From 8d724acf40c4df12fc2407c4eb626f10773505e8 Mon Sep 17 00:00:00 2001
From: Erik Olsson <valross2@gmail.com>
Date: Mon, 9 Dec 2024 15:26:47 +0100
Subject: [PATCH] simple mls work queue embryo

---
 packages/sdk/src/mlsQueue.ts | 107 +++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 packages/sdk/src/mlsQueue.ts

diff --git a/packages/sdk/src/mlsQueue.ts b/packages/sdk/src/mlsQueue.ts
new file mode 100644
index 000000000..44a0ed7d0
--- /dev/null
+++ b/packages/sdk/src/mlsQueue.ts
@@ -0,0 +1,107 @@
+import { EntitlementsDelegate, MlsEncryptionEvent } from "@river-build/encryption";
+import { Client } from "./client";
+import { check, dlog, dlogError, DLogger } from "@river-build/dlog";
+
+interface MlsQueueItem {
+    respondAfter: Date
+    event: MlsEncryptionEvent
+}
+
+export class MlsQueue {
+
+    private started: boolean = false
+    private inProgressTick?: Promise<void>
+    private timeoutId?: NodeJS.Timeout
+    private queue = new Array<MlsQueueItem>()
+    protected log: {
+        debug: DLogger
+        info: DLogger
+        error: DLogger
+    }
+
+    constructor(
+        private readonly client: Client,
+        delegate: EntitlementsDelegate,
+    ) {
+        this.log = {
+            debug: dlog('csb:mls:debug'),
+            info: dlog('csb:mls'),
+            error: dlogError('csb:mls:error'),
+        }
+        // to subscribe, call something like :
+        // client.on('mls...') and add corresponding event
+    }
+
+    public start() {
+        check(!this.started, 'start() called twice, please re-instantiate instead')
+        this.started = true
+    }
+
+    public stop() {
+        
+    }
+
+    checkStartTicking() {
+        // TODO: pause if take mobile safari is backgrounded (idb issue)
+        if (!this.started || this.timeoutId) {
+            return
+        }
+
+        this.timeoutId = setTimeout(() => {
+            this.inProgressTick = this.tick()
+            this.inProgressTick
+                .catch((e) => this.log.error('MLS ProcessTick Error', e))
+                .finally(() => {
+                    this.timeoutId = undefined
+                    this.checkStartTicking()
+                })
+        }, 0)
+    }
+
+    stopTicking() {
+
+    }
+
+    async tick() {
+        const item = this.dequeueWorkItem()
+        if (!item) {
+            return
+        }
+        this.processItem(item)
+    }
+
+    async processItem(item: MlsEncryptionEvent) {
+        // call out to client etc
+    }
+
+    dequeueWorkItem(): MlsEncryptionEvent | undefined {
+        if (this.queue.length === 0) {
+            return undefined
+        }
+        const now = new Date()
+        if (this.queue[0].respondAfter > now) {
+            return undefined
+        }
+        const index = this.queue.findIndex((x) => x.respondAfter <= now)
+        if (index === -1) {
+            return undefined
+        }
+        return this.queue.splice(index, 1)[0].event
+    }
+    
+    insertWorkItem(event: MlsEncryptionEvent,respondAfter?: Date) {
+        let position = this.queue.length
+        let workItem: MlsQueueItem = {
+            respondAfter: respondAfter ?? new Date(),
+            event: event
+        }
+        // Iterate backwards to find the correct position
+        for (let i = this.queue.length - 1; i >= 0; i--) {
+            if (this.queue[i].respondAfter <= workItem.respondAfter) {
+                position = i + 1
+                break
+            }
+        }
+        this.queue.splice(position, 0, workItem)
+    }
+}
\ No newline at end of file