feat(mobx): start work on migrations

src/mobx/stores/Sync.ts

@@ -0,0 +1,70 @@
+import {
+    action,
+    computed,
+    makeAutoObservable,
+    ObservableMap,
+    ObservableSet,
+} from "mobx";
+import { Client } from "revolt.js";
+
+import { mapToRecord } from "../../lib/conversion";
+
+import Persistent from "../interfaces/Persistent";
+import Store from "../interfaces/Store";
+
+export type SyncKeys = "theme" | "appearance" | "locale" | "notifications";
+
+export const SYNC_KEYS: SyncKeys[] = [
+    "theme",
+    "appearance",
+    "locale",
+    "notifications",
+];
+
+interface Data {
+    disabled: SyncKeys[];
+}
+
+/**
+ * Handles syncing settings data.
+ */
+export default class Sync implements Store, Persistent<Data> {
+    private disabled: ObservableSet<SyncKeys>;
+
+    /**
+     * Construct new Sync store.
+     */
+    constructor() {
+        this.disabled = new ObservableSet();
+        makeAutoObservable(this);
+        this.isEnabled = this.isEnabled.bind(this);
+    }
+
+    get id() {
+        return "sync";
+    }
+
+    toJSON() {
+        return {
+            enabled: [...this.disabled],
+        };
+    }
+
+    @action hydrate(data: Data) {
+        if (data.disabled) {
+            for (const key of data.disabled) {
+                this.disabled.add(key as SyncKeys);
+            }
+        }
+    }
+
+    @computed isEnabled(key: SyncKeys) {
+        return !this.disabled.has(key);
+    }
+
+    async pull(client: Client) {
+        const data = await client.syncFetchSettings(
+            SYNC_KEYS.filter(this.isEnabled),
+        );
+    }
+}