#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Pin Definitions
#define RESET_BUTTON_PIN 5
#define LAST_LAP_BUTTON_PIN 6
#define LINE_A_BUTTON_PIN 2
#define LINE_B_BUTTON_PIN 3
#define LINE_C_BUTTON_PIN 4
#define BUZZER_PIN 7

// LCD Settings
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Variables
unsigned long lapStartTime = 0;
unsigned int lapCounter = 0;
unsigned long lapTimes[3] = {0, 0, 0};
int winnerLane = -1;
unsigned long winnerTime = 0;
bool raceStarted = false;
bool stopTimer = false;
bool lastLapButtonReleased = true;

// Button State Variables
bool resetButtonState = false;
bool lastLapButtonState = false;
bool lineAButtonState = false;
bool lineBButtonState = false;
bool lineCButtonState = false;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Initialize LCD
  lcd.begin(16, 2);
  lcd.clear();

  // Display boot status on LCD
  lcd.setCursor(0, 0);
  lcd.print("Race Counter Device");
  lcd.setCursor(0, 1);
  lcd.print("Ready!");

  // Set up button pins as inputs
  pinMode(RESET_BUTTON_PIN, INPUT);
  pinMode(LAST_LAP_BUTTON_PIN, INPUT);
  pinMode(LINE_A_BUTTON_PIN, INPUT);
  pinMode(LINE_B_BUTTON_PIN, INPUT);
  pinMode(LINE_C_BUTTON_PIN, INPUT);

  // Set up buzzer pin as output
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  // Update button states
  updateButtonStates();

  // Check if reset button is pressed
  if (resetButtonState) {
    resetRace();
    // Display reset status on LCD
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Race Reset!");
    raceStarted = false;
    stopTimer = false;
  }

  // Check if last lap button is pressed and released
  if (lastLapButtonState && lastLapButtonReleased) {
    if (raceStarted) {
      stopTimer = true;
    }
    lastLapButtonReleased = false;
  } else if (!lastLapButtonState) {
    lastLapButtonReleased = true;
  }

  // Check if line buttons are pressed
  if ((lineAButtonState || lineBButtonState || lineCButtonState) && !raceStarted) {
    startRace();
  } else if ((lineAButtonState || lineBButtonState || lineCButtonState) && raceStarted) {
    handleLapTrigger();
  }

  // Check if race finished
  if (raceStarted && stopTimer) {
    stopRace();
    displayWinner();
  }
}

void updateButtonStates() {
  static bool lastResetButtonState = false;
  static bool lastLastLapButtonState = false;
  static bool lastLineAButtonState = false;
  static bool lastLineBButtonState = false;
  static bool lastLineCButtonState = false;

  // Update reset button state
  bool currentResetButtonState = digitalRead(RESET_BUTTON_PIN);
  resetButtonState = (currentResetButtonState != lastResetButtonState) && currentResetButtonState;
  lastResetButtonState = currentResetButtonState;

  // Update last lap button state
  bool currentLastLapButtonState = digitalRead(LAST_LAP_BUTTON_PIN);
  lastLapButtonState = (currentLastLapButtonState != lastLastLapButtonState) && currentLastLapButtonState;
  lastLastLapButtonState = currentLastLapButtonState;

  // Update line A button state
  bool currentLineAButtonState = digitalRead(LINE_A_BUTTON_PIN);
  lineAButtonState = (currentLineAButtonState != lastLineAButtonState) && currentLineAButtonState;
  lastLineAButtonState = currentLineAButtonState;

  // Update line B button state
  bool currentLineBButtonState = digitalRead(LINE_B_BUTTON_PIN);
  lineBButtonState = (currentLineBButtonState != lastLineBButtonState) && currentLineBButtonState;
  lastLineBButtonState = currentLineBButtonState;

  // Update line C button state
  bool currentLineCButtonState = digitalRead(LINE_C_BUTTON_PIN);
  lineCButtonState = (currentLineCButtonState != lastLineCButtonState) && currentLineCButtonState;
  lastLineCButtonState = currentLineCButtonState;
}

void startRace() {
  lapStartTime = millis();
  lapCounter++;
  lapTimes[0] = 0;
  lapTimes[1] = 0;
  lapTimes[2] = 0;
  raceStarted = true;

  // Display race start status on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Race Started!");
  lcd.setCursor(0, 1);
  lcd.print("Lap 1");
}

void handleLapTrigger() {
  if (lapCounter > 0) {
    unsigned long currentTime = millis() - lapStartTime;
    lapTimes[0] = (lineAButtonState || stopTimer) ? currentTime : lapTimes[0];
    lapTimes[1] = (lineBButtonState || stopTimer) ? currentTime : lapTimes[1];
    lapTimes[2] = (lineCButtonState || stopTimer) ? currentTime : lapTimes[2];

    // Increment lap counter
    lapCounter++;

    // Display lap count on LCD
    lcd.setCursor(0, 1);
    lcd.print("Lap ");
    lcd.print(lapCounter);
  }

  digitalWrite(BUZZER_PIN, HIGH);
  delay(100); // Buzzer beep duration
  digitalWrite(BUZZER_PIN, LOW);
}

void stopRace() {
  stopTimer = false;
  findWinner();
  raceStarted = false;
}

void resetRace() {
  lapStartTime = 0;
  lapCounter = 0;
  winnerLane = -1;
  for (int i = 0; i < 3; i++) {
    lapTimes[i] = 0;
  }
  lcd.clear();
}

void displayWinner() {
  lcd.setCursor(0, 0);
  lcd.print("Winner: Lane ");
  lcd.print(char('A' + winnerLane));
  lcd.setCursor(0, 1);
  lcd.print("Time: ");
  lcd.print(winnerTime);
  lcd.print("ms");
}

void findWinner() {
  unsigned long fastestTime = lapTimes[0];
  winnerLane = 0;
  for (int i = 1; i < 3; i++) {
    if (lapTimes[i] < fastestTime) {
      fastestTime = lapTimes[i];
      winnerLane = i;
    }
  }
  winnerTime = fastestTime;
}