From 093ca6df3be9a909bdaaa21e5a1dc26b40c17035 Mon Sep 17 00:00:00 2001
From: Adam Brown <adampsbrown@gmail.com>
Date: Sat, 5 Nov 2022 10:48:47 +0000
Subject: [PATCH] add 6 args flow combine

---
 .../dapk/st/core/extensions/FlowExtensions.kt | 23 +++++++++++++++++++
 .../app/dapk/st/engine/DirectoryUseCase.kt    | 21 ++++++++---------
 2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/core/src/main/kotlin/app/dapk/st/core/extensions/FlowExtensions.kt b/core/src/main/kotlin/app/dapk/st/core/extensions/FlowExtensions.kt
index 967c5b5..919a808 100644
--- a/core/src/main/kotlin/app/dapk/st/core/extensions/FlowExtensions.kt
+++ b/core/src/main/kotlin/app/dapk/st/core/extensions/FlowExtensions.kt
@@ -20,3 +20,26 @@ suspend fun <T> Flow<T>.firstOrNull(count: Int, predicate: suspend (T) -> Boolea
 
     return result
 }
+
+inline fun <T1, T2, T3, T4, T5, T6, R> combine(
+    flow: Flow<T1>,
+    flow2: Flow<T2>,
+    flow3: Flow<T3>,
+    flow4: Flow<T4>,
+    flow5: Flow<T5>,
+    flow6: Flow<T6>,
+    crossinline transform: suspend (T1, T2, T3, T4, T5, T6) -> R
+): Flow<R> {
+    return kotlinx.coroutines.flow.combine(flow, flow2, flow3, flow4, flow5, flow6) { args: Array<*> ->
+        @Suppress("UNCHECKED_CAST")
+        transform(
+            args[0] as T1,
+            args[1] as T2,
+            args[2] as T3,
+            args[3] as T4,
+            args[4] as T5,
+            args[5] as T6,
+        )
+    }
+}
+
diff --git a/matrix-chat-engine/src/main/kotlin/app/dapk/st/engine/DirectoryUseCase.kt b/matrix-chat-engine/src/main/kotlin/app/dapk/st/engine/DirectoryUseCase.kt
index b8033cd..2543fbc 100644
--- a/matrix-chat-engine/src/main/kotlin/app/dapk/st/engine/DirectoryUseCase.kt
+++ b/matrix-chat-engine/src/main/kotlin/app/dapk/st/engine/DirectoryUseCase.kt
@@ -1,12 +1,16 @@
 package app.dapk.st.engine
 
+import app.dapk.st.core.extensions.combine
 import app.dapk.st.matrix.common.*
 import app.dapk.st.matrix.message.MessageService
 import app.dapk.st.matrix.room.RoomService
 import app.dapk.st.matrix.sync.RoomStore
 import app.dapk.st.matrix.sync.SyncService
 import app.dapk.st.matrix.sync.SyncService.SyncEvent.Typing
-import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flatMapConcat
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.map
 
 internal class DirectoryUseCase(
     private val syncService: SyncService,
@@ -17,14 +21,15 @@ internal class DirectoryUseCase(
 ) {
 
     fun state(): Flow<DirectoryState> {
-        return flow { emit(credentialsStore.credentials()!!.userId) }.flatMapMerge { userId ->
+        return flow { emit(credentialsStore.credentials()!!.userId) }.flatMapConcat { userId ->
             combine(
-                overviewDatasource(),
+                syncService.startSyncing(),
+                syncService.overview().map { it.map { it.engine() } },
                 messageService.localEchos(),
                 roomStore.observeUnreadCountById(),
                 syncService.events(),
                 roomStore.observeMuted(),
-            ) { overviewState, localEchos, unread, events, muted ->
+            ) { _, overviewState, localEchos, unread, events, muted ->
                 overviewState.mergeWithLocalEchos(localEchos, userId).map { roomOverview ->
                     DirectoryItem(
                         overview = roomOverview,
@@ -37,11 +42,6 @@ internal class DirectoryUseCase(
         }
     }
 
-    private fun overviewDatasource() = combine(
-        syncService.startSyncing(),
-        syncService.overview().map { it.map { it.engine() } }
-    ) { _, overview -> overview }.filterNotNull()
-
     private suspend fun OverviewState.mergeWithLocalEchos(localEchos: Map<RoomId, List<MessageService.LocalEcho>>, userId: UserId): OverviewState {
         return when {
             localEchos.isEmpty() -> this
@@ -80,6 +80,3 @@ internal class DirectoryUseCase(
     }
 
 }
-
-
-