LibreTube/app/src/main/java/com/github/libretube/util/BackupHelper.kt

package com.github.libretube.util

import android.content.Context
import android.content.SharedPreferences
import android.net.Uri
import androidx.preference.PreferenceManager
import java.io.FileInputStream
import java.io.FileOutputStream
import java.io.IOException
import java.io.ObjectInputStream
import java.io.ObjectOutputStream

/**
 * Backup and restore the preferences
 */
class BackupHelper(
    private val context: Context
) {
    private val TAG = this::class.java.name

    /**
     * Backup the default shared preferences to a file
     */
    fun backupSharedPreferences(uri: Uri?) {
        if (uri == null) return
        var output: ObjectOutputStream? = null
        try {
            val fileDescriptor = context.contentResolver.openFileDescriptor(uri, "w")?.fileDescriptor
            output = ObjectOutputStream(FileOutputStream(fileDescriptor))
            val pref: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)
            // write all preference objects to the output file
            output.writeObject(pref.all)
        } catch (e: Exception) {
            e.printStackTrace()
        } finally {
            try {
                // close the outputStream
                if (output != null) {
                    output.flush()
                    output.close()
                }
            } catch (ex: IOException) {
                ex.printStackTrace()
            }
        }
    }

    /**
     * restore the default shared preferences from a file
     */
    @Suppress("UNCHECKED_CAST")
    fun restoreSharedPreferences(uri: Uri?) {
        if (uri == null) return
        var input: ObjectInputStream? = null
        try {
            val fileDescriptor = context.contentResolver.openFileDescriptor(uri, "r")?.fileDescriptor
            input = ObjectInputStream(FileInputStream(fileDescriptor))
            val editor = PreferenceManager.getDefaultSharedPreferences(context).edit()

            // clear the previous settings
            editor.clear()

            // map all the preference keys and their values
            val entries = input.readObject() as Map<String, *>

            // decide for each preference which type it is and save it to the preferences
            for ((key, value) in entries) {
                if (value is Boolean) editor.putBoolean(key, value)
                else if (value is Float) editor.putFloat(key, value)
                else if (value is Int) editor.putInt(key, value)
                else if (value is Long) editor.putLong(key, value)
                else if (value is String) editor.putString(key, value)
            }
            editor.commit()
        } catch (e: Exception) {
            e.printStackTrace()
        } finally {
            try {
                if (input != null) {
                    input.close()
                }
            } catch (ex: IOException) {
                ex.printStackTrace()
            }
        }
    }
}