wip refactor effects prejoin

- avoid props drillig, rely on localstorage
- using an explicit flag to trigger the entry instead of depending of userconfig state (better encapsulation)
- init processor from video initiation, avoid weird blink, less hook and callback

overall, simplify and improve the user experience

src/frontend/src/features/rooms/components/Conference.tsx

@@ -1,7 +1,10 @@
 import { useEffect, useMemo, useState } from 'react'
 import { useQuery } from '@tanstack/react-query'
 import { useTranslation } from 'react-i18next'
-import { LiveKitRoom } from '@livekit/components-react'
+import {
+  LiveKitRoom,
+  usePersistentUserChoices,
+} from '@livekit/components-react'
 import {
   DisconnectReason,
   MediaDeviceFailure,
@@ -29,18 +32,20 @@ import { isFireFox } from '@/utils/livekit'
 
 export const Conference = ({
   roomId,
-  userConfig,
   initialRoomData,
   mode = 'join',
 }: {
   roomId: string
-  userConfig: LocalUserChoices
   mode?: 'join' | 'create'
   initialRoomData?: ApiRoom
 }) => {
   const posthog = usePostHog()
   const { data: apiConfig } = useConfig()
 
+  const { userChoices: userConfig } = usePersistentUserChoices() as {
+    userChoices: LocalUserChoices
+  }
+
   useEffect(() => {
     posthog.capture('visit-room', { slug: roomId })
   }, [roomId, posthog])

src/frontend/src/features/rooms/components/Join.tsx

@@ -2,7 +2,7 @@ import { useTranslation } from 'react-i18next'
 import { usePreviewTracks } from '@livekit/components-react'
 import { css } from '@/styled-system/css'
 import { Screen } from '@/layout/Screen'
-import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import { LocalVideoTrack, Track } from 'livekit-client'
 import { H } from '@/primitives/H'
 import { SelectToggleDevice } from '../livekit/components/controls/SelectToggleDevice'
@@ -27,7 +27,6 @@ import { ApiLobbyStatus, ApiRequestEntry } from '../api/requestEntry'
 import { Spinner } from '@/primitives/Spinner'
 import { ApiAccessLevel } from '../api/ApiRoom'
 import { useLoginHint } from '@/hooks/useLoginHint'
-import { LocalUserChoices } from '@/stores/userChoices'
 
 const onError = (e: Error) => console.error('ERROR', e)
 
@@ -107,10 +106,10 @@ const Effects = ({
 }
 
 export const Join = ({
-  onSubmit,
+  enterRoom,
   roomId,
 }: {
-  onSubmit: (choices: LocalUserChoices) => void
+  enterRoom: () => void
   roomId: string
 }) => {
   const { t } = useTranslation('rooms', { keyPrefix: 'join' })
@@ -132,23 +131,14 @@ export const Join = ({
     saveProcessorSerialized,
   } = usePersistentUserChoices()
 
-  const [processor, setProcessor] = useState(
-    BackgroundProcessorFactory.deserializeProcessor(processorSerialized)
-  )
-
-  useEffect(() => {
-    saveProcessorSerialized(processor?.serialize())
-  }, [
-    processor,
-    saveProcessorSerialized,
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-    JSON.stringify(processor?.serialize()),
-  ])
-
   const tracks = usePreviewTracks(
     {
       audio: { deviceId: audioDeviceId },
-      video: { deviceId: videoDeviceId },
+      video: {
+        deviceId: videoDeviceId,
+        processor:
+          BackgroundProcessorFactory.deserializeProcessor(processorSerialized),
+      },
     },
     onError
   )
@@ -192,25 +182,6 @@ export const Join = ({
     }
   }, [videoTrack, videoEnabled])
 
-  const enterRoom = useCallback(() => {
-    onSubmit({
-      audioEnabled,
-      videoEnabled,
-      audioDeviceId,
-      videoDeviceId,
-      username,
-      processorSerialized: processor?.serialize(),
-    })
-  }, [
-    onSubmit,
-    audioEnabled,
-    videoEnabled,
-    audioDeviceId,
-    videoDeviceId,
-    username,
-    processor,
-  ])
-
   // Room data strategy:
   // 1. Initial fetch is performed to check access and get LiveKit configuration
   // 2. Data remains valid for 6 hours to avoid unnecessary refetches
@@ -269,16 +240,6 @@ export const Join = ({
     enterRoom()
   }
 
-  // This hook is used to setup the persisted user choice processor on initialization.
-  // So it's on purpose that processor is not included in the deps.
-  // We just want to wait for the videoTrack to be loaded to apply the default processor.
-  useEffect(() => {
-    if (processor && videoTrack && !videoTrack.getProcessor()) {
-      videoTrack.setProcessor(processor)
-    }
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [videoTrack])
-
   const renderWaitingState = () => {
     switch (status) {
       case ApiLobbyStatus.TIMEOUT:
@@ -453,7 +414,12 @@ export const Join = ({
                   </p>
                 </div>
               )}
-              <Effects videoTrack={videoTrack} onSubmit={setProcessor} />
+              <Effects
+                videoTrack={videoTrack}
+                onSubmit={(processor) =>
+                  saveProcessorSerialized(processor?.serialize())
+                }
+              />
             </div>
             <HStack justify="center" padding={1.5}>
               <SelectToggleDevice

src/frontend/src/features/rooms/routes/Room.tsx

@@ -1,5 +1,4 @@
 import { useEffect, useState } from 'react'
-import { usePersistentUserChoices } from '@livekit/components-react'
 import { useLocation, useParams } from 'wouter'
 import { ErrorScreen } from '@/components/ErrorScreen'
 import { useUser, UserAware } from '@/features/auth'
@@ -10,12 +9,10 @@ import {
   isRoomValid,
   normalizeRoomId,
 } from '@/features/rooms/utils/isRoomValid'
-import { LocalUserChoices } from '@/stores/userChoices'
 
 export const Room = () => {
   const { isLoggedIn } = useUser()
-  const { userChoices: existingUserChoices } = usePersistentUserChoices()
-  const [userConfig, setUserConfig] = useState<LocalUserChoices | null>(null)
+  const [hasSubmittedEntry, setHasSubmittedEntry] = useState(false)
 
   const { roomId } = useParams()
   const [location, setLocation] = useLocation()
@@ -48,10 +45,10 @@ export const Room = () => {
     return <ErrorScreen />
   }
 
-  if (!userConfig && !skipJoinScreen) {
+  if (!hasSubmittedEntry && !skipJoinScreen) {
     return (
       <UserAware>
-        <Join onSubmit={setUserConfig} roomId={roomId} />
+        <Join enterRoom={() => setHasSubmittedEntry(true)} roomId={roomId} />
       </UserAware>
     )
   }
@@ -62,10 +59,6 @@ export const Room = () => {
         initialRoomData={initialRoomData}
         roomId={roomId}
         mode={mode}
-        userConfig={{
-          ...existingUserChoices,
-          ...userConfig,
-        }}
       />
     </UserAware>
   )