#include <WiFi.h>
#include "PubSubClient.h"
#include <WebServer.h>
#include <ArduinoJson.h>
#include "DHTesp.h"
#include <LiquidCrystal_I2C.h>

const int DHT_PIN = 15;

DHTesp dhtSensor;

#define BUTTON_PIN 25
#define LED_PIN    2
int led_state = LOW;
int button_state;
int last_button_state;

const char *MQTTServer = "broker.emqx.io";
const char *MQTT_Topic = "19004036";
const char *MQTT_ID = "MyClient";
int Port = 1883;

WiFiClient espClient;
PubSubClient client(espClient);

LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 20, 4);


void WIFIConnect() {
  Serial.println("Connecting to SSID: Wokwi-GUEST");
  WiFi.begin("Wokwi-GUEST", ""); 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected, IP address: ");
  Serial.println(WiFi.localIP());
}


void MQTT_Reconnect() {
  while (!client.connected()) {
    if (client.connect(MQTT_ID)) {
      Serial.print("MQTT Client: ");
      Serial.print(MQTT_ID);
      Serial.println(" connected");
      client.subscribe(MQTT_Topic);
    } else {
      Serial.print("MQTT connection failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}


void callback(char *topic, byte *message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.println(topic);
  Serial.print("Message: ");
  String stMessage;

  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    stMessage += (char)message[i];
  }


  StaticJsonDocument<200> doc;
  DeserializationError err = deserializeJson(doc, stMessage);

  

  client.publish(MQTT_Topic, "Thanh cong");
}


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

  LCD.init();
  LCD.backlight();
  // LCD.setCursor(0, 0);
  // LCD.print("Connecting to ");
  // LCD.setCursor(0, 1);
  // LCD.print("WiFi ");


  WIFIConnect();
  client.setServer(MQTTServer, Port);
  client.setCallback(callback);
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  button_state = digitalRead(BUTTON_PIN);
}

void loop() {
  TempAndHumidity  data = dhtSensor.getTempAndHumidity();
  Serial.println("Temp: " + String(data.temperature, 2) + "°C");
  Serial.println("Humidity: " + String(data.humidity, 1) + "%");
  Serial.println("---");

  LCD.setCursor(0, 0);
  LCD.print("Temp: " + String(data.temperature, 2) + "°C");
  LCD.setCursor(0, 1);
  LCD.print("Humidity: " + String(data.humidity, 1) + "%");

  StaticJsonDocument<200> doc;
  doc["temperature"] = data.temperature;
  doc["humidity"] = data.humidity;

  String jsonString;
  serializeJson(doc, jsonString);


  client.publish(MQTT_Topic, jsonString.c_str());


  // Led Button
  last_button_state = button_state;
  button_state = digitalRead(BUTTON_PIN);
  delay(10);
  if (last_button_state == HIGH && button_state == LOW) {
    Serial.println("The button is pressed");
    led_state = !led_state;
    digitalWrite(LED_PIN, led_state);
  }


  if (WiFi.status() == WL_CONNECTED) {
    if (!client.connected()) {
      MQTT_Reconnect();
    }
    client.loop();
  }
  delay(2000);
}