/*
 * Wemos d1 mini
 * Flash Size: 4M (1M SPIFFS)
 */

#include <Homie.h>
#define FW_NAME "tischlicht"
#define FW_VERSION "1.0.1"

//#define DEBUG //turns on continuous serial debug printing

/*
 * To Update configuration (wifi credentials) from data/homie/config.json:
 * Connect to serial. On ESP-12E connect flash jumper
 * Apply Power to ESP
 * Optional: upload sketch
 * Tools - Sketch Data Upload
 * Remove jumper
 * /

//http://homieiot.github.io/homie-esp8266/docs/develop/configuration/json-configuration-file/
//curl -X PUT http://homie.config/config -d @config.json --header "Content-Type: application/json"
/*Example data/homie/config.json
{
"name": "pringleslight",
"device_id": "pringleslight",
"wifi": {
"ssid": "CTDO-IoT",
"password": "12345678"
},
"mqtt": {
"host": "raum.ctdo.de",
"port": 1883,
"auth": false
},
"ota": {
"enabled": false
}
}
 */

HomieNode lightNode("light", "light");

//(pin x) nunbering CCW starting with rst


#define LED_WW 14 //D5 = GPIO14 (pin5)
#define LED_CW 12 //D6 = GPIO12 (pin6)

#define BTN_A 13 //D7 = GPIO13 (pin 7)
#define BTN_B 15 //D8 = GPIO15 (pin 10)


/*
 * VCC (pin 8)
 * GND (pin 9)
 */

#define PWM_MAX 1023 //10 bit dac
#define PWM_FREQUENCY 1000 //default: 1000 Hz

boolean sleep=true; //true turns lights off. like set_..
float sleep_fadevalue=0; //0=off, 1=on
float sleep_fadevalue_change_per_loop=0.01; //fixed value. For manual calculatoin: sleep_fadevalue_change_per_loop=_difference/fadetime*UPDATETIME;

float set_brightness=2; //0 to 1
#define BRIGHTNESS_MIN 0.0
#define BRIGHTNESS_MAX 2.0 //if temperature is in between both strips brightness of 2 means both are at full power. otherwise brightness will be clipped
float brightness=set_brightness;
float brightness_change_per_loop=0; //will be calculated by Handler


#define TEMPERATURE_MIN 2760 //temperature of warm white leds
#define TEMPERATURE_MAX 5640//temperature of cold white leds
float set_temperature=(TEMPERATURE_MAX+TEMPERATURE_MIN)/2;
float temperature=set_temperature;
float temperature_change_per_loop=0; //will be calculated by Handler

uint16_t fadetime=0; //0=instant. value is time in milliseconds
#define FADETIME_MIN 0
#define FADETIME_MAX 60000

long last_updatetime=0;
#define UPDATETIME 10 //after how many ms pwm values will be updated

//Button stuff
#define BUTTONUPDATETIME 20
long last_buttonupdatetime=0;
uint8_t btnAstate=0; //for button state machine
long btnAtime=0;
uint8_t btnBstate=0; //for button state machine
long btnBtime=0;
#define BTNHOLDTIME 1000

boolean holdDirection_brightness=false;
boolean holdDirection_temperature=false;

#define HOLDBRIGHTNESSCHANGE_PER_LOOP 0.01 //depends on BUTTONUPDATETIME. BUTTONUPDATETIME/1000/HOLDBRIGHTNESSCHANGE_PER_LOOP=seconds to change a full cycle(0 to 1)
#define HOLDTEMPERATURECHANGE_PER_LOOP 10.0 //  (TEMPERATURE_MAX-TEMPERATURE_MIN)*BUTTONUPDATETIME/1000/HOLDBRIGHTNESSCHANGE_PER_LOOP=seconds to change a full cycle (min to max)

boolean flag_updatePWM=false; //if manually set brightness or temperature, set this flag

//Debug
long last_debugupdatetime=0;
#define DEBUGUPDATETIME 500

void setup() {
  Serial.begin(115200);
  Serial.println("Hello");
  pinMode(LED_WW, OUTPUT);
  pinMode(LED_CW, OUTPUT);
  analogWriteFreq(PWM_FREQUENCY);
  analogWrite(LED_CW, PWM_MAX); //high = off
  analogWrite(LED_WW, PWM_MAX); //high = off

  pinMode(BTN_A, INPUT);
  pinMode(BTN_B, INPUT);

  Homie_setFirmware(FW_NAME, FW_VERSION);
  Homie_setBrand(FW_NAME);
  Homie.setLoopFunction(loopHandler);

  lightNode.advertise("brightness").settable(brightnessHandler);
  lightNode.advertise("temperature").settable(temperatureHandler);
  lightNode.advertise("fadetime").settable(fadetimeHandler);
  lightNode.advertise("sleep").settable(sleepHandler);
  

  Homie.setup();
}

void loop() {
  Homie.loop();  
}

void loopHandler() {
  long loopmillis=millis();

  

  if (loopmillis >= last_buttonupdatetime+BUTTONUPDATETIME ) {
    last_buttonupdatetime = loopmillis;


    // #### Button A ####
    boolean flag_btnApress=false; //short press on release
    boolean flag_btnAholdstart=false; //long press on start
    boolean flag_btnAhold=false; //long press after long press time
    boolean flag_btnAholdrelease=false; //long press on release
    
    if (digitalRead(BTN_A)) { //Button State Machine
      switch (btnAstate) {
        case 0: //was not pressed
          btnAstate=1;
          btnAtime=loopmillis; //start timer
        break;
        case 1: //was pressed last time checked
          if (loopmillis>btnAtime+BTNHOLDTIME) {
            btnAstate=2;
            flag_btnAholdstart=true;
          }
        break;
        case 2: //button hold time reached
          flag_btnAhold=true;
        break;
      }
    }else {
      if (btnAstate==1) { //short press
        btnAstate=0; //reset state
        flag_btnApress=true;
      }else if(btnAstate==2) { //long press released
        flag_btnAholdrelease=true;
        btnAstate=0; //reset state
      }
    }
    // #### END Button A Check ####

    // #### Button B ####
    boolean flag_btnBpress=false; //short press on release
    boolean flag_btnBholdstart=false; //long press on start
    boolean flag_btnBhold=false; //long press after long press time
    boolean flag_btnBholdrelease=false; //long press on release
    
    if (digitalRead(BTN_B)) { //Button State Machine
      switch (btnBstate) {
        case 0: //was not pressed
          btnBstate=1;
          btnBtime=loopmillis; //start timer
        break;
        case 1: //was pressed last time checked
          if (loopmillis>btnBtime+BTNHOLDTIME) {
            btnBstate=2;
            flag_btnBholdstart=true;
          }
        break;
        case 2: //button hold time reached
          flag_btnBhold=true;
        break;
      }
    }else {
      if (btnBstate==1) { //short press
        btnBstate=0; //reset state
        flag_btnBpress=true;
      }else if(btnBstate==2) { //long press released
        flag_btnBholdrelease=true;
        btnBstate=0; //reset state
      }
    }
    // #### END Button B Check ####
    

    //Button handling
    if (flag_btnApress || flag_btnBpress){ //short press either button
      sleep = !sleep; //switch on/off
      flag_updatePWM=true; //update pwm values
    }
    if (sleep && flag_btnAholdstart ) { //in sleep mode and brightness button held down
      sleep=false; //enabled light
      set_brightness=0; //reset brightness
      brightness=set_brightness; //immediately
    }

    if (!sleep) { //only change values if not in sleep mode
      // Button A Longpress Handling
      if (flag_btnAholdstart) {
        /*  //Change only hold direction at extremes
        if (set_brightness>=BRIGHTNESS_MAX) { //if hold started with brightness at one extreme
          holdDirection_brightness=false; //direction decrease
        }
        if (set_brightness<=BRIGHTNESS_MIN) { //if hold started with brightness at one extreme
          holdDirection_brightness=true; //direction increase
        }
        */
        holdDirection_brightness=!holdDirection_brightness; //change direction everytime
        
      }
      if (flag_btnAhold) { //brightness
        if (holdDirection_brightness) {
          set_brightness += HOLDBRIGHTNESSCHANGE_PER_LOOP;
        }else{
          set_brightness -= HOLDBRIGHTNESSCHANGE_PER_LOOP;  
        }
        set_brightness = constrain(set_brightness, BRIGHTNESS_MIN, BRIGHTNESS_MAX);
  
        brightness=set_brightness; //change immediately
        flag_updatePWM=true; //update pwm values
      }
      if (flag_btnAholdrelease) {
        
      }

      // Button B Longpress Handling
      if (flag_btnBholdstart) {
        /*  //Change only hold direction at extremes
        if (set_temperature>=TEMPERATURE_MAX) { //if hold started with brightness at one extreme
          holdDirection_temperature=false; //direction decrease
        }
        if (set_temperature<=TEMPERATURE_MIN) { //if hold started with brightness at one extreme
          holdDirection_temperature=true; //direction increase
        }
        */
        holdDirection_temperature=!holdDirection_temperature; //change direction everytime
      }
      if (flag_btnBhold) { //brightness
        if (holdDirection_temperature) {
          set_temperature += HOLDTEMPERATURECHANGE_PER_LOOP;
        }else{
          set_temperature -= HOLDTEMPERATURECHANGE_PER_LOOP;  
        }
        set_temperature = constrain(set_temperature, TEMPERATURE_MIN, TEMPERATURE_MAX);
  
        temperature=set_temperature; //change immediately
        flag_updatePWM=true; //update pwm values
      }
      if (flag_btnBholdrelease) {
        
      }
    }

  }

  if (loopmillis >= last_updatetime+UPDATETIME ) {
    last_updatetime = loopmillis;

    
    float old_brightness = brightness; //store last brightness
    if ( (brightness_change_per_loop<0 && brightness>set_brightness) || (brightness_change_per_loop>0 && brightness<set_brightness)) { //if brightness not reached
      brightness += brightness_change_per_loop;
      if ( ( old_brightness <= set_brightness && set_brightness <= brightness ) || ( old_brightness >= set_brightness && set_brightness >= brightness ) ) { //overshot set value
        brightness = set_brightness;
      }
      flag_updatePWM=true; //force update
    }
    
    float old_temperature = temperature; //store last temperature
    if ( (temperature_change_per_loop<0 && temperature>set_temperature) || (temperature_change_per_loop>0 && temperature<set_temperature)) { //if temperature not reached
      temperature += temperature_change_per_loop;
      if ( ( old_temperature <= set_temperature && set_temperature <= temperature ) || ( old_temperature >= set_temperature && set_temperature >= temperature ) ) { //overshot set value
        temperature = set_temperature;
      }
      flag_updatePWM=true; //force update
    }

    //Sleep
    if ( (sleep && sleep_fadevalue>0) || (!sleep && sleep_fadevalue<1) ) { //not fully turned off or on
      if (sleep) { //turn off
        sleep_fadevalue-=sleep_fadevalue_change_per_loop;
      }else{ //turn on
        sleep_fadevalue+=sleep_fadevalue_change_per_loop;
      }
      if (sleep_fadevalue>1) { sleep_fadevalue=1; } //limit
      if (sleep_fadevalue<0) { sleep_fadevalue=0; }
      flag_updatePWM=true; //force update
    }

    //calculate and update pwm
    if (brightness != set_brightness || temperature != set_temperature || flag_updatePWM) { //if target not reached
      flag_updatePWM=false; // reset flag
      //calculate pwm values
      uint16_t pwmCW;
      uint16_t pwmWW;
      float temp=mapFloat(temperature, TEMPERATURE_MIN, TEMPERATURE_MAX, 0.0,1.0); //0=warmwhite, 1=coldwhite
      pwmCW=(brightness*sleep_fadevalue)*PWM_MAX*temp;
      pwmWW=(brightness*sleep_fadevalue)*PWM_MAX*(1-temp);

      if (pwmCW>PWM_MAX) { pwmCW=PWM_MAX; } //limit
      if (pwmWW>PWM_MAX) { pwmWW=PWM_MAX; } //limit

      analogWrite(LED_WW, PWM_MAX-pwmWW); //full pwm is led off
      analogWrite(LED_CW, PWM_MAX-pwmCW); //full pwm is led off

      /*
      if (!sleep) {
        analogWrite(LED_WW, PWM_MAX-pwmWW); //full pwm is led off
        analogWrite(LED_CW, PWM_MAX-pwmCW); //full pwm is led off
      }else{
        analogWrite(LED_WW, PWM_MAX); //light off
        analogWrite(LED_CW, PWM_MAX); //light off
      }*/
    }
  }

  #ifdef DEBUG
  if (loopmillis >= last_debugupdatetime+DEBUGUPDATETIME ) {
    last_debugupdatetime = loopmillis;

    if (sleep) { Serial.print("Sleep. "); }
    Serial.print("bright=");
    Serial.print(brightness);
    Serial.print(" set=");
    Serial.print(set_brightness);
    Serial.print("| temp=");
    Serial.print(temperature);
    Serial.print(" set=");
    Serial.print(set_temperature);
    Serial.print(" change=");
    Serial.print(brightness_change_per_loop);
    Serial.print(" sleep_fadevalue=");
    Serial.println(sleep_fadevalue);

    /*
    uint16_t pwmCW;
    uint16_t pwmWW;
    float temp=mapFloat(temperature, TEMPERATURE_MIN, TEMPERATURE_MAX, 0.0,1.0); //0=warmwhite, 1=coldwhite
    pwmCW=brightness*PWM_MAX*temp;
    pwmWW=brightness*PWM_MAX*(1-temp);

    if (pwmCW>PWM_MAX) { pwmCW=PWM_MAX; } //limit
    if (pwmWW>PWM_MAX) { pwmWW=PWM_MAX; } //limit
    
    if (!sleep) {
      Serial.print(PWM_MAX-pwmWW);
      Serial.print(", ");
      Serial.println(PWM_MAX-pwmCW);
    }else{
      Serial.print(0);
      Serial.print(", ");
      Serial.println(0);
    }
    */
    
  }
  #endif

}



bool brightnessHandler(const HomieRange& range, const String& value) {
  if (range.isRange) {
    return false; //if range is given but index is not in allowed range
  }
  Homie.getLogger() << "brightness " << ": " << value << endl;
  lightNode.setProperty("brightness").send(value);
  if (value.toFloat() >= BRIGHTNESS_MIN && value.toFloat() <= BRIGHTNESS_MAX) {
    set_brightness=value.toFloat(); 
  }else {
    Homie.getLogger() << "Value outside range" << endl;
    return false;  
  }

  float _difference=set_brightness-brightness;
  if (fadetime>0) {
    brightness_change_per_loop = _difference/fadetime*UPDATETIME;
  } else { //special case for instant change
    brightness_change_per_loop = _difference;
  }
  
  return true;
}

bool temperatureHandler(const HomieRange& range, const String& value) {
  if (range.isRange) {
    return false; //if range is given but index is not in allowed range
  }
  Homie.getLogger() << "temperature " << ": " << value << endl;
  lightNode.setProperty("temperature").send(value);
  
  if (value.toFloat() >= TEMPERATURE_MIN && value.toFloat() <= TEMPERATURE_MAX) {
    set_temperature=value.toFloat(); 
  }else {
    Homie.getLogger() << "Value outside range" << endl;
    return false;  
  }

  float _difference=set_temperature-temperature;
  if (fadetime>0) {
    temperature_change_per_loop = _difference/fadetime*UPDATETIME;
  } else { //special case for instant change
    temperature_change_per_loop = _difference;
  }
  
  
  return true;
}

bool fadetimeHandler(const HomieRange& range, const String& value) { //fadetime for temperature and brightness in milliseconds
  if (range.isRange) {
    return false; //if range is given but index is not in allowed range
  }
  Homie.getLogger() << "fadetime " << ": " << value << endl;
  lightNode.setProperty("fadetime").send(value);
  
  if (value.toInt() >= FADETIME_MIN && value.toInt() <= FADETIME_MAX) {
    fadetime=value.toInt(); 
  }else {
    Homie.getLogger() << "Value outside range" << endl;
    return false;  
  }
  
  return true;
}

bool sleepHandler(const HomieRange& range, const String& value) { //change on off
  if (range.isRange) {
    return false; //if range is given but index is not in allowed range
  }
  Homie.getLogger() << "sleep " << ": " << value << endl;
  lightNode.setProperty("sleep").send(value);
  
  if (value.toInt() == 0) {
    sleep=true;
  } else if(value.toInt() == 1) {
    sleep=false;
  } else {
    Homie.getLogger() << "Value outside range" << endl;
    return false;  
  }

  flag_updatePWM=true; //force update
  
  return true;
}

float mapFloat(float x, float in_min, float in_max, float out_min, float out_max) {
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}