Added ability to restore

app/src/main/java/code/name/monkey/retromusic/helper/BackupHelper.kt

@@ -2,17 +2,20 @@ package code.name.monkey.retromusic.helper
 
 import android.content.Context
 import android.os.Environment
+import android.widget.Toast
 import code.name.monkey.retromusic.BuildConfig
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import java.io.*
 import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
 import java.util.zip.ZipOutputStream
 
 object BackupHelper {
     suspend fun createBackup(context: Context) {
         withContext(Dispatchers.IO) {
-            val finalPath = backupRootPath + System.currentTimeMillis().toString() + backupExt
+            val finalPath =
+                backupRootPath + System.currentTimeMillis().toString() + APPEND_EXTENSION
             val zipItems = mutableListOf<ZipItem>()
             zipItems.addAll(getDatabaseZipItems(context))
             zipItems.addAll(getSettingsZipItems(context))
@@ -39,7 +42,7 @@ object BackupHelper {
         return context.databaseList().filter {
             it.endsWith(".db")
         }.map {
-            ZipItem(context.getDatabasePath(it).absolutePath, "databases${File.separator}$it")
+            ZipItem(context.getDatabasePath(it).absolutePath, "$DATABASES_PATH${File.separator}$it")
         }
     }
 
@@ -49,7 +52,7 @@ object BackupHelper {
             "${BuildConfig.APPLICATION_ID}_preferences.xml", // App settings pref path
             "$THEME_PREFS_KEY_DEFAULT.xml"  // appthemehelper pref path
         ).map {
-            ZipItem(sharedPrefPath + it, "preferences${File.separator}$it")
+            ZipItem(sharedPrefPath + it, "$SETTINGS_PATH${File.separator}$it")
         }
     }
 
@@ -57,15 +60,91 @@ object BackupHelper {
         return context.filesDir.listFiles { _, name ->
             name.endsWith(".jpg")
         }?.map {
-            ZipItem(it.absolutePath, "userImages${File.separator}${it.name}")
+            ZipItem(it.absolutePath, "$IMAGES_PATH${File.separator}${it.name}")
+        }
+    }
+
+    suspend fun restoreBackup(context: Context, file: File) {
+        withContext(Dispatchers.IO) {
+            ZipInputStream(FileInputStream(file)).use {
+                var entry = it.nextEntry
+                while (entry != null) {
+                    if (entry.isDatabaseEntry()) restoreDatabase(context, it, entry)
+                    if (entry.isPreferenceEntry()) restorePreferences(context, it, entry)
+                    if (entry.isImageEntry()) restoreImages(context, it, entry)
+                    entry = it.nextEntry
+                }
+            }
+            withContext(Dispatchers.Main) {
+                Toast.makeText(context, "Restore Completed Successfully", Toast.LENGTH_SHORT).show()
+            }
+        }
+    }
+
+    private fun restoreImages(context: Context, zipIn: ZipInputStream, zipEntry: ZipEntry) {
+        val filePath =
+            context.filesDir.path + File.separator + zipEntry.getFileName()
+        BufferedOutputStream(FileOutputStream(filePath)).use { bos ->
+            val bytesIn = ByteArray(DEFAULT_BUFFER_SIZE)
+            var read: Int
+            while (zipIn.read(bytesIn).also { read = it } != -1) {
+                bos.write(bytesIn, 0, read)
+            }
+        }
+    }
+
+    private fun restorePreferences(context: Context, zipIn: ZipInputStream, zipEntry: ZipEntry) {
+        val file = File(
+            context.filesDir.parent!! + File.separator + "shared_prefs" + File.separator + zipEntry.getFileName()
+        )
+        if (file.exists()) {
+            file.delete()
+        }
+        BufferedOutputStream(FileOutputStream(file)).use { bos ->
+            val bytesIn = ByteArray(DEFAULT_BUFFER_SIZE)
+            var read: Int
+            while (zipIn.read(bytesIn).also { read = it } != -1) {
+                bos.write(bytesIn, 0, read)
+            }
+        }
+    }
+
+    private fun restoreDatabase(context: Context, zipIn: ZipInputStream, zipEntry: ZipEntry) {
+        val filePath =
+            context.filesDir.parent!! + File.separator + DATABASES_PATH + File.separator + zipEntry.getFileName()
+        BufferedOutputStream(FileOutputStream(filePath)).use { bos ->
+            val bytesIn = ByteArray(DEFAULT_BUFFER_SIZE)
+            var read: Int
+            while (zipIn.read(bytesIn).also { read = it } != -1) {
+                bos.write(bytesIn, 0, read)
+            }
         }
     }
 
     val backupRootPath =
         Environment.getExternalStorageDirectory().toString() + "/RetroMusic/Backups/"
-    const val backupExt = ".rmbak"
+    const val BACKUP_EXTENSION = "zip"
+    private const val APPEND_EXTENSION = ".$BACKUP_EXTENSION"
+    private const val DATABASES_PATH = "databases"
+    private const val SETTINGS_PATH = "prefs"
+    private const val IMAGES_PATH = "userImages"
     private const val THEME_PREFS_KEY_DEFAULT = "[[kabouzeid_app-theme-helper]]"
 
+    private fun ZipEntry.isDatabaseEntry(): Boolean {
+        return name.startsWith(DATABASES_PATH)
+    }
+
+    private fun ZipEntry.isPreferenceEntry(): Boolean {
+        return name.startsWith(SETTINGS_PATH)
+    }
+
+    private fun ZipEntry.isImageEntry(): Boolean {
+        return name.startsWith(IMAGES_PATH)
+    }
+
+    private fun ZipEntry.getFileName(): String {
+        return name.substring(name.lastIndexOf(File.separator))
+    }
 }
 
 data class ZipItem(val filePath: String, val zipPath: String)