#include <ESP32Servo.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// Pin definitions
#define TRIG_PIN_GATE 4
#define ECHO_PIN_GATE 5
#define TRIG_PIN_1 12
#define ECHO_PIN_1 13
#define TRIG_PIN_2 14
#define ECHO_PIN_2 27
#define TRIG_PIN_3 26
#define ECHO_PIN_3 25
#define TRIG_PIN_4 33
#define ECHO_PIN_4 32
#define SERVO_PIN 18

// OLED display dimensions
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

// Initialize components
Servo myServo;
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Global variables
bool parking1Occupied = false;
bool parking2Occupied = false;
bool parking3Occupied = false;
bool parking4Occupied = false;

void setup() {
  Serial.begin(115200);

  // Initialize sensor pins
  pinMode(TRIG_PIN_GATE, OUTPUT);
  pinMode(ECHO_PIN_GATE, INPUT);
  pinMode(TRIG_PIN_1, OUTPUT);
  pinMode(ECHO_PIN_1, INPUT);
  pinMode(TRIG_PIN_2, OUTPUT);
  pinMode(ECHO_PIN_2, INPUT);
  pinMode(TRIG_PIN_3, OUTPUT);
  pinMode(ECHO_PIN_3, INPUT);
  pinMode(TRIG_PIN_4, OUTPUT);
  pinMode(ECHO_PIN_4, INPUT);

  // Attach servo
  myServo.attach(SERVO_PIN);
  myServo.write(0);

  // Initialize OLED display
  if (!display.begin(SSD1306_PAGEADDR, 0x3C)) { // Address 0x3C for most OLEDs
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("ParkIQ Ease");
  display.setCursor(0, 10);
  display.print("Solution");
  display.display();
  delay(5000); // Display Brand Name for 5 seconds
}

void loop() {
  // Measure distance from the gate sensor
  float gateDistance = getDistance(TRIG_PIN_GATE, ECHO_PIN_GATE);

  // Measure distances from parking sensors
  float distance1 = getDistance(TRIG_PIN_1, ECHO_PIN_1);
  float distance2 = getDistance(TRIG_PIN_2, ECHO_PIN_2);
  float distance3 = getDistance(TRIG_PIN_3, ECHO_PIN_3);
  float distance4 = getDistance(TRIG_PIN_4, ECHO_PIN_4);

  // Update parking statuses
  parking1Occupied = (distance1 > 0 && distance1 <= 20);
  parking2Occupied = (distance2 > 0 && distance2 <= 20);
  parking3Occupied = (distance3 > 0 && distance3 <= 20);
  parking4Occupied = (distance4 > 0 && distance4 <= 20);

  // Control the servo for the gate
  if (gateDistance > 0 && gateDistance <= 20) {
    myServo.write(90); // Open gate
  } else {
    myServo.write(0); // Close gate
  }

  // Update OLED display
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Parking Status:");

  display.setCursor(0, 10);
  if (!parking1Occupied) {
    display.print("Parking 1 Open");
  } else if (!parking2Occupied) {
    display.print("Parking 2 Open");
  } else if (!parking3Occupied) {
    display.print("Parking 3 Open");
  } else if (!parking4Occupied) {
    display.print("Parking 4 Open");
  } else {
    display.print("Parking Full");
  }

  display.display();
  delay(200); // Small delay for stable readings
}

float getDistance(int trigPin, int echoPin) {
  // Send a 10-microsecond pulse to the TRIG_PIN
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the duration of the pulse on the ECHO_PIN
  long duration = pulseIn(echoPin, HIGH);

  // Calculate distance in cm
  float distance = duration * 0.034 / 2;

  // Return distance
  return distance;
}