From 83eb723c623bbdbf87ca344e7b0e5dc95d32e59f Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Fri, 27 Mar 2026 13:33:46 -1000
Subject: [PATCH] [binary_sensor] Use std::array in AutorepeatFilter

---
 esphome/components/binary_sensor/__init__.py |  3 +-
 esphome/components/binary_sensor/filter.cpp  | 27 +++++------------
 esphome/components/binary_sensor/filter.h    | 32 +++++++++++++++++---
 3 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/esphome/components/binary_sensor/__init__.py b/esphome/components/binary_sensor/__init__.py
index 37cccc01be..c3868586f4 100644
--- a/esphome/components/binary_sensor/__init__.py
+++ b/esphome/components/binary_sensor/__init__.py
@@ -266,6 +266,7 @@ async def delayed_off_filter_to_code(config, filter_id):
                 ): cv.positive_time_period_milliseconds,
             }
         ),
+        cv.Length(max=254),
     ),
 )
 async def autorepeat_filter_to_code(config, filter_id):
@@ -294,7 +295,7 @@ async def autorepeat_filter_to_code(config, filter_id):
                 ),
             )
         ]
-    var = cg.new_Pvariable(filter_id, timings)
+    var = cg.new_Pvariable(filter_id, cg.TemplateArguments(len(timings)), timings)
     await cg.register_component(var, {})
     return var
 
diff --git a/esphome/components/binary_sensor/filter.cpp b/esphome/components/binary_sensor/filter.cpp
index 5d525e967d..914060ce13 100644
--- a/esphome/components/binary_sensor/filter.cpp
+++ b/esphome/components/binary_sensor/filter.cpp
@@ -76,14 +76,11 @@ float DelayedOffFilter::get_setup_priority() const { return setup_priority::HARD
 
 optional<bool> InvertFilter::new_value(bool value) { return !value; }
 
-AutorepeatFilter::AutorepeatFilter(std::initializer_list<AutorepeatFilterTiming> timings) : timings_(timings) {}
-
-optional<bool> AutorepeatFilter::new_value(bool value) {
+// AutorepeatFilterBase
+optional<bool> AutorepeatFilterBase::new_value(bool value) {
   if (value) {
-    // Ignore if already running
     if (this->active_timing_ != 0)
       return {};
-
     this->next_timing_();
     return true;
   } else {
@@ -94,34 +91,26 @@ optional<bool> AutorepeatFilter::new_value(bool value) {
   }
 }
 
-void AutorepeatFilter::next_timing_() {
-  // Entering this method
-  // 1st time: starts waiting the first delay
-  // 2nd time: starts waiting the second delay and starts toggling with the first time_off / _on
-  // last time: no delay to start but have to bump the index to reflect the last
-  if (this->active_timing_ < this->timings_.size()) {
+void AutorepeatFilterBase::next_timing_() {
+  if (this->active_timing_ < this->timings_count_) {
     this->set_timeout(AUTOREPEAT_TIMING_ID, this->timings_[this->active_timing_].delay,
                       [this]() { this->next_timing_(); });
   }
-
-  if (this->active_timing_ <= this->timings_.size()) {
+  if (this->active_timing_ <= this->timings_count_) {
     this->active_timing_++;
   }
-
   if (this->active_timing_ == 2)
     this->next_value_(false);
-
-  // Leaving this method: if the toggling is started, it has to use [active_timing_ - 2] for the intervals
 }
 
-void AutorepeatFilter::next_value_(bool val) {
+void AutorepeatFilterBase::next_value_(bool val) {
   const AutorepeatFilterTiming &timing = this->timings_[this->active_timing_ - 2];
-  this->output(val);  // This is at least the second one so not initial
+  this->output(val);
   this->set_timeout(AUTOREPEAT_ON_OFF_ID, val ? timing.time_on : timing.time_off,
                     [this, val]() { this->next_value_(!val); });
 }
 
-float AutorepeatFilter::get_setup_priority() const { return setup_priority::HARDWARE; }
+float AutorepeatFilterBase::get_setup_priority() const { return setup_priority::HARDWARE; }
 
 LambdaFilter::LambdaFilter(std::function<optional<bool>(bool)> f) : f_(std::move(f)) {}
 
diff --git a/esphome/components/binary_sensor/filter.h b/esphome/components/binary_sensor/filter.h
index 0813847ca2..27b622fcd1 100644
--- a/esphome/components/binary_sensor/filter.h
+++ b/esphome/components/binary_sensor/filter.h
@@ -3,6 +3,8 @@
 #include "esphome/core/defines.h"
 #ifdef USE_BINARY_SENSOR_FILTER
 
+#include <array>
+
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/helpers.h"
@@ -86,22 +88,42 @@ struct AutorepeatFilterTiming {
   uint32_t time_on;
 };
 
-class AutorepeatFilter : public Filter, public Component {
+/// Non-template base for AutorepeatFilter — all methods in filter.cpp.
+/// Lambdas capture this base pointer, so set_timeout/cancel_timeout are instantiated once.
+class AutorepeatFilterBase : public Filter, public Component {
  public:
-  explicit AutorepeatFilter(std::initializer_list<AutorepeatFilterTiming> timings);
-
   optional<bool> new_value(bool value) override;
-
   float get_setup_priority() const override;
 
  protected:
+  AutorepeatFilterBase() = default;
   void next_timing_();
   void next_value_(bool val);
 
-  FixedVector<AutorepeatFilterTiming> timings_;
+  const AutorepeatFilterTiming *timings_{nullptr};
+  uint8_t timings_count_{0};
   uint8_t active_timing_{0};
 };
 
+/// Template wrapper that provides inline std::array storage for timings.
+/// N is set by code generation to match the exact number of timings configured in YAML.
+template<size_t N> class AutorepeatFilter : public AutorepeatFilterBase {
+ public:
+  explicit AutorepeatFilter(std::initializer_list<AutorepeatFilterTiming> timings) {
+    size_t i = 0;
+    for (const auto &t : timings) {
+      if (i >= N)
+        break;
+      this->timings_storage_[i++] = t;
+    }
+    this->timings_ = this->timings_storage_.data();
+    this->timings_count_ = N;
+  }
+
+ protected:
+  std::array<AutorepeatFilterTiming, N> timings_storage_{};
+};
+
 class LambdaFilter : public Filter {
  public:
   explicit LambdaFilter(std::function<optional<bool>(bool)> f);