feat(bottom-bar): pin a whole NIP-29 relay or a single Concord channel

The bottom-bar settings picker only exposed one level of each grouped chat
system: NIP-29 let you pin an individual group but not the host relay, while
Concord let you pin a community but not an individual channel. Since a NIP-29
relay is the analog of a Concord community (the container) and a Concord
channel is the analog of a NIP-29 group (the item), both systems now offer
both levels.

- Add BottomBarEntry.RelayServer(relayUrl) -> Route.RelayGroupServer (the
  relay's home page of all joined groups) and BottomBarEntry.ConcordChannel(
  communityId, channelId, relays) -> Route.Concord (a specific channel), with
  stable @SerialName discriminators and stableKeys.
- Resolve their live avatar/label/route: the relay via its cached NIP-11 doc,
  the channel via the community session's folded Control Plane (community icon
  + channel name).
- Regroup the picker by container: each relay/community is an addable "server"
  row with its groups/channels nested beneath it, so you can add the whole
  server or a single room in both systems.
- Bootstrap a pinned channel's community list (importConcordCommunities and the
  pinned-community preloader now also read ConcordChannel entries).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012v531djZmQBxVoyCm45BNY

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/bottombars/AppBottomBar.kt

@@ -235,7 +235,9 @@ internal fun rememberBottomBarSlot(
         }
         is BottomBarEntry.PublicChat,
         is BottomBarEntry.RelayGroup,
+        is BottomBarEntry.RelayServer,
         is BottomBarEntry.Concord,
+        is BottomBarEntry.ConcordChannel,
         is BottomBarEntry.Geohash,
         -> {
             val display = rememberGroupEntryDisplay(entry, accountViewModel) ?: return null

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/bottombars/BottomBarEntry.kt

@@ -38,6 +38,11 @@ import kotlinx.serialization.Serializable
  * - [PublicChat], [RelayGroup] and [Concord] each pin one specific joined chat the user picked from
  *   their joined list (NIP-28 channel, NIP-29 relay group, or a Concord community). The bar resolves
  *   each to the chat's avatar + name from the local cache and to its chat/home route for navigation.
+ * - [RelayServer] and [ConcordChannel] pin the *other* level of the two grouped chat systems: a NIP-29
+ *   host relay (whose home page lists every group on it) and one channel inside a Concord community.
+ *   A NIP-29 relay is the analog of a Concord community (the container), and a Concord channel is the
+ *   analog of a NIP-29 group (the item) — so together the five group entries let the user pin either
+ *   the whole server or a single room in both systems.
  */
 @Serializable
 sealed interface BottomBarEntry {
@@ -70,6 +75,17 @@ sealed interface BottomBarEntry {
         val relayUrl: String,
     ) : BottomBarEntry
 
+    /**
+     * A pinned NIP-29 host relay ("server"), keyed by its relay url; opens the relay's home page that
+     * lists every group the user has joined on it. The relay-level analog of pinning a whole [Concord]
+     * community, so both grouped chat systems can pin the container as well as an individual room.
+     */
+    @Serializable
+    @SerialName("relayServer")
+    data class RelayServer(
+        val relayUrl: String,
+    ) : BottomBarEntry
+
     /**
      * A pinned Concord community, keyed by its community id; opens the community's channel list.
      *
@@ -88,6 +104,20 @@ sealed interface BottomBarEntry {
         val relays: List<String> = emptyList(),
     ) : BottomBarEntry
 
+    /**
+     * A pinned Concord channel inside a community, keyed by the (community id, channel id) pair; opens
+     * that specific channel. The channel-level analog of pinning a single [RelayGroup]. [relays] carry
+     * the community's bootstrap relays (same reason as [Concord.relays]) so a pinned channel whose
+     * community list we haven't cached can still be resolved.
+     */
+    @Serializable
+    @SerialName("concordChannel")
+    data class ConcordChannel(
+        val communityId: String,
+        val channelId: String,
+        val relays: List<String> = emptyList(),
+    ) : BottomBarEntry
+
     /** A pinned Bitchat geohash location channel, keyed by its geohash cell; opens the location chat. */
     @Serializable
     @SerialName("geohash")
@@ -107,7 +137,9 @@ val BottomBarEntry.stableKey: String
             is BottomBarEntry.Favorite -> "favorite:$favoriteId"
             is BottomBarEntry.PublicChat -> "publicChat:$channelId"
             is BottomBarEntry.RelayGroup -> "relayGroup:$relayUrl|$groupId"
+            is BottomBarEntry.RelayServer -> "relayServer:$relayUrl"
             is BottomBarEntry.Concord -> "concord:$communityId"
+            is BottomBarEntry.ConcordChannel -> "concordChannel:$communityId|$channelId"
             is BottomBarEntry.Geohash -> "geohash:$geohash"
         }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/bottombars/GroupBottomBarEntries.kt

@@ -38,6 +38,7 @@ import com.vitorpamplona.amethyst.commons.model.ChannelState
 import com.vitorpamplona.amethyst.commons.model.nip28PublicChats.PublicChatChannel
 import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
 import com.vitorpamplona.amethyst.model.LocalCache
+import com.vitorpamplona.amethyst.model.nip11RelayInfo.loadRelayInfo
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.channel.ChannelFinderFilterAssemblerSubscription
 import com.vitorpamplona.amethyst.ui.components.RobohashFallbackAsyncImage
 import com.vitorpamplona.amethyst.ui.navigation.routes.Route
@@ -45,6 +46,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.concord.rememberConcordImageModel
 import com.vitorpamplona.amethyst.ui.stringRes
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.displayUrl
 import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
 import kotlinx.coroutines.flow.MutableStateFlow
 
@@ -132,6 +134,29 @@ fun rememberRelayGroupEntryDisplay(
     )
 }
 
+/**
+ * A pinned NIP-29 host relay ("server"). Its name/icon come from the relay's NIP-11 document (cached,
+ * shared with the browse/server rows), falling back to the display host; tapping opens the relay's
+ * home page listing every joined group on it.
+ */
+@Composable
+fun rememberRelayServerEntryDisplay(
+    entry: BottomBarEntry.RelayServer,
+    accountViewModel: AccountViewModel,
+): GroupEntryDisplay {
+    val relay = remember(entry.relayUrl) { RelayUrlNormalizer.normalizeOrNull(entry.relayUrl) }
+    val host = remember(relay, entry.relayUrl) { relay?.displayUrl() ?: entry.relayUrl }
+    // NIP-11 is its own HTTP cache (not a relay REQ), so this is safe even for the read-only picker.
+    val info = relay?.let { loadRelayInfo(it) }
+    val name = info?.value?.name?.takeIf { it.isNotBlank() } ?: host
+    return GroupEntryDisplay(
+        label = name,
+        robotSeed = entry.relayUrl,
+        model = info?.value?.icon?.ifBlank { null },
+        route = Route.RelayGroupServer(entry.relayUrl),
+    )
+}
+
 /** [observeChannelMetadata] tolerant of a null channel (unresolvable relay), so callers avoid an early return. */
 @Composable
 private fun observeChannelMetadataOrNull(
@@ -169,6 +194,40 @@ fun rememberConcordEntryDisplay(
     )
 }
 
+/**
+ * A pinned Concord channel inside a community. The label is the channel's folded name; the avatar is
+ * the *community's* icon (so the tab reads as "this community's channel"), keyed by the channel id so
+ * distinct channels still get distinct robohash fallbacks. Tapping opens that channel directly.
+ */
+@Composable
+fun rememberConcordChannelEntryDisplay(
+    entry: BottomBarEntry.ConcordChannel,
+    accountViewModel: AccountViewModel,
+): GroupEntryDisplay {
+    val account = accountViewModel.account
+    val revision by account.concordSessions.revision.collectAsStateWithLifecycle()
+    val session = remember(entry.communityId, revision) { account.concordSessions.sessionFor(entry.communityId) }
+    val state by (session?.state ?: remember { MutableStateFlow(null) }).collectAsStateWithLifecycle()
+
+    val folded = state.takeIf { revision >= 0 }
+    val channelName =
+        folded
+            ?.channels
+            ?.get(entry.channelId)
+            ?.definition
+            ?.name
+            ?.ifBlank { null }
+    val label = channelName ?: entry.channelId.take(8)
+    val model = rememberConcordImageModel(folded?.metadata?.icon, accountViewModel)
+
+    return GroupEntryDisplay(
+        label = label,
+        robotSeed = entry.channelId,
+        model = model,
+        route = Route.Concord(entry.communityId, entry.channelId),
+    )
+}
+
 /**
  * A pinned geohash location channel. Anonymous by design — no metadata REQ; the row is a location
  * pin robohash keyed by the cell, labelled with the geohash, opening the location chat.
@@ -198,7 +257,9 @@ fun rememberGroupEntryDisplay(
     when (entry) {
         is BottomBarEntry.PublicChat -> rememberPublicChatEntryDisplay(entry, accountViewModel, subscribe)
         is BottomBarEntry.RelayGroup -> rememberRelayGroupEntryDisplay(entry, accountViewModel, subscribe)
+        is BottomBarEntry.RelayServer -> rememberRelayServerEntryDisplay(entry, accountViewModel)
         is BottomBarEntry.Concord -> rememberConcordEntryDisplay(entry, accountViewModel)
+        is BottomBarEntry.ConcordChannel -> rememberConcordChannelEntryDisplay(entry, accountViewModel)
         is BottomBarEntry.Geohash -> rememberGeohashEntryDisplay(entry)
         is BottomBarEntry.BuiltIn -> null
         is BottomBarEntry.Favorite -> null

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

@@ -685,9 +685,13 @@ class AccountViewModel(
         viewModelScope.launch(Dispatchers.IO) {
             val pinnedRelays =
                 settings.uiSettingsFlow.bottomBarItems.value
-                    .filterIsInstance<BottomBarEntry.Concord>()
+                    .flatMap {
-                    .flatMap { it.relays }
+                        when (it) {
-                    .mapNotNullTo(HashSet()) { RelayUrlNormalizer.normalizeOrNull(it) }
+                            is BottomBarEntry.Concord -> it.relays
+                            is BottomBarEntry.ConcordChannel -> it.relays
+                            else -> emptyList()
+                        }
+                    }.mapNotNullTo(HashSet()) { RelayUrlNormalizer.normalizeOrNull(it) }
             account.importConcordCommunities(pinnedRelays)
         }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/concord/datasource/ConcordChannelSubscription.kt

@@ -127,9 +127,14 @@ private fun bootstrapPinnedCommunities(accountViewModel: AccountViewModel) {
         remember(items, communities) {
             val known = communities.mapTo(HashSet()) { it.id }
             items
-                .filterIsInstance<BottomBarEntry.Concord>()
+                .mapNotNull {
-                .map { it.communityId }
+                    // Both a pinned community and a pinned channel need their community's list fetched.
-                .filterTo(sortedSetOf()) { it !in known }
+                    when (it) {
+                        is BottomBarEntry.Concord -> it.communityId
+                        is BottomBarEntry.ConcordChannel -> it.communityId
+                        else -> null
+                    }
+                }.filterTo(sortedSetOf()) { it !in known }
         }
 
     LaunchedEffect(missingPinned) {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/settings/BottomBarSettingsScreen.kt

@@ -99,6 +99,9 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.mockAccountViewModel
 import com.vitorpamplona.amethyst.ui.stringRes
 import com.vitorpamplona.amethyst.ui.theme.Size20dp
 import com.vitorpamplona.amethyst.ui.theme.ThemeComparisonRow
+import com.vitorpamplona.quartz.concord.cord02Community.ConcordCommunityListEntry
+import com.vitorpamplona.quartz.nip51Lists.simpleGroupList.GroupTag
+import kotlinx.coroutines.flow.MutableStateFlow
 
 /** The chat catalog items whose picker row expands to a per-item picker (favorites / joined groups). */
 private val ExpandableItems =
@@ -557,7 +560,7 @@ private fun PickerChildren(
                         label = fav.label,
                         pinned = entry.stableKey in pinnedKeys,
                         onToggle = { onTogglePin(entry) },
-                        indent = true,
+                        indentLevel = 1,
                     )
                 }
             }
@@ -573,20 +576,41 @@ private fun PickerChildren(
         NavBarItem.RELAY_GROUPS -> {
             val groups by accountViewModel.account.relayGroupList.liveRelayGroupList
                 .collectAsStateWithLifecycle()
-            val entries =
+            if (groups.isEmpty()) {
-                remember(groups) {
+                EmptyChildHint(R.string.bottom_bar_settings_no_groups)
-                    groups
+            } else {
-                        .sortedBy { (it.name ?: it.groupId).lowercase() }
+                // Group joined groups by their host relay: the relay itself is addable (opens its home
-                        .map { BottomBarEntry.RelayGroup(it.groupId, it.relayUrl) }
+                // page listing every group on it) with each individual group nested beneath it. NIP-29
+                // relays are the container, like Concord communities below.
+                val byRelay =
+                    remember(groups) {
+                        groups
+                            .groupBy { it.relayUrl }
+                            .toList()
+                            .sortedBy { it.first.lowercase() }
+                    }
+                byRelay.forEach { (relayUrl, relayGroups) ->
+                    key(relayUrl) {
+                        RelayServerPickerGroup(relayUrl, relayGroups, pinnedKeys, accountViewModel, onTogglePin)
+                    }
                 }
-            GroupChildList(entries, pinnedKeys, accountViewModel, onTogglePin)
+            }
         }
 
         NavBarItem.CONCORD -> {
             val communities by accountViewModel.account.concordChannelList.liveCommunities
                 .collectAsStateWithLifecycle()
-            val entries = remember(communities) { communities.map { BottomBarEntry.Concord(it.id, it.relays) } }
+            if (communities.isEmpty()) {
-            GroupChildList(entries, pinnedKeys, accountViewModel, onTogglePin)
+                EmptyChildHint(R.string.bottom_bar_settings_no_groups)
+            } else {
+                // Group by community: the community itself is addable (opens its channel list) with each
+                // channel nested beneath it — the mirror of the relay-group layout above.
+                communities.forEach { community ->
+                    key(community.id) {
+                        ConcordServerPickerGroup(community, pinnedKeys, accountViewModel, onTogglePin)
+                    }
+                }
+            }
         }
 
         NavBarItem.GEOHASH_CHATS -> {
@@ -619,7 +643,110 @@ private fun GroupChildList(
             label = display.label,
             pinned = entry.stableKey in pinnedKeys,
             onToggle = { onTogglePin(entry) },
-            indent = true,
+            indentLevel = 1,
+        )
+    }
+}
+
+/**
+ * One NIP-29 host relay in the picker: the relay "server" row (level 1 — pin the whole relay, opening
+ * its home page of all joined groups) followed by each individual joined group nested at level 2.
+ */
+@Composable
+private fun RelayServerPickerGroup(
+    relayUrl: String,
+    relayGroups: List<GroupTag>,
+    pinnedKeys: Set<String>,
+    accountViewModel: AccountViewModel,
+    onTogglePin: (BottomBarEntry) -> Unit,
+) {
+    val serverEntry = remember(relayUrl) { BottomBarEntry.RelayServer(relayUrl) }
+    val serverDisplay = rememberGroupEntryDisplay(serverEntry, accountViewModel, subscribe = false)
+    AvailableRow(
+        leading = {
+            if (serverDisplay != null) {
+                GroupEntryAvatar(serverDisplay, 34.dp, accountViewModel)
+            } else {
+                LeadingGlyph(MaterialSymbols.Dns)
+            }
+        },
+        label = serverDisplay?.label ?: relayUrl,
+        pinned = serverEntry.stableKey in pinnedKeys,
+        onToggle = { onTogglePin(serverEntry) },
+        indentLevel = 1,
+    )
+
+    val sorted = remember(relayGroups) { relayGroups.sortedBy { (it.name ?: it.groupId).lowercase() } }
+    sorted.forEach { tag ->
+        val entry = BottomBarEntry.RelayGroup(tag.groupId, tag.relayUrl)
+        val display = rememberGroupEntryDisplay(entry, accountViewModel, subscribe = false) ?: return@forEach
+        AvailableRow(
+            leading = { GroupEntryAvatar(display, 30.dp, accountViewModel) },
+            label = display.label,
+            pinned = entry.stableKey in pinnedKeys,
+            onToggle = { onTogglePin(entry) },
+            indentLevel = 2,
+        )
+    }
+}
+
+/**
+ * One Concord community in the picker: the community "server" row (level 1 — pin the whole community,
+ * opening its channel list) followed by each folded channel nested at level 2. Channels come from the
+ * community session's folded Control Plane; before it folds (or if its relays are dead) the list is
+ * empty and only the community itself can be pinned.
+ */
+@Composable
+private fun ConcordServerPickerGroup(
+    community: ConcordCommunityListEntry,
+    pinnedKeys: Set<String>,
+    accountViewModel: AccountViewModel,
+    onTogglePin: (BottomBarEntry) -> Unit,
+) {
+    val serverEntry = remember(community.id, community.relays) { BottomBarEntry.Concord(community.id, community.relays) }
+    val serverDisplay = rememberGroupEntryDisplay(serverEntry, accountViewModel, subscribe = false)
+    AvailableRow(
+        leading = {
+            if (serverDisplay != null) {
+                GroupEntryAvatar(serverDisplay, 34.dp, accountViewModel)
+            } else {
+                LeadingGlyph(MaterialSymbols.Group)
+            }
+        },
+        label = serverDisplay?.label ?: community.name.ifBlank { community.id.take(8) },
+        pinned = serverEntry.stableKey in pinnedKeys,
+        onToggle = { onTogglePin(serverEntry) },
+        indentLevel = 1,
+    )
+
+    val account = accountViewModel.account
+    val revision by account.concordSessions.revision.collectAsStateWithLifecycle()
+    val session = remember(community.id, revision) { account.concordSessions.sessionFor(community.id) }
+    val state by (session?.state ?: remember { MutableStateFlow(null) }).collectAsStateWithLifecycle()
+
+    val channels =
+        remember(state) {
+            state
+                ?.channels
+                ?.values
+                ?.toList()
+                .orEmpty()
+        }
+    channels.forEach { channel ->
+        val entry = BottomBarEntry.ConcordChannel(community.id, channel.channelIdHex, community.relays)
+        val def = channel.definition
+        val icon =
+            when {
+                def.voice -> MaterialSymbols.Mic
+                def.private -> MaterialSymbols.Lock
+                else -> MaterialSymbols.Tag
+            }
+        AvailableRow(
+            leading = { LeadingGlyph(icon) },
+            label = def.name.ifBlank { channel.channelIdHex.take(8) },
+            pinned = entry.stableKey in pinnedKeys,
+            onToggle = { onTogglePin(entry) },
+            indentLevel = 2,
         )
     }
 }
@@ -628,20 +755,32 @@ private fun GroupChildList(
 // Rows & shared bits
 // ------------------------------------------------------------------------------------------------
 
+/**
+ * Start padding per nesting depth: 0 = a top-level catalog row, 1 = an item under an expandable
+ * category (a favorite, or a relay/community "server" row), 2 = a room nested under its server (a
+ * NIP-29 group under its relay, or a Concord channel under its community).
+ */
+private fun indentPadding(level: Int) =
+    when (level) {
+        0 -> 13.dp
+        1 -> 24.dp
+        else -> 40.dp
+    }
+
 @Composable
 private fun AvailableRow(
     leading: @Composable () -> Unit,
     label: String,
     pinned: Boolean,
     onToggle: () -> Unit,
-    indent: Boolean = false,
+    indentLevel: Int = 0,
 ) {
     Row(
         modifier =
             Modifier
                 .fillMaxWidth()
                 .clickable(onClick = onToggle)
-                .padding(start = if (indent) 24.dp else 13.dp, end = 13.dp, top = 7.dp, bottom = 7.dp),
+                .padding(start = indentPadding(indentLevel), end = 13.dp, top = 7.dp, bottom = 7.dp),
         verticalAlignment = Alignment.CenterVertically,
         horizontalArrangement = Arrangement.spacedBy(12.dp),
     ) {
@@ -773,12 +912,15 @@ private fun SectionHeader(title: String) {
 }
 
 @Composable
-private fun EmptyChildHint(textRes: Int) {
+private fun EmptyChildHint(
+    textRes: Int,
+    indentLevel: Int = 1,
+) {
     Text(
         text = stringRes(textRes),
         style = MaterialTheme.typography.bodySmall,
         color = MaterialTheme.colorScheme.onSurfaceVariant,
-        modifier = Modifier.padding(start = 24.dp, end = 13.dp, top = 6.dp, bottom = 6.dp),
+        modifier = Modifier.padding(start = indentPadding(indentLevel), end = 13.dp, top = 6.dp, bottom = 6.dp),
     )
 }
 
@@ -835,7 +977,9 @@ private fun rememberPinnedVisual(
         }
         is BottomBarEntry.PublicChat,
         is BottomBarEntry.RelayGroup,
+        is BottomBarEntry.RelayServer,
         is BottomBarEntry.Concord,
+        is BottomBarEntry.ConcordChannel,
         is BottomBarEntry.Geohash,
         -> {
             // Read-only: the settings list resolves from cache; the live bar owns the subscription.

amethyst/src/test/java/com/vitorpamplona/amethyst/navigation/BottomBarEntrySerializationTest.kt

@@ -40,7 +40,9 @@ class BottomBarEntrySerializationTest {
             BottomBarEntry.Favorite("url:https://example.com"),
             BottomBarEntry.PublicChat("25e5c82273a271cb1a840d0060391a0bf4965cafeb029d5ab55350b418953fbb"),
             BottomBarEntry.RelayGroup("abcd1234", "wss://groups.example.com"),
+            BottomBarEntry.RelayServer("wss://groups.example.com"),
             BottomBarEntry.Concord("f".repeat(64), listOf("wss://relay.ditto.pub", "wss://community.example.com")),
+            BottomBarEntry.ConcordChannel("f".repeat(64), "a".repeat(32), listOf("wss://relay.ditto.pub")),
         )
 
     @Test
@@ -50,7 +52,11 @@ class BottomBarEntrySerializationTest {
         assertTrue("expected stable discriminators, got: $json", json.contains("\"builtIn\"") && json.contains("\"favorite\""))
         assertTrue(
             "expected group discriminators, got: $json",
-            json.contains("\"publicChat\"") && json.contains("\"relayGroup\"") && json.contains("\"concord\""),
+            json.contains("\"publicChat\"") &&
+                json.contains("\"relayGroup\"") &&
+                json.contains("\"relayServer\"") &&
+                json.contains("\"concord\"") &&
+                json.contains("\"concordChannel\""),
         )
         assertEquals(sample, JsonMapper.fromJson<List<BottomBarEntry>>(json))
     }