From ceaa37fe0dd1f818d7775d3b67d984dbf5998ead Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Sun, 1 Oct 2023 21:49:15 +0300
Subject: [PATCH] Simplify set_dialog_is_pinned implementation.

---
 td/telegram/MessagesManager.cpp | 48 +++++++++++++++------------------
 tdutils/td/utils/algorithm.h    |  4 +--
 2 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/td/telegram/MessagesManager.cpp b/td/telegram/MessagesManager.cpp
index f1909ac25..961232340 100644
--- a/td/telegram/MessagesManager.cpp
+++ b/td/telegram/MessagesManager.cpp
@@ -15119,35 +15119,31 @@ bool MessagesManager::set_dialog_is_pinned(DialogListId dialog_list_id, Dialog *
   if (!list->are_pinned_dialogs_inited_) {
     return false;
   }
-  bool was_pinned = false;
-  for (size_t pos = 0; pos < list->pinned_dialogs_.size(); pos++) {
-    auto &pinned_dialog = list->pinned_dialogs_[pos];
-    if (pinned_dialog.get_dialog_id() == d->dialog_id) {
-      // the dialog was already pinned
-      if (is_pinned) {
-        if (pos == 0) {
-          return false;
-        }
-        auto order = get_next_pinned_dialog_order();
-        pinned_dialog = DialogDate(order, d->dialog_id);
-        std::rotate(list->pinned_dialogs_.begin(), list->pinned_dialogs_.begin() + pos,
-                    list->pinned_dialogs_.begin() + pos + 1);
-        list->pinned_dialog_id_orders_[d->dialog_id] = order;
-      } else {
-        list->pinned_dialogs_.erase(list->pinned_dialogs_.begin() + pos);
-        list->pinned_dialog_id_orders_.erase(d->dialog_id);
-      }
-      was_pinned = true;
-      break;
-    }
-  }
-  if (!was_pinned) {
-    if (!is_pinned) {
+  auto dialog_id = d->dialog_id;
+  auto is_changed_dialog = [dialog_id](const DialogDate &dialog_date) {
+    return dialog_date.get_dialog_id() == dialog_id;
+  };
+  if (is_pinned) {
+    if (!list->pinned_dialogs_.empty() && is_changed_dialog(list->pinned_dialogs_[0])) {
       return false;
     }
     auto order = get_next_pinned_dialog_order();
-    list->pinned_dialogs_.insert(list->pinned_dialogs_.begin(), {order, d->dialog_id});
-    list->pinned_dialog_id_orders_.emplace(d->dialog_id, order);
+    DialogDate dialog_date(order, dialog_id);
+    add_to_top_if(list->pinned_dialogs_, list->pinned_dialogs_.size() + 1, dialog_date, is_changed_dialog);
+    auto it = list->pinned_dialog_id_orders_.find(dialog_id);
+    if (it != list->pinned_dialog_id_orders_.end()) {
+      CHECK(list->pinned_dialogs_[0] != dialog_date);
+      list->pinned_dialogs_[0] = dialog_date;
+      it->second = order;
+    } else {
+      CHECK(list->pinned_dialogs_[0] == dialog_date);
+      list->pinned_dialog_id_orders_.emplace(dialog_id, order);
+    }
+  } else {
+    if (!td::remove_if(list->pinned_dialogs_, is_changed_dialog)) {
+      return false;
+    }
+    list->pinned_dialog_id_orders_.erase(dialog_id);
   }
 
   LOG(INFO) << "Set " << d->dialog_id << " is pinned in " << dialog_list_id << " to " << is_pinned;
diff --git a/tdutils/td/utils/algorithm.h b/tdutils/td/utils/algorithm.h
index 28fb9708c..d6ace2506 100644
--- a/tdutils/td/utils/algorithm.h
+++ b/tdutils/td/utils/algorithm.h
@@ -98,7 +98,7 @@ void add_to_top(V &v, size_t max_size, T value) {
   }
   if (i == size) {
     if (size < max_size || i == 0) {
-      v.emplace_back();
+      v.emplace_back(value);
     } else {
       i--;
     }
@@ -122,7 +122,7 @@ void add_to_top_if(V &v, size_t max_size, T value, const F &is_equal_to_value) {
   }
   if (i == size) {
     if (size < max_size || i == 0) {
-      v.emplace_back();
+      v.emplace_back(value);
     } else {
       i--;
     }