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

// Ultrasound sensor pins
#define TRIG_PIN 12
#define ECHO_PIN 14

// LED pins
#define RED_LED_PIN 16
#define YELLOW_LED_PIN 4
#define GREEN_LED_PIN 2

// Buzzer pin
#define BUZZER_PIN 17

LiquidCrystal_I2C lcd(0x27, 16, 2);

const char *ssid = "Wokwi-GUEST";
const char *password = "";
const char *thingspeak_api_key = "your_thingspeak_api_key";

void setup()
{
  Serial.begin(115200);
  // Kết nối WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }

  // Khởi tạo LCD & pin
  lcd.init();
  lcd.backlight();

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(YELLOW_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
}

float readDistanceCM()
{
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2;
  return distance;
}

void uploadToThingSpeak(float distance)
{
  if (WiFi.status() == WL_CONNECTED)
  {
    String url = String("http://api.thingspeak.com/update?api_key=") + thingspeak_api_key + "&field1=" + String(distance);
    HTTPClient http;
    http.begin(url);
    int httpCode = http.GET();
    http.end();
  }
}

void loop()
{
  float distance = readDistanceCM();

  lcd.setCursor(0, 0);
  lcd.print("Distance:        ");
  lcd.setCursor(10, 0);
  lcd.print(distance, 1);
  lcd.print("cm");

  if (distance < 100)
  {
    digitalWrite(RED_LED_PIN, HIGH);
    digitalWrite(YELLOW_LED_PIN, HIGH);
    digitalWrite(GREEN_LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, HIGH);
    uploadToThingSpeak(distance);
  }
  else if (distance < 120)
  {
    digitalWrite(RED_LED_PIN, LOW);
    digitalWrite(YELLOW_LED_PIN, HIGH);
    digitalWrite(GREEN_LED_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
  }
  else
  {
    digitalWrite(RED_LED_PIN, LOW);
    digitalWrite(YELLOW_LED_PIN, LOW);
    digitalWrite(GREEN_LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, LOW);
  }

  delay(1000);
}