#include <LiquidCrystal.h>

// define constants for pins and timings
const int redPin = 40;                                                    //PIN FOR RED LED
const int yellowPin = 39;                                                 //PIN FOR YELLOW LED
const int greenPin = 38;                                                  //PIN FOR GREEN LED
const int buzzerPin = 37;                                                 //PIN FOR BUZZER
const int bluePin = 41;                                                   //PIN FOR BLUE PIN

const unsigned long redDuration = 3000;  // 3 SECOND TIME FRAME NEEDED
const unsigned long yellowDuration = 2000; // 2 SECOND TIME FRAME NEEDED
const unsigned long greenDuration = 7000;// 7 SECOND TIME FRAME NEEDED

// create LiquidCrystal object for LCD display
LiquidCrystal lcd(3, 2, 4, 5, 6, 7);



unsigned long timeStart;
unsigned long timeElapsed;

// define variables for state and button
int state = 1;
int lastState = 0;



void setup() {
  Serial.begin(115200, SERIAL_8N1);
  // initialize pins
  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(bluePin, OUTPUT);


  // initialize LCD display
  lcd.begin(16, 2);
  lcd.print("Traffic Light");

  timeStart = millis();
  state = 1; //SET INITIAL STATE TO 1
}

void loop() {

  switch (state) {
    case 1: //INITIAL RED LIGHT ON MODE
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1); //LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("1  ");
        Serial.println("THE STATE IS 1"); //SERIAL PRINT STATE
        digitalWrite(redPin, HIGH);
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, LOW);
      }
      timeElapsed = millis() - timeStart;
      if (timeElapsed > redDuration) { //CHECKING TIME FOR NEXT STATE
        timeStart = millis();
        if (CheckSerial()) //IF KEY IS PRESSED GO STATE IS 9
        {
          state = 9;
        }
        else  { //THERE IS NOTHING ON SERAIL IS PRESSED STATE IS 2
          state = 2;
        }
      }
      break;

    case 2:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("2  ");
        Serial.println("THE STATE IS 2");//SERIAL PRINT STATE
        digitalWrite(redPin, LOW);//GREEN LED ON ONLY
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, HIGH);
      }
      timeElapsed = millis() - timeStart;
      if (CheckSerial()) { //CHECK FOR KEY PRESS ON SERIAL
        if (timeElapsed > yellowDuration) { //IF KEY IS PRESSED AND TIME IS MORE THAN 2 SECONDS STATE CHANGE TO 7
          timeStart = millis();
          state = 7;
        }
      }
      else { //THERE IS NOTHING ON SERAIL IS PRESSED STATE IS 3
        if (timeElapsed > greenDuration) { //IF NO KEY PRESS AND TIME IS MORE THAN 7 SECONDS STATE IS 3
          timeStart = millis();
          state = 3;
        }
      }


      break;
    case 3:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("3  ");
        Serial.println("THE STATE IS 3");//SERIAL PRINT STATE
        digitalWrite(redPin, LOW); //YELLOW LED ON ONLY
        digitalWrite(yellowPin, HIGH);
        digitalWrite(greenPin, LOW);
      }
      timeElapsed = millis() - timeStart;
      if (timeElapsed > yellowDuration) { //IF TIME IS MORE THAN 2 SECONDS PROCESSED
        timeStart = millis();
        if (CheckSerial()) { //IF KEY PRESSED STATE IS 9
          state = 9;
        }
        else { //IF THE NOTHING ON SERAIL IS PRESSED STATE IS 4
          state = 4;
        }

      }
      break;
    case 4:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("4  ");
        Serial.println("THE STATE IS 4");//SERIAL PRINT STATE
        digitalWrite(redPin, HIGH);//RED LED ON ONLY
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, LOW);
      }
      timeElapsed = millis() - timeStart;
      if (timeElapsed > redDuration) { //CHECK IF TIME IS MORE THAN 3 SECONDS
        timeStart = millis();
        if (CheckSerial()) { //IF KEY PRESSED STATE IS 9
          state = 9;
        }
        else //IF THE NOTHING ON SERAIL IS PRESSED STATE IS 5
          state = 5;

      }
      break;
    case 5:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("5  ");
        Serial.println("THE STATE IS 5");//SERIAL PRINT STATE
        digitalWrite(redPin, HIGH);//RED LED ON ONLY
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, LOW);
      }
      timeElapsed = millis() - timeStart;
      if (!CheckSerial()) { //IF THE NOTHING ON SERAIL IS PRESSED WAIT 7 SECONDS AND STATE IS 6
        if (timeElapsed > greenDuration) {
          timeStart = millis();
          state = 6;
        }
      }
      else  {
        if (timeElapsed > yellowDuration) {//THERE IS SOMETHING ON SERAIL IS PRESSED WAIT 2 SECONDS AND STATE IS 8
          timeStart = millis();
          state = 8;
        }
      }
      break;
    case 6:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("6  ");
        Serial.println("THE STATE IS 6");//SERIAL PRINT STATE
        digitalWrite(redPin, HIGH);//RED LED ON ONLY
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, LOW);
      }
      timeElapsed = millis() - timeStart;
      if (timeElapsed > yellowDuration) { //WAIT 2 SECONDS
        timeStart = millis();
        if (!CheckSerial()) { //IF THE NOTHING ON SERAIL IS PRESSED STATE IS 1
          state = 1;
        }
        else  { //THERE IS SOMETHING ON SERIAL IS PRESSED  STATE IS 9
          state = 9;
        }
      }
      break;
    case 7:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("7  ");
        Serial.println("THE STATE IS 7");//SERIAL PRINT STATE
        digitalWrite(redPin, LOW);//YELLOW LED ON ONLY
        digitalWrite(yellowPin, HIGH);
        digitalWrite(greenPin, LOW);
      }
      timeElapsed = millis() - timeStart;
      if (timeElapsed > yellowDuration) { //WAIT 2 SECONDS
        timeStart = millis();
        state = 9;
      } //STATE CHANGE TO 9
      break;

    case 8:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("8  ");
        Serial.println("THE STATE IS 8");//SERIAL PRINT STATE
        digitalWrite(redPin, HIGH);//RED LED ON ONLY
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, LOW);
      }
      timeElapsed = millis() - timeStart;
      if (timeElapsed > yellowDuration) { //WAIT 2 SECONDS
        timeStart = millis();
        state = 9;
      } //STATE CHANGE TO 9
      break;

    case 9:
      if (lastState != state) {
        lastState = state;
        lcd.setCursor(0, 1);//LCD PRINT STATE
        lcd.print("State: ");
        lcd.print("9  ");
        Serial.println("THE STATE IS 9");//SERIAL PRINT STATE
        digitalWrite(redPin, LOW);
        digitalWrite(yellowPin, LOW);
        digitalWrite(greenPin, LOW);
        digitalWrite(bluePin, HIGH); //TURN ONLY ON BLUE LED
      }
      timeElapsed = millis() - timeStart;
      if (timeElapsed > greenDuration) { //STAY FOR 7 SECONDS
        timeStart = millis();
        state = 1; //STATE CHANGE TO 1
        digitalWrite(bluePin, LOW);
      }// TURN BLUE LED OFF
      break;
  }
}

bool CheckSerial()
{
  bool GotSome = false;
    if (Serial.available())
    {
      GotSome = true;
      while (Serial.available()) Serial.read();
    }
    return GotSome;
}