/* * 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.wallet.backend import android.app.Application import android.content.ComponentName import android.content.Context import android.content.Intent import android.content.ServiceConnection import android.os.Handler import android.os.IBinder import android.os.Message import android.os.Messenger import android.util.Log import android.util.SparseArray import org.json.JSONObject import java.lang.ref.WeakReference import java.util.LinkedList class WalletBackendApi( private val app: Application, private val onConnected: (() -> Unit), private val notificationHandler: ((payload: JSONObject) -> Unit) ) { private var walletBackendMessenger: Messenger? = null private val queuedMessages = LinkedList() private val handlers = SparseArray<(isError: Boolean, message: JSONObject) -> Unit>() private var nextRequestID = 1 private val walletBackendConn = object : ServiceConnection { override fun onServiceDisconnected(p0: ComponentName?) { Log.w(TAG, "wallet backend service disconnected (crash?)") walletBackendMessenger = null } override fun onServiceConnected(componentName: ComponentName?, binder: IBinder?) { Log.i(TAG, "connected to wallet backend service") val bm = Messenger(binder) walletBackendMessenger = bm pumpQueue(bm) val msg = Message.obtain(null, WalletBackendService.MSG_SUBSCRIBE_NOTIFY) msg.replyTo = incomingMessenger bm.send(msg) onConnected.invoke() } } private class IncomingHandler(strongApi: WalletBackendApi) : Handler() { private val weakApi = WeakReference(strongApi) override fun handleMessage(msg: Message) { val api = weakApi.get() ?: return when (msg.what) { WalletBackendService.MSG_REPLY -> { val requestID = msg.data.getInt("requestID", 0) val operation = msg.data.getString("operation", "??") Log.i(TAG, "got reply for operation $operation ($requestID)") val h = api.handlers.get(requestID) if (h == null) { Log.e(TAG, "request ID not associated with a handler") return } val response = msg.data.getString("response") if (response == null) { Log.e(TAG, "response did not contain response payload") return } val isError = msg.data.getBoolean("isError") val json = JSONObject(response) h(isError, json) } WalletBackendService.MSG_NOTIFY -> { val payloadStr = msg.data.getString("payload") if (payloadStr == null) { Log.e(TAG, "Notification had no payload: $msg") } else { val payload = JSONObject(payloadStr) api.notificationHandler.invoke(payload) } } } } } private val incomingMessenger = Messenger(IncomingHandler(this)) init { Intent(app, WalletBackendService::class.java).also { intent -> app.bindService(intent, walletBackendConn, Context.BIND_AUTO_CREATE) } } private fun pumpQueue(bm: Messenger) { while (true) { val msg = queuedMessages.pollFirst() ?: return bm.send(msg) } } fun sendRequest( operation: String, args: JSONObject? = null, onResponse: (isError: Boolean, message: JSONObject) -> Unit = { _, _ -> } ) { val requestID = nextRequestID++ Log.i(TAG, "sending request for operation $operation ($requestID)") val msg = Message.obtain(null, WalletBackendService.MSG_COMMAND) handlers.put(requestID, onResponse) msg.replyTo = incomingMessenger val data = msg.data data.putString("operation", operation) data.putInt("requestID", requestID) if (args != null) { data.putString("args", args.toString()) } val bm = walletBackendMessenger if (bm != null) { bm.send(msg) } else { queuedMessages.add(msg) } } fun destroy() { // FIXME: implement this! } companion object { const val TAG = "WalletBackendApi" } }