From b0533db2eb80143a40c650d52edeec7a9123ceb7 Mon Sep 17 00:00:00 2001
From: dgtal1 <27864579+dgtal1@users.noreply.github.com>
Date: Wed, 8 Sep 2021 05:15:57 +0200
Subject: [PATCH] Add new trigger to fan component `on_speed_set` (#2246)

---
 esphome/components/fan/__init__.py  | 10 ++++++++++
 esphome/components/fan/automation.h | 18 ++++++++++++++++++
 esphome/const.py                    |  1 +
 tests/test1.yaml                    |  3 +++
 4 files changed, 32 insertions(+)

diff --git a/esphome/components/fan/__init__.py b/esphome/components/fan/__init__.py
index 6bf0d1ca1a..46ff0c2d53 100644
--- a/esphome/components/fan/__init__.py
+++ b/esphome/components/fan/__init__.py
@@ -15,6 +15,7 @@ from esphome.const import (
     CONF_SPEED_COMMAND_TOPIC,
     CONF_SPEED_STATE_TOPIC,
     CONF_NAME,
+    CONF_ON_SPEED_SET,
     CONF_ON_TURN_OFF,
     CONF_ON_TURN_ON,
     CONF_TRIGGER_ID,
@@ -41,6 +42,7 @@ ToggleAction = fan_ns.class_("ToggleAction", automation.Action)
 
 FanTurnOnTrigger = fan_ns.class_("FanTurnOnTrigger", automation.Trigger.template())
 FanTurnOffTrigger = fan_ns.class_("FanTurnOffTrigger", automation.Trigger.template())
+FanSpeedSetTrigger = fan_ns.class_("FanSpeedSetTrigger", automation.Trigger.template())
 
 FanIsOnCondition = fan_ns.class_("FanIsOnCondition", automation.Condition.template())
 FanIsOffCondition = fan_ns.class_("FanIsOffCondition", automation.Condition.template())
@@ -71,6 +73,11 @@ FAN_SCHEMA = cv.NAMEABLE_SCHEMA.extend(cv.MQTT_COMMAND_COMPONENT_SCHEMA).extend(
                 cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(FanTurnOffTrigger),
             }
         ),
+        cv.Optional(CONF_ON_SPEED_SET): automation.validate_automation(
+            {
+                cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(FanSpeedSetTrigger),
+            }
+        ),
     }
 )
 
@@ -110,6 +117,9 @@ async def setup_fan_core_(var, config):
     for conf in config.get(CONF_ON_TURN_OFF, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(trigger, [], conf)
+    for conf in config.get(CONF_ON_SPEED_SET, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [], conf)
 
 
 async def register_fan(var, config):
diff --git a/esphome/components/fan/automation.h b/esphome/components/fan/automation.h
index abcad82569..7ff7c720df 100644
--- a/esphome/components/fan/automation.h
+++ b/esphome/components/fan/automation.h
@@ -103,5 +103,23 @@ class FanTurnOffTrigger : public Trigger<> {
   bool last_on_;
 };
 
+class FanSpeedSetTrigger : public Trigger<> {
+ public:
+  FanSpeedSetTrigger(FanState *state) {
+    state->add_on_state_callback([this, state]() {
+      auto speed = state->speed;
+      auto should_trigger = speed != !this->last_speed_;
+      this->last_speed_ = speed;
+      if (should_trigger) {
+        this->trigger();
+      }
+    });
+    this->last_speed_ = state->speed;
+  }
+
+ protected:
+  int last_speed_;
+};
+
 }  // namespace fan
 }  // namespace esphome
diff --git a/esphome/const.py b/esphome/const.py
index 6342e2a848..aff03b244b 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -425,6 +425,7 @@ CONF_ON_PRESS = "on_press"
 CONF_ON_RAW_VALUE = "on_raw_value"
 CONF_ON_RELEASE = "on_release"
 CONF_ON_SHUTDOWN = "on_shutdown"
+CONF_ON_SPEED_SET = "on_speed_set"
 CONF_ON_STATE = "on_state"
 CONF_ON_TAG = "on_tag"
 CONF_ON_TAG_REMOVED = "on_tag_removed"
diff --git a/tests/test1.yaml b/tests/test1.yaml
index bfdf9c3bea..da3289843d 100644
--- a/tests/test1.yaml
+++ b/tests/test1.yaml
@@ -1881,6 +1881,9 @@ fan:
     oscillation_command_topic: oscillation/command/topic
     speed_state_topic: speed/state/topic
     speed_command_topic: speed/command/topic
+    on_speed_set:
+      then:
+        - logger.log: "Fan speed was changed!"
 
 interval:
   - interval: 10s