#include <SevSeg.h>

SevSeg sevseg;  //Instantiate a seven segment object

#define btnpin 3    //button
#define ledpin 10   //led
#define buzzpin 9   //buzzer
#define pingPin 11  //range finder
#define echoPin 12  //range finder
#define potpin A0   //pin used to read the potentiometer

// Declare variables
int ledState = LOW;         // Current led state
int lastButtonState;        // The previous state of the button
int currentButtonState;     // The current state of the button
bool systemActive = false;  // Flag to track system activation
const int startDist = 1000;
long difference;

void setup() {



  //SEVSEG SETUP VARIABLES
  byte numDigits = 4;
  byte digitPins[] = { 32, 29, 28, 26 };
  byte segmentPins[] = { 31, 27, 24, 22, 34, 36, 25 };
  bool resistorsOnSegments = false;      // 'false' means resistors are on digit pins
  byte hardwareConfig = COMMON_CATHODE;  // See README.md for options
  bool updateWithDelays = false;         // Default 'false' is Recommended
  bool leadingZeros = false;             // Use 'true' if you'd like to keep the leading zeros
  bool disableDecPoint = true;           // Use 'true' if your decimal point doesn't exist or isn't connected. Then, you only need to specify 7 segmentPins[]
  sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments,
               updateWithDelays, leadingZeros, disableDecPoint);
  //END SEVSEG SETUP

  pinMode(btnpin, INPUT_PULLUP);
  pinMode(ledpin, OUTPUT);
  pinMode(buzzpin, OUTPUT);
  Serial.begin(9600);
  // Initialization of currentButtonState and lastButtonState
  currentButtonState = digitalRead(btnpin);
  lastButtonState = currentButtonState;
}

void loop() {

  // Update currentButtonState - MOVED FROM SETUP
  currentButtonState = digitalRead(btnpin);  //TAKES ACTUAL PIN READING (HIGH OR LOW) AND SAVES VALUE TO THE VARIABLE, 'CURRENTBUTTONSTATE'.
  int potval = analogRead(potpin);           //identifies a variable to hold the voltage value of the potentiometer
  int potinch = map(potval, 0, 1023, 1, 72);


  //PRINTS 'POTINCH' TO THE 7 SEG DISPLAY
  sevseg.setNumber(potinch, 2);  //prints the 'POTINCH' VARIABLE TO THE 7-SEGMENT DISPLAY
  sevseg.refreshDisplay();       //REFRESHES THE DISPLAY

  // Toggle system activation upon button press
  if (lastButtonState == HIGH && currentButtonState == LOW) {
    systemActive = !systemActive;

    // Control RED LED based on system activation
    if (systemActive) {
      digitalWrite(ledpin, HIGH);  // Turn on the LED when system is activated
    } else {
      digitalWrite(ledpin, LOW);   // Turn off the LED when system is deactivated
      digitalWrite(buzzpin, LOW);  // Turn off the buzzer when system is deactivated
    }
  }

  lastButtonState = currentButtonState;  // Update the last button state

  if (systemActive) {

    long duration, inches, cm;
    // The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
    // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:

    pinMode(pingPin, OUTPUT);
    digitalWrite(pingPin, LOW);
    delayMicroseconds(2);
    digitalWrite(pingPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(pingPin, LOW);

    pinMode(echoPin, INPUT);                    //THIS SETS UP THE PIN THAT SENDS TIMING DATA TO THE ARDUINO.
    duration = pulseIn(echoPin, HIGH, 250000);  //*Adding a timeout doesn't make the lcd more stable


    // convert the time into a distance -these call to the functions at the bottom of this sketch.
    inches = microsecondsToInches(duration);
    cm = microsecondsToCentimeters(duration);
    Serial.print(" inches= ");
    Serial.println(inches);


    // Code to activate buzzer based on distance
    if (inches < potinch) {
      //compares measured distance against the desired triggering distance.
      Serial.println("beep");
      // digitalWrite(buzzpin, HIGH);  // Activate buzzer if distance is less than 10ft
    } else {
  //    digitalWrite(buzzpin, LOW);  // Deactivate buzzer if distance is greater than 10ft
    }
  }
}

//FUNCTIONS BELOW

long microsecondsToInches(long microseconds) {
  // According to Parallax's datasheet for the PING))), there are 73.746
  // microseconds per inch (i.e. sound travels at 1130 feet per second).
  // This gives the distance travelled by the ping, outbound and return,
  // so we divide by 2 to get the distance of the obstacle.
  // See: https://www.parallax.com/package/ping-ultrasonic-distance-sensor-downloads/
  return microseconds / 74 / 2;
}

long microsecondsToCentimeters(long microseconds) {
  // The speed of sound is 340 m/s or 29 microseconds per centimeter.
  // The ping travels out and back, so to find the distance of the object we
  // take half of the distance travelled.
  return microseconds / 29 / 2;
}