Sort message reactions by the number of choosers.

td/telegram/MessageReaction.cpp

@@ -276,6 +276,23 @@ void MessageReactions::update_from(const MessageReactions &old_reactions) {
   }
 }
 
+void MessageReactions::sort(const std::unordered_map<string, size_t> &active_reaction_pos) {
+  std::sort(reactions_.begin(), reactions_.end(), [&active_reaction_pos](const MessageReaction &lhs, const MessageReaction &rhs) {
+    if (lhs.get_choose_count() != rhs.get_choose_count()) {
+      return lhs.get_choose_count() > rhs.get_choose_count();
+    }
+    auto lhs_it = active_reaction_pos.find(lhs.get_reaction());
+    auto lhs_pos = lhs_it != active_reaction_pos.end() ? lhs_it->second : active_reaction_pos.size();
+    auto rhs_it = active_reaction_pos.find(rhs.get_reaction());
+    auto rhs_pos = rhs_it != active_reaction_pos.end() ? rhs_it->second : active_reaction_pos.size();
+    if (lhs_pos != rhs_pos) {
+      return lhs_pos < rhs_pos;
+    }
+
+    return lhs.get_reaction() < rhs.get_reaction();
+  });
+}
+
 bool MessageReactions::need_update_message_reactions(const MessageReactions *old_reactions,
                                                      const MessageReactions *new_reactions) {
   if (old_reactions == nullptr) {

td/telegram/MessageReaction.h

@@ -18,6 +18,7 @@
 #include "td/utils/common.h"
 #include "td/utils/StringBuilder.h"
 
+#include <unordered_map>
 #include <utility>
 
 namespace td {
@@ -64,6 +65,10 @@ class MessageReaction {
 
   void set_is_chosen(bool is_chosen, DialogId chooser_dialog_id = DialogId());
 
+  int32 get_choose_count() const {
+    return choose_count_;
+  }
+
   const vector<DialogId> &get_recent_chooser_dialog_ids() const {
     return recent_chooser_dialog_ids_;
   }
@@ -104,6 +109,8 @@ struct MessageReactions {
 
   void update_from(const MessageReactions &old_reactions);
 
+  void sort(const std::unordered_map<string, size_t> &active_reaction_pos);
+
   static bool need_update_message_reactions(const MessageReactions *old_reactions,
                                             const MessageReactions *new_reactions);
 

td/telegram/MessagesManager.cpp

@@ -7012,6 +7012,9 @@ bool MessagesManager::update_message_interaction_info(DialogId dialog_id, Messag
   if (has_reactions && reactions != nullptr && m->reactions != nullptr) {
     reactions->update_from(*m->reactions);
   }
+  if (has_reactions && reactions != nullptr) {
+    reactions->sort(active_reaction_pos_);
+  }
   bool need_update_reactions =
       has_reactions && MessageReactions::need_update_message_reactions(m->reactions.get(), reactions.get());
   if (view_count > m->view_count || forward_count > m->forward_count || need_update_reply_info ||
@@ -8263,6 +8266,9 @@ void MessagesManager::set_active_reactions(vector<string> active_reactions) {
 
   auto old_active_reactions = std::move(active_reactions_);
   active_reactions_ = std::move(active_reactions);
+  for (size_t i = 0; i < active_reactions_.size(); i++) {
+    active_reaction_pos_[active_reactions_[i]] = i;
+  }
 
   for (const auto &dialog : dialogs_) {
     const Dialog *d = dialog.second.get();
@@ -23774,13 +23780,13 @@ void MessagesManager::set_message_reaction(FullMessageId full_message_id, string
   }
   // m->reactions->has_pending_reaction_ = true;
   if (!is_found && !reaction.empty()) {
-    // TODO place to the correct position
     vector<DialogId> recent_chooser_dialog_ids;
     if (!is_broadcast_channel(dialog_id)) {
       recent_chooser_dialog_ids.push_back(get_my_dialog_id());
     }
     m->reactions->reactions_.emplace_back(reaction, 1, true, std::move(recent_chooser_dialog_ids), Auto());
   }
+  m->reactions->sort(active_reaction_pos_);
 
   send_update_message_interaction_info(dialog_id, m);
   on_message_changed(d, m, true, "set_message_reaction");

td/telegram/MessagesManager.h

@@ -3603,6 +3603,7 @@ class MessagesManager final : public Actor {
   std::unordered_map<DialogId, MessageId, DialogIdHash> previous_repaired_read_inbox_max_message_id_;
 
   vector<string> active_reactions_;
+  std::unordered_map<string, size_t> active_reaction_pos_;
 
   uint32 scheduled_messages_sync_generation_ = 1;