Merge pull request #2666 from vitorpamplona/claude/fix-nest-room-status-3Mmq9

Add NestLobbyScreen for read-only room preview before joining

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -128,6 +128,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.lists.memberEdit.FollowList
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.livestreams.LiveStreamsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.longs.LongsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.NestsScreen
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.lobby.NestLobbyScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.newUser.ImportFollowListPickFollowsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.newUser.ImportFollowListSelectUserScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.notifications.NotificationScreen
@@ -247,6 +248,7 @@ fun BuildNavigation(
         composableFromEnd<Route.FollowPacks> { FollowPacksScreen(accountViewModel, nav) }
         composableFromEnd<Route.LiveStreams> { LiveStreamsScreen(accountViewModel, nav) }
         composableFromEnd<Route.Nests> { NestsScreen(accountViewModel, nav) }
+        composableFromEndArgs<Route.NestLobby> { NestLobbyScreen(it.addressValue, accountViewModel, nav) }
         composableFromEnd<Route.Longs> { LongsScreen(accountViewModel, nav) }
         composableFromEnd<Route.Articles> { ArticlesScreen(accountViewModel, nav) }
         composableFromEnd<Route.NewHlsVideo> { NewHlsVideoScreen(accountViewModel, nav) }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/routes/Routes.kt

@@ -91,6 +91,10 @@ sealed class Route {
 
     @Serializable object Nests : Route()
 
+    @Serializable data class NestLobby(
+        val addressValue: String,
+    ) : Route()
+
     @Serializable object Longs : Route()
 
     @Serializable object Articles : Route()

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/MeetingSpace.kt

@@ -177,7 +177,7 @@ fun RenderMeetingSpaceEventInner(
         } else {
             com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.lobby.JoinNestButton(
                 event = noteEvent,
-                accountViewModel = accountViewModel,
+                nav = nav,
             )
         }
     }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/nests/NestsFeedLoaded.kt

@@ -49,7 +49,6 @@ import androidx.compose.ui.Alignment.Companion.TopEnd
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.layout.ContentScale
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
@@ -63,6 +62,7 @@ import com.vitorpamplona.amethyst.ui.actions.CrossfadeIfEnabled
 import com.vitorpamplona.amethyst.ui.components.SensitivityWarning
 import com.vitorpamplona.amethyst.ui.layouts.rememberFeedContentPadding
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.navigation.routes.routeFor
 import com.vitorpamplona.amethyst.ui.note.DisplayAuthorBanner
 import com.vitorpamplona.amethyst.ui.note.Gallery
@@ -77,8 +77,6 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.nip53L
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.nip53LiveActivities.ScheduledFlag
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.discover.nip53LiveActivities.LoadParticipants
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.datasource.NestRoomFilterAssemblerSubscription
-import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.activity.NestActivity
-import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.activity.NestBridge
 import com.vitorpamplona.amethyst.ui.stringRes
 import com.vitorpamplona.amethyst.ui.theme.DividerThickness
 import com.vitorpamplona.amethyst.ui.theme.DoubleVertSpacer
@@ -137,9 +135,10 @@ fun NestsFeedLoaded(
 
 /**
  * Audio-rooms list card. Mirrors [ObserveAndRenderSpace] visually but
- * routes a tap straight into [NestActivity] when the underlying event
- * is a [MeetingSpaceEvent], instead of the thread view that the generic
- * `ChannelCardCompose` → `ClickableNote` chain would otherwise open.
+ * routes a tap into the in-app [NestLobbyScreen] when the underlying
+ * event is a joinable [MeetingSpaceEvent]. The lobby is read-only —
+ * launching the audio activity (and any host-side kind-30312 refresh)
+ * still requires an explicit tap on the lobby's Open Room button.
  */
 @Composable
 private fun NestFeedCard(
@@ -149,7 +148,6 @@ private fun NestFeedCard(
     nav: INav,
 ) {
     val meetingEvent = baseNote.event as? MeetingSpaceEvent ?: return
-    val context = LocalContext.current
 
     val onClick =
         remember(meetingEvent) {
@@ -158,11 +156,7 @@ private fun NestFeedCard(
                 val endpoint = meetingEvent.endpoint()
                 val dTag = meetingEvent.address().dTag
                 if (!service.isNullOrBlank() && !endpoint.isNullOrBlank() && dTag.isNotBlank()) {
-                    NestBridge.set(accountViewModel)
-                    NestActivity.launch(
-                        context = context,
-                        addressValue = meetingEvent.address().toValue(),
-                    )
+                    nav.nav(Route.NestLobby(meetingEvent.address().toValue()))
                 } else {
                     nav.nav { routeFor(baseNote, accountViewModel.account) }
                 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/nests/room/lobby/NestJoinCard.kt

@@ -50,6 +50,7 @@ import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.commons.model.nip53LiveActivities.LiveActivitiesChannel
 import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.navigation.routes.routeFor
 import com.vitorpamplona.amethyst.ui.note.ClickableUserPicture
 import com.vitorpamplona.amethyst.ui.note.LoadAddressableNote
@@ -260,7 +261,7 @@ private fun NestJoinCardContent(
                 ) {
                     JoinNestButton(
                         event = event,
-                        accountViewModel = accountViewModel,
+                        nav = nav,
                     )
                 }
             }
@@ -269,12 +270,15 @@ private fun NestJoinCardContent(
 }
 
 /**
- * Standalone "Join nest" button. Reusable from any composable that has
- * a [MeetingSpaceEvent] in hand — the lobby card, the in-feed note
- * renderer (so a `nostr:naddr1...` deep-link to a kind-30312 lands one
- * tap away from the room), and any future room-list surface. Renders
- * nothing for events without a service / endpoint / d-tag — those
- * rooms can't be joined on the audio plane.
+ * "Join nest" entry button — navigates to [NestLobbyScreen] rather
+ * than launching the audio activity directly. The lobby is read-only
+ * (cached chat, host, status), so a user who's just coming back to
+ * check on an old room doesn't trigger a MoQ handshake or the host's
+ * kind-30312 republish path. The actual room launch lives behind
+ * [OpenNestRoomButton] inside the lobby.
+ *
+ * Renders nothing for events without a service / endpoint / d-tag —
+ * those rooms can't be joined on the audio plane.
  *
  * [primaryColorOverride] lets the lobby card paint the button with
  * the room's themed primary color (`["c", hex, "primary"]`); other
@@ -283,7 +287,7 @@ private fun NestJoinCardContent(
 @Composable
 fun JoinNestButton(
     event: MeetingSpaceEvent,
-    accountViewModel: AccountViewModel,
+    nav: INav,
     primaryColorOverride: Color? = null,
 ) {
     val serviceBase = event.service()
@@ -291,7 +295,6 @@ fun JoinNestButton(
     val roomId = event.address().dTag
     if (serviceBase.isNullOrBlank() || endpoint.isNullOrBlank() || roomId.isBlank()) return
 
-    val context = LocalContext.current
     val colors =
         if (primaryColorOverride != null) {
             androidx.compose.material3.ButtonDefaults
@@ -301,6 +304,33 @@ fun JoinNestButton(
                 .buttonColors()
         }
 
+    val addressValue = event.address().toValue()
+    Button(
+        onClick = { nav.nav(Route.NestLobby(addressValue)) },
+        colors = colors,
+    ) {
+        Text(stringRes(R.string.nest_join))
+    }
+}
+
+/**
+ * Lobby's primary CTA. This is the only place that actually launches
+ * [NestActivity] — meaning a host re-entering an old room only
+ * triggers the audio session (and any rejoin-time event refresh)
+ * when they explicitly opt in here.
+ */
+@Composable
+fun OpenNestRoomButton(
+    event: MeetingSpaceEvent,
+    accountViewModel: AccountViewModel,
+    modifier: Modifier = Modifier,
+) {
+    val serviceBase = event.service()
+    val endpoint = event.endpoint()
+    val roomId = event.address().dTag
+    if (serviceBase.isNullOrBlank() || endpoint.isNullOrBlank() || roomId.isBlank()) return
+
+    val context = LocalContext.current
     Button(
         onClick = {
             NestBridge.set(accountViewModel)
@@ -309,8 +339,8 @@ fun JoinNestButton(
                 addressValue = event.address().toValue(),
             )
         },
-        colors = colors,
+        modifier = modifier,
     ) {
-        Text(stringRes(R.string.nest_join))
+        Text(stringRes(R.string.nest_lobby_open_room))
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/nests/room/lobby/NestLobbyScreen.kt

@@ -0,0 +1,386 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.lobby
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyListScope
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import coil3.compose.AsyncImage
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.model.LocalCache
+import com.vitorpamplona.amethyst.model.Note
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.routeFor
+import com.vitorpamplona.amethyst.ui.navigation.topbars.TopBarWithBackButton
+import com.vitorpamplona.amethyst.ui.note.ClickableUserPicture
+import com.vitorpamplona.amethyst.ui.note.LoadAddressableNote
+import com.vitorpamplona.amethyst.ui.note.UsernameDisplay
+import com.vitorpamplona.amethyst.ui.note.types.MeetingSpaceClosedFlag
+import com.vitorpamplona.amethyst.ui.note.types.MeetingSpaceOpenFlag
+import com.vitorpamplona.amethyst.ui.note.types.MeetingSpacePlannedFlag
+import com.vitorpamplona.amethyst.ui.note.types.MeetingSpacePrivateFlag
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.feed.ChatroomMessageCompose
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.datasource.NestRoomFilterAssemblerSubscription
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.amethyst.ui.theme.StdHorzSpacer
+import com.vitorpamplona.quartz.nip01Core.core.Address
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip53LiveActivities.chat.LiveActivitiesChatMessageEvent
+import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingSpaceEvent
+import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.tags.StatusTag
+import com.vitorpamplona.quartz.nip53LiveActivities.presence.MeetingRoomPresenceEvent
+import com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags.ROLE
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+/**
+ * In-app navigation lobby for a NIP-53 audio room (kind-30312). Sits
+ * between the feed / share-link entry points and [com.vitorpamplona.amethyst
+ * .ui.screen.loggedIn.nests.room.activity.NestActivity], so a user who's
+ * just coming back to read the chat or check who's hosting doesn't
+ * trigger a MoQ handshake or a host-side kind-30312 republish. Only the
+ * "Open room" button on this screen launches the audio activity.
+ *
+ * The lobby is read-only: it mounts the room's relay subscription
+ * ([NestRoomFilterAssemblerSubscription]) so cached chat / presence
+ * stay fresh, but it does NOT open a [com.vitorpamplona.amethyst.commons
+ * .viewmodels.NestViewModel], does NOT publish kind-10312 presence,
+ * and does NOT touch the audio pipeline.
+ */
+@Composable
+fun NestLobbyScreen(
+    addressValue: String,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val address = remember(addressValue) { Address.parse(addressValue) } ?: return
+    LoadAddressableNote(address, accountViewModel) { addressableNote ->
+        addressableNote ?: return@LoadAddressableNote
+        val event = addressableNote.event as? MeetingSpaceEvent ?: return@LoadAddressableNote
+        NestLobbyContent(event, accountViewModel, nav)
+    }
+}
+
+@Composable
+private fun NestLobbyContent(
+    event: MeetingSpaceEvent,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val roomATag = remember(event) { event.address().toValue() }
+
+    // Keep cached chat / presence warm while the user is on the lobby.
+    // No MoQ session is opened — that's gated behind the Open Room button.
+    NestRoomFilterAssemblerSubscription(roomATag, accountViewModel)
+
+    Scaffold(
+        topBar = {
+            TopBarWithBackButton(
+                caption = event.room().orEmpty(),
+                nav = nav,
+            )
+        },
+        bottomBar = {
+            Box(
+                modifier =
+                    Modifier
+                        .fillMaxWidth()
+                        .background(MaterialTheme.colorScheme.surface)
+                        .padding(16.dp),
+            ) {
+                OpenNestRoomButton(
+                    event = event,
+                    accountViewModel = accountViewModel,
+                    modifier = Modifier.fillMaxWidth(),
+                )
+            }
+        },
+    ) { padding ->
+        LazyColumn(
+            modifier =
+                Modifier
+                    .fillMaxSize()
+                    .padding(padding),
+            state = rememberLazyListState(),
+        ) {
+            item("header") {
+                RoomHeader(event, accountViewModel, nav)
+            }
+            item("listeners") {
+                CachedListenerCount(roomATag)
+            }
+            item("chat-header") {
+                Text(
+                    text = stringRes(R.string.nest_lobby_recent_chat),
+                    style = MaterialTheme.typography.titleSmall,
+                    modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+                )
+            }
+            cachedChatItems(roomATag, accountViewModel, nav)
+        }
+    }
+}
+
+@Composable
+private fun RoomHeader(
+    event: MeetingSpaceEvent,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val image = remember(event) { event.image() }
+    val summary = remember(event) { event.summary() }
+    val status = remember(event) { event.status() }
+    val starts = remember(event) { event.starts() }
+    val hostPubkey = event.pubKey
+    val participants = remember(event) { event.participants() }
+    val speakers =
+        remember(participants, hostPubkey) {
+            participants.filter { p ->
+                p.pubKey != hostPubkey &&
+                    (p.role.equals(ROLE.SPEAKER.code, true) || p.role.equals(ROLE.MODERATOR.code, true))
+            }
+        }
+    val hostUser = remember(hostPubkey) { LocalCache.getOrCreateUser(hostPubkey) }
+
+    Column(modifier = Modifier.fillMaxWidth()) {
+        if (!image.isNullOrBlank()) {
+            AsyncImage(
+                model = image,
+                contentDescription = null,
+                modifier =
+                    Modifier
+                        .fillMaxWidth()
+                        .aspectRatio(16f / 9f),
+                contentScale = ContentScale.Crop,
+            )
+        }
+
+        Column(modifier = Modifier.padding(16.dp)) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                when (status) {
+                    StatusTag.STATUS.LIVE -> {
+                        MeetingSpaceOpenFlag()
+                    }
+
+                    StatusTag.STATUS.PRIVATE -> {
+                        MeetingSpacePrivateFlag()
+                    }
+
+                    StatusTag.STATUS.ENDED -> {
+                        MeetingSpaceClosedFlag()
+                    }
+
+                    StatusTag.STATUS.PLANNED -> {
+                        MeetingSpacePlannedFlag(starts)
+                    }
+
+                    null -> {}
+                }
+            }
+
+            if (!summary.isNullOrBlank()) {
+                Spacer(Modifier.height(12.dp))
+                Text(
+                    text = summary,
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
+            Spacer(Modifier.height(16.dp))
+
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                ClickableUserPicture(
+                    baseUser = hostUser,
+                    size = 40.dp,
+                    accountViewModel = accountViewModel,
+                    onClick = { user -> nav.nav(routeFor(user)) },
+                )
+                Spacer(StdHorzSpacer)
+                UsernameDisplay(
+                    baseUser = hostUser,
+                    weight = Modifier.weight(1f),
+                    accountViewModel = accountViewModel,
+                )
+                Spacer(StdHorzSpacer)
+                Text(
+                    text = stringRes(R.string.nest_lobby_host_label),
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
+            if (speakers.isNotEmpty()) {
+                Spacer(Modifier.height(12.dp))
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.spacedBy(4.dp),
+                ) {
+                    val cap = 8
+                    val visible = remember(speakers) { speakers.take(cap) }
+                    visible.forEach { tag ->
+                        ClickableUserPicture(
+                            baseUserHex = tag.pubKey,
+                            size = 28.dp,
+                            accountViewModel = accountViewModel,
+                            onClick = { hex ->
+                                nav.nav(
+                                    com.vitorpamplona.amethyst.ui.navigation.routes.Route
+                                        .Profile(hex),
+                                )
+                            },
+                        )
+                    }
+                    if (speakers.size > visible.size) {
+                        Text(
+                            text = "+${speakers.size - visible.size}",
+                            style = MaterialTheme.typography.labelMedium,
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Live listener count from cached kind-10312 presence events. Mirrors
+ * the staleness window used inside the room (PRESENCE_STALE_THRESHOLD_SEC
+ * in NestRoomEventCollectors): a peer that's missed one heartbeat plus a
+ * 5-min "still here" window stops counting.
+ */
+@Composable
+private fun CachedListenerCount(roomATag: String) {
+    var count by remember(roomATag) { mutableStateOf(0) }
+    LaunchedEffect(roomATag) {
+        val filter =
+            Filter(
+                kinds = listOf(MeetingRoomPresenceEvent.KIND),
+                tags = mapOf("a" to listOf(roomATag)),
+            )
+        LocalCache.observeEvents<MeetingRoomPresenceEvent>(filter).collect { events ->
+            // Latest event per pubkey within the staleness window.
+            val cutoff = TimeUtils.now() - LISTENER_FRESHNESS_SEC
+            count =
+                events
+                    .groupBy { it.pubKey }
+                    .values
+                    .count { perAuthor -> perAuthor.maxOf { it.createdAt } >= cutoff }
+        }
+    }
+    Text(
+        text =
+            if (count == 0) {
+                stringRes(R.string.nest_lobby_no_listeners)
+            } else {
+                stringRes(R.string.nest_lobby_listeners_count, count)
+            },
+        style = MaterialTheme.typography.bodyMedium,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+        modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+    )
+}
+
+private fun LazyListScope.cachedChatItems(
+    roomATag: String,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    item("chat-list") {
+        CachedChatList(roomATag, accountViewModel, nav)
+    }
+}
+
+@Composable
+private fun CachedChatList(
+    roomATag: String,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val messages by produceState(initialValue = emptyList<Note>(), roomATag) {
+        val filter =
+            Filter(
+                kinds = listOf(LiveActivitiesChatMessageEvent.KIND),
+                tags = mapOf("a" to listOf(roomATag)),
+            )
+        LocalCache.observeNotes(filter).collect { notes ->
+            value = notes.sortedByDescending { it.createdAt() ?: 0L }.take(LOBBY_CHAT_LIMIT)
+        }
+    }
+
+    val routeForLastRead = remember(roomATag) { "NestLobbyChat/$roomATag" }
+
+    if (messages.isEmpty()) {
+        Text(
+            text = stringRes(R.string.nest_chat_empty),
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 12.dp),
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
+        return
+    }
+
+    Column(modifier = Modifier.fillMaxWidth()) {
+        messages.forEach { note ->
+            ChatroomMessageCompose(
+                baseNote = note,
+                routeForLastRead = routeForLastRead,
+                accountViewModel = accountViewModel,
+                nav = nav,
+                onWantsToReply = {},
+                onWantsToEditDraft = {},
+            )
+        }
+    }
+}
+
+private const val LOBBY_CHAT_LIMIT = 50
+
+// 6 minutes — matches PRESENCE_STALE_THRESHOLD_SEC in NestRoomEventCollectors.
+private const val LISTENER_FRESHNESS_SEC: Long = 6L * 60L

amethyst/src/main/res/values/strings.xml

@@ -533,6 +533,10 @@
     <string name="nest_notification_stop">Stop</string>
     <string name="nest_join">Join nest</string>
     <string name="nest_lobby_host_label">Host</string>
+    <string name="nest_lobby_open_room">Open room</string>
+    <string name="nest_lobby_recent_chat">Recent chat</string>
+    <string name="nest_lobby_no_listeners">No one is in the room right now.</string>
+    <string name="nest_lobby_listeners_count">%1$d listening</string>
     <string name="nest_role_host">Host</string>
     <string name="nest_role_moderator">Moderator</string>
     <string name="nest_state_muted">Microphone muted</string>