provide cloud backup functionality

[mobile-ledger.git] / app / src / main / java / net / ktnx / mobileledger / backup / MobileLedgerBackupAgent.java

diff --git a/app/src/main/java/net/ktnx/mobileledger/backup/MobileLedgerBackupAgent.java b/app/src/main/java/net/ktnx/mobileledger/backup/MobileLedgerBackupAgent.java
new file mode 100644 (file)
index 0000000..ea09e51
--- /dev/null
+++ b/app/src/main/java/net/ktnx/mobileledger/backup/MobileLedgerBackupAgent.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright © 2021 Damyan Ivanov.
+ * This file is part of MoLe.
+ * MoLe is free software: you can distribute it and/or modify it
+ * under the term of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your opinion), any later version.
+ *
+ * MoLe is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License terms for details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.ktnx.mobileledger.backup;
+
+import android.app.backup.BackupAgentHelper;
+import android.app.backup.BackupDataInput;
+import android.app.backup.BackupDataOutput;
+import android.os.ParcelFileDescriptor;
+
+import net.ktnx.mobileledger.db.DB;
+import net.ktnx.mobileledger.utils.Logger;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+class MobileLedgerBackupAgent extends BackupAgentHelper {
+    private static final int READ_BUF_LEN = 10;
+    public static String SETTINGS_KEY = "settings";
+    @Override
+    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
+                         ParcelFileDescriptor newState) throws IOException {
+        super.onBackup(oldState, data, newState);
+        backupSettings(data);
+        newState.close();
+    }
+    private void backupSettings(BackupDataOutput data) throws IOException {
+        Logger.debug ("backup", "Starting cloud backup");
+        ByteArrayOutputStream output = new ByteArrayOutputStream(4096);
+        RawConfigWriter saver = new RawConfigWriter(output);
+        saver.writeConfig();
+        byte[] bytes = output.toByteArray();
+        data.writeEntityHeader(SETTINGS_KEY, bytes.length);
+        data.writeEntityData(bytes, bytes.length);
+        Logger.debug("backup", "Done writing backup data");
+    }
+    @Override
+    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
+            throws IOException {
+        Logger.debug("restore", "Starting cloud restore");
+        if (data.readNextHeader()) {
+            String key = data.getKey();
+            if (key.equals(SETTINGS_KEY)) {
+                restoreSettings(data);
+            }
+        }
+    }
+    private void restoreSettings(BackupDataInput data) throws IOException {
+        byte[] bytes = new byte[data.getDataSize()];
+        data.readEntityData(bytes, 0, bytes.length);
+        RawConfigReader reader = new RawConfigReader(new ByteArrayInputStream(bytes));
+        reader.readConfig();
+        Logger.debug("restore", "Successfully read restore data. Wiping database");
+        DB.get().deleteAllSync();
+        Logger.debug("restore", "Database wiped");
+        reader.restoreAll();
+        Logger.debug("restore", "All data restored from the cloud");
+    }
+}