#include <Arduino.h>
#include <U8g2lib.h>

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif

#define ButtonR 9
#define ButtonG 10
#define ButtonB 11
#define ButtonY 12
#define ButtonM 13
#define TempPin A0
#define BatteryPin A1
#define ADCtoVbatt 0.12 //Conversion constant for ADC to Voltage for battery
#define BattZero 3.2 //Zero percent voltage
#define BattScale 100 //Scale factor for battery conversion
#define UpdateInterval 1000

uint8_t Buttons = 0;
uint16_t TempLogPosition = 0;
uint8_t TempLog[400];
uint16_t TempFifteenSec = 0;
uint8_t TempFifteenCursor = 0;
uint16_t TimerOld = 0;
uint16_t Timer = 0;
uint8_t TimerMin = 0;
uint16_t TimerPreheatS = 0;
uint8_t TimerPreheatM = 0;
uint16_t TempAvg = 0;
uint16_t TempPeaks[10];
uint16_t TempCurrent = 0;
float BattVoltage = 0.0;
uint8_t BattPercentage = 0;
unsigned long pMillis = 0;

struct {
   unsigned int QuarterMin : 1;
   unsigned int HalfMin : 1;
   unsigned int FullMin : 1;
   unsigned int Error : 1;
   unsigned int MaxReached : 1;
   unsigned int Record : 1;
   unsigned int Pause : 1;
   unsigned int Stop : 1;
   unsigned int Scale : 2; //0 = SCALE400; 1 = SCALE200; 2 = SCALE100; 3 = SCALE50
} Status;

void setup() {
  // put your setup code here, to run once:
  u8g2.begin();
  pinMode(ButtonR, INPUT);
  pinMode(ButtonG, INPUT);
  pinMode(ButtonB, INPUT);
  pinMode(ButtonY, INPUT);
  pinMode(ButtonM, INPUT);
  batteryMeasurement();
  Status.QuarterMin = 1;
  Status.HalfMin = 0;
  Status.FullMin = 0;
  Status.Error = 0;
  Status.MaxReached = 0;
  Status.Record = 0;
  Status.Pause = 0;
  Status.Stop = 1;
  Status.Scale = 0;
  TempCurrent = getTemperature(TempPin);
  
  
//----Start screen
  u8g2.clearBuffer();					// clear the internal memory
  u8g2.setFont(u8g2_font_tiny5_tf);	// choose a suitable font
  drawScreenBase();

  u8g2.sendBuffer();
//----End




}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void loop() {
  // put your main code here, to run repeatedly:
if(digitalRead(ButtonR) == 0){ //START PAUSE button
  Buttons = 1;
  if(Status.Stop == 1){

  Status.Record = 1;
  //Status.Stop = 0;
  }
  else if(Status.Pause == 1){
    Status.Record = 1;
    Status.Pause = 0;

  }
  else if(Status.Record == 1){
    Status.Record = 0;
    Status.Pause = 1;

  }
  delay(1000);
}
else if(digitalRead(ButtonG) == 0){ //STOP button
  Buttons = 2;
}
else if(digitalRead(ButtonB) == 0){ //SCALE + button
  Buttons = 4;
}
else if(digitalRead(ButtonY) == 0){ //SCALE - button
  Buttons = 8;
}
else{
  Buttons = 0;
}

if(Status.Record == 1){
  if(Status.Stop == 1){ //check if the start just been pressed
    Status.Stop = 0; //clearing first start flag
    startTimer();

  }
  if(pMillis <= millis()-UpdateInterval){
    TimerIncrement();
    pMillis = millis();
    updateTT();
  }
  TempCurrent = getTemperature(TempPin);
  if(Timer == TimerOld+1){
    TempFifteenSec = TempFifteenSec + TempCurrent;
    TempFifteenCursor++;
    if (TempFifteenCursor == 15){
      TempFifteenCursor = 0;
      TempLog[TempLogPosition] = TempFifteenSec/15;
      TempFifteenSec = 0;
      
      
    }

  }

  u8g2.clearBuffer();					// clear the internal memory
  u8g2.setFont(u8g2_font_tiny5_tf);	// choose a suitable font
  drawScreenBase();

  
  plotGraph(TempLogPosition);

  u8g2.sendBuffer();



}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


/*
  u8g2.clearBuffer();					// clear the internal memory
  u8g2.setFont(u8g2_font_tiny5_tf);	// choose a suitable font
  u8g2.drawStr(0,10,"0123456789ABCDEabcde");	// write something to the internal memory
  u8g2.setCursor(0, 20);
  switch (Buttons){
  case 0: 
  u8g2.print("OFF");
  break;
  case 1:
  u8g2.print("RED");
  break;
  case 2:
  u8g2.print("GREEN");
  break;
  case 4:
  u8g2.print("BLUE");
  break;
  case 8:
  u8g2.print("YELLOW");
  break;
  }
  u8g2.setCursor(0, 40);
  u8g2.print(analogRead(TempPin));
  u8g2.setCursor(10, 60);
  u8g2.print(analogRead(BatteryPin));
  u8g2.sendBuffer();					// transfer internal memory to the display */
  delay(1000);  

}


void drawScreenBase(void){
  u8g2.setCursor(4, 5);
  TimerMin = Timer/60;
  u8g2.print(TimerMin);
  u8g2.setCursor(8, 5);
  u8g2.print(":");
  u8g2.setCursor(10, 5);
  u8g2.print(Timer-(TimerMin*60));

  TimerPreheatM = TimerPreheatS/60;

  u8g2.setCursor(16, 5);
  u8g2.print(TimerPreheatM);
  u8g2.setCursor(21, 5);
  u8g2.print(":");
  u8g2.setCursor(25, 5);
  u8g2.print(TimerPreheatS-(TimerPreheatM*60));

  u8g2.setCursor(36, 5);
  u8g2.print(TempAvg);
  u8g2.setCursor(40, 5);
  u8g2.print("F");

  u8g2.setCursor(50, 5);
  u8g2.print(TempCurrent);
  u8g2.setCursor(60, 5);
  u8g2.print("F");

  u8g2.setCursor(107, 5);
  u8g2.print(BattPercentage);
  u8g2.setCursor(115, 5);
  u8g2.print("%");

  drawBattery();

  u8g2.drawHLine(0, 6, 128); //Top line

  u8g2.drawHLine(0, 14, 128); //Middle line

  u8g2.drawHLine(0, 56, 128); //Bottom line
  
  for(int i = 1; i<33; i++){
    u8g2.drawPixel((i*4)-1, 57); //Digit marks
    };

    u8g2.setCursor(6, 64);
    u8g2.print("2");
    u8g2.setCursor(14, 64);
    u8g2.print("4");
    u8g2.setCursor(22, 64);
    u8g2.print("6");
    u8g2.setCursor(30, 64);
    u8g2.print("8");
    u8g2.setCursor(36, 64);
    u8g2.print("10");
    u8g2.setCursor(52, 64);
    u8g2.print("14");
    u8g2.setCursor(68, 64);
    u8g2.print("18");
    u8g2.setCursor(84, 64);
    u8g2.print("22");
    u8g2.setCursor(100, 64);
    u8g2.print("26");
    u8g2.setCursor(116, 64);
    u8g2.print("30");
    


  

};

void drawBattery(void){
  u8g2.drawFrame(121, 0, 7, 5);
  u8g2.drawVLine(120, 1, 3);
  if(BattPercentage>90){
    u8g2.drawBox(122, 1, 5, 3); //Battery percentage
  }
  else if(BattPercentage>70){
    u8g2.drawBox(123, 1, 4, 3); //Battery percentage
  }
  else if(BattPercentage>50){
    u8g2.drawBox(124, 1, 3, 3); //Battery percentage
  }
  else if(BattPercentage>30){
    u8g2.drawBox(125, 1, 2, 3); //Battery percentage
  }
  else if(BattPercentage>10){
    u8g2.drawVLine(126, 1, 3); //Battery percentage
  };




};

void batteryMeasurement(void){
  BattVoltage = ADCtoVbatt*analogRead(BatteryPin);
  BattPercentage = (BattVoltage-BattZero)*BattScale;
};

uint16_t getTemperature(uint8_t pin){
  uint16_t Temperature = 1 / (log(1 / (1023. / analogRead(pin) - 1)) / 3950. + 1.0 / 298.15) - 273.15;\
  return Temperature;
};

void startTimer(void){
  pMillis = millis();

};

void TimerIncrement(void){
  Timer++;


};

void plotGraph( uint16_t pos ){
  for(byte i; i<pos; i++){
    uint8_t Pixel = 0;
    switch(Status.Scale){
      case 0: //SCALE400
      Pixel = -0.1*TempLog[i]+63;
      break;
      case 1: //SCALE200
      Pixel = -0.2*TempLog[i]+93;
      break;
      case 2: //SCALE100
      Pixel = -0.4*TempLog[i]+173;
      break;
      case 3: //SCALE50
      //-0.1*TempLog[i]+63;
      break;
    }
    u8g2.drawPixel(i,Pixel);
  }
  


};

void updateTT(void){


};