon = { Icon(painterResource(R.drawable.ic_download), contentDescription = null) },
+    )
+}

app/src/main/res/values/strings.xml

@@ -164,6 +164,9 @@
   <string name="play_protect_warning_ok">Continue</string>
   <string name="play_protect_warning_open_gpp">Open Play Protect</string>
 
+  <string name="alt_downloader_dialog_title">Alternative Downloader</string>
+  <string name="alt_downloader_dialog_desc">This download failed with a specific error that may indicate issues with the system\'s DownloadManager. Would you like to retry with the the alternative downloader implementation?</string>
+
   <string name="fun_fact_prefix">Fun Fact: %s</string>
   <string name="fun_fact_1">Did you know that Google Play Protect is useless?</string>
   <string name="fun_fact_2">Did you know Aliucord with 150+ plugins somehow runs better than Discord\'s new app?</string>