// we created those constants to understand the code easily

// Pin of the LEDs 
const int led_green = 7;
const int led_yellow = 6;
const int led_red = 5;  
// Pin of the seven segment display
const int pins[] = {1, 3, 4, 8, 9, 10, 11}; // equivalent of pins[] = {A, B, C, D, E, F, G};
const int num_pins = 7;
// Pin for  the push button as interrupt
const int push_button = 2;

// delays we need for this project as follows (3 seconds, 1 second)
const int delay_3_sec = 3000;
const int delay_1_sec = 1000;


// create variable state (we have for states )
int state = 1; // inialise the varialbe to state 1 where Red is ON 

int debounce = LOW; // used to debounce the push button
// values to control 7 segment display common cathode 
const int num_to_display[10][7] = {
  {1, 1, 1, 1, 1, 1, 0}, // 0
  {0, 1, 1, 0, 0, 0, 0}, // 1
  {1, 1, 0, 1, 1, 0, 1}, // 2
  {1, 1, 1, 1, 0, 0, 1}, // 3
  {0, 1, 1, 0, 0, 1, 1}, // 4
  {1, 0, 1, 1, 0, 1, 1}, // 5
  {1, 0, 1, 1, 1, 1, 1}, // 6
  {1, 1, 1, 0, 0, 0, 0}, // 7
  {1, 1, 1, 1, 1, 1, 1}, // 8
  {1, 1, 1, 1, 0, 1, 1}  // 9
};
void handleInt() { // ISR for the push boutton
  if (digitalRead(push_button) == HIGH) {
        // Wait for the button to stabilize (debounce)
        while (digitalRead(push_button) == HIGH) {
            // Do nothing, just wait until the button is released
        }
        debounce = HIGH;
    }
}
void setup() {
  pinMode(led_green, OUTPUT);// set the green led as output so we can turn it on and off:
  pinMode(led_red, OUTPUT);// set the red led as output so we can turn it on and off:
  pinMode(led_yellow, OUTPUT);// set the yellow led as output so we can turn it on and off:
  pinMode(push_button, INPUT);// set the push button as input so we can read it 
  attachInterrupt(INT0, handleInt, CHANGE); // set the interrupt 
   for (int i = 0; i < num_pins; i++ ) {
    pinMode(pins[i], OUTPUT); // set the seven_segment display as outputs for all the pins using a loop
  }
}

// we created for functions to turn on and off the leds. A function for each state  
//  state_1 = red on , yellow off, green off 
void state_1 () {
    digitalWrite(led_red, HIGH);
    digitalWrite(led_yellow, LOW);
    digitalWrite(led_green, LOW);
}
 //  state_2 = red off , yellow off, green off 
void state_2 () {
    digitalWrite(led_red, LOW);
    digitalWrite(led_yellow, LOW);
    digitalWrite(led_green, LOW);
}
 //  state_3 = red off , yellow off, green on 
void state_3 () {
    digitalWrite(led_red, LOW);
    digitalWrite(led_yellow, LOW);
    digitalWrite(led_green, HIGH);
}
  // state_4 = red off , yellow on, green off  
void state_4() {
    digitalWrite(led_red, LOW);
    digitalWrite(led_yellow, HIGH);
    digitalWrite(led_green, LOW);
}
// we created function to control the seven segement
void seven_segment_display (){
  
  
 // we use the nested loop concept  
  for (int counter = 9 ; counter >= 0; counter--){// first loop counts the numbers be displayed 
    for (int i = 0; i < num_pins; i++ ) {// second loop controls the pins depending on the number to be dispayed
      digitalWrite(pins[i], num_to_display[counter][i]);
    }
    delay (delay_1_sec); // delay of one second between the numbers
    
     
  }

}

void loop() {
  
  bool condition = true;// used in closed loop
  for (int i = 0; i < num_pins; i++ ) {// set the seven to zero at the inialisation
      digitalWrite(pins[i], num_to_display[0][i]);
    }
  
 

 
  state_1 (); // inialise the system to an initial state (for security) ( state_1 = red on , yellow off, green off )
  while (condition == true){
    // The design simulate the real trafic simulation lights
    // so the state goes as follows:
    //                              state_1 = red on , yellow off, green off (3 seconds)
    //                              state_2 = red off , yellow off, green off (1 second)
    //                              state_3 = red off , yellow off, green on (3 seconds) 
    //                              state_4 = red off , yellow on, green off  (1 second)
    // 
      if (state == 1) {// if it is in state_1 after 3 seconds it goes to state_2
          delay (delay_3_sec);
          state = 2;
          state_2();
      }
      if (state == 2) { // if it is in state_2 after 1 second it goes to state_3
          state = 3;
          delay (delay_1_sec);
          state_3();
      }  
       if (state == 3) {//  if it is in state_3 after 3 seconds it goes to state_4, 
          delay (delay_3_sec);
          if (debounce == HIGH){ //if the push button is pushed and realeased it wil add 9 more seconds and call seven segment controll function
        

            seven_segment_display();
             
            debounce = LOW; 
          }
          
          state = 4;
          state_4();        
       }
     
       if (state = 4) { // if it is in state_4 after 1 second it goes to state_4
          delay(delay_1_sec);
          state = 1;
          state_1();        
      }

    
    


  }
  
}