From ff69158fea6ae46ec088eaf958968b3bb7106531 Mon Sep 17 00:00:00 2001
From: Gonzalo DCL <gonzalo@decentraland.org>
Date: Thu, 17 Oct 2024 14:00:45 -0300
Subject: [PATCH] expose stateIsSyncronized flag to check if the crdt state is
 initialized

---
 packages/@dcl/sdk/src/network/index.ts        |  9 ++--
 .../@dcl/sdk/src/network/message-bus-sync.ts  | 52 ++++++++++++++++---
 2 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/packages/@dcl/sdk/src/network/index.ts b/packages/@dcl/sdk/src/network/index.ts
index aa09f36ce..0376aaf12 100644
--- a/packages/@dcl/sdk/src/network/index.ts
+++ b/packages/@dcl/sdk/src/network/index.ts
@@ -4,10 +4,7 @@ import { addSyncTransport } from './message-bus-sync'
 import { getUserData } from '~system/UserIdentity'
 
 // initialize sync transport for sdk engine
-const { getChildren, syncEntity, parentEntity, getParent, myProfile, removeParent, getFirstChild } = addSyncTransport(
-  engine,
-  sendBinary,
-  getUserData
-)
+const { getChildren, syncEntity, parentEntity, getParent, myProfile, removeParent, getFirstChild, stateIsSyncronized } =
+  addSyncTransport(engine, sendBinary, getUserData)
 
-export { getFirstChild, getChildren, syncEntity, parentEntity, getParent, myProfile, removeParent }
+export { getFirstChild, getChildren, syncEntity, parentEntity, getParent, myProfile, removeParent, stateIsSyncronized }
diff --git a/packages/@dcl/sdk/src/network/message-bus-sync.ts b/packages/@dcl/sdk/src/network/message-bus-sync.ts
index 0a9faf970..cb8cdecfc 100644
--- a/packages/@dcl/sdk/src/network/message-bus-sync.ts
+++ b/packages/@dcl/sdk/src/network/message-bus-sync.ts
@@ -1,4 +1,4 @@
-import { IEngine, Transport, RealmInfo } from '@dcl/ecs'
+import { IEngine, Transport, RealmInfo, PlayerIdentityData } from '@dcl/ecs'
 import { type SendBinaryRequest, type SendBinaryResponse } from '~system/CommunicationsController'
 
 import { syncFilter } from './filter'
@@ -61,23 +61,58 @@ export function addSyncTransport(
     if (sender !== myProfile.userId) return
     DEBUG_NETWORK_MESSAGES() && console.log('[Processing CRDT State]', data.byteLength)
     transport.onmessage!(data)
+    stateIsSyncronized = true
   })
 
-  binaryMessageBus.on(CommsMessage.REQ_CRDT_STATE, (message, userId) => {
+  binaryMessageBus.on(CommsMessage.REQ_CRDT_STATE, async (message, userId) => {
+    console.log(`Sending CRDT State to: ${userId}`)
     transport.onmessage!(message)
     binaryMessageBus.emit(CommsMessage.RES_CRDT_STATE, encodeCRDTState(userId, engineToCrdt(engine)))
   })
 
+  async function sleep(ms: number) {
+    let timer = 0
+    function system(dt: number) {
+      timer += dt
+      if (timer >= ms) {
+        engine.removeSystem(system)
+        return Promise.resolve()
+      }
+    }
+    engine.addSystem(system)
+  }
+
   const players = definePlayerHelper(engine)
 
+  let stateIsSyncronized = false
+
   let requestCrdtStateWhenConnected = false
 
+  async function requestState() {
+    requestCrdtStateWhenConnected = false
+    let players = Array.from(engine.getEntitiesWith(PlayerIdentityData))
+    DEBUG_NETWORK_MESSAGES() && console.log(`Requesting state. Players connected: ${players.length - 1}`)
+    binaryMessageBus.emit(CommsMessage.REQ_CRDT_STATE, engineToCrdt(engine))
+    await sleep(3000)
+    players = Array.from(engine.getEntitiesWith(PlayerIdentityData))
+
+    if (!stateIsSyncronized) {
+      if (players.length > 1) {
+        DEBUG_NETWORK_MESSAGES() &&
+          console.log(`Requesting state again (no response). Players connected: ${players.length - 1}`)
+        void requestState()
+      } else {
+        DEBUG_NETWORK_MESSAGES() && console.log('No active players. State syncronized')
+        stateIsSyncronized = true
+      }
+    }
+  }
+
   players.onEnterScene((player) => {
     DEBUG_NETWORK_MESSAGES() && console.log('[onEnterScene]', player.userId)
     if (player.userId === myProfile.userId && !requestCrdtStateWhenConnected) {
       if (RealmInfo.getOrNull(engine.RootEntity)?.isConnectedSceneRoom) {
-        DEBUG_NETWORK_MESSAGES() && console.log('Requesting state')
-        binaryMessageBus.emit(CommsMessage.REQ_CRDT_STATE, engineToCrdt(engine))
+        void requestState()
       } else {
         DEBUG_NETWORK_MESSAGES() && console.log('Waiting to be conneted')
         requestCrdtStateWhenConnected = true
@@ -87,15 +122,15 @@ export function addSyncTransport(
 
   RealmInfo.onChange(engine.RootEntity, (value) => {
     if (value?.isConnectedSceneRoom && requestCrdtStateWhenConnected) {
-      DEBUG_NETWORK_MESSAGES() && console.log('Requesting state.')
-      requestCrdtStateWhenConnected = false
-      binaryMessageBus.emit(CommsMessage.REQ_CRDT_STATE, engineToCrdt(engine))
+      void requestState()
     }
   })
 
   players.onLeaveScene((userId) => {
     DEBUG_NETWORK_MESSAGES() && console.log('[onLeaveScene]', userId)
     if (userId === myProfile.userId) {
+      DEBUG_NETWORK_MESSAGES() && console.log('Disconnected from comms')
+      stateIsSyncronized = false
       requestCrdtStateWhenConnected = false
     }
   })
@@ -109,7 +144,8 @@ export function addSyncTransport(
 
   return {
     ...entityDefinitions,
-    myProfile
+    myProfile,
+    stateIsSyncronized
   }
 }