refactor(chat): drive the reaction sheets from ChatViewModel state

apps/flipcash/core/src/main/kotlin/com/flipcash/app/core/chat/ChatStep.kt

@@ -136,5 +136,5 @@ sealed interface ChatStep : FlowStep, Parcelable {
      */
     @Parcelize
     @Serializable
-    data class Reactors(val messageId: Long) : ChatStep, Sheet, HalfSheet
+    data class Reactors(val chatId: ChatId, val messageId: Long) : ChatStep, Sheet, HalfSheet
 }

apps/flipcash/features/messenger/src/main/kotlin/com/flipcash/app/messenger/ChatFlowScreen.kt

@@ -6,7 +6,6 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.hilt.lifecycle.viewmodel.compose.hiltViewModel
@@ -28,8 +27,10 @@ import com.flipcash.app.messenger.internal.GroupInviteViewModel
 import com.flipcash.app.messenger.internal.StartSendCashOnceReady
 import com.flipcash.app.messenger.internal.screens.GroupInviteSheet
 import com.flipcash.app.messenger.internal.screens.MessengerScreen
+import com.flipcash.app.messenger.internal.screens.EmojiPickerViewModel
 import com.flipcash.app.messenger.internal.screens.ReactionPickerSheet
 import com.flipcash.app.messenger.internal.screens.ReactorsSheet
+import com.flipcash.app.messenger.internal.screens.ReactorsViewModel
 import com.flipcash.app.messenger.internal.screens.cash.ChatAmountEntryContent
 import com.flipcash.app.messenger.internal.screens.cash.ChatInitPaymentSheet
 import com.flipcash.app.messenger.internal.screens.profile.ChatProfileScreen
@@ -39,6 +40,7 @@ import com.flipcash.app.messenger.internal.screens.profile.edit.EditGroupNameScr
 import com.flipcash.app.messenger.internal.screens.profile.edit.EditGroupPictureScreen
 import com.flipcash.app.messenger.internal.screens.profile.edit.EditGroupScreen
 import com.getcode.navigation.annotatedEntry
+import com.flipcash.services.models.chat.ChatId
 import com.getcode.navigation.core.LocalCodeNavigator
 import com.getcode.navigation.flow.FlowHost
 import com.getcode.navigation.flow.flowSharedViewModel
@@ -57,7 +59,6 @@ import kotlinx.coroutines.flow.filterIsInstance
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
-import kotlinx.coroutines.launch
 
 @Composable
 fun ChatFlowScreen(
@@ -128,7 +129,7 @@ private fun chatEntryProvider(
         FlowReactionPickerScreen(step.messageId)
     }
     annotatedEntry<ChatStep.Reactors> { step ->
-        FlowReactorsScreen(step.messageId)
+        FlowReactorsScreen(step.chatId, step.messageId)
     }
 }
 
@@ -354,16 +355,23 @@ private fun FlowEditGroupPictureScreen() {
     EditGroupPictureScreen(flowSharedViewModel<ChatViewModel>())
 }
 
-/** The full emoji picker for [messageId] — a tap on any emoji toggles it and dismisses. */
+/**
+ * The full emoji picker for [messageId] — a tap on any emoji toggles it and dismisses. The search
+ * lives in the entry's own [EmojiPickerViewModel]; only the toggle goes to the chat.
+ */
 @Composable
 private fun FlowReactionPickerScreen(messageId: Long) {
-    val viewModel = flowSharedViewModel<ChatViewModel>()
+    val chatViewModel = flowSharedViewModel<ChatViewModel>()
+    val viewModel = hiltViewModel<EmojiPickerViewModel>()
     val dismissSheet = LocalBottomSheetDismissDispatcher.current
+    val state by viewModel.stateFlow.collectAsStateWithLifecycle()
 
     ReactionPickerSheet(
-        loadSections = { query -> viewModel.emojiPickerSections(query) },
+        searchState = state.searchFieldState,
+        sections = state.sections,
+        loaded = state.loaded,
         onSelected = { emoji ->
-            viewModel.dispatchEvent(
+            chatViewModel.dispatchEvent(
                 ChatViewModel.Event.ToggleReaction(messageId, emoji, clearsSelection = true)
             )
             dismissSheet()
@@ -373,50 +381,29 @@ private fun FlowReactionPickerScreen(messageId: Long) {
 }
 
 /**
- * Who reacted to [messageId], and with what. Tapping a row dismisses this sheet first, then opens
- * the reactor's profile — [ChatViewModel.reactorParticipant] resolves a [ChatParticipant] even for
- * a reactor absent from `senderProfiles`.
+ * Who reacted to [messageId], and with what, from the entry's own [ReactorsViewModel]. Tapping a
+ * named row dismisses this sheet, then opens that person's profile on the chat.
  */
 @Composable
-private fun FlowReactorsScreen(messageId: Long) {
-    val viewModel = flowSharedViewModel<ChatViewModel>()
+private fun FlowReactorsScreen(chatId: ChatId, messageId: Long) {
+    val viewModel = hiltViewModel<ReactorsViewModel>()
     val navigator = LocalCodeNavigator.current
     val dismissSheet = LocalBottomSheetDismissDispatcher.current
-    val coroutineScope = rememberCoroutineScope()
-
-    val pills by remember(viewModel, messageId) { viewModel.reactionPills(messageId) }
-        .collectAsStateWithLifecycle(initialValue = emptyList())
-    val rows by remember(viewModel, messageId) { viewModel.reactorsRows(messageId) }
-        .collectAsStateWithLifecycle(initialValue = emptyList())
-    val loading by remember(viewModel, messageId) { viewModel.reactorsLoading(messageId) }
-        .collectAsStateWithLifecycle(initialValue = true)
-
-    // OpenReactors already started the fetch; this catches reactions that change while the sheet
-    // is up. Collected here rather than off `pills` above, whose empty initial value would read as
-    // "every reaction removed". The first emission is a no-op unless the pills moved since the
-    // long-press.
-    LaunchedEffect(viewModel, messageId) {
-        viewModel.reactionPills(messageId).collect { viewModel.syncReactors(messageId, it) }
+    val state by viewModel.stateFlow.collectAsStateWithLifecycle()
+    LaunchedEffect(viewModel, chatId, messageId) {
+        viewModel.dispatchEvent(ReactorsViewModel.Event.Open(chatId, messageId))
     }
 
     ReactorsSheet(
-        pills = pills,
-        rows = rows,
-        loading = loading,
-        hasMore = { viewModel.reactorsHasMore(messageId) },
-        resolveDisplay = { userId -> viewModel.reactorDisplay(userId) },
-        onLoadMore = { viewModel.loadMoreReactors(messageId) },
+        pills = state.pills,
+        rows = state.rows,
+        loading = state.loading,
+        hasMore = state.hasMore,
+        onLoadMore = { viewModel.dispatchEvent(ReactorsViewModel.Event.LoadMore) },
         onOpenProfile = { userId ->
-            // Dismiss first (decision: profile opens after the sheet closes), then resolve the
-            // participant — a row is only tappable once reactorDisplay has already resolved it, so
-            // this is a re-read of state already on screen rather than a fresh network round trip
-            // in the common case; reactorParticipant only reaches further (member roster, cached
-            // profile store) for a reactor absent from senderProfiles.
+            val profile = state.rows.firstOrNull { it.userId == userId }?.display?.profile
             dismissSheet()
-            coroutineScope.launch {
-                val participant = viewModel.reactorParticipant(userId) ?: return@launch
-                navigator.push(ChatStep.Profile(contact = participant))
-            }
+            if (profile != null) navigator.push(ChatStep.Profile(contact = ChatParticipant.TipUser(userId, profile)))
         },
         onDismiss = dismissSheet,
     )