#define IR1 2   // the sensor at the front of the robot
#define IR2 3   // the sensor at the back of the robot
#define IR3 4   // the sensor at the right side of the robot
#define IR4 5   // the sensor at the left side of the robot
#define right_motor1 6
#define right_motor2 7
#define left_motor1 8
#define left_motor2 9
#define right_motor_EN 10
#define left_motor_EN 11
int signal1 =0;     // the signal recieved from the first IR (front) sensor
int signal2 =0;     // the signal recieved from the secend IR (back) sensor
int signal3 =0;     // the signal recieved from the third IR (right) sensor
int signal4 =0;     // the signal recieved from the fourth IR (left) sensor
void setup() {
  pinMode(IR1, INPUT);
  pinMode(IR2, INPUT);
  pinMode(IR3, INPUT);
  pinMode(IR4, INPUT);
  pinMode(right_motor1, OUTPUT);
  pinMode(right_motor2, OUTPUT);
  pinMode(left_motor1, OUTPUT);
  pinMode(left_motor2, OUTPUT);
  pinMode(right_motor_EN, OUTPUT);
  pinMode(left_motor_EN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite(right_motor_EN, HIGH);  // set the value of the enable of the right motor to high (like we turn the motor on)
  digitalWrite(left_motor_EN, HIGH);   // set the value of the enable of the left motor to high (like we turn the motor on)
  signal1 = digitalRead(IR1);   // read the signal of the first IR (front) sensor
  signal2 = digitalRead(IR2);   // read the signal of the second IR (back) sensor      
  signal3 = digitalRead(IR3);   // read the signal of the third IR (right) sensor
  signal4 = digitalRead(IR4);   // read the signal of the fourth IR (left) sensor
  Serial.println(signal1);      // print the data from the first sensor on the serial monitor
  Serial.println(signal2);      // print the data from the secend sensor on the serial monitor
  Serial.println(signal3);      // print the data from the third sensor on the serial monitor
  Serial.println(signal4);      // print the data from the fourth sensor on the serial monitor

  // we will give the priority to the right turns (right hand algorithm)
  switch (signal1){
    case HIGH :
      switch (signal2){
        case HIGH :
          switch (signal3){
            case HIGH :
              digitalWrite(right_motor1, HIGH);
              digitalWrite(right_motor2, LOW);
              digitalWrite(left_motor1, LOW);
              digitalWrite(right_motor1, HIGH); // this block of code let the robot turn right 
              break ;
            case LOW :
              switch (signal4){
                case HIGH :
                  digitalWrite(right_motor1, LOW);
                  digitalWrite(right_motor2, HIGH);
                  digitalWrite(left_motor1, HIGH);
                  digitalWrite(right_motor1, LOW); // this block of code let the robot turn left
                  break ;
                case LOW :
                  digitalWrite(right_motor1, HIGH);
                  digitalWrite(right_motor2, LOW);
                  digitalWrite(left_motor1, HIGH);
                  digitalWrite(right_motor1, LOW); // this block of code let the robot move forward
                  break ;
              }
          }
      }
    case LOW :
      switch (signal2){
        case HIGH :
          switch (signal3){
            case HIGH :
              digitalWrite(right_motor1, HIGH);
              digitalWrite(right_motor2, LOW);
              digitalWrite(left_motor1, LOW);
              digitalWrite(right_motor1, HIGH); // this block of code let the robot turn right
              break ;
            case LOW :
              switch (signal4){
                case HIGH :
                  digitalWrite(right_motor1, LOW);
                  digitalWrite(right_motor2, HIGH);
                  digitalWrite(left_motor1, HIGH);
                  digitalWrite(right_motor1, LOW); // this block of code let the robot turn left 
                  break;
                case LOW :
                  
                 while(signal2==HIGH^signal1==LOW) {
                  digitalWrite(right_motor1, HIGH);
                  digitalWrite(right_motor2, LOW);
                  digitalWrite(left_motor1, HIGH);
                  digitalWrite(right_motor1, LOW); // this block of code let the robot move forward in case of the robot comes into a cut
                 }
                 
                 do {
                  digitalWrite(right_motor1, HIGH);
                  digitalWrite(right_motor2, LOW);
                  digitalWrite(left_motor1, LOW);
                  digitalWrite(right_motor1, HIGH); // this block of code let the robot turn right
                 }
                 while(signal1==LOW);
                 break ; //  this piece of code let the robot  turn around but Im not sure
              }  
          }
      }
    default :
      digitalWrite(right_motor1, LOW);
      digitalWrite(right_motor2, LOW);
      digitalWrite(left_motor1, LOW);
      digitalWrite(right_motor1, LOW); // this block of code let the robot stop
      break ;
  

  }
}