#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// OLED display settings
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Pin definitions
const int buttonPin = 2;
const int resetRedPin = 3;
const int resetGreenPin = 4;
const int resetBluePin = 5;
const int trigPin = 6;
const int echoPin = 7;
const int buzzerPin = 8;
const int distRedPin = 9;
const int distGreenPin = 10;
const int distBluePin = 11;

// Distance sensor settings
const int distanceThreshold = 10; // threshold distance in cm

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Initialize OLED display
  if(!display.begin(SSD1306_I2C_ADDRESS, OLED_RESET)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.clearDisplay();
  display.display();

  // Initialize pins
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(resetRedPin, OUTPUT);
  pinMode(resetGreenPin, OUTPUT);
  pinMode(resetBluePin, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(distRedPin, OUTPUT);
  pinMode(distGreenPin, OUTPUT);
  pinMode(distBluePin, OUTPUT);
}

void loop() {
  // Read button state
  if(digitalRead(buttonPin) == LOW) {
    resetDisplay();
  }

  // Measure distance
  long duration, distance;
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration / 2) / 29.1;

  // Display distance
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("Distance: ");
  display.print(distance);
  display.println(" cm");
  display.display();

  // Activate buzzer and LED if distance is below threshold
  if(distance < distanceThreshold) {
    digitalWrite(buzzerPin, HIGH);
    setDistanceLEDColor(255, 0, 0); // Red color
  } else {
    digitalWrite(buzzerPin, LOW);
    setDistanceLEDColor(0, 255, 0); // Green color
  }

  delay(100);
}

void resetDisplay() {
  display.clearDisplay();
  display.display();
  setResetLEDColor(0, 0, 255); // Blue color
  delay(500);
  setResetLEDColor(0, 0, 0); // Turn off
}

void setResetLEDColor(int red, int green, int blue) {
  analogWrite(resetRedPin, red);
  analogWrite(resetGreenPin, green);
  analogWrite(resetBluePin, blue);
}

void setDistanceLEDColor(int red, int green, int blue) {
  analogWrite(distRedPin, red);
  analogWrite(distGreenPin, green);
  analogWrite(distBluePin, blue);
}