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

// OLED display resolution
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

// OLED display object
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire);

// Pin definitions for the buttons
const int startButtonPin = 2;
const int stopButtonPin = 3;
const int resetButtonPin = 4;
int start=0;
int stp=digitalRead(stopButtonPin);


// Variables to store button state
bool startButtonState = false;
bool stopButtonState = false;
bool resetButtonState = false;

// Variables to store the current time
unsigned long startTime;
unsigned long currentTime;
unsigned long elapsedTime = 0;
bool isRunning = false;



void setup() {
  Serial.begin(115200);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // initialize OLED display
  display.clearDisplay(); // clear the display's memory
  display.display(); // update the display
  
  // Set the button pins as inputs
  pinMode(startButtonPin, INPUT_PULLUP);
  pinMode(stopButtonPin, INPUT_PULLUP);
  pinMode(resetButtonPin, INPUT_PULLUP);
stp=digitalRead(stopButtonPin);
 
}

void loop() {

   
  startButtonState = digitalRead(startButtonPin) == LOW;
  stopButtonState = digitalRead(stopButtonPin) == 0;
  resetButtonState = digitalRead(resetButtonPin) == LOW;
  
  // Start the stopwatch if the start button is pressed
  if (startButtonState && !isRunning) {

    start=start+1;
    
  }
  else{
    elapsedTime = 0;

    start=0;}
  if(start==1){
    startTime = millis();
    isRunning = true;
  }
  
  // Stop the stopwatch if the stop button is pressed
  if(stp == 1){
  if (stopButtonState && isRunning) {
    currentTime = millis();
    elapsedTime = currentTime - startTime + elapsedTime;
    isRunning = false;
    
  }
  }
  if (stp == 0){
    if (!stopButtonState && isRunning) {
    currentTime = millis();
    elapsedTime = currentTime - startTime + elapsedTime;
    isRunning = false;
    
  }
  }

  
  // Reset the stopwatch if the reset button is pressed
  if (resetButtonState) {
    elapsedTime = 0;
    isRunning = false;
  }
  


  display.clearDisplay(); // clear the display's memory
  display.setTextSize(2); // set text size to 2
  display.setTextColor(WHITE); // set text color to white
    
    // Display "Timer" on the first line
  display.setCursor(12, 05);
  display.println("*Sverker*");
  display.setCursor(25, 28);
  
  display.setCursor(12, 50);
  display.println("MM:SS:Mls");
  
  // Display the elapsed time in the middle of the second line
  if (isRunning) {
    currentTime = millis();
    unsigned long runningTime = currentTime - startTime + elapsedTime;
    display.setCursor(25, 28);
    display.print((runningTime / 60000L));
    display.print(":");
    display.print(((runningTime % 60000L) / 1000L));
    display.print(":");
    display.println(((runningTime % 1000L)));
  } else {
    display.setCursor(25, 28);
    display.print((elapsedTime / 60000L));
    display.print(":");
    display.print(((elapsedTime % 60000L) / 1000L));
    display.print(":");
    display.println(((elapsedTime % 1000L)));
  }
  display.display(); // update the display
}