#include <Wire.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <Arduino.h>
#include <LiquidCrystal_I2C.h>

// LCD I2C Konfigurasi
#define lcd_ADDR 0x27
#define lcd_COLUMNS 16
#define lcd_ROWS 2
LiquidCrystal_I2C lcd(lcd_ADDR, lcd_COLUMNS, lcd_ROWS);

// WiFi dan MQTT Konfigurasi
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
#define THINGSBOARD_SERVER "thingsboard.cloud"
#define THINGSBOARD_TOKEN "kbusQW1u5hByj6xfYcaC"

// Pin LED dan Sensor
#define PULSE_PIN 35
#define redLEDPin 12
#define greenLEDPin 14

// Objek untuk WiFi dan MQTT
WiFiClient espClient;
PubSubClient client(espClient);

// Variabel Detak Jantung
int minHeartRate = 60;
int maxHeartRate = 100;

void setup() {
  // Inisialisasi LCD
  lcd.init();
  lcd.backlight();

  // Inisialisasi Serial Monitor
  Serial.begin(115200);
  lcd.print("Heart Monitor");
  
  // Inisialisasi Pin
  pinMode(redLEDPin, OUTPUT);
  pinMode(greenLEDPin, OUTPUT);

  // Hubungkan ke WiFi
  connectToWiFi();

  // Konfigurasi MQTT server
  client.setServer(THINGSBOARD_SERVER, 1883);
  client.setCallback(mqttCallback);

  // Hubungkan ke ThingsBoard
  connectToThingsBoard();
}

void loop() {
  // Periksa Koneksi MQTT
  if (!client.connected()) {
    connectToThingsBoard();
  }
  client.loop();

  // Baca dan kirim data detak jantung
  int heartRate = readHeartRate();
  sendTelemetry(heartRate);
  delay(1000);
}

void connectToWiFi() {
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("Menghubungkan ke WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
    lcd.setCursor(0, 1);
    lcd.print("WiFi Connecting...");
  }
  Serial.println("\nWiFi Connected");
  lcd.setCursor(0, 1);
  lcd.print("WiFi Connected");
}

void connectToThingsBoard() {
  while (!client.connected()) {
    Serial.println("Menghubungkan ke ThingsBoard...");
    lcd.clear();
    lcd.print("Connecting TB...");

    if (client.connect("ESP32", THINGSBOARD_TOKEN, NULL)) {
      Serial.println("Terhubung ke ThingsBoard!");
      lcd.print("TB Connected!");
    } else {
      Serial.print("Gagal terhubung ke ThingsBoard, rc=");
      Serial.println(client.state());
      lcd.print("TB Conn Failed");
      delay(5000);
    }
  }
}

int readHeartRate() {
  // Simulasi pembacaan detak jantung dari sensor
  int pulseValue = analogRead(PULSE_PIN);
  float voltage = pulseValue * (5.0 / 4095.0);
  return (voltage / 3.3) * 675; // Kalkulasi detak jantung
}

void sendTelemetry(int heartRate) {
  String payload = "{\"heartRate\":";
  payload += heartRate;
  payload += "}";
  client.publish("v1/devices/me/telemetry", payload.c_str());
  Serial.println("Data dikirim: " + payload);
}

void mqttCallback(char *topic, byte *payload, unsigned int length) {
  Serial.print("Pesan diterima [");
  Serial.print(topic);
  Serial.print("]: ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}