From 96e46db272839a2408337e44f77c634cf7337cf1 Mon Sep 17 00:00:00 2001
From: Anthony Uk <1492471+dataway@users.noreply.github.com>
Date: Wed, 19 May 2021 06:12:43 +0200
Subject: [PATCH] Added fan triggers on_turn_on and on_turn_off (#1726)

---
 esphome/components/fan/__init__.py  | 23 ++++++++++++++++++
 esphome/components/fan/automation.h | 36 +++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/esphome/components/fan/__init__.py b/esphome/components/fan/__init__.py
index 10e38682e7..43d9297f96 100644
--- a/esphome/components/fan/__init__.py
+++ b/esphome/components/fan/__init__.py
@@ -14,6 +14,9 @@ from esphome.const import (
     CONF_SPEED_COMMAND_TOPIC,
     CONF_SPEED_STATE_TOPIC,
     CONF_NAME,
+    CONF_ON_TURN_OFF,
+    CONF_ON_TURN_ON,
+    CONF_TRIGGER_ID,
 )
 from esphome.core import CORE, coroutine, coroutine_with_priority
 
@@ -28,6 +31,9 @@ TurnOnAction = fan_ns.class_("TurnOnAction", automation.Action)
 TurnOffAction = fan_ns.class_("TurnOffAction", automation.Action)
 ToggleAction = fan_ns.class_("ToggleAction", automation.Action)
 
+FanTurnOnTrigger = fan_ns.class_("FanTurnOnTrigger", automation.Trigger.template())
+FanTurnOffTrigger = fan_ns.class_("FanTurnOffTrigger", automation.Trigger.template())
+
 FAN_SCHEMA = cv.MQTT_COMMAND_COMPONENT_SCHEMA.extend(
     {
         cv.GenerateID(): cv.declare_id(FanState),
@@ -44,6 +50,16 @@ FAN_SCHEMA = cv.MQTT_COMMAND_COMPONENT_SCHEMA.extend(
         cv.Optional(CONF_SPEED_COMMAND_TOPIC): cv.All(
             cv.requires_component("mqtt"), cv.subscribe_topic
         ),
+        cv.Optional(CONF_ON_TURN_ON): automation.validate_automation(
+            {
+                cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(FanTurnOnTrigger),
+            }
+        ),
+        cv.Optional(CONF_ON_TURN_OFF): automation.validate_automation(
+            {
+                cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(FanTurnOffTrigger),
+            }
+        ),
     }
 )
 
@@ -77,6 +93,13 @@ def setup_fan_core_(var, config):
                 mqtt_.set_custom_speed_command_topic(config[CONF_SPEED_COMMAND_TOPIC])
             )
 
+    for conf in config.get(CONF_ON_TURN_ON, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        yield automation.build_automation(trigger, [], conf)
+    for conf in config.get(CONF_ON_TURN_OFF, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        yield automation.build_automation(trigger, [], conf)
+
 
 @coroutine
 def register_fan(var, config):
diff --git a/esphome/components/fan/automation.h b/esphome/components/fan/automation.h
index 25c92075ba..fbfc71c720 100644
--- a/esphome/components/fan/automation.h
+++ b/esphome/components/fan/automation.h
@@ -46,5 +46,41 @@ template<typename... Ts> class ToggleAction : public Action<Ts...> {
   FanState *state_;
 };
 
+class FanTurnOnTrigger : public Trigger<> {
+ public:
+  FanTurnOnTrigger(FanState *state) {
+    state->add_on_state_callback([this, state]() {
+      auto is_on = state->state;
+      auto should_trigger = is_on && !this->last_on_;
+      this->last_on_ = is_on;
+      if (should_trigger) {
+        this->trigger();
+      }
+    });
+    this->last_on_ = state->state;
+  }
+
+ protected:
+  bool last_on_;
+};
+
+class FanTurnOffTrigger : public Trigger<> {
+ public:
+  FanTurnOffTrigger(FanState *state) {
+    state->add_on_state_callback([this, state]() {
+      auto is_on = state->state;
+      auto should_trigger = !is_on && this->last_on_;
+      this->last_on_ = is_on;
+      if (should_trigger) {
+        this->trigger();
+      }
+    });
+    this->last_on_ = state->state;
+  }
+
+ protected:
+  bool last_on_;
+};
+
 }  // namespace fan
 }  // namespace esphome