1 files changed, 72 insertions, 0 deletions
diff --git a/engine/systems/NetworkUpdate.ts b/engine/systems/NetworkUpdate.ts
new file mode 100644
index 0000000..6d13574
--- /dev/null
+++ b/engine/systems/NetworkUpdate.ts
@@ -0,0 +1,72 @@
+import { System, SystemNames } from '.';
+import { Game } from '../Game';
+import { ComponentNames } from '../components';
+import {
+  type MessageQueueProvider,
+  type MessagePublisher,
+  type MessageProcessor,
+  MessageType,
+  EntityUpdateBody
+} from '../network';
+
+export class NetworkUpdate extends System {
+  private queueProvider: MessageQueueProvider;
+  private publisher: MessagePublisher;
+  private messageProcessor: MessageProcessor;
+
+  private entityUpdateTimers: Map<string, number>;
+
+  constructor(
+    queueProvider: MessageQueueProvider,
+    publisher: MessagePublisher,
+    messageProcessor: MessageProcessor
+  ) {
+    super(SystemNames.NetworkUpdate);
+
+    this.queueProvider = queueProvider;
+    this.publisher = publisher;
+    this.messageProcessor = messageProcessor;
+
+    this.entityUpdateTimers = new Map();
+  }
+
+  public update(dt: number, game: Game) {
+    // 1. process new messages
+    this.queueProvider
+      .getNewMessages()
+      .forEach((message) => this.messageProcessor.process(message));
+    this.queueProvider.clearMessages();
+
+    // 2. send entity updates
+    const updateMessages: EntityUpdateBody[] = [];
+    game.forEachEntityWithComponent(
+      ComponentNames.NetworkUpdateable,
+      (entity) => {
+        let timer = this.entityUpdateTimers.get(entity.id) ?? dt;
+        timer -= dt;
+        this.entityUpdateTimers.set(entity.id, timer);
+
+        if (timer > 0) return;
+        this.entityUpdateTimers.set(entity.id, this.getNextUpdateTimeMs());
+
+        if (entity.hasComponent(ComponentNames.NetworkUpdateable)) {
+          updateMessages.push({
+            id: entity.id,
+            args: entity.serialize()
+          });
+        }
+      }
+    );
+    this.publisher.addMessage({
+      type: MessageType.UPDATE_ENTITIES,
+      body: updateMessages
+    });
+
+    // 3. publish changes
+    this.publisher.publish();
+  }
+
+  private getNextUpdateTimeMs() {
+    return Math.random() * 70 + 50;
+  }
+}