1 files changed, 95 insertions, 0 deletions
diff --git a/wallet/src/main/java/net/taler/wallet/backend/BackendManager.kt b/wallet/src/main/java/net/taler/wallet/backend/BackendManager.kt
new file mode 100644
index 0000000..9292ef5
--- /dev/null
+++ b/wallet/src/main/java/net/taler/wallet/backend/BackendManager.kt
@@ -0,0 +1,95 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2022 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 <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.wallet.backend
+
+import android.util.Log
+import kotlinx.serialization.json.Json
+import net.taler.qtart.TalerWalletCore
+import net.taler.wallet.BuildConfig
+import org.json.JSONObject
+import java.util.concurrent.atomic.AtomicBoolean
+import kotlin.coroutines.resume
+import kotlin.coroutines.suspendCoroutine
+
+
+fun interface NotificationReceiver {
+    fun onNotificationReceived(payload: NotificationPayload)
+}
+
+class BackendManager(
+    private val notificationReceiver: NotificationReceiver,
+) {
+
+    companion object {
+        private const val TAG = "BackendManager"
+        private const val TAG_CORE = "taler-wallet-embedded"
+        val json = Json {
+            ignoreUnknownKeys = true
+            coerceInputValues = true
+        }
+        @JvmStatic
+        private val initialized = AtomicBoolean(false)
+    }
+
+    private val walletCore = TalerWalletCore()
+    private val requestManager = RequestManager()
+
+    init {
+        // TODO using Dagger/Hilt and @Singleton would be nice as well
+        if (initialized.getAndSet(true)) error("Already initialized")
+        walletCore.setMessageHandler { onMessageReceived(it) }
+        walletCore.setCurlHttpClient()
+        if (BuildConfig.DEBUG) walletCore.setStdoutHandler {
+            Log.d(TAG_CORE, it)
+        }
+    }
+
+    fun run() {
+        walletCore.run()
+    }
+
+    suspend fun send(operation: String, args: JSONObject? = null): ApiResponse =
+        suspendCoroutine { cont ->
+            requestManager.addRequest(cont) { id ->
+                val request = JSONObject().apply {
+                    put("id", id)
+                    put("operation", operation)
+                    if (args != null) put("args", args)
+                }
+                Log.d(TAG, "sending message:\n${request.toString(2)}")
+                walletCore.sendRequest(request.toString())
+            }
+        }
+
+    private fun onMessageReceived(msg: String) {
+        Log.d(TAG, "message received: $msg")
+        when (val message = json.decodeFromString<ApiMessage>(msg)) {
+            is ApiMessage.Notification -> {
+                notificationReceiver.onNotificationReceived(message.payload)
+            }
+            is ApiResponse -> {
+                val id = message.id
+                val cont = requestManager.getAndRemoveContinuation(id)
+                if (cont == null) {
+                    Log.e(TAG, "wallet returned unknown request ID ($id)")
+                } else {
+                    cont.resume(message)
+                }
+            }
+        }
+    }
+}