Automatic backup: change save method to SAF

uhabits-android/src/main/java/org/isoron/uhabits/database/PublicBackupWorker.kt

@@ -2,13 +2,11 @@ package org.isoron.uhabits.database
 
 import android.content.Context
 import android.net.Uri
+import android.util.Log
 import androidx.work.CoroutineWorker
 import androidx.work.WorkerParameters
 import org.isoron.uhabits.HabitsApplication
 import org.isoron.uhabits.utils.DatabaseUtils
-import org.isoron.uhabits.utils.UriUtils
-import java.io.File
-import java.io.IOException
 
 class PublicBackupWorker(
     appContext: Context,
@@ -19,13 +17,13 @@ class PublicBackupWorker(
         val app = applicationContext as HabitsApplication
         val prefs = app.component.preferences
         val uriString = prefs.publicBackupUri ?: return Result.failure()
-        val path = UriUtils.getPathFromTreeUri(applicationContext, Uri.parse(uriString))
+        val folderUri = Uri.parse(uriString)
-            ?: return Result.failure()
         return try {
             val addDate = prefs.isPublicBackupAddDateEnabled
-            DatabaseUtils.saveDatabaseCopy(applicationContext, File(path), addDate)
+            DatabaseUtils.saveDatabaseCopy(applicationContext, folderUri, addDate)
             Result.success()
-        } catch (e: IOException) {
+        } catch (e: Exception) {
+            Log.e("PublicBackupWorker", "backup failed", e)
             Result.retry()
         }
     }

uhabits-android/src/main/java/org/isoron/uhabits/utils/DatabaseUtils.kt

@@ -20,7 +20,9 @@ package org.isoron.uhabits.utils
 
 import android.content.Context
 import android.database.sqlite.SQLiteDatabase
+import android.net.Uri
 import android.util.Log
+import androidx.documentfile.provider.DocumentFile
 import org.isoron.uhabits.HabitsApplication.Companion.isTestMode
 import org.isoron.uhabits.HabitsDatabaseOpener
 import org.isoron.uhabits.core.DATABASE_FILENAME
@@ -73,6 +75,35 @@ object DatabaseUtils {
         return dbCopy.absolutePath
     }
 
+    @JvmStatic
+    @Throws(IOException::class)
+    fun saveDatabaseCopy(
+        context: Context,
+        folderUri: Uri,
+        add_date: Boolean = true
+    ): String {
+        val dateFormat: SimpleDateFormat = getBackupDateFormat()
+        val filename = if (add_date) {
+            val date = dateFormat.format(getLocalTime())
+            "Loop Habits Backup $date.db"
+        } else {
+            "Loop Habits Backup.db"
+        }
+
+        val folder = DocumentFile.fromTreeUri(context, folderUri)
+            ?: throw IOException("Invalid folder uri")
+        val document = folder.createFile("application/octet-stream", filename)
+            ?: throw IOException("Failed to create backup file")
+
+        context.contentResolver.openOutputStream(document.uri).use { outStream ->
+            val out = outStream ?: throw IOException("Cannot open output stream")
+            getDatabaseFile(context).inputStream().use { inStream ->
+                inStream.copyTo(out)
+            }
+        }
+        return document.uri.toString()
+    }
+
     fun openDatabase(): SQLiteDatabase {
         checkNotNull(opener)
         return opener!!.writableDatabase