From 4ac15190bb1a13c0fb15abb54795b37e01c17438 Mon Sep 17 00:00:00 2001
From: nielsandriesse <andriesseniels@gmail.com>
Date: Mon, 10 Aug 2020 09:53:37 +1000
Subject: [PATCH] Implement ClosedGroupPoller

---
 .../securesms/loki/api/ClosedGroupPoller.kt   | 81 +++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 src/org/thoughtcrime/securesms/loki/api/ClosedGroupPoller.kt

diff --git a/src/org/thoughtcrime/securesms/loki/api/ClosedGroupPoller.kt b/src/org/thoughtcrime/securesms/loki/api/ClosedGroupPoller.kt
new file mode 100644
index 0000000000..6a3aa9fe8f
--- /dev/null
+++ b/src/org/thoughtcrime/securesms/loki/api/ClosedGroupPoller.kt
@@ -0,0 +1,81 @@
+package org.thoughtcrime.securesms.loki.api
+
+import android.content.Context
+import android.os.Handler
+import nl.komponents.kovenant.functional.bind
+import nl.komponents.kovenant.functional.map
+import org.thoughtcrime.securesms.jobs.PushContentReceiveJob
+import org.thoughtcrime.securesms.logging.Log
+import org.thoughtcrime.securesms.loki.database.SharedSenderKeysDatabase
+import org.thoughtcrime.securesms.loki.utilities.successBackground
+import org.whispersystems.signalservice.api.messages.SignalServiceEnvelope
+import org.whispersystems.signalservice.loki.api.SnodeAPI
+import org.whispersystems.signalservice.loki.api.SwarmAPI
+import org.whispersystems.signalservice.loki.utilities.getRandomElementOrNull
+
+class ClosedGroupPoller private constructor(private val context: Context, private val database: SharedSenderKeysDatabase) {
+    private var isPolling = false
+    private val handler = Handler()
+
+    private val task = object : Runnable {
+
+        override fun run() {
+            poll()
+            handler.postDelayed(this, ClosedGroupPoller.pollInterval)
+        }
+    }
+
+    // region Settings
+    companion object {
+        private val pollInterval: Long = 2 * 1000
+
+        public lateinit var shared: ClosedGroupPoller
+
+        public fun configureIfNeeded(context: Context, sskDatabase: SharedSenderKeysDatabase) {
+            if (::shared.isInitialized) { return; }
+            shared = ClosedGroupPoller(context, sskDatabase)
+        }
+    }
+    // endregion
+
+    // region Error
+    public class InsufficientSnodesException() : Exception("No snodes left to poll.")
+    public class PollingCanceledException() : Exception("Polling canceled.")
+    // endregion
+
+    // region Public API
+    public fun startIfNeeded() {
+        if (isPolling) { return }
+        isPolling = true
+        task.run()
+    }
+
+    public fun stopIfNeeded() {
+        isPolling = false
+        handler.removeCallbacks(task)
+    }
+    // endregion
+
+    // region Private API
+    private fun poll() {
+        if (!isPolling) { return }
+        val publicKeys = database.getAllClosedGroupPublicKeys()
+        publicKeys.forEach { publicKey ->
+            SwarmAPI.shared.getSwarm(publicKey).bind { swarm ->
+                val snode = swarm.getRandomElementOrNull() ?: throw InsufficientSnodesException() // Should be cryptographically secure
+                if (!isPolling) { throw PollingCanceledException() }
+                SnodeAPI.shared.getRawMessages(snode).map {SnodeAPI.shared.parseRawMessagesResponse(it, snode) }
+            }.successBackground { messages ->
+                if (messages.isNotEmpty()) {
+                    Log.d("Loki", "Received ${messages.count()} new message(s) in closed group with public key: $publicKey.")
+                }
+                messages.forEach {
+                    PushContentReceiveJob(context).processEnvelope(SignalServiceEnvelope(it), false)
+                }
+            }.fail {
+                Log.d("Loki", "Polling failed for closed group with public key: $publicKey due to error: $it.")
+            }
+        }
+    }
+    // endregion
+}