#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <HTTPClient.h>

// Wi-Fi credentials
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""

// Firebase project URL and API Key
#define DATABASE_URL "https://hantu-815c4-default-rtdb.asia-southeast1.firebasedatabase.app"
#define API_KEY "AIzaSyBRS2GWYraVW0XVHibGg5EQe1zx7r-5fWU"

#define LEDBUZ 27
#define TRIG 5
#define ECHO 17
#define BUZZER 26

LiquidCrystal_I2C lcd(0x27, 16, 2);
#define LED 2

unsigned long previousMillis = 0;
unsigned long intervalClose = 1;  // 1 ms interval for close distance alert
unsigned long intervalMedium = 3000;  // 3 seconds interval for medium distance alert
bool ledState = LOW;
bool buzzerState = LOW;

void setup() {
  Serial.begin(115200);
  Serial.println("BARISANJUANG!");
  pinMode(LEDBUZ, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(LED, OUTPUT);

  lcd.backlight();
  lcd.init();
  lcd.setCursor(0, 0);
  lcd.print("BARISANJUANG");

  // Connect to Wi-Fi
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");
}

void loop() {
  int distance = measureDistance();
  sendDataToFirebase("/JARAK", distance);
  int value = getDataFromFirebase("/JARAK");

  lcd.setCursor(0, 1);
  lcd.print("Jarak: ");
  lcd.print(distance);
  lcd.print(" cm");

  if (distance >= 100) {
    stopAlert();
  } else if (distance > 50 && distance < 100) {
    alertMedium();
  } else if (distance <= 50) {
    alertClose();
  }

  delay(50); // Delay for debounce
}

void sendDataToFirebase(String path, int value) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String(DATABASE_URL) + path + ".json?auth=" + API_KEY;

    http.begin(url);
    http.addHeader("Content-Type", "application/json");

    String payload = String("{\"value\":") + value + "}";
    int httpResponseCode = http.PUT(payload);

    http.end();
  } else {
    Serial.println("WiFi Disconnected");
  }
}

int getDataFromFirebase(String path) {
  int value = 0;

  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String(DATABASE_URL) + path + ".json?auth=" + API_KEY;

    http.begin(url);
    int httpResponseCode = http.GET();

    if (httpResponseCode > 0) {
      String payload = http.getString();
      Serial.println(payload);
      value = payload.toInt();
    } else {
      Serial.printf("Error code: %d\n", httpResponseCode);
    }

    http.end();
  } else {
    Serial.println("WiFi Disconnected");
  }
  return value;
}

void alertClose() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= intervalClose) {
    previousMillis = currentMillis;
    ledState = !ledState;
    buzzerState = !buzzerState;
    digitalWrite(LEDBUZ, ledState);
    if (buzzerState) {
      tone(BUZZER, 1000); // Frequency 1000 Hz
    } else {
      noTone(BUZZER);
    }
  }
}

void alertMedium() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= intervalMedium) {
    previousMillis = currentMillis;
    ledState = !ledState;
    buzzerState = !buzzerState;
    digitalWrite(LEDBUZ, ledState);
    if (buzzerState) {
      tone(BUZZER, 1000, 500); // Frequency 1000 Hz, Duration 500 ms
    } else {
      noTone(BUZZER);
    }
  }
}

void stopAlert() {
  digitalWrite(LEDBUZ, LOW);
  noTone(BUZZER);
}

int measureDistance() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  int duration = pulseIn(ECHO, HIGH);
  int distance = duration / 58.2; // Convert to centimeters
  return distance;
}