#include <TM1637Display.h>

// Define the connections pins for display
#define CLK 2
#define DIO 3

// Define other pin connections
#define UP_BUTTON 8
#define DOWN_BUTTON 9
#define START_BUTTON 4
#define BUZZER 5

int duration;      // Duration in seconds
int setDuration;
byte inProcess = 0;
unsigned long startTime = millis();
unsigned long timer = 1000ul ;// DURATION TIME
// Create display object of type TM1637Display:
TM1637Display display = TM1637Display(CLK, DIO);

// Set the individual segments for the word displays:
const uint8_t seg_end[] = {
  SEG_A | SEG_D | SEG_E | SEG_F | SEG_G,         // E
  SEG_C | SEG_E | SEG_G,                         // n
  SEG_B | SEG_C | SEG_D | SEG_E | SEG_G,          // d
  0x00                                           // All off
};

const uint8_t seg_go[] = {
  SEG_A | SEG_C | SEG_D | SEG_F | SEG_G,          // s
  SEG_D | SEG_E | SEG_F | SEG_G,                  // t
  0x00,                                           // All off
  0x00                                           // All off
};

void setup() {
  pinMode(UP_BUTTON, INPUT_PULLUP);
  pinMode(DOWN_BUTTON, INPUT_PULLUP);
  pinMode(START_BUTTON, INPUT_PULLUP);
  pinMode(BUZZER, OUTPUT);
  Serial.begin(9600);
  duration = 0;              // Default to 10 seconds
  display.setBrightness(5);   // 0 to 7 change if required
  ShowTime(duration);
}

void loop() {
  // Function will checks for time change buttons and only return
  // when start button pressed
  WaitForStart();
  // Start the duration timer
  TimeDuration();
}

void WaitForStart() {
  // Check for button presses every 0.15 seconds
  if (digitalRead(START_BUTTON) == HIGH) {
    // inProcess=0;
  }
  if (digitalRead(START_BUTTON) == LOW) {
    inProcess = inProcess == 0 ? 1 : 0;
    if (inProcess == 0) {
      duration = 0;
      ShowTime(duration);
      tone(BUZZER, 1500, 100);
      display.clear();
      display.setSegments(seg_end);
      Serial.println("Stop Counter");
      delay(150);
    }
    if (inProcess == 1) {
      Serial.println("Start Counter");
      timer = 1000ul * duration;

      startTime = millis();
      tone(BUZZER, 1500, 100);
      display.clear();
      display.setSegments(seg_go);
      delay(150);
    }

  }
  //while (digitalRead(START_BUTTON) == HIGH){
  //inProcess=1;
  // Check if up or down has been pressed
  //if time > 60 then increment by 10 seconds
  if (digitalRead(UP_BUTTON) == LOW) {
    if (duration < 900) {
      Serial.println("Increment Duration");
      duration += 60;
    }
    ShowTime(duration);
    delay(150);
  }
  if (digitalRead(DOWN_BUTTON) == LOW) {
    if (duration > 0) {
      Serial.println("Decrement Duration");
      duration -= 60;
    }
    ShowTime(duration);
    delay(150);
  }

  //}
  // Start button has been pressed
  //tone(BUZZER, 1500, 100);
  //display.clear();
  //display.setSegments(seg_go);
}

void TimeDuration() {
  // While loop will continue until time up

  // Repeatedly check if time is up

  if ((millis() - startTime) <= timer && inProcess == 1) {
    Serial.print("millis: ");
    Serial.print(millis());
    Serial.print(" startTime: ");
    Serial.print(startTime);
    Serial.print(" timer: ");
    Serial.print(timer);
    // Calculate time elapsed in seconds
    int elapsed = int((millis() - startTime) / 1000);

    Serial.print(" duration: ");
    Serial.print(duration);
    Serial.print(" Elapsed: ");
    Serial.println(elapsed);
    ShowTime(duration - elapsed);
    delay(250);
    // Only start to display countdown after 3 seconds
    // if ((millis() - startTime) > 1000) {
    //   ShowTime(duration - elapsed);
    // }
    //startTime = millis();
  }
  // Time up
  //tone(BUZZER, 500, 1000);

  // Wait 5 seconds and reset display
  delay(000);
  // Show duration for next player
  //ShowTime(duration);
  //if (lastTime == 0) {
  //display.clear();
  //display.setSegments(seg_end);
  //}

}

void ShowTime(int value) {
  static int lastTime = -1;
  // Update the display if time has changed
  if (1 == 1) {
    //lastTime = value;
    int iMinutes = value / 60;
    int iSeconds = value - (iMinutes * 60);
    // Show on 4 digit display
    uint16_t number = iMinutes * 100 + iSeconds;
    display.showNumberDecEx(number, 0b01000000, true, 4, 0);
  }
}