From 9427c0561db44be70a476cf6f66ddc26d8d984b5 Mon Sep 17 00:00:00 2001
From: Maurice Makaay <account+github@makaay.nl>
Date: Wed, 18 Aug 2021 12:01:50 +0200
Subject: [PATCH] Compatibility fix: custom light transformer implementation
 (#50)

* New light transformer implementation
* Fixed missing ; in the code, thanks Jos!
* Removed backward compatibility code for v1.20.x (because there were too many other changes that broke the build, and for which creating a work-around was not feasible).
* Fixed duplicate api section in the example.yaml (thanks @badbroechten\!) and updated the example to not use an underscore in the hostname.
* Prepare for release
---
 CHANGELOG.md                                  |  16 +--
 README.md                                     |   2 +-
 components/xiaomi_bslamp2/light/__init__.py   |   2 -
 .../light/{gpio_outputs.h => color_handler.h} |  23 +--
 ...nstant_handler.h => color_handler_chain.h} |  35 +++--
 ...ht.h => color_handler_color_temperature.h} |  12 +-
 ...ht_light.h => color_handler_night_light.h} |   8 +-
 .../{color_off.h => color_handler_off.h}      |   6 +-
 ...{color_rgb_light.h => color_handler_rgb.h} |  12 +-
 .../light/color_transition_handler.h          | 136 ------------------
 components/xiaomi_bslamp2/light/interfaces.h  |  16 ---
 components/xiaomi_bslamp2/light/light_modes.h |  15 --
 .../xiaomi_bslamp2/light/light_output.h       |  53 ++-----
 components/xiaomi_bslamp2/light/light_state.h |  16 +--
 .../xiaomi_bslamp2/light/light_transformer.h  |  62 ++++++++
 components/xiaomi_bslamp2/light_hal.h         |  91 +++++++++---
 doc/installation.md                           |   2 +-
 doc/testplan.md                               |   8 ++
 example.yaml                                  |  22 ++-
 19 files changed, 207 insertions(+), 330 deletions(-)
 rename components/xiaomi_bslamp2/light/{gpio_outputs.h => color_handler.h} (55%)
 rename components/xiaomi_bslamp2/light/{color_instant_handler.h => color_handler_chain.h} (56%)
 rename components/xiaomi_bslamp2/light/{color_white_light.h => color_handler_color_temperature.h} (95%)
 rename components/xiaomi_bslamp2/light/{color_night_light.h => color_handler_night_light.h} (92%)
 rename components/xiaomi_bslamp2/light/{color_off.h => color_handler_off.h} (84%)
 rename components/xiaomi_bslamp2/light/{color_rgb_light.h => color_handler_rgb.h} (99%)
 delete mode 100644 components/xiaomi_bslamp2/light/color_transition_handler.h
 delete mode 100644 components/xiaomi_bslamp2/light/light_modes.h
 create mode 100644 components/xiaomi_bslamp2/light/light_transformer.h

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 54ff06d..75ce405 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,22 +4,22 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [1.2.0-RC1]
+## [2021.8.0]
 
-**Note**: This release requires ESPHome v1.21.0 and Home Assistant 2021.8.0 or newer.
-The code will compile with ESPHome v1.20.0, but the lamp will not be controllable
-through the Home Assistant GUI when using Home Assistant 2021.8.0 or newer.
-Only turn on/off and brightness will be available, not the RGB and Color Temperature
-tabs..
+**Note**: This release requires ESPHome 2021.8.0 and Home Assistant 2021.8.0 or newer.
 
 ### Added
 - Preset identifiers (`group` and `preset`) for the `preset.activate` action are now
   validated at compile time. This prevents us from building a firmware with incorrect
   preset identifiers. Before this change, using an invalid preset name would only
-  result in a warning message in the device log.
+  result in a warning message in the device log, which is only moderately useful.
 
 ### Changed
-- The code has been made compatible with the new color mode support in Home Assistant.
+- The code has been made compatible with the new color mode support in Home Assistant
+  and ESPHome. 
+- My project will follow the Home Assistant / ESPHome versioning scheme from now on
+  (<year>.<month>.<patch>), because the ESPHome project adopted this versioning
+  scheme too.
 
 ## [1.1.0]
 
diff --git a/README.md b/README.md
index 028dbce..dbcfbc8 100644
--- a/README.md
+++ b/README.md
@@ -49,7 +49,7 @@ aspect of the lamp and to integrate the lamp in your Home Assistant setup.
 
 For those who have experience with flashing ESPHome onto devices:
 
-* Make sure you are using ESPHome v1.21.0 or newer.
+* Make sure you are using ESPHome 2021.8.0 or newer.
 * Copy [`example.yaml`](example.yaml) to `<CONFIG_DIR>/<NODE_NAME>.yaml`.
 * Modify the configuration to your needs (see the [configuration guide](doc/configuration.md)).
 * Compile the `firmware.bin` file and download it to the device to which you have connected your
diff --git a/components/xiaomi_bslamp2/light/__init__.py b/components/xiaomi_bslamp2/light/__init__.py
index 43927c0..d57e6d6 100644
--- a/components/xiaomi_bslamp2/light/__init__.py
+++ b/components/xiaomi_bslamp2/light/__init__.py
@@ -225,8 +225,6 @@ def light_output_to_code(config):
     yield light.register_light(light_output_var, config)
     light_hal_var = yield cg.get_variable(config[CONF_LIGHT_HAL_ID])
     cg.add(light_output_var.set_parent(light_hal_var))
-    if hasattr(light, "types") and hasattr(light.types, "COLOR_MODES"):
-        cg.add_define('HAS_COLOR_MODES')
 
 @coroutine
 def on_brightness_to_code(config):
diff --git a/components/xiaomi_bslamp2/light/gpio_outputs.h b/components/xiaomi_bslamp2/light/color_handler.h
similarity index 55%
rename from components/xiaomi_bslamp2/light/gpio_outputs.h
rename to components/xiaomi_bslamp2/light/color_handler.h
index 555dea7..7d8cdea 100644
--- a/components/xiaomi_bslamp2/light/gpio_outputs.h
+++ b/components/xiaomi_bslamp2/light/color_handler.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "light_modes.h"
+#include "../light_hal.h"
 
 namespace esphome {
 namespace xiaomi {
@@ -11,14 +11,8 @@ namespace bslamp2 {
  * LightColorValues into the required GPIO PWM duty cycle levels to represent
  * the requested color on the physical device.
  */
-class GPIOOutputs {
+class ColorHandler : public GPIOOutputValues {
  public:
-  float red = 0.0f;
-  float green = 0.0f;
-  float blue = 0.0f;
-  float white = 0.0f;
-  std::string light_mode = LIGHT_MODE_OFF;
-
   /**
    * Sets the red, green, blue, white fields to the PWM duty cycles
    * that are required to represent the requested light color for
@@ -27,19 +21,6 @@ class GPIOOutputs {
    * Returns true when the input can be handled, false otherwise.
    */
   virtual bool set_light_color_values(light::LightColorValues v) = 0;
-
-  /**
-   * Copies the current output values to another GPIOOutputs object.
-   */
-  void copy_to(GPIOOutputs *other) {
-    other->red = red;
-    other->green = green;
-    other->blue = blue;
-    other->white = white;
-    other->light_mode = light_mode;
-  }
-
-  void log(const char *prefix) { ESP_LOGD(TAG, "%s: RGB=[%f,%f,%f], white=%f", prefix, red, green, blue, white); }
 };
 
 }  // namespace bslamp2
diff --git a/components/xiaomi_bslamp2/light/color_instant_handler.h b/components/xiaomi_bslamp2/light/color_handler_chain.h
similarity index 56%
rename from components/xiaomi_bslamp2/light/color_instant_handler.h
rename to components/xiaomi_bslamp2/light/color_handler_chain.h
index b2e90d1..243e28a 100644
--- a/components/xiaomi_bslamp2/light/color_instant_handler.h
+++ b/components/xiaomi_bslamp2/light/color_handler_chain.h
@@ -4,20 +4,19 @@
 #include <stdexcept>
 
 #include "../common.h"
-#include "color_night_light.h"
-#include "color_off.h"
-#include "color_rgb_light.h"
-#include "color_white_light.h"
-#include "gpio_outputs.h"
+#include "color_handler.h"
+#include "color_handler_off.h"
+#include "color_handler_rgb.h"
+#include "color_handler_color_temperature.h"
+#include "color_handler_night_light.h"
 
 namespace esphome {
 namespace xiaomi {
 namespace bslamp2 {
 
 /**
- * This class translates LightColorValues into GPIO duty cycles that
- * can be used for representing a requested light color on the
- * physical device.
+ * This class translates LightColorValues into GPIO duty cycles that can be
+ * used for representing a requested light color on the physical device.
  *
  * The code handles all known light modes for the device:
  *
@@ -26,13 +25,13 @@ namespace bslamp2 {
  * - white light: based on color temperature + brightness
  * - RGB light: based on RGB values + brightness
  */
-class ColorInstantHandler : public GPIOOutputs {
+class ColorHandlerChain : public ColorHandler {
  public:
   bool set_light_color_values(light::LightColorValues v) {
-    // The actual implementation of the various light modes is in
-    // separated targeted classes. These classes are called here
-    // in a chain of command-like pattern, to let the first one
-    // that can handle the light settings do the honours.
+    // The actual implementation of the various light modes is in separate
+    // targeted classes. These classes are called here in a chain of
+    // command-like pattern, to let the first one that can handle the light
+    // settings do the honours.
     if (off_light_->set_light_color_values(v))
       off_light_->copy_to(this);
     else if (night_light_->set_light_color_values(v))
@@ -42,7 +41,7 @@ class ColorInstantHandler : public GPIOOutputs {
     else if (rgb_light_->set_light_color_values(v))
       rgb_light_->copy_to(this);
     else {
-      ESP_LOGE(TAG, "Light color error: (None of the GPIOOutputs classes handles the requested light state; defaulting to 'off'");
+      ESP_LOGE(TAG, "Light color error: (None of the ColorHandler classes handles the requested light state; defaulting to 'off'");
       off_light_->copy_to(this);
     }
 
@@ -50,10 +49,10 @@ class ColorInstantHandler : public GPIOOutputs {
   }
 
  protected:
-  GPIOOutputs *off_light_ = new ColorOff();
-  GPIOOutputs *rgb_light_ = new ColorRGBLight();
-  GPIOOutputs *white_light_ = new ColorWhiteLight();
-  GPIOOutputs *night_light_ = new ColorNightLight();
+  ColorHandler *off_light_ = new ColorHandlerOff();
+  ColorHandler *rgb_light_ = new ColorHandlerRGB();
+  ColorHandler *white_light_ = new ColorHandlerColorTemperature();
+  ColorHandler *night_light_ = new ColorHandlerNightLight();
 };
 
 }  // namespace bslamp2
diff --git a/components/xiaomi_bslamp2/light/color_white_light.h b/components/xiaomi_bslamp2/light/color_handler_color_temperature.h
similarity index 95%
rename from components/xiaomi_bslamp2/light/color_white_light.h
rename to components/xiaomi_bslamp2/light/color_handler_color_temperature.h
index 365339c..f27b206 100644
--- a/components/xiaomi_bslamp2/light/color_white_light.h
+++ b/components/xiaomi_bslamp2/light/color_handler_color_temperature.h
@@ -4,8 +4,8 @@
 #include <stdexcept>
 
 #include "../common.h"
-#include "light_modes.h"
-#include "gpio_outputs.h"
+#include "../light_hal.h"
+#include "color_handler.h"
 
 namespace esphome {
 namespace xiaomi {
@@ -75,20 +75,14 @@ static const RGBWLevelsTable rgbw_levels_100_ {{
  * This class can handle the GPIO outputs for the white light mode,
  * based on color temperature + brightness.
  */
-class ColorWhiteLight : public GPIOOutputs {
+class ColorHandlerColorTemperature : public ColorHandler {
  public:
   bool set_light_color_values(light::LightColorValues v) {
     light_mode = LIGHT_MODE_WHITE;
 
-#ifdef HAS_COLOR_MODES
     if (v.get_color_mode() != light::ColorMode::COLOR_TEMPERATURE) {
       return false;
     }
-#else
-    if (v.get_white() == 0.0f) {
-      return false;
-    }
-#endif
 
     auto temperature = clamp_temperature_(v.get_color_temperature());
     auto brightness = clamp_brightness_(v.get_brightness());
diff --git a/components/xiaomi_bslamp2/light/color_night_light.h b/components/xiaomi_bslamp2/light/color_handler_night_light.h
similarity index 92%
rename from components/xiaomi_bslamp2/light/color_night_light.h
rename to components/xiaomi_bslamp2/light/color_handler_night_light.h
index 4af8f3d..026f13f 100644
--- a/components/xiaomi_bslamp2/light/color_night_light.h
+++ b/components/xiaomi_bslamp2/light/color_handler_night_light.h
@@ -1,8 +1,8 @@
 #pragma once
 
 #include "../common.h"
-#include "gpio_outputs.h"
-#include "light_modes.h"
+#include "../light_hal.h"
+#include "color_handler.h"
 
 namespace esphome {
 namespace xiaomi {
@@ -22,7 +22,7 @@ namespace bslamp2 {
  * light mode toggle, then this still could be implemented through the
  * device's yaml configuration.
  */
-class ColorNightLight : public GPIOOutputs {
+class ColorHandlerNightLight : public ColorHandler {
  public:
   bool set_light_color_values(light::LightColorValues v) {
     light_mode = LIGHT_MODE_NIGHT;
@@ -36,7 +36,7 @@ class ColorNightLight : public GPIOOutputs {
     // This night light mode is activated when white light is selected.
     // Based on measurements using the original device firmware, so it
     // matches the night light of the original firmware.
-    if (v.get_white() > 0) {
+    if (v.get_color_mode() == light::ColorMode::COLOR_TEMPERATURE) {
       red = 0.968f;
       green = 0.968f;
       blue = 0.972f;
diff --git a/components/xiaomi_bslamp2/light/color_off.h b/components/xiaomi_bslamp2/light/color_handler_off.h
similarity index 84%
rename from components/xiaomi_bslamp2/light/color_off.h
rename to components/xiaomi_bslamp2/light/color_handler_off.h
index cd97b5d..527df28 100644
--- a/components/xiaomi_bslamp2/light/color_off.h
+++ b/components/xiaomi_bslamp2/light/color_handler_off.h
@@ -1,8 +1,8 @@
 #pragma once
 
 #include "../common.h"
-#include "gpio_outputs.h"
-#include "light_modes.h"
+#include "../light_hal.h"
+#include "color_handler.h"
 
 namespace esphome {
 namespace xiaomi {
@@ -11,7 +11,7 @@ namespace bslamp2 {
 /**
  * This class can handle the GPIO outputs in case the light of turned off.
  */
-class ColorOff : public GPIOOutputs {
+class ColorHandlerOff : public ColorHandler {
  public:
   bool set_light_color_values(light::LightColorValues v) {
     light_mode = LIGHT_MODE_OFF;
diff --git a/components/xiaomi_bslamp2/light/color_rgb_light.h b/components/xiaomi_bslamp2/light/color_handler_rgb.h
similarity index 99%
rename from components/xiaomi_bslamp2/light/color_rgb_light.h
rename to components/xiaomi_bslamp2/light/color_handler_rgb.h
index 757d048..7d2896c 100644
--- a/components/xiaomi_bslamp2/light/color_rgb_light.h
+++ b/components/xiaomi_bslamp2/light/color_handler_rgb.h
@@ -4,8 +4,8 @@
 #include <cmath>
 
 #include "../common.h"
-#include "gpio_outputs.h"
-#include "light_modes.h"
+#include "../light_hal.h"
+#include "color_handler.h"
 
 namespace esphome {
 namespace xiaomi {
@@ -247,20 +247,14 @@ static const RGBCircle rgb_circle_ {{
  * This class can handle the GPIO outputs for the RGB light mode,
  * based on RGB color values + brightness.
  */
-class ColorRGBLight : public GPIOOutputs {
+class ColorHandlerRGB : public ColorHandler {
  public:
   bool set_light_color_values(light::LightColorValues v) {
     light_mode = LIGHT_MODE_RGB;
 
-#ifdef HAS_COLOR_MODES
     if (v.get_color_mode() != light::ColorMode::RGB) {
       return false;
     }
-#else
-    if (v.get_white() > 0.0f) {
-      return false;
-    }
-#endif
 
     // Determine the ring level for the color. This is a value between 0
     // and 7, determining in what ring of the RGB circle the requested
diff --git a/components/xiaomi_bslamp2/light/color_transition_handler.h b/components/xiaomi_bslamp2/light/color_transition_handler.h
deleted file mode 100644
index ebf940d..0000000
--- a/components/xiaomi_bslamp2/light/color_transition_handler.h
+++ /dev/null
@@ -1,136 +0,0 @@
-#pragma once
-
-#include "../common.h"
-#include "color_instant_handler.h"
-#include "interfaces.h"
-#include "gpio_outputs.h"
-
-namespace esphome {
-namespace xiaomi {
-namespace bslamp2 {
-
-/**
- * This class is used to handle specific light color transition requirements
- * for the device.
- *
- * When using the default ESPHome logic, transitioning is done by
- * transitioning all light properties linearly from the original values to
- * the new values, and letting the light output object translate these
- * properties into light outputs on every step of the way. While this does
- * work, it does not work nicely.
- *
- * For example, when transitioning from warm to cold white light, the color
- * temperature would be transitioned from the old value to the new value.
- * While doing so, the transition hits the middle white light setting, which
- * shows up as a bright flash in the middle of the transition. The original
- * firmware however, shows a smooth transition from warm to cold white
- * light, without any flash.
- *
- * This class handles transitions by not varying the light properties over
- * time, but by transitioning the LEDC duty cycle output levels over time.
- * This matches the behavior of the original firmware.
- */
-class ColorTransitionHandler : public GPIOOutputs {
- public:
-  ColorTransitionHandler(LightStateTransformerInspector *inspector) : transformer_(inspector) {}
-
-  light::LightColorValues get_end_values() { return end_light_values_; }
-
-  bool set_light_color_values(light::LightColorValues values) {
-    if (!light_state_has_active_transition_()) {
-      // Remember the last active light color values. When a transition
-      // is detected, we'll use these as the starting point. It is not
-      // possible to use the current values at that point, because the
-      // transition is already in progress by the time the transition
-      // is detected.
-      start_light_values_ = values;
-
-      active_ = false;
-      return false;
-    }
-
-    // When a fresh transition is started, then compute the GPIO outputs
-    // to use for both the start and end point. This transition handler
-    // will then transition linearly between these two.
-    if (is_fresh_transition_()) {
-      start_->set_light_color_values(start_light_values_);
-      end_light_values_ = transformer_->get_end_values();
-      end_->set_light_color_values(end_light_values_);
-      active_ = true;
-    }
-    // When a transition is modified, then use the current GPIO outputs
-    // as the new starting point.
-    else if (is_modified_transition_()) {
-      this->copy_to(start_);
-      end_light_values_ = transformer_->get_end_values();
-      end_->set_light_color_values(end_light_values_);
-    }
-
-    light_mode = end_->light_mode;
-    progress_ = transformer_->get_progress();
-
-    // Determine required GPIO outputs for current transition progress.
-
-    // In night light mode, do not use actual transitions. Transitioning
-    // between colors at the very low LED output levels of the night light,
-    // results in light drops, which are plain ugly to watch.
-    if (light_mode == "night") {
-      red = end_->red;
-      green = end_->green;
-      blue = end_->blue;
-      white = end_->white;
-    }
-    // In other light modes, apply smooth transitioning.
-    else {
-      auto smoothed = light::LightTransitionTransformer::smoothed_progress(progress_);
-      red = esphome::lerp(smoothed, start_->red, end_->red);
-      green = esphome::lerp(smoothed, start_->green, end_->green);
-      blue = esphome::lerp(smoothed, start_->blue, end_->blue);
-      white = esphome::lerp(smoothed, start_->white, end_->white);
-    }
-
-    return true;
-  }
-
- protected:
-  bool active_ = false;
-  float progress_ = 0.0f;
-  LightStateTransformerInspector *transformer_;
-  light::LightColorValues start_light_values_;
-  light::LightColorValues end_light_values_;
-  GPIOOutputs *start_ = new ColorInstantHandler();
-  GPIOOutputs *end_ = new ColorInstantHandler();
-
-  /**
-   * Checks if the LightState currently has an active LightTransformer.
-   */
-  bool light_state_has_active_transition_() {
-    if (!transformer_->is_active())
-      return false;
-    if (!transformer_->is_transition())
-      return false;
-    return true;
-  }
-
-  /**
-   * Checks if a fresh transitioning is started.
-   * A transitioning is fresh when no existing transition is active.
-   */
-  bool is_fresh_transition_() { return active_ == false; }
-
-  /**
-   * Checks if a new end state is set, while an existing transition
-   * is active. This might be detected in two ways:
-   * - the end color has been updated
-   * - the progress has been reverted
-   */
-  bool is_modified_transition_() {
-    auto new_end_light_values = transformer_->get_end_values();
-    auto new_progress = transformer_->get_progress();
-    return (new_end_light_values != end_light_values_ || new_progress < progress_);
-  }
-};
-
-}  // namespace bslamp2
-}  // namespace xiaomi
-}  // namespace esphome
diff --git a/components/xiaomi_bslamp2/light/interfaces.h b/components/xiaomi_bslamp2/light/interfaces.h
index f9e47cb..1c69a41 100644
--- a/components/xiaomi_bslamp2/light/interfaces.h
+++ b/components/xiaomi_bslamp2/light/interfaces.h
@@ -4,22 +4,6 @@ namespace esphome {
 namespace xiaomi {
 namespace bslamp2 {
 
-/**
- * This is an interface definition that is used to extend the LightState
- * class with functionality to inspect LightTransformer data from
- * within other classes.
- *
- * This interface is required for the ColorTransitionHandler, so it can
- * check whether or not a light color transition is in progress.
- */
-class LightStateTransformerInspector {
- public:
-  virtual bool is_active() = 0;
-  virtual bool is_transition() = 0;
-  virtual light::LightColorValues get_end_values() = 0;
-  virtual float get_progress() = 0;
-};
-
 /**
  * This is an interface definition that is used to extend the LightState
  * class with functionality for disco actions (immediate light updates,
diff --git a/components/xiaomi_bslamp2/light/light_modes.h b/components/xiaomi_bslamp2/light/light_modes.h
deleted file mode 100644
index 2111d95..0000000
--- a/components/xiaomi_bslamp2/light/light_modes.h
+++ /dev/null
@@ -1,15 +0,0 @@
-#pragma once
-
-namespace esphome {
-namespace xiaomi {
-namespace bslamp2 {
-
-static const std::string LIGHT_MODE_UNKNOWN{"unknown"};
-static const std::string LIGHT_MODE_OFF{"off"};
-static const std::string LIGHT_MODE_RGB{"rgb"};
-static const std::string LIGHT_MODE_WHITE{"white"};
-static const std::string LIGHT_MODE_NIGHT{"night"};
-
-}  // namespace bslamp2
-}  // namespace xiaomi
-}  // namespace esphome
diff --git a/components/xiaomi_bslamp2/light/light_output.h b/components/xiaomi_bslamp2/light/light_output.h
index 4a399c8..7d14e79 100644
--- a/components/xiaomi_bslamp2/light/light_output.h
+++ b/components/xiaomi_bslamp2/light/light_output.h
@@ -2,8 +2,9 @@
 
 #include "../common.h"
 #include "../light_hal.h"
-#include "color_instant_handler.h"
-#include "color_transition_handler.h"
+#include "color_handler_chain.h"
+#include "light_transformer.h"
+#include "esphome/core/component.h"
 #include "esphome/components/ledc/ledc_output.h"
 
 namespace esphome {
@@ -28,20 +29,16 @@ class XiaomiBslamp2LightOutput : public Component, public light::LightOutput {
    */
   light::LightTraits get_traits() override {
     auto traits = light::LightTraits();
-#ifdef HAS_COLOR_MODES
     traits.set_supported_color_modes({light::ColorMode::RGB, light::ColorMode::COLOR_TEMPERATURE});
-#else
-    traits.set_supports_rgb(true);
-    traits.set_supports_color_temperature(true);
-    traits.set_supports_brightness(true);
-    traits.set_supports_rgb_white_value(false);
-    traits.set_supports_color_interlock(true);
-#endif
     traits.set_min_mireds(MIRED_MIN);
     traits.set_max_mireds(MIRED_MAX);
     return traits;
   }
 
+  std::unique_ptr<light::LightTransformer> create_default_transition() override {
+    return make_unique<XiaomiBslamp2LightTransitionTransformer>(light_);
+  }
+
   void add_on_light_mode_callback(std::function<void(std::string)> &&callback) {
     light_mode_callback_.add(std::move(callback));
   }
@@ -56,21 +53,9 @@ class XiaomiBslamp2LightOutput : public Component, public light::LightOutput {
   void write_state(light::LightState *state) {
     auto values = state->current_values;
 
-    // The color must either be set instantly, or the color is
-    // transitioning to an end color. The transition handler will do its
-    // own inspection to see if a transition is currently active or not.
-    // Based on the outcome, use either the instant or transition handler.
-    GPIOOutputs *delegate;
-    if (transition_handler_->set_light_color_values(values)) {
-      delegate = transition_handler_;
-      light_mode_callback_.call(delegate->light_mode);
-      state_callback_.call(transition_handler_->get_end_values());
-    } else {
-      instant_handler_->set_light_color_values(values);
-      delegate = instant_handler_;
-      light_mode_callback_.call(delegate->light_mode);
-      state_callback_.call(values);
-    }
+    color_handler_chain->set_light_color_values(values);
+    light_mode_callback_.call(color_handler_chain->light_mode);
+    state_callback_.call(values);
 
     // Note: one might think that it is more logical to turn on the LED
     // circuitry master switch after setting the individual channels,
@@ -80,8 +65,8 @@ class XiaomiBslamp2LightOutput : public Component, public light::LightOutput {
     if (values.get_state() != 0)
       light_->turn_on();
 
-    // Apply the current GPIO output levels from the selected handler.
-    light_->set_rgbw(delegate->red, delegate->green, delegate->blue, delegate->white);
+    // Apply the GPIO output levels as defined by the color handler.
+    light_->set_state(color_handler_chain);
 
     if (values.get_state() == 0)
       light_->turn_off();
@@ -89,21 +74,9 @@ class XiaomiBslamp2LightOutput : public Component, public light::LightOutput {
 
  protected:
   LightHAL *light_;
-  ColorTransitionHandler *transition_handler_;
-  ColorInstantHandler *instant_handler_ = new ColorInstantHandler();
+  ColorHandler *color_handler_chain = new ColorHandlerChain();
   CallbackManager<void(std::string)> light_mode_callback_{};
   CallbackManager<void(light::LightColorValues)> state_callback_{};
-
-  friend class XiaomiBslamp2LightState;
-
-  /**
-   * Called by the XiaomiBslamp2LightState class, to set the object that can be
-   * used to access the protected LightTransformer data from the LightState
-   * object.
-   */
-  void set_transformer_inspector(LightStateTransformerInspector *exposer) {
-    transition_handler_ = new ColorTransitionHandler(exposer);
-  }
 };
 
 }  // namespace bslamp2
diff --git a/components/xiaomi_bslamp2/light/light_state.h b/components/xiaomi_bslamp2/light/light_state.h
index 5ff05b4..1f18cd3 100644
--- a/components/xiaomi_bslamp2/light/light_state.h
+++ b/components/xiaomi_bslamp2/light/light_state.h
@@ -24,22 +24,12 @@ struct MyLightStateRTCState {
 /**
  * A custom LightState class for the Xiaomi Bedside Lamp 2.
  *
- * This class is used by the ColorTransitionHandler class to inspect if
- * an ongoing light color transition is active in the LightState object.
- *
- * It is also used by the DiscoAction to apply immediate light output
+ * It is used by the DiscoAction to apply immediate light output
  * updates, without saving or publishing the new state.
  */
-class XiaomiBslamp2LightState : public light::LightState, public LightStateTransformerInspector, public LightStateDiscoSupport {
+class XiaomiBslamp2LightState : public light::LightState, public LightStateDiscoSupport {
  public:
-  XiaomiBslamp2LightState(const std::string &name, XiaomiBslamp2LightOutput *output) : light::LightState(name, output) {
-    output->set_transformer_inspector(this);
-  }
-
-  bool is_active() { return transformer_ != nullptr; }
-  bool is_transition() { return transformer_->is_transition(); }
-  light::LightColorValues get_end_values() { return transformer_->get_end_values(); }
-  float get_progress() { return transformer_->get_progress(); }
+  XiaomiBslamp2LightState(const std::string &name, XiaomiBslamp2LightOutput *output) : light::LightState(name, output) { }
 
   void disco_stop() {
     MyLightStateRTCState recovered{};
diff --git a/components/xiaomi_bslamp2/light/light_transformer.h b/components/xiaomi_bslamp2/light/light_transformer.h
new file mode 100644
index 0000000..c70d631
--- /dev/null
+++ b/components/xiaomi_bslamp2/light/light_transformer.h
@@ -0,0 +1,62 @@
+#pragma once
+
+#include "../common.h"
+#include "../light_hal.h" 
+#include "color_handler_chain.h"
+#include "esphome/components/light/light_transformer.h"
+#include "esphome/components/light/light_color_values.h"
+
+namespace esphome {
+namespace xiaomi {
+namespace bslamp2 {
+
+/**
+ * A LightTransitionTransformer class for the Xiaomi Mijia Bedside Lamp 2.
+ */
+class XiaomiBslamp2LightTransitionTransformer : public light::LightTransitionTransformer {
+ public:
+  explicit XiaomiBslamp2LightTransitionTransformer(LightHAL *light) : light_(light) { }
+
+  bool is_finished() override {
+      return force_finish_ || get_progress_() >= 1.0f;
+  }
+
+  void start() override {
+    // Compute the GPIO outputs to use for the end point.
+    // This light transition transformer will then transition linearly between
+    // the current GPIO outputs and the target ones.
+    light_->copy_to(start_);
+    end_->set_light_color_values(target_values_);
+  }
+
+  optional<light::LightColorValues> apply() override { 
+    if (end_->light_mode == "night") {
+      light_->set_state(end_);
+      force_finish_ = true;
+    }
+    else {
+      auto smoothed = light::LightTransitionTransformer::smoothed_progress(get_progress_());
+      light_->set_rgbw(
+        esphome::lerp(smoothed, start_->red, end_->red),
+        esphome::lerp(smoothed, start_->green, end_->green),
+        esphome::lerp(smoothed, start_->blue, end_->blue),
+        esphome::lerp(smoothed, start_->white, end_->white));
+    }
+
+    if (is_finished()) {
+      return target_values_;
+    } else {
+      return {};
+    }
+  }
+
+ protected:
+  LightHAL *light_;
+  bool force_finish_ = false;
+  GPIOOutputValues *start_ = new GPIOOutputValues();
+  ColorHandler *end_ = new ColorHandlerChain();
+};
+
+}  // namespace bslamp2
+}  // namespace xiaomi
+}  // namespace esphome
diff --git a/components/xiaomi_bslamp2/light_hal.h b/components/xiaomi_bslamp2/light_hal.h
index 9711b9b..dfeff8c 100644
--- a/components/xiaomi_bslamp2/light_hal.h
+++ b/components/xiaomi_bslamp2/light_hal.h
@@ -8,39 +8,86 @@ namespace esphome {
 namespace xiaomi {
 namespace bslamp2 {
 
-class LightHAL : Component {
+static const std::string LIGHT_MODE_UNKNOWN{"unknown"};
+static const std::string LIGHT_MODE_OFF{"off"};
+static const std::string LIGHT_MODE_RGB{"rgb"};
+static const std::string LIGHT_MODE_WHITE{"white"};
+static const std::string LIGHT_MODE_NIGHT{"night"};
+
+class GPIOOutputValues {
  public:
-  void set_red_pin(ledc::LEDCOutput *pin) { red_ = pin; }
-  void set_green_pin(ledc::LEDCOutput *pin) { green_ = pin; }
-  void set_blue_pin(ledc::LEDCOutput *pin) { blue_ = pin; }
-  void set_white_pin(ledc::LEDCOutput *pin) { white_ = pin; }
-  void set_master1_pin(gpio::GPIOBinaryOutput *pin) { master1_ = pin; }
-  void set_master2_pin(gpio::GPIOBinaryOutput *pin) { master2_ = pin; }
+  float red = 0.0f;
+  float green = 0.0f;
+  float blue = 0.0f;
+  float white = 0.0f;
+  std::string light_mode = LIGHT_MODE_OFF;
 
-  void turn_on() {
-    master1_->turn_on();
-    master2_->turn_on();
+  /**
+   * Copies the current output values to another GPIOOutputValues object.
+   */
+  void copy_to(GPIOOutputValues *other) {
+    other->red = red;
+    other->green = green;
+    other->blue = blue;
+    other->white = white;
+    other->light_mode = light_mode;
   }
 
+  void log(const char *prefix) { ESP_LOGD(TAG, "%s: RGB=[%f,%f,%f], white=%f", prefix, red, green, blue, white); }
+};
+
+class LightHAL : Component, public GPIOOutputValues {
+ public:
+  void set_red_pin(ledc::LEDCOutput *pin) { red_pin_ = pin; }
+  void set_green_pin(ledc::LEDCOutput *pin) { green_pin_ = pin; }
+  void set_blue_pin(ledc::LEDCOutput *pin) { blue_pin_ = pin; }
+  void set_white_pin(ledc::LEDCOutput *pin) { white_pin_ = pin; }
+  void set_master1_pin(gpio::GPIOBinaryOutput *pin) { master1_pin_ = pin; }
+  void set_master2_pin(gpio::GPIOBinaryOutput *pin) { master2_pin_ = pin; }
+
+  /**
+   * Turn on the master switch for the LEDs.
+   */
+  void turn_on() {
+    master1_pin_->turn_on();
+    master2_pin_->turn_on();
+  }
+ 
+  /**
+   * Turn off the master switch for the LEDs.
+   */
   void turn_off() {
-    master1_->turn_off();
-    master2_->turn_off();
+    master1_pin_->turn_off();
+    master2_pin_->turn_off();
+  }
+
+  void set_state(GPIOOutputValues *new_state) {
+    new_state->copy_to(this);
+    red_pin_->set_level(this->red);
+    green_pin_->set_level(this->green);
+    blue_pin_->set_level(this->blue);
+    white_pin_->set_level(this->white);
   }
 
   void set_rgbw(float r, float g, float b, float w) {
-    red_->set_level(r);
-    green_->set_level(g);
-    blue_->set_level(b);
-    white_->set_level(w);
+    red_pin_->set_level(r);
+    green_pin_->set_level(g);
+    blue_pin_->set_level(b);
+    white_pin_->set_level(w);
+
+    this->red = r;
+    this->green = g;
+    this->blue = b;
+    this->white = w;
   }
 
  protected:
-  ledc::LEDCOutput *red_;
-  ledc::LEDCOutput *green_;
-  ledc::LEDCOutput *blue_;
-  ledc::LEDCOutput *white_;
-  gpio::GPIOBinaryOutput *master1_;
-  gpio::GPIOBinaryOutput *master2_;
+  ledc::LEDCOutput *red_pin_;
+  ledc::LEDCOutput *green_pin_;
+  ledc::LEDCOutput *blue_pin_;
+  ledc::LEDCOutput *white_pin_;
+  gpio::GPIOBinaryOutput *master1_pin_;
+  gpio::GPIOBinaryOutput *master2_pin_;
 };
 
 }  // namespace bslamp2
diff --git a/doc/installation.md b/doc/installation.md
index e04ff72..4732382 100644
--- a/doc/installation.md
+++ b/doc/installation.md
@@ -2,7 +2,7 @@
 
 # Installation guide
 
-The code must be compiled into a firmware using ESPHome v1.19.0 or later. Therefore, a prerequisite
+The code must be compiled into a firmware using ESPHome 2021.8.0 or later. Therefore, a prerequisite
 is that you have ESPHome up and running in some form (command line, docker container, web dashboard,
 possibly from within Home Assistant as an add-on). For information on this, please refer to the
 documentation on the [ESPHome website](https://esphome.io).
diff --git a/doc/testplan.md b/doc/testplan.md
index b500829..8de87f5 100644
--- a/doc/testplan.md
+++ b/doc/testplan.md
@@ -65,3 +65,11 @@ been introduced.
 ## Step 3: Release the new version
 
 Only after performing these tests successfully, the new version can be released.
+
+Before release, check if the minimum version requirement for ESPHome is documented
+correctly in the following files:
+
+  * doc/installation.md
+  * README.md
+  * CHANGELOG.md
+
diff --git a/example.yaml b/example.yaml
index d5769ac..11d934a 100644
--- a/example.yaml
+++ b/example.yaml
@@ -3,17 +3,18 @@
 # --------------------------------------------------------------------------
 
 substitutions:
-  name: bedside_lamp
+  name: bedside-lamp
   friendly_name: Bedside Lamp
   transition_length: 500ms
 
-  # Derive component identifiers, based on the name.
-  id_light: ${name}
-  id_light_mode: ${name}_light_mode
-  id_power_button: ${name}_power_button
-  id_color_button: ${name}_color_button
-  id_slider_level: ${name}_slider_level
-  id_front_panel_illumination: ${name}_front_panel_illumination
+  # Component identifiers.
+  prefix: bedside_lamp
+  id_light: ${prefix}
+  id_light_mode: ${prefix}_light_mode
+  id_power_button: ${prefix}_power_button
+  id_color_button: ${prefix}_color_button
+  id_slider_level: ${prefix}_slider_level
+  id_front_panel_illumination: ${prefix}_front_panel_illumination
 
 # --------------------------------------------------------------------------
 # Use your own preferences for these components.
@@ -39,9 +40,6 @@ api:
   # flicker.
   reboot_timeout: 0s
 
-api:
-  password: !secret api_password
-
   # If you want to use light presets (see below) from Home Assistant,
   # then you can expose the required functionality as a service here.
   # This is an example of how you could expose the activation of a preset.
@@ -190,7 +188,7 @@ light:
 # for the lamp in Home Assistant.
 text_sensor:
   - platform: xiaomi_bslamp2
-    name: ${name} Light Mode
+    name: ${friendly_name} Light Mode
     id: ${id_light_mode}
 
 # This float output controls the front panel illumination + level indicator.