Add mxid to autocomplete suggestion if more than one user in a room has the same displayname, closes #1823

improve performance of duplicate displayname finding

fix code formatting

move member autocomplete disambiguation to AutocompleteMemberPresenter and preserve original order

Add mxid to autocomplete suggestion if more than one user in a room has the same displayname, closes #1823

changelog.d/1823.bugfix

@@ -0,0 +1 @@
+- Add mxid to autocomplete suggestion if more than one user in a room has the same displayname

vector/src/main/java/im/vector/app/features/autocomplete/member/AutocompleteMemberPresenter.kt

@@ -71,6 +71,23 @@ class AutocompleteMemberPresenter @AssistedInject constructor(context: Context,
         val members = room.getRoomMembers(queryParams)
                 .asSequence()
                 .sortedBy { it.displayName }
+                .disambiguate()
         controller.setData(members.toList())
     }
 }
+
+private fun Sequence<RoomMemberSummary>.disambiguate(): Sequence<RoomMemberSummary> {
+    val displayNames = hashMapOf<String, Int>().also { map ->
+        for (item in this) {
+            item.displayName?.lowercase()?.also { displayName ->
+                map[displayName] = map.getOrPut(displayName, { 0 }) + 1
+            }
+        }
+    }
+
+    return map { roomMemberSummary ->
+        if (displayNames[roomMemberSummary.displayName?.lowercase()] ?: 0 > 1) {
+            roomMemberSummary.copy(displayName = roomMemberSummary.displayName + " " + roomMemberSummary.userId)
+        } else roomMemberSummary
+    }
+}