teapod/app/src/main/java/org/mosad/teapod/util/StorageController.kt

89 lines
2.6 KiB
Kotlin

package org.mosad.teapod.util
import android.content.Context
import android.net.Uri
import android.util.Log
import com.google.gson.Gson
import com.google.gson.JsonParser
import kotlinx.coroutines.*
import java.io.File
import java.io.FileReader
import java.io.FileWriter
/**
* This controller contains the logic for permanently saved data.
* On load, it loads the saved files into the variables
*/
object StorageController {
private const val fileNameMyList = "my_list.json"
val myList = ArrayList<Int>() // a list of saved mediaIds
fun load(context: Context) {
loadMyList(context)
}
fun loadMyList(context: Context) {
val file = File(context.filesDir, fileNameMyList)
if (!file.exists()) runBlocking { saveMyList(context).join() }
try {
myList.clear()
myList.addAll(JsonParser.parseString(file.readText()).asJsonArray.map { it.asInt }.distinct())
} catch (ex: Exception) {
myList.clear()
Log.e(javaClass.name, "Parsing of My-List failed.")
}
}
fun saveMyList(context: Context): Job {
val file = File(context.filesDir, fileNameMyList)
return CoroutineScope(Dispatchers.IO).launch {
file.writeText(Gson().toJson(myList.distinct()))
}
}
fun exportMyList(context: Context, uri: Uri) {
try {
context.contentResolver.openFileDescriptor(uri, "w")?.use {
FileWriter(it.fileDescriptor).use { writer ->
writer.write(Gson().toJson(myList.distinct()))
}
}
} catch (ex: Exception) {
Log.e(javaClass.name, "Exporting my list failed.", ex)
}
}
/**
* import my list from a (previously exported) json file
* @param context the current context
* @param uri the uri of the selected file
* @return 0 if import was successfull, else 1
*/
fun importMyList(context: Context, uri: Uri): Int {
try {
val text = context.contentResolver.openFileDescriptor(uri, "r")?.use {
FileReader(it.fileDescriptor).use { reader ->
reader.readText()
}
}
myList.clear()
myList.addAll(JsonParser.parseString(text).asJsonArray.map { it.asInt }.distinct())
// after the list has been imported also save it
saveMyList(context)
} catch (ex: Exception) {
myList.clear()
Log.e(javaClass.name, "Importing my list failed.", ex)
return 1
}
return 0
}
}