#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

Adafruit_SSD1306 display = Adafruit_SSD1306(128, 64, &Wire);

unsigned int time=0.00;
unsigned int alarmtime=0.00;
int count;
int clockx=90;
int clocky=32;
byte runstopwatch=0;
byte openstopwatch=0;
byte openalarm=0;
byte plusone=0;
byte next=0;
byte alarminc=0;
long start;
long stop;
const float BETA = 3950;
float temp;
byte showtemp;
int analogValue;
float celsius;
bool stopwatchreset=0;



void setup() {
  set(); // set start time
  //enable oled display
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  Serial.begin(9600);
  //enable pins
  pinMode(2, INPUT_PULLUP);
  pinMode(0,OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);

  //external interupt
  attachInterrupt(0,buttonpress,CHANGE);

  //timer interupt
  cli();

  TCCR1A = 0;
  TCCR1B = 0;
  TCNT1 = 0;
  OCR1A = 62499;
  TCCR1B |= (1 << WGM12);
  TCCR1B |= (1 << CS12);
  TIMSK1 |= (1 << OCIE1A);

  sei();



}
ISR(TIMER1_COMPA_vect) {
  //tick function progresses the clock by 1 second every second
  tick();
  analogValue = analogRead(A0);
  celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
  //change rgb led colour depending on tempreture
  if (celsius>30){
    digitalWrite(3,LOW);
    digitalWrite(4,HIGH);
    digitalWrite(5,HIGH);

  }
  else if(celsius>15){
    digitalWrite(3,LOW);
    digitalWrite(4,LOW);
    digitalWrite(5,HIGH);

  }
  else{
    digitalWrite(3,HIGH);
    digitalWrite(4,LOW);
    digitalWrite(5,HIGH);

  }


}

//main code is all handled in seperate functions so the loop function just takes care of which function to trigger at any given time.
void loop() {
  if(openstopwatch!=0){
    stopwatch();
  }
  else if(openalarm!=0){
    alarm();
  }
  else if(openstopwatch==0){
  clock();
  }
  if(alarmtime==time+1){
    analogWrite(7,245);
  }
  else if(alarmtime==time-5){
    analogWrite(7,0);
  }


  
  
  
  //display to screen
  display.display();
  display.clearDisplay();

}
void set(){
  //set start time
  Serial.begin(9600);
  Serial.println("Please Enter Hour: ");
  while(Serial.available()==0){}
  time+=Serial.parseInt()*3600;
  Serial.end();
  Serial.begin(9600);
  Serial.println("Please Enter Minute: ");
  while(Serial.available()==0){}
  time+=Serial.parseInt()*60;
  Serial.end();
  Serial.begin(9600);
  Serial.println("Please Enter Second: ");
  while(Serial.available()==0){}
  time+=Serial.parseInt();
}
//progresses time by 1 second 
void tick(){
  //add to second value every second
  time+=1;
  if(time>=46800){
    time=3600;
  }
}

//converts a time in only seconds to hours min and sec
String digitaltime(unsigned int count){
  unsigned int second=count%60;
  unsigned int minute=((count-second)%3600)/60;
  unsigned int hour=(count-(count%3600))/3600;
  return String(hour)+":"+String(minute)+":"+String(second);
}

//interupt function
void buttonpress(){
  //find button press duration
  int presstime;
  if(digitalRead(2)==0){
    start=millis();
    stop=0;
  }
  else if(digitalRead(2)==1){
    stop=millis();
    presstime=stop-start;
    Serial.println(presstime);
  

    //enable different menues depending on how long button is pressed
    if(presstime>3000){
      showtemp+=128;
    }
    
    else if(presstime>300 & openalarm==0){
      openstopwatch+=128;
    }
    else if(presstime>25 & openstopwatch==128){
      runstopwatch+=128;
    }
    else if(presstime>25 & openstopwatch==0 & openalarm==0){
      openalarm+=128;
    }
    else if(presstime>300 & openalarm==128){
      next+=128;
    }
    else if(presstime>25 & openalarm==128){
      plusone+=128;
    }
  }



}

//handle all clock menu display and functionality
void clock(){
    //display diital clock text and clock text
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.print(digitaltime(time));
  display.setCursor(clockx-5,clocky-25);
  display.print("12");
  display.setCursor(clockx+20,clocky-3);
  display.print("3");
  display.setCursor(clockx-2,clocky+20);
  display.print("6");
  display.setCursor(clockx-25,clocky-3);
  display.print("9");
  display.drawCircle(clockx,clocky,30,WHITE);
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,50);
  if(showtemp==128){
    display.print("T:");
    display.print(celsius);
  }

  
  

  //calculate clock hand angle
  float angle=(2*PI*((time)/43200.00));


  //draw hour min and sec hands
  display.drawLine(clockx,clocky,clockx-10*cos(angle+(PI/2)),clocky-10*sin(angle+(PI/2)),WHITE);
  display.drawLine(clockx,clocky,clockx-15*cos(12*angle+(PI/2)),clocky-15*sin(12*angle+(PI/2)),WHITE);
  display.drawLine(clockx,clocky,clockx-20*cos(720*angle+(PI/2)),clocky-20*sin(720*angle+(PI/2)),WHITE);
}

//handle all stopwatch display and functionality
void stopwatch(){
  //print timer
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println("Stop Watch");
  display.setTextSize(3);
  //start and stop stopwatch
  if(runstopwatch==0){
    //count=0;
    stopwatchreset=0;
    display.print(digitaltime(count));
  }
  else if(runstopwatch!=0){
    if(stopwatchreset==0){
      stopwatchreset=1;
      count=0;
    }
    count++;
    display.print(digitaltime(count));
    delay(1000);
  }

  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,50);
  if(showtemp==128){
    display.print("T:");
    display.print(celsius);
  }

  
}


void alarm(){
  //print numbers
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println("Alarm");
  display.println(digitaltime(alarmtime));

  //change between hours min and sec
  //add incrament the hour min and sec time for alarm
  if(next==128){
    next=0;
    alarminc++;
  }
  if(plusone!=0 & alarminc==0){
    alarmtime+=3600;
    plusone=0;
  }
  else if(plusone!=0 & alarminc==1){
    alarmtime+=60;
    plusone=0;
  }
  else if(plusone!=0 & alarminc==2){
    alarmtime+=1;
    plusone=0;
  }
  if(alarminc==3){
    alarminc=0;
    openalarm+=128;
  }
  if(alarmtime>=46800){
    alarmtime=alarmtime-43200;
  }


  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,50);
  if(showtemp==128){
    display.print("T:");
    display.print(celsius);
  }
}