refactor: rename states to view controllers (#1060)

app/assets/javascripts/Controllers/SyncStatusController.ts

@@ -0,0 +1,33 @@
+import { SyncOpStatus } from '@standardnotes/snjs'
+import { action, makeObservable, observable } from 'mobx'
+
+export class SyncStatusController {
+  inProgress = false
+  errorMessage?: string = undefined
+  humanReadablePercentage?: string = undefined
+
+  constructor() {
+    makeObservable(this, {
+      inProgress: observable,
+      errorMessage: observable,
+      humanReadablePercentage: observable,
+      update: action,
+    })
+  }
+
+  update = (status: SyncOpStatus): void => {
+    this.errorMessage = status.error?.message
+    this.inProgress = status.syncInProgress
+    const stats = status.getStats()
+    const completionPercentage =
+      stats.uploadCompletionCount === 0 ? 0 : stats.uploadCompletionCount / stats.uploadTotalCount
+
+    if (completionPercentage === 0) {
+      this.humanReadablePercentage = undefined
+    } else {
+      this.humanReadablePercentage = completionPercentage.toLocaleString(undefined, {
+        style: 'percent',
+      })
+    }
+  }
+}