Split MediaViewModel into multiple files

src/state/media/RemoteUserMediaViewModel.ts

@@ -0,0 +1,82 @@
+/*
+Copyright 2023, 2024 New Vector Ltd.
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { type RemoteParticipant } from "livekit-client";
+import { combineLatest, map, of, switchMap } from "rxjs";
+
+import { type Behavior } from "../Behavior";
+import { createVolumeControls, type VolumeControls } from "../VolumeControls";
+import {
+  type BaseUserMediaInputs,
+  type BaseUserMediaViewModel,
+  createBaseUserMedia,
+} from "./UserMediaViewModel";
+import { type ObservableScope } from "../ObservableScope";
+
+export interface RemoteUserMediaViewModel
+  extends BaseUserMediaViewModel, VolumeControls {
+  local: false;
+  /**
+   * Whether we are waiting for this user's LiveKit participant to exist. This
+   * could be because either we or the remote party are still connecting.
+   */
+  waitingForMedia$: Behavior<boolean>;
+}
+
+export interface RemoteUserMediaInputs extends Omit<
+  BaseUserMediaInputs,
+  "statsType"
+> {
+  participant$: Behavior<RemoteParticipant | null>;
+  pretendToBeDisconnected$: Behavior<boolean>;
+}
+
+export function createRemoteUserMedia(
+  scope: ObservableScope,
+  { pretendToBeDisconnected$, ...inputs }: RemoteUserMediaInputs,
+): RemoteUserMediaViewModel {
+  const baseUserMedia = createBaseUserMedia(scope, {
+    ...inputs,
+    statsType: "inbound-rtp",
+  });
+
+  return {
+    ...baseUserMedia,
+    ...createVolumeControls(scope, {
+      pretendToBeDisconnected$,
+      sink$: scope.behavior(
+        inputs.participant$.pipe(map((p) => (volume) => p?.setVolume(volume))),
+      ),
+    }),
+    local: false,
+    speaking$: scope.behavior(
+      pretendToBeDisconnected$.pipe(
+        switchMap((disconnected) =>
+          disconnected ? of(false) : baseUserMedia.speaking$,
+        ),
+      ),
+    ),
+    videoEnabled$: scope.behavior(
+      pretendToBeDisconnected$.pipe(
+        switchMap((disconnected) =>
+          disconnected ? of(false) : baseUserMedia.videoEnabled$,
+        ),
+      ),
+    ),
+    waitingForMedia$: scope.behavior(
+      combineLatest(
+        [inputs.livekitRoom$, inputs.participant$],
+        (livekitRoom, participant) =>
+          // If livekitRoom is undefined, the user is not attempting to publish on
+          // any transport and so we shouldn't expect a participant. (They might
+          // be a subscribe-only bot for example.)
+          livekitRoom !== undefined && participant === null,
+      ),
+    ),
+  };
+}