/*
* 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.withdraw
import android.app.Application
import android.graphics.Bitmap
import android.os.CountDownTimer
import android.util.Log
import androidx.annotation.UiThread
import androidx.lifecycle.LiveData
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Job
import kotlinx.coroutines.launch
import net.taler.cashier.BalanceResult
import net.taler.cashier.HttpHelper.makeJsonGetRequest
import net.taler.cashier.HttpHelper.makeJsonPostRequest
import net.taler.cashier.HttpJsonResult.Error
import net.taler.cashier.HttpJsonResult.Success
import net.taler.cashier.MainViewModel
import net.taler.cashier.R
import net.taler.common.QrCodeManager.makeQrCode
import org.json.JSONObject
import java.util.concurrent.TimeUnit.MINUTES
import java.util.concurrent.TimeUnit.SECONDS
private val TAG = WithdrawManager::class.java.simpleName
private val INTERVAL = SECONDS.toMillis(1)
private val TIMEOUT = MINUTES.toMillis(2)
class WithdrawManager(
private val app: Application,
private val viewModel: MainViewModel
) {
private val scope
get() = viewModel.viewModelScope
private val config
get() = viewModel.config
private val currency: String?
get() = viewModel.currency.value
private var withdrawStatusCheck: Job? = null
private val mWithdrawAmount = MutableLiveData()
val withdrawAmount: LiveData = mWithdrawAmount
private val mWithdrawResult = MutableLiveData()
val withdrawResult: LiveData = mWithdrawResult
private val mWithdrawStatus = MutableLiveData()
val withdrawStatus: LiveData = mWithdrawStatus
private val mLastTransaction = MutableLiveData()
val lastTransaction: LiveData = mLastTransaction
@UiThread
fun hasSufficientBalance(amount: Int): Boolean {
val balanceResult = viewModel.balance.value
if (balanceResult !is BalanceResult.Success) return false
val balanceStr = balanceResult.amount.amount
val balanceDouble = balanceStr.toDouble()
return amount <= balanceDouble
}
@UiThread
fun withdraw(amount: Int) {
check(amount > 0) { "Withdraw amount was <= 0" }
check(currency != null) { "Currency is null" }
mWithdrawResult.value = null
mWithdrawAmount.value = "$amount $currency"
scope.launch(Dispatchers.IO) {
val url = "${config.bankUrl}/accounts/${config.username}/withdrawals"
Log.d(TAG, "Starting withdrawal at $url")
val body = JSONObject(mapOf("amount" to "${currency}:${amount}")).toString()
when (val result = makeJsonPostRequest(url, body, config)) {
is Success -> {
val talerUri = result.json.getString("taler_withdraw_uri")
val withdrawResult = WithdrawResult.Success(
id = result.json.getString("withdrawal_id"),
talerUri = talerUri,
qrCode = makeQrCode(talerUri)
)
mWithdrawResult.postValue(withdrawResult)
timer.start()
}
is Error -> {
val errorStr = app.getString(R.string.withdraw_error_fetch)
mWithdrawResult.postValue(WithdrawResult.Error(errorStr))
}
}
}
}
private val timer: CountDownTimer = object : CountDownTimer(TIMEOUT, INTERVAL) {
override fun onTick(millisUntilFinished: Long) {
val result = withdrawResult.value
if (result is WithdrawResult.Success) {
// check for active jobs and only do one at a time
val hasActiveCheck = withdrawStatusCheck?.isActive ?: false
if (!hasActiveCheck) {
withdrawStatusCheck = checkWithdrawStatus(result.id)
}
} else {
cancel()
}
}
override fun onFinish() {
abort()
mWithdrawStatus.postValue(WithdrawStatus.Error)
cancel()
}
}
private fun checkWithdrawStatus(withdrawalId: String) = scope.launch(Dispatchers.IO) {
val url = "${config.bankUrl}/accounts/${config.username}/withdrawals/${withdrawalId}"
Log.d(TAG, "Checking withdraw status at $url")
val response = makeJsonGetRequest(url, config)
if (response !is Success) return@launch // ignore errors and continue trying
val oldStatus = mWithdrawStatus.value
when {
response.json.getBoolean("aborted") -> {
cancelWithdrawStatusCheck()
mWithdrawStatus.postValue(WithdrawStatus.Aborted)
}
response.json.getBoolean("confirmation_done") -> {
if (oldStatus !is WithdrawStatus.Success) {
cancelWithdrawStatusCheck()
mWithdrawStatus.postValue(WithdrawStatus.Success)
viewModel.getBalance()
}
}
response.json.getBoolean("selection_done") -> {
// only update status, if there's none, yet
// so we don't re-notify or overwrite newer status info
if (oldStatus == null) {
mWithdrawStatus.postValue(WithdrawStatus.SelectionDone(withdrawalId))
}
}
}
}
private fun cancelWithdrawStatusCheck() {
timer.cancel()
withdrawStatusCheck?.cancel()
}
/**
* Aborts the last [withdrawResult], if it exists und there is no [withdrawStatus].
* Otherwise this is a no-op.
*/
@UiThread
fun abort() {
val result = withdrawResult.value
val status = withdrawStatus.value
if (result is WithdrawResult.Success && status == null) {
cancelWithdrawStatusCheck()
abort(result.id)
}
}
private fun abort(withdrawalId: String) = scope.launch(Dispatchers.IO) {
val url = "${config.bankUrl}/accounts/${config.username}/withdrawals/${withdrawalId}/abort"
Log.d(TAG, "Aborting withdrawal at $url")
makeJsonPostRequest(url, "", config)
}
@UiThread
fun confirm(withdrawalId: String) {
mWithdrawStatus.value = WithdrawStatus.Confirming
scope.launch(Dispatchers.IO) {
val url =
"${config.bankUrl}/accounts/${config.username}/withdrawals/${withdrawalId}/confirm"
Log.d(TAG, "Confirming withdrawal at $url")
when (val result = makeJsonPostRequest(url, "", config)) {
is Success -> {
// no-op still waiting for [timer] to confirm our confirmation
}
is Error -> {
Log.e(TAG, "Error confirming withdrawal. Status code: ${result.statusCode}")
mWithdrawStatus.postValue(WithdrawStatus.Error)
}
}
}
}
@UiThread
fun completeTransaction() {
mLastTransaction.value = LastTransaction(withdrawAmount.value!!, withdrawStatus.value!!)
withdrawStatusCheck = null
mWithdrawAmount.value = null
mWithdrawResult.value = null
mWithdrawStatus.value = null
}
}
sealed class WithdrawResult {
object InsufficientBalance : WithdrawResult()
class Error(val msg: String) : WithdrawResult()
class Success(val id: String, val talerUri: String, val qrCode: Bitmap) : WithdrawResult()
}
sealed class WithdrawStatus {
object Error : WithdrawStatus()
object Aborted : WithdrawStatus()
class SelectionDone(val withdrawalId: String) : WithdrawStatus()
object Confirming : WithdrawStatus()
object Success : WithdrawStatus()
}
data class LastTransaction(
val withdrawAmount: String,
val withdrawStatus: WithdrawStatus
)