#include <stdio.h>
#include <Wire.h>
#include <WiFi.h>
#include <LiquidCrystal_I2C.h>
#include "DHTesp.h"
#include <ArduinoJson.h>
#include <string.h>
#include <stdlib.h>
#include <PubSubClient.h>

#define LED_PIN 32
#define DHT_PIN 15
#define PIR_SENSOR 12

#define LCD_ADDRESS 0x27
#define LCD_COLUMNS 16
#define LCD_ROWS 2
// Thông tin MQTT Broker
const char* mqtt_server = "broker.hivemq.com";
const int mqtt_port = 1883;
const char* mqtt_topic = "20205013";
WiFiClient espClient;
PubSubClient client(espClient);
LiquidCrystal_I2C lcd(LCD_ADDRESS, LCD_COLUMNS, LCD_ROWS);
DHTesp dhtSensor;

void reconnect() {
  while (!client.connected()) {
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.print("Connected to MQTT broker as ");
      Serial.println(clientId);
      client.subscribe(mqtt_topic);
    } else {
      Serial.print("Failed to connect to MQTT broker, rc=");
      Serial.print(client.state());
      Serial.println(" Trying again in 5 seconds...");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  // Convert payload to string
  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println("Received message: " + message);
Serial.println(message.charAt(0));
  // Check if the message topic matches mqtt_topic
    if (strcmp(topic, mqtt_topic) == 0) {
    if (message.charAt(0) == '{') {
      // Bật đèn LED
      digitalWrite(LED_PIN, HIGH);
      Serial.println("LED turned ON");
    } else {
      // Tắt đèn LED
      digitalWrite(LED_PIN, LOW);
      Serial.println("LED turned OFF");
    }
  }
  else{
    Serial.println("Wrong topic");
  }
  delay(5000);
}

void setup() {
  pinMode(BUILTIN_LED, OUTPUT);     
  Serial.begin(9600);
  Serial.println("ESP32 collecting sensor data");
  
  // Connect to WiFi
  Serial.print("Connecting to WiFi");
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println("WiFi Connected!");
  
  // Setup MQTT client
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);

  // Setup LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");

  // Setup pins
  pinMode(LED_PIN, OUTPUT);
  pinMode(PIR_SENSOR, INPUT);

  // Setup DHT sensor
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);
}

void loop() {
  // Read DHT22 sensor data
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  int temp = data.temperature;
  int humid = data.humidity;

  // Display data on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: " + String(temp) + "C");
  lcd.setCursor(0, 1);
  lcd.print("Humidity: " + String(humid) + "%");

  // Send data via Serial
  Serial.println("Temp: " + String(temp) + "C");
  Serial.println("Humidity: " + String(humid) + "%");

  // Read PIR motion sensor status
  int pir_value = digitalRead(PIR_SENSOR);

  // Handle PIR motion sensor status
  if (pir_value == HIGH) {
    digitalWrite(LED_PIN, HIGH);
    Serial.println("Motion detected");
  } else {
    digitalWrite(LED_PIN, LOW);
    Serial.println("Motion ended");
  }

  // Reconnect to MQTT broker if necessary
  if (!client.connected()) {
    reconnect();
  }

  // Send JSON data to MQTT broker
  if (WiFi.status() == WL_CONNECTED) {
    StaticJsonDocument<200> root;
    root["temperature"] = temp;
    root["humidity"] = humid;
    String json;
    serializeJson(root, json);
    
    Serial.println(json);
    if (client.publish(mqtt_topic, json.c_str())) {
      Serial.println("Message published successfully");
    } else {
      Serial.println("Failed to publish message");
    }
    delay(2000); 
  }

  // Listen for messages from MQTT broker
  client.loop();
}