Add support for controlling fan direction (#1051)

* Fix fan oscillation trait not being used

* Add fan direction support to SpeedFan

* Add fan direction to API

* Add fan direction support to BinaryFan

* Fix CI errors

* Fix python format

* Change some ordering to trigger CI

* Add test for the configuration

esphome/components/fan/fan_state.cpp

@@ -22,6 +22,7 @@ struct FanStateRTCState {
   bool state;
   FanSpeed speed;
   bool oscillating;
+  FanDirection direction;
 };
 
 void FanState::setup() {
@@ -34,6 +35,7 @@ void FanState::setup() {
   call.set_state(recovered.state);
   call.set_speed(recovered.speed);
   call.set_oscillating(recovered.oscillating);
+  call.set_direction(recovered.direction);
   call.perform();
 }
 float FanState::get_setup_priority() const { return setup_priority::HARDWARE - 1.0f; }
@@ -46,6 +48,9 @@ void FanStateCall::perform() const {
   if (this->oscillating_.has_value()) {
     this->state_->oscillating = *this->oscillating_;
   }
+  if (this->direction_.has_value()) {
+    this->state_->direction = *this->direction_;
+  }
   if (this->speed_.has_value()) {
     switch (*this->speed_) {
       case FAN_SPEED_LOW:
@@ -63,6 +68,7 @@ void FanStateCall::perform() const {
   saved.state = this->state_->state;
   saved.speed = this->state_->speed;
   saved.oscillating = this->state_->oscillating;
+  saved.direction = this->state_->direction;
   this->state_->rtc_.save(&saved);
 
   this->state_->state_callback_.call();

esphome/components/fan/fan_state.h

@@ -15,6 +15,9 @@ enum FanSpeed {
   FAN_SPEED_HIGH = 2     ///< The fan is running on high/full speed.
 };
 
+/// Simple enum to represent the direction of a fan
+enum FanDirection { FAN_DIRECTION_FORWARD = 0, FAN_DIRECTION_REVERSE = 1 };
+
 class FanState;
 
 class FanStateCall {
@@ -46,6 +49,14 @@ class FanStateCall {
     return *this;
   }
   FanStateCall &set_speed(const char *speed);
+  FanStateCall &set_direction(FanDirection direction) {
+    this->direction_ = direction;
+    return *this;
+  }
+  FanStateCall &set_direction(optional<FanDirection> direction) {
+    this->direction_ = direction;
+    return *this;
+  }
 
   void perform() const;
 
@@ -54,6 +65,7 @@ class FanStateCall {
   optional<bool> binary_state_;
   optional<bool> oscillating_{};
   optional<FanSpeed> speed_{};
+  optional<FanDirection> direction_{};
 };
 
 class FanState : public Nameable, public Component {
@@ -76,6 +88,8 @@ class FanState : public Nameable, public Component {
   bool oscillating{false};
   /// The current fan speed.
   FanSpeed speed{FAN_SPEED_HIGH};
+  /// The current direction of the fan
+  FanDirection direction{FAN_DIRECTION_FORWARD};
 
   FanStateCall turn_on();
   FanStateCall turn_off();

esphome/components/fan/fan_traits.h

@@ -6,7 +6,8 @@ namespace fan {
 class FanTraits {
  public:
   FanTraits() = default;
-  FanTraits(bool oscillation, bool speed) : oscillation_(oscillation), speed_(speed) {}
+  FanTraits(bool oscillation, bool speed, bool direction)
+      : oscillation_(oscillation), speed_(speed), direction_(direction) {}
 
   /// Return if this fan supports oscillation.
   bool supports_oscillation() const { return this->oscillation_; }
@@ -16,10 +17,15 @@ class FanTraits {
   bool supports_speed() const { return this->speed_; }
   /// Set whether this fan supports speed modes.
   void set_speed(bool speed) { this->speed_ = speed; }
+  /// Return if this fan supports changing direction
+  bool supports_direction() const { return this->direction_; }
+  /// Set whether this fan supports changing direction
+  void set_direction(bool direction) { this->direction_ = direction; }
 
  protected:
   bool oscillation_{false};
   bool speed_{false};
+  bool direction_{false};
 };
 
 }  // namespace fan