feat: add support for reaction (#52)

Reviewed-on: https://git.reya.su/reya/coop-mobile/pulls/52

composeApp/src/androidMain/kotlin/su/reya/coop/screens/chat/ChatMessage.kt

@@ -5,9 +5,13 @@ import androidx.compose.foundation.interaction.MutableInteractionSource
 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.fillMaxWidth
+import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.widthIn
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
@@ -34,6 +38,7 @@ import androidx.compose.ui.text.buildAnnotatedString
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextDecoration
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
 import coil3.compose.AsyncImage
 import rust.nostr.sdk.EventId
 import rust.nostr.sdk.PublicKey
@@ -46,6 +51,13 @@ import su.reya.coop.formatAsTime
 import su.reya.coop.isImageUrl
 import su.reya.coop.removeImageUrls
 
+@Immutable
+data class ReactionGroup(
+    val emoji: String,
+    val authors: List<PublicKey>,
+    val containsMe: Boolean
+)
+
 @Immutable
 data class MessageModel(
     val id: EventId,
@@ -54,15 +66,20 @@ data class MessageModel(
     val images: List<String>,
     val timestamp: String,
     val isMine: Boolean,
-    val replyEventIds: List<EventId>
+    val replyEventIds: List<EventId>,
+    val reactions: List<ReactionGroup> = emptyList()
 )
 
 @Composable
-fun rememberMessageModel(event: UnsignedEvent, currentUser: PublicKey? = null): MessageModel {
+fun rememberMessageModel(
+    event: UnsignedEvent,
+    reactions: List<UnsignedEvent> = emptyList(),
+    currentUser: PublicKey? = null
+): MessageModel {
     val settings = LocalSettings.current
     val isMobileData = LocalConnectivity.current
 
-    return remember(event, currentUser, settings, isMobileData) {
+    return remember(event, reactions, currentUser, settings, isMobileData) {
         val id = event.ensureId().id()!!
         val isMine = currentUser == event.author()
         val content = event.content()
@@ -104,6 +121,16 @@ fun rememberMessageModel(event: UnsignedEvent, currentUser: PublicKey? = null):
             append(cleanedContent.substring(lastIndex))
         }
 
+        val groupedReactions = reactions.groupBy { it.content() }
+            .map { (emoji, events) ->
+                val authors = events.map { it.author() }
+                ReactionGroup(
+                    emoji = emoji,
+                    authors = authors,
+                    containsMe = authors.any { it == currentUser }
+                )
+            }
+
         MessageModel(
             id = id,
             author = event.author(),
@@ -111,7 +138,8 @@ fun rememberMessageModel(event: UnsignedEvent, currentUser: PublicKey? = null):
             images = images,
             timestamp = event.createdAt().formatAsTime(),
             isMine = isMine,
-            replyEventIds = replyEventIds
+            replyEventIds = replyEventIds,
+            reactions = groupedReactions
         )
     }
 }
@@ -157,6 +185,15 @@ fun ChatMessage(
             ),
             horizontalAlignment = if (model.isMine) Alignment.End else Alignment.Start,
             verticalArrangement = Arrangement.spacedBy(4.dp)
+        ) {
+            Box(contentAlignment = Alignment.BottomEnd) {
+                Column(
+                    modifier = Modifier.padding(
+                        bottom = if (model.reactions.isNotEmpty()) 4.dp else 0.dp,
+                        end = if (model.reactions.isNotEmpty() && !model.isMine) 8.dp else 0.dp
+                    ),
+                    horizontalAlignment = if (model.isMine) Alignment.End else Alignment.Start,
+                    verticalArrangement = Arrangement.spacedBy(4.dp)
                 ) {
                     if (model.annotatedContent.isNotBlank()) {
                         Surface(
@@ -188,16 +225,69 @@ fun ChatMessage(
                             )
                         }
                     }
+                }
+
+                if (model.reactions.isNotEmpty()) {
+                    MessageReactions(
+                        reactions = model.reactions,
+                        modifier = Modifier.offset(y = 12.dp)
+                    )
+                }
+            }
+
             if (isMessageClicked) {
                 Text(
                     text = model.timestamp,
                     style = MaterialTheme.typography.labelSmall,
                     color = MaterialTheme.colorScheme.outline,
-                    modifier = Modifier.align(
+                    modifier = Modifier.padding(top = if (model.reactions.isNotEmpty()) 8.dp else 0.dp)
-                        if (model.isMine) Alignment.End else Alignment.Start
-                    )
                 )
             }
         }
     }
 }
+
+@Composable
+private fun MessageReactions(
+    reactions: List<ReactionGroup>,
+    modifier: Modifier = Modifier
+) {
+    val totalCount = reactions.sumOf { it.authors.size }
+    val displayEmojis = reactions.take(3).map { it.emoji }
+
+    Row(
+        modifier = modifier,
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(4.dp)
+    ) {
+        displayEmojis.forEach { emoji ->
+            Surface(
+                modifier = Modifier.size(24.dp),
+                color = MaterialTheme.colorScheme.surface,
+                shape = CircleShape,
+            ) {
+                Box(contentAlignment = Alignment.Center) {
+                    Text(
+                        text = emoji,
+                        fontSize = 12.sp,
+                    )
+                }
+            }
+        }
+        if (totalCount > 2) {
+            Surface(
+                modifier = Modifier.size(24.dp),
+                color = MaterialTheme.colorScheme.surface,
+                shape = CircleShape,
+            ) {
+                Box(contentAlignment = Alignment.Center) {
+                    Text(
+                        text = totalCount.toString(),
+                        style = MaterialTheme.typography.labelSmall,
+                        fontSize = 10.sp,
+                    )
+                }
+            }
+        }
+    }
+}

composeApp/src/androidMain/kotlin/su/reya/coop/screens/chat/ChatScreen.kt

@@ -80,6 +80,7 @@ import androidx.compose.ui.platform.LocalWindowInfo
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import coop.composeapp.generated.resources.Res
 import coop.composeapp.generated.resources.ic_arrow_back
@@ -91,6 +92,7 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.jetbrains.compose.resources.painterResource
 import rust.nostr.sdk.EventId
+import rust.nostr.sdk.KindStandard
 import rust.nostr.sdk.UnsignedEvent
 import su.reya.coop.LocalNavigator
 import su.reya.coop.LocalProfileCache
@@ -144,10 +146,21 @@ fun ChatScreen(
     val loading = viewModel.loading
     val newOtherMessages = viewModel.newOtherMessages
     val requireScreening = viewModel.requireScreening
-    val messages = viewModel.messages
+    val allEvents = viewModel.messages
+
+    val displayMessages by remember {
+        derivedStateOf { allEvents.filter { it.kind().asStd() != KindStandard.REACTION } }
+    }
+
+    val reactionsByMessage by remember {
+        derivedStateOf {
+            allEvents.filter { it.kind().asStd() == KindStandard.REACTION }
+                .groupBy { it.tags().eventIds().firstOrNull() }
+        }
+    }
 
     val groupedMessages =
-        remember { derivedStateOf { messages.groupBy { it.createdAt().formatAsGroup() } } }
+        remember { derivedStateOf { displayMessages.groupBy { it.createdAt().formatAsGroup() } } }
 
     val roomState by remember(id, currentUser?.publicKey) {
         (room as Room).uiStateFlow(profileCache, currentUser?.publicKey)
@@ -170,7 +183,7 @@ fun ChatScreen(
 
                 for (group in groupedMessages.value) {
                     val msgInGroup = group.value
-                    val idx = msgInGroup.indexOfFirst { it.id() == eventId }
+                    val idx = msgInGroup.indexOfFirst { it.ensureId().id() == eventId }
                     if (idx != -1) {
                         targetIndex = currentIndex + idx
                         break
@@ -214,8 +227,8 @@ fun ChatScreen(
             }
         }
 
-    LaunchedEffect(messages.size) {
+    LaunchedEffect(allEvents.size) {
-        if (messages.isNotEmpty()) {
+        if (displayMessages.isNotEmpty()) {
             listState.animateScrollToItem(0)
         }
     }
@@ -293,7 +306,7 @@ fun ChatScreen(
                             room?.let { ScreenerCard(accountViewModel, it) }
                         }
 
-                        when (messages.isNotEmpty()) {
+                        when (displayMessages.isNotEmpty()) {
                             true -> {
                                 LazyColumn(
                                     modifier = Modifier
@@ -308,14 +321,15 @@ fun ChatScreen(
                                             items = messagesInGroup,
                                             key = { it.ensureId().id()?.toHex()!! }
                                         ) { event ->
+                                            val msgReactions = reactionsByMessage[event.id()] ?: emptyList()
                                             val model =
-                                                rememberMessageModel(event, currentUser?.publicKey)
+                                                rememberMessageModel(event, msgReactions, currentUser?.publicKey)
 
                                             val replyPreview =
-                                                remember(model.replyEventIds, messages.size) {
+                                                remember(model.replyEventIds, displayMessages.size) {
                                                     model.replyEventIds.firstOrNull()
                                                         ?.let { replyId ->
-                                                            messages.find { it.id() == replyId }
+                                                            displayMessages.find { it.ensureId().id() == replyId }
                                                         }
                                                 }
 
@@ -464,14 +478,11 @@ fun ChatScreen(
             val (model, bounds) = selectedMessage ?: return@AnimatedVisibility
 
             val density = LocalDensity.current
-            val windowInfo = LocalWindowInfo.current
-            val windowHeight = windowInfo.containerSize.height
             val scrollState = rememberScrollState()
 
             var menuHeight by remember { mutableFloatStateOf(0f) }
-            val spacing = with(density) { 12.dp.toPx() }
+            var toolbarHeight by remember { mutableFloatStateOf(0f) }
-            val showAbove =
+            val spacing = with(density) { 6.dp.toPx() }
-                (windowHeight - bounds.bottom) < (menuHeight + spacing) && bounds.top > (menuHeight + spacing)
 
             Box(
                 modifier = Modifier
@@ -480,11 +491,30 @@ fun ChatScreen(
                     .clickable { selectedMessage = null }
                     .verticalScroll(scrollState),
             ) {
-                val totalExtraHeight = if (menuHeight > 0) menuHeight + spacing else 300f
+                val totalExtraHeight = (if (menuHeight > 0) menuHeight + spacing else 300f) +
+                        (if (toolbarHeight > 0) toolbarHeight + spacing else 100f)
                 val contentBottom = with(density) { (bounds.bottom + totalExtraHeight).toDp() }
 
                 Spacer(modifier = Modifier.height(contentBottom + 200.dp))
 
+                // Reaction Toolbar (Above)
+                Box(
+                    modifier = Modifier
+                        .offset { IntOffset(0, (bounds.top - toolbarHeight - spacing).toInt().coerceAtLeast(0)) }
+                        .onGloballyPositioned { toolbarHeight = it.size.height.toFloat() }
+                        .fillMaxWidth()
+                        .padding(horizontal = 16.dp),
+                    contentAlignment = if (model.isMine) Alignment.CenterEnd else Alignment.CenterStart
+                ) {
+                    ReactionToolbar(
+                        onReaction = { reaction ->
+                            viewModel.sendReaction(model.id, reaction)
+                            selectedMessage = null
+                        }
+                    )
+                }
+
+                // Message Preview
                 ChatMessage(
                     model = model,
                     modifier = Modifier
@@ -492,21 +522,17 @@ fun ChatScreen(
                         .padding(horizontal = 16.dp)
                 )
 
-                val menuOffset = if (showAbove) {
+                // Action Menu (Below)
-                    bounds.top - menuHeight - spacing
-                } else {
-                    bounds.bottom + spacing
-                }
-
                 Box(
                     modifier = Modifier
-                        .offset { IntOffset(0, menuOffset.toInt().coerceAtLeast(0)) }
+                        .offset { IntOffset(0, (bounds.bottom + spacing).toInt()) }
                         .onGloballyPositioned { menuHeight = it.size.height.toFloat() }
                         .fillMaxWidth()
                         .padding(horizontal = 16.dp),
                     contentAlignment = if (model.isMine) Alignment.CenterEnd else Alignment.CenterStart
                 ) {
-                    ContextMenu { action ->
+                    ContextMenu(
+                        onAction = { action ->
                             when (action) {
                                 "Copy" -> {
                                     scope.launch {
@@ -524,6 +550,7 @@ fun ChatScreen(
                             }
                             selectedMessage = null
                         }
+                    )
                 }
             }
         }
@@ -622,9 +649,41 @@ private fun ReplyPreview(
     }
 }
 
+@Composable
+private fun ReactionToolbar(
+    onReaction: (String) -> Unit
+) {
+    val reactionEmojis = listOf("👍", "❤️", "😂", "😮", "😢", "😡", "🎉")
+
+    Surface(
+        color = MaterialTheme.colorScheme.surfaceContainerHigh,
+        shape = RoundedCornerShape(24.dp),
+        shadowElevation = 1.dp
+    ) {
+        Row(
+            modifier = Modifier
+                .padding(horizontal = 12.dp, vertical = 8.dp),
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            reactionEmojis.forEach { emoji ->
+                Text(
+                    text = emoji,
+                    modifier = Modifier
+                        .clickable { onReaction(emoji) }
+                        .padding(4.dp),
+                    fontSize = 24.sp
+                )
+            }
+        }
+    }
+}
+
 @OptIn(ExperimentalMaterial3ExpressiveApi::class)
 @Composable
-private fun ContextMenu(onAction: (String) -> Unit) {
+private fun ContextMenu(
+    onAction: (String) -> Unit
+) {
     val menuItems = listOf(
         "Copy" to Res.drawable.ic_copy,
         "Reply" to Res.drawable.ic_reply
@@ -633,6 +692,8 @@ private fun ContextMenu(onAction: (String) -> Unit) {
     DropdownMenuGroup(
         shapes = MenuDefaults.groupShape(1, 1),
         containerColor = MenuDefaults.groupVibrantContainerColor,
+        tonalElevation = 1.dp,
+        shadowElevation = 1.dp,
         modifier = Modifier.width(220.dp)
     ) {
         val itemCount = menuItems.size

shared/src/commonMain/kotlin/su/reya/coop/nostr/Messaging.kt

@@ -144,12 +144,15 @@ class MessageManager(private val nostr: Nostr) {
 
     private suspend fun setCachedRumor(giftId: EventId, rumor: UnsignedEvent) {
         try {
+            val isReaction = rumor.kind().asStd() == KindStandard.REACTION
+            val kValue = if (isReaction) "reaction" else "dm"
+
             // Construct reference tags
             val tags = listOf(
                 Tag.identifier(giftId.toHex()),
                 Tag.publicKey(rumor.author()),
                 Tag.custom("r", listOf(rumor.roomId().toString())),
-                Tag.custom("k", listOf("14"))
+                Tag.custom("k", listOf("14", kValue))
             )
 
             // Set event kind
@@ -176,12 +179,13 @@ class MessageManager(private val nostr: Nostr) {
             val kind = Kind.fromStd(KindStandard.APPLICATION_SPECIFIC_DATA)
             val kTag = SingleLetterTag.lowercase(Alphabet.K)
 
-            // Get all DM events
+            // Get all rumors (DMs and Reactions)
-            val filter = Filter().kind(kind).customTags(kTag, listOf("14", "dm"))
+            val filter = Filter().kind(kind).customTags(kTag, listOf("14", "dm", "reaction"))
             val events = client?.database()?.query(filter)?.toVec() ?: return null
 
             // Collect rooms
             val roomsMap: MutableMap<Long, Room> = mutableMapOf()
+            val lastDmTimestampMap: MutableMap<Long, ULong> = mutableMapOf()
 
             events
                 .map { UnsignedEvent.fromJson(it.content()) }
@@ -189,18 +193,41 @@ class MessageManager(private val nostr: Nostr) {
                 .forEach { rumor ->
                     val id = rumor.roomId()
                     val isFromMe = rumor.author() == userPubkey
+                    val isReaction = rumor.kind().asStd() == KindStandard.REACTION
                     val existing = roomsMap[id]
                     val createdAt = rumor.createdAt()
 
-                    // If the room is new or the current rumor is newer than the existing one
+                    if (existing == null) {
-                    if (existing == null || createdAt.asSecs() > existing.createdAt.asSecs()) {
-                        // A room is "Ongoing" if it was already marked as such or if the current rumor is from the user
-                        val isOngoing = (existing?.kind == RoomKind.Ongoing) || isFromMe
                         val room = Room.new(rumor = rumor, userPubkey = userPubkey, id = id)
-                        roomsMap[id] = if (isOngoing) room.copy(kind = RoomKind.Ongoing) else room
+                        // If the first event we see is a reaction, don't use it as lastMessage
-                    } else if (isFromMe && existing.kind != RoomKind.Ongoing) {
+                        roomsMap[id] = if (isReaction) {
-                        // If it's an older rumor but sent by the user, mark the room as Ongoing
+                            room.copy(lastMessage = null)
-                        roomsMap[id] = existing.copy(kind = RoomKind.Ongoing)
+                        } else {
+                            lastDmTimestampMap[id] = createdAt.asSecs()
+                            room
+                        }
+                        if (isFromMe) {
+                            roomsMap[id] = roomsMap[id]!!.copy(kind = RoomKind.Ongoing)
+                        }
+                    } else {
+                        // Update the overall room timestamp (for sorting) if this event is newer
+                        if (createdAt.asSecs() > existing.createdAt.asSecs()) {
+                            roomsMap[id] = roomsMap[id]!!.copy(createdAt = createdAt)
+                        }
+
+                        // Update the last message content if this is a DM and it's newer than the last DM we've seen
+                        if (!isReaction) {
+                            val lastDmTs = lastDmTimestampMap[id] ?: 0uL
+                            if (createdAt.asSecs() >= lastDmTs) {
+                                lastDmTimestampMap[id] = createdAt.asSecs()
+                                roomsMap[id] = roomsMap[id]!!.copy(lastMessage = rumor.content())
+                            }
+                        }
+
+                        // If any event is from the user, mark the room as Ongoing
+                        if (isFromMe && roomsMap[id]?.kind != RoomKind.Ongoing) {
+                            roomsMap[id] = roomsMap[id]!!.copy(kind = RoomKind.Ongoing)
+                        }
                     }
                 }
 
@@ -348,4 +375,64 @@ class MessageManager(private val nostr: Nostr) {
             throw IllegalStateException("Failed to send message: ${e.message}", e)
         }
     }
+
+    suspend fun sendReaction(
+        to: Set<PublicKey>,
+        targetEventId: EventId,
+        reaction: String,
+        onRumorCreated: ((UnsignedEvent) -> Unit)? = null,
+    ) {
+        try {
+            val currentUser =
+                signer.getPublicKeyAsync() ?: throw IllegalStateException("User not signed in")
+
+            val tags = mutableListOf<Tag>()
+            tags.add(Tag.event(targetEventId))
+            // Add public key tags for each recipient (including me) to ensure roomId consistency
+            to.forEach { pubkey ->
+                tags.add(Tag.publicKey(pubkey))
+            }
+
+            for (receiver in setOf(currentUser) + to) {
+                // Construct the rumor event
+                val rumor = EventBuilder(Kind.fromStd(KindStandard.REACTION), reaction)
+                    .tags(tags)
+                    .finalizeUnsigned(currentUser)
+                    .ensureId()
+
+                // Emit the rumor to the chat screen
+                if (receiver == currentUser) {
+                    onRumorCreated?.invoke(rumor)
+                }
+
+                // Construct the gift wrap event
+                val gift = nip59MakeGiftWrapAsync(
+                    signer = signer,
+                    receiverPubkey = receiver,
+                    rumor = rumor,
+                    extraTags = listOf(
+                        Tag.custom("k", listOf("14"))
+                    )
+                )
+
+                // Send the event to receiver's NIP-17 relays
+                val output = client?.sendEvent(
+                    event = gift,
+                    target = SendEventTarget.toNip17(),
+                    ackPolicy = AckPolicy.none(),
+                    authenticationTimeout = Duration.parse("2s")
+                )
+
+                if (output != null) {
+                    // Keep track of rumor IDs
+                    val id = rumor.id() ?: throw IllegalStateException("Rumor ID is null")
+                    rumorMap[id] = output.id
+                }
+            }
+        } catch (e: CancellationException) {
+            throw e
+        } catch (e: Exception) {
+            throw IllegalStateException("Failed to send reaction: ${e.message}", e)
+        }
+    }
 }

shared/src/commonMain/kotlin/su/reya/coop/repository/ChatRepository.kt

@@ -241,8 +241,29 @@ class ChatRepository(
         }
     }
 
+    fun sendReaction(roomId: Long, targetEventId: EventId, reaction: String) {
+        scope.launch(defaultDispatcher) {
+            try {
+                val room = getChatRoom(roomId) ?: throw IllegalArgumentException("Room not found")
+                nostr.messages.sendReaction(
+                    to = room.members,
+                    targetEventId = targetEventId,
+                    reaction = reaction,
+                    onRumorCreated = {
+                        scope.launch(defaultDispatcher) {
+                            updateRoomState(it, roomId)
+                        }
+                    },
+                )
+            } catch (e: Exception) {
+                showError("Error: ${e.message}")
+            }
+        }
+    }
+
     private suspend fun updateRoomState(event: UnsignedEvent, roomId: Long = event.roomId()) {
         val currentUser = nostr.signer.getPublicKeyAsync() ?: return
+        val isReaction = event.kind().asStd() == KindStandard.REACTION
 
         _state.update { currentState ->
             val rooms = currentState.rooms.toMutableMap()
@@ -256,22 +277,24 @@ class ChatRepository(
                 // New room discovery
                 val newRoom = Room.new(event, currentUser, roomId).copy(
                     kind = newKind,
-                    unreadCount = if (isFromMe) 0 else 1
+                    unreadCount = if (isFromMe || isReaction) 0 else 1,
+                    lastMessage = if (isReaction) null else event.content()
                 )
                 rooms[newRoom.id] = newRoom
             } else if (event.createdAt().asSecs() >= existingRoom.createdAt.asSecs()) {
-                // Only update preview if message is newer (handles sync/late arrivals)
+                // Update timestamp for any newer event (DM or Reaction)
+                // But only update preview if it's a DM
                 rooms[roomId] = existingRoom.copy(
-                    lastMessage = event.content(),
+                    lastMessage = if (isReaction) existingRoom.lastMessage else event.content(),
                     createdAt = event.createdAt(),
                     kind = newKind,
-                    unreadCount = if (isFromMe) existingRoom.unreadCount else existingRoom.unreadCount + 1
+                    unreadCount = if (isFromMe || isReaction) existingRoom.unreadCount else existingRoom.unreadCount + 1
                 )
             } else if (isFromMe && existingRoom.kind != RoomKind.Ongoing) {
-                // Even if it's an older message, if it's from me, the room is ongoing
+                // Even if it's an older message or reaction, if it's from me, the room is ongoing
                 rooms[roomId] = existingRoom.copy(kind = RoomKind.Ongoing)
             } else {
-                // Don't update the room list state for older messages
+                // Don't update the room list state for older messages or reactions that don't change preview
                 return@update currentState
             }
             currentState.copy(rooms = rooms)

shared/src/commonMain/kotlin/su/reya/coop/viewmodel/ChatScreenViewModel.kt

@@ -74,4 +74,8 @@ class ChatScreenViewModel(
     fun sendFileMessage(file: ByteArray?, type: String?) {
         chatRepository.sendFileMessage(id, file, type)
     }
+
+    fun sendReaction(targetEventId: EventId, reaction: String) {
+        chatRepository.sendReaction(id, targetEventId, reaction)
+    }
 }