From a3a62b6dbb330019384b8ffa4dcc20e9a37acc1f Mon Sep 17 00:00:00 2001
From: Niels Andriesse <andriesseniels@gmail.com>
Date: Fri, 21 May 2021 10:24:48 +1000
Subject: [PATCH] Implement ClosedGroupPollerV2

---
 .../pollers/ClosedGroupPollerV2.kt            | 50 +++++++++++++++++--
 1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPollerV2.kt b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPollerV2.kt
index 8dfcf78ffc..1466ed9dd1 100644
--- a/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPollerV2.kt
+++ b/libsession/src/main/java/org/session/libsession/messaging/sending_receiving/pollers/ClosedGroupPollerV2.kt
@@ -1,10 +1,24 @@
 package org.session.libsession.messaging.sending_receiving.pollers
 
 import nl.komponents.kovenant.Promise
+import nl.komponents.kovenant.functional.bind
+import nl.komponents.kovenant.functional.map
 import org.session.libsession.messaging.MessagingModuleConfiguration
+import org.session.libsession.messaging.jobs.JobQueue
+import org.session.libsession.messaging.jobs.MessageReceiveJob
+import org.session.libsession.snode.SnodeAPI
+import org.session.libsignal.crypto.getRandomElementOrNull
+import org.session.libsignal.utilities.Log
+import org.session.libsignal.utilities.successBackground
+import java.util.concurrent.Executors
+import java.util.concurrent.ScheduledFuture
+import java.util.concurrent.TimeUnit
+import kotlin.math.min
 
 class ClosedGroupPollerV2 {
+    private val executorService = Executors.newScheduledThreadPool(4)
     private var isPolling = mutableMapOf<String, Boolean>()
+    private var futures = mutableMapOf<String, ScheduledFuture<*>>()
 
     private fun isPolling(groupPublicKey: String): Boolean {
         return isPolling[groupPublicKey] ?: false
@@ -39,7 +53,7 @@ class ClosedGroupPollerV2 {
     }
 
     fun stopPolling(groupPublicKey: String) {
-        // TODO: Invalidate future
+        futures[groupPublicKey]?.cancel(false)
         isPolling[groupPublicKey] = false
     }
 
@@ -56,11 +70,39 @@ class ClosedGroupPollerV2 {
         if (!isPolling(groupPublicKey)) { return }
         // Get the received date of the last message in the thread. If we don't have any messages yet, pick some
         // reasonable fake time interval to use instead.
-
+        val timeSinceLastMessage = 5 * 60 * 1000 // TODO: Implement
+        val minPollInterval = Companion.minPollInterval
+        val limit = 12 * 60 * 60 * 1000
+        val a = (Companion.maxPollInterval - minPollInterval).toDouble() / limit.toDouble()
+        val nextPollInterval = a * min(timeSinceLastMessage, limit) + minPollInterval
+        Log.d("Loki", "Next poll interval for closed group with public key: $groupPublicKey is ${nextPollInterval / 1000} s.")
+        executorService?.schedule({
+            poll(groupPublicKey).success {
+                pollRecursively(groupPublicKey)
+            }.fail {
+                // The error is logged in poll(_:)
+                pollRecursively(groupPublicKey)
+            }
+        }, nextPollInterval.toLong(), TimeUnit.MILLISECONDS)
     }
 
     private fun poll(groupPublicKey: String): Promise<Unit, Exception> {
-        return Promise.ofFail(InsufficientSnodesException())
+        if (!isPolling(groupPublicKey)) { return Promise.of(Unit) }
+        val promise = SnodeAPI.getSwarm(groupPublicKey).bind { swarm ->
+            val snode = swarm.getRandomElementOrNull() ?: throw InsufficientSnodesException() // Should be cryptographically secure
+            if (!isPolling(groupPublicKey)) { throw PollingCanceledException() }
+            SnodeAPI.getRawMessages(snode, groupPublicKey).map { SnodeAPI.parseRawMessagesResponse(it, snode, groupPublicKey) }
+        }
+        promise.success { envelopes ->
+            if (!isPolling(groupPublicKey)) { return@success }
+            envelopes.forEach { envelope ->
+                val job = MessageReceiveJob(envelope.toByteArray())
+                JobQueue.shared.add(job)
+            }
+        }
+        promise.fail {
+            Log.d("Loki", "Polling failed for closed group with public key: $groupPublicKey due to error: $it.")
+        }
+        return promise.map { }
     }
-
 }