#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// تعريف الثوابت
#define TRIG_PIN 9
#define ECHO_PIN 10
#define BUTTON1_PIN 8
#define BUTTON2_PIN 11
#define LCD_ADDRESS 0x27
#define LCD_COLS 16
#define LCD_ROWS 2

LiquidCrystal_I2C lcd(LCD_ADDRESS, LCD_COLS, LCD_ROWS);

float distance;
float length;
float width;
float area;
bool button1_pressed;
bool button2_pressed;
float addValue;
unsigned long button2PressTime = 0;
unsigned long button2PressDuration = 0;
bool areaDisplayed = false; // حالة عرض المساحة

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUTTON1_PIN, INPUT_PULLUP);
  pinMode(BUTTON2_PIN, INPUT_PULLUP);
  
  lcd.init();
  lcd.backlight();
  
  distance = 0;
  length = 0;
  width = 0;
  area = 0;
  button1_pressed = false;
  button2_pressed = false;
  addValue = 0.05;
}

void loop() {
  distance = measureDistance() + addValue;
  
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distance);
  lcd.print(" m     ");
  
  button1_pressed = digitalRead(BUTTON1_PIN) == LOW;
  
  if (button1_pressed) {
    length = distance;
    lcd.setCursor(0, 1);
    lcd.print("Length: ");
    lcd.print(length);
    lcd.print(" m     ");
    while (digitalRead(BUTTON1_PIN) == LOW); // Wait until button is released
    areaDisplayed = false; // إخفاء المساحة
  }
  
  // Check if BUTTON2 is pressed
  if (digitalRead(BUTTON2_PIN) == LOW) {
    // Start timing
    if (button2PressTime == 0) {
      button2PressTime = millis();
    } else {
      // Calculate how long the button has been pressed
      button2PressDuration = millis() - button2PressTime;
      if (button2PressDuration > 1000) {
        // If pressed for more than 1000 ms, calculate area
        area = length * width;
        areaDisplayed = true; // عرض المساحة
      }
    }
  } else {
    // If the button was pressed for a short time, update width
    if (button2PressDuration > 0 && button2PressDuration <= 1000) {
      width = distance;
      lcd.setCursor(0, 1);
      lcd.print("Width: ");
      lcd.print(width);
      lcd.print(" m     ");
    }
    // Reset the timing as the button is released
    button2PressTime = 0;
    button2PressDuration = 0;
  }

  // Display area if it has been calculated
  if (areaDisplayed) {
    lcd.setCursor(0, 1);
    lcd.print("Area: ");
    lcd.print(area);
    lcd.print(" m2     ");
  }
}

// Function to measure distance
float measureDistance() {
  float duration;
  // Trigger the ultrasonic pulse
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  // Read the return pulse
  duration = pulseIn(ECHO_PIN, HIGH);
  // Calculate the distance
  return (duration * 0.034 / 2) / 100;
}