From f3f419077bb5d1b7d5eea3d735b8b0b4c58678c5 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Tue, 21 Oct 2025 11:29:27 -1000
Subject: [PATCH] [wifi] Optimize WiFi network storage with FixedVector

---
 esphome/components/wifi/__init__.py        | 23 +++++++++++++++-------
 esphome/components/wifi/wifi_component.cpp |  7 ++-----
 esphome/components/wifi/wifi_component.h   |  4 ++--
 3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/esphome/components/wifi/__init__.py b/esphome/components/wifi/__init__.py
index 494470cb48..19c1f28f47 100644
--- a/esphome/components/wifi/__init__.py
+++ b/esphome/components/wifi/__init__.py
@@ -1,6 +1,7 @@
 from esphome import automation
 from esphome.automation import Condition
 import esphome.codegen as cg
+from esphome.codegen import MockObj
 from esphome.components.const import CONF_USE_PSRAM
 from esphome.components.esp32 import add_idf_sdkconfig_option, const, get_esp32_variant
 from esphome.components.network import IPAddress
@@ -378,14 +379,22 @@ async def to_code(config):
     # Track if any network uses Enterprise authentication
     has_eap = False
 
-    def add_sta(ap, network):
-        ip_config = network.get(CONF_MANUAL_IP, config.get(CONF_MANUAL_IP))
-        cg.add(var.add_sta(wifi_network(network, ap, ip_config)))
+    # Build all WiFiAP objects
+    networks = config.get(CONF_NETWORKS, [])
+    if networks:
+        wifi_aps: list[MockObj] = []
+        for network in networks:
+            if CONF_EAP in network:
+                has_eap = True
+            ip_config = network.get(CONF_MANUAL_IP, config.get(CONF_MANUAL_IP))
+            # Create a WiFiAP variable for each network
+            ap_var = cg.new_variable(network[CONF_ID], WiFiAP())
+            # Configure the WiFiAP
+            wifi_network(network, ap_var, ip_config)
+            wifi_aps.append(ap_var)
 
-    for network in config.get(CONF_NETWORKS, []):
-        if CONF_EAP in network:
-            has_eap = True
-        cg.with_local_variable(network[CONF_ID], WiFiAP(), add_sta, network)
+        # Set all WiFi networks at once
+        cg.add(var.set_stas(wifi_aps))
 
     if CONF_AP in config:
         conf = config[CONF_AP]
diff --git a/esphome/components/wifi/wifi_component.cpp b/esphome/components/wifi/wifi_component.cpp
index c89384d742..a7b66114c8 100644
--- a/esphome/components/wifi/wifi_component.cpp
+++ b/esphome/components/wifi/wifi_component.cpp
@@ -330,11 +330,8 @@ float WiFiComponent::get_loop_priority() const {
   return 10.0f;  // before other loop components
 }
 
-void WiFiComponent::add_sta(const WiFiAP &ap) { this->sta_.push_back(ap); }
-void WiFiComponent::set_sta(const WiFiAP &ap) {
-  this->clear_sta();
-  this->add_sta(ap);
-}
+void WiFiComponent::set_stas(const std::initializer_list<WiFiAP> &aps) { this->sta_ = aps; }
+void WiFiComponent::set_sta(const WiFiAP &ap) { this->set_stas({ap}); }
 void WiFiComponent::clear_sta() { this->sta_.clear(); }
 void WiFiComponent::save_wifi_sta(const std::string &ssid, const std::string &password) {
   SavedWifiSettings save{};  // zero-initialized - all bytes set to \0, guaranteeing null termination
diff --git a/esphome/components/wifi/wifi_component.h b/esphome/components/wifi/wifi_component.h
index 10aa82a065..0bcfd7445a 100644
--- a/esphome/components/wifi/wifi_component.h
+++ b/esphome/components/wifi/wifi_component.h
@@ -219,7 +219,7 @@ class WiFiComponent : public Component {
 
   void set_sta(const WiFiAP &ap);
   WiFiAP get_sta() { return this->selected_ap_; }
-  void add_sta(const WiFiAP &ap);
+  void set_stas(const std::initializer_list<WiFiAP> &aps);
   void clear_sta();
 
 #ifdef USE_WIFI_AP
@@ -393,7 +393,7 @@ class WiFiComponent : public Component {
 #endif
 
   std::string use_address_;
-  std::vector<WiFiAP> sta_;
+  FixedVector<WiFiAP> sta_;
   std::vector<WiFiSTAPriority> sta_priorities_;
   wifi_scan_vector_t<WiFiScanResult> scan_result_;
   WiFiAP selected_ap_;