From 7adad0ee4920e47ef0735cf4a5f5a0b18bff6ef4 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Tue, 9 Sep 2025 02:03:35 -0500
Subject: [PATCH] [core] Refactor insertion sort functions to eliminate code
 duplication (#10653)

---
 esphome/core/application.cpp | 33 +++++++++------------------------
 1 file changed, 9 insertions(+), 24 deletions(-)

diff --git a/esphome/core/application.cpp b/esphome/core/application.cpp
index 5371d1b56f..1be193bb7e 100644
--- a/esphome/core/application.cpp
+++ b/esphome/core/application.cpp
@@ -34,37 +34,20 @@ namespace esphome {
 
 static const char *const TAG = "app";
 
-// Helper function for insertion sort of components by setup priority
+// Helper function for insertion sort of components by priority
 // Using insertion sort instead of std::stable_sort saves ~1.3KB of flash
 // by avoiding template instantiations (std::rotate, std::stable_sort, lambdas)
 // IMPORTANT: This sort is stable (preserves relative order of equal elements),
 // which is necessary to maintain user-defined component order for same priority
-template<typename Iterator> static void insertion_sort_by_setup_priority(Iterator first, Iterator last) {
+template<typename Iterator, float (Component::*GetPriority)() const>
+static void insertion_sort_by_priority(Iterator first, Iterator last) {
   for (auto it = first + 1; it != last; ++it) {
     auto key = *it;
-    float key_priority = key->get_actual_setup_priority();
+    float key_priority = (key->*GetPriority)();
     auto j = it - 1;
 
     // Using '<' (not '<=') ensures stability - equal priority components keep their order
-    while (j >= first && (*j)->get_actual_setup_priority() < key_priority) {
-      *(j + 1) = *j;
-      j--;
-    }
-    *(j + 1) = key;
-  }
-}
-
-// Helper function for insertion sort of components by loop priority
-// IMPORTANT: This sort is stable (preserves relative order of equal elements),
-// which is required when components are re-sorted during setup() if they block
-template<typename Iterator> static void insertion_sort_by_loop_priority(Iterator first, Iterator last) {
-  for (auto it = first + 1; it != last; ++it) {
-    auto key = *it;
-    float key_priority = key->get_loop_priority();
-    auto j = it - 1;
-
-    // Using '<' (not '<=') ensures stability - equal priority components keep their order
-    while (j >= first && (*j)->get_loop_priority() < key_priority) {
+    while (j >= first && ((*j)->*GetPriority)() < key_priority) {
       *(j + 1) = *j;
       j--;
     }
@@ -91,7 +74,8 @@ void Application::setup() {
   ESP_LOGV(TAG, "Sorting components by setup priority");
 
   // Sort by setup priority using our helper function
-  insertion_sort_by_setup_priority(this->components_.begin(), this->components_.end());
+  insertion_sort_by_priority<decltype(this->components_.begin()), &Component::get_actual_setup_priority>(
+      this->components_.begin(), this->components_.end());
 
   // Initialize looping_components_ early so enable_pending_loops_() works during setup
   this->calculate_looping_components_();
@@ -108,7 +92,8 @@ void Application::setup() {
       continue;
 
     // Sort components 0 through i by loop priority
-    insertion_sort_by_loop_priority(this->components_.begin(), this->components_.begin() + i + 1);
+    insertion_sort_by_priority<decltype(this->components_.begin()), &Component::get_loop_priority>(
+        this->components_.begin(), this->components_.begin() + i + 1);
 
     do {
       uint8_t new_app_state = STATUS_LED_WARNING;