From 4a7570770b0b36cfc2495ad3795d4ae3c7df66bb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Ebbinghaus?= <bjoern@ebbinghaus.me>
Date: Fri, 2 Aug 2024 01:58:59 +0200
Subject: [PATCH] Implement 'round to nearest multiple' filter (#7142)

---
 esphome/components/sensor/__init__.py | 19 +++++++++++++++++++
 esphome/components/sensor/filter.cpp  |  8 ++++++++
 esphome/components/sensor/filter.h    |  9 +++++++++
 esphome/config_validation.py          |  1 +
 esphome/const.py                      |  1 +
 5 files changed, 38 insertions(+)

diff --git a/esphome/components/sensor/__init__.py b/esphome/components/sensor/__init__.py
index 262e69d75b..3b76466dec 100644
--- a/esphome/components/sensor/__init__.py
+++ b/esphome/components/sensor/__init__.py
@@ -17,6 +17,7 @@ from esphome.const import (
     CONF_ICON,
     CONF_ID,
     CONF_IGNORE_OUT_OF_RANGE,
+    CONF_MULTIPLE,
     CONF_ON_RAW_VALUE,
     CONF_ON_VALUE,
     CONF_ON_VALUE_RANGE,
@@ -249,6 +250,7 @@ CalibratePolynomialFilter = sensor_ns.class_("CalibratePolynomialFilter", Filter
 SensorInRangeCondition = sensor_ns.class_("SensorInRangeCondition", Filter)
 ClampFilter = sensor_ns.class_("ClampFilter", Filter)
 RoundFilter = sensor_ns.class_("RoundFilter", Filter)
+RoundMultipleFilter = sensor_ns.class_("RoundMultipleFilter", Filter)
 
 validate_unit_of_measurement = cv.string_strict
 validate_accuracy_decimals = cv.int_
@@ -734,6 +736,23 @@ async def round_filter_to_code(config, filter_id):
     )
 
 
+@FILTER_REGISTRY.register(
+    "round_to_multiple_of",
+    RoundMultipleFilter,
+    cv.maybe_simple_value(
+        {
+            cv.Required(CONF_MULTIPLE): cv.positive_not_null_float,
+        },
+        key=CONF_MULTIPLE,
+    ),
+)
+async def round_multiple_filter_to_code(config, filter_id):
+    return cg.new_Pvariable(
+        filter_id,
+        config[CONF_MULTIPLE],
+    )
+
+
 async def build_filters(config):
     return await cg.build_registry_list(FILTER_REGISTRY, config)
 
diff --git a/esphome/components/sensor/filter.cpp b/esphome/components/sensor/filter.cpp
index eaa909429b..bcf1fc8269 100644
--- a/esphome/components/sensor/filter.cpp
+++ b/esphome/components/sensor/filter.cpp
@@ -472,5 +472,13 @@ optional<float> RoundFilter::new_value(float value) {
   return value;
 }
 
+RoundMultipleFilter::RoundMultipleFilter(float multiple) : multiple_(multiple) {}
+optional<float> RoundMultipleFilter::new_value(float value) {
+  if (std::isfinite(value)) {
+    return value - remainderf(value, this->multiple_);
+  }
+  return value;
+}
+
 }  // namespace sensor
 }  // namespace esphome
diff --git a/esphome/components/sensor/filter.h b/esphome/components/sensor/filter.h
index c13cb3420a..92b1d8d240 100644
--- a/esphome/components/sensor/filter.h
+++ b/esphome/components/sensor/filter.h
@@ -431,5 +431,14 @@ class RoundFilter : public Filter {
   uint8_t precision_;
 };
 
+class RoundMultipleFilter : public Filter {
+ public:
+  explicit RoundMultipleFilter(float multiple);
+  optional<float> new_value(float value) override;
+
+ protected:
+  float multiple_;
+};
+
 }  // namespace sensor
 }  // namespace esphome
diff --git a/esphome/config_validation.py b/esphome/config_validation.py
index d93f8aed9a..6e1d3ba2f9 100644
--- a/esphome/config_validation.py
+++ b/esphome/config_validation.py
@@ -464,6 +464,7 @@ zero_to_one_float = float_range(min=0, max=1)
 negative_one_to_one_float = float_range(min=-1, max=1)
 positive_int = int_range(min=0)
 positive_not_null_int = int_range(min=0, min_included=False)
+positive_not_null_float = float_range(min=0, min_included=False)
 
 
 def validate_id_name(value):
diff --git a/esphome/const.py b/esphome/const.py
index 39dd48d3f8..fcb630badd 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -503,6 +503,7 @@ CONF_MOTION = "motion"
 CONF_MOVEMENT_COUNTER = "movement_counter"
 CONF_MQTT = "mqtt"
 CONF_MQTT_ID = "mqtt_id"
+CONF_MULTIPLE = "multiple"
 CONF_MULTIPLEXER = "multiplexer"
 CONF_MULTIPLY = "multiply"
 CONF_NAME = "name"