/* * This file is part of GNU Taler * (C) 2020 Taler Systems S.A. * * GNU Taler is free software; you can redistribute it and/or modify it under the * terms of the GNU General Public License as published by the Free Software * Foundation; either version 3, or (at your option) any later version. * * GNU Taler 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 for more details. * * You should have received a copy of the GNU General Public License along with * GNU Taler; see the file COPYING. If not, see */ package net.taler.cashier import android.annotation.SuppressLint import android.app.Application import android.util.Log import androidx.annotation.UiThread import androidx.annotation.WorkerThread import androidx.lifecycle.AndroidViewModel import androidx.lifecycle.LiveData import androidx.lifecycle.MutableLiveData import androidx.lifecycle.viewModelScope import androidx.security.crypto.EncryptedSharedPreferences import androidx.security.crypto.EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV import androidx.security.crypto.EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM import androidx.security.crypto.MasterKeys import androidx.security.crypto.MasterKeys.AES256_GCM_SPEC import kotlinx.coroutines.Dispatchers import kotlinx.coroutines.launch import net.taler.cashier.HttpHelper.makeJsonGetRequest import net.taler.cashier.withdraw.WithdrawManager import net.taler.common.AmountParserException import net.taler.common.SignedAmount import net.taler.common.isOnline private val TAG = MainViewModel::class.java.simpleName private const val PREF_NAME = "net.taler.cashier.prefs" private const val PREF_KEY_BANK_URL = "bankUrl" private const val PREF_KEY_USERNAME = "username" private const val PREF_KEY_PASSWORD = "password" private const val PREF_KEY_CURRENCY = "currency" class MainViewModel(private val app: Application) : AndroidViewModel(app) { val configDestination = ConfigFragmentDirections.actionGlobalConfigFragment() private val masterKeyAlias = MasterKeys.getOrCreate(AES256_GCM_SPEC) private val prefs = EncryptedSharedPreferences.create( PREF_NAME, masterKeyAlias, app, AES256_SIV, AES256_GCM ) internal var config = Config( bankUrl = prefs.getString(PREF_KEY_BANK_URL, "")!!, username = prefs.getString(PREF_KEY_USERNAME, "")!!, password = prefs.getString(PREF_KEY_PASSWORD, "")!! ) private val mCurrency = MutableLiveData( prefs.getString(PREF_KEY_CURRENCY, null) ) internal val currency: LiveData = mCurrency private val mConfigResult = MutableLiveData() val configResult: LiveData = mConfigResult private val mBalance = MutableLiveData() val balance: LiveData = mBalance internal val withdrawManager = WithdrawManager(app, this) fun hasConfig() = config.bankUrl.isNotEmpty() && config.username.isNotEmpty() && config.password.isNotEmpty() /** * Start observing [configResult] after calling this to get the result async. * Warning: Ignore null results that are used to reset old results. */ @UiThread fun checkAndSaveConfig(config: Config) { mConfigResult.value = null viewModelScope.launch(Dispatchers.IO) { val url = "${config.bankUrl}/accounts/${config.username}/balance" Log.d(TAG, "Checking config: $url") val result = when (val response = makeJsonGetRequest(url, config)) { is HttpJsonResult.Success -> { val balance = response.json.getString("balance") try { val amount = SignedAmount.fromJSONString(balance) mCurrency.postValue(amount.amount.currency) prefs.edit().putString(PREF_KEY_CURRENCY, amount.amount.currency).apply() // save config saveConfig(config) ConfigResult.Success } catch (e: AmountParserException) { ConfigResult.Error(false, "Invalid Amount: $balance") } } is HttpJsonResult.Error -> { if (response.statusCode > 0 && app.isOnline()) { ConfigResult.Error(response.statusCode == 401, response.msg) } else { ConfigResult.Offline } } } mConfigResult.postValue(result) } } @WorkerThread @SuppressLint("ApplySharedPref") private fun saveConfig(config: Config) { this.config = config prefs.edit() .putString(PREF_KEY_BANK_URL, config.bankUrl) .putString(PREF_KEY_USERNAME, config.username) .putString(PREF_KEY_PASSWORD, config.password) .commit() } fun getBalance() = viewModelScope.launch(Dispatchers.IO) { check(hasConfig()) { "No config to get balance" } val url = "${config.bankUrl}/accounts/${config.username}/balance" Log.d(TAG, "Checking balance at $url") val result = when (val response = makeJsonGetRequest(url, config)) { is HttpJsonResult.Success -> { val balance = response.json.getString("balance") try { BalanceResult.Success(SignedAmount.fromJSONString(balance)) } catch (e: AmountParserException) { BalanceResult.Error("invalid amount: $balance") } } is HttpJsonResult.Error -> { if (app.isOnline()) BalanceResult.Error(response.msg) else BalanceResult.Offline } } mBalance.postValue(result) } fun lock() { saveConfig(config.copy(password = "")) } } data class Config( val bankUrl: String, val username: String, val password: String ) sealed class ConfigResult { class Error(val authError: Boolean, val msg: String) : ConfigResult() object Offline : ConfigResult() object Success : ConfigResult() }