feat: add snjs package

packages/snjs/lib/Client/FileViewController.ts

@@ -0,0 +1,41 @@
+import { FileItem } from '@standardnotes/models'
+import { ContentType } from '@standardnotes/common'
+import { SNApplication } from '../Application/Application'
+import { ItemViewControllerInterface } from './ItemViewControllerInterface'
+
+export class FileViewController implements ItemViewControllerInterface {
+  public dealloced = false
+  private removeStreamObserver?: () => void
+
+  constructor(private application: SNApplication, public item: FileItem) {}
+
+  deinit() {
+    this.dealloced = true
+    this.removeStreamObserver?.()
+    ;(this.removeStreamObserver as unknown) = undefined
+    ;(this.application as unknown) = undefined
+    ;(this.item as unknown) = undefined
+  }
+
+  async initialize() {
+    this.streamItems()
+  }
+
+  private streamItems() {
+    this.removeStreamObserver = this.application.streamItems<FileItem>(ContentType.File, ({ changed, inserted }) => {
+      if (this.dealloced) {
+        return
+      }
+
+      const files = changed.concat(inserted)
+
+      const matchingFile = files.find((item) => {
+        return item.uuid === this.item.uuid
+      })
+
+      if (matchingFile) {
+        this.item = matchingFile
+      }
+    })
+  }
+}