#include <WiFi.h>
#include <PubSubClient.h>
#include "DHT.h"


#define   ssid  "Wokwi-GUEST";     
#define password    "";

//  MQTT 
const char* mqtt_server = "51.75.35.138";
const int mqtt_port = 1883;
const char* mqtt_user = "youpilab_iot";
const char* mqtt_pass = "rootAdmin";

const char* device_id = "BURB7D0C";
const char* topic_tx = "youpilab/devices/BURB7D0C/tx";
const char* topic_rx = "youpilab/devices/BURB7D0C/rx";

//  PINS 
#define DHTPIN 4
#define DHTTYPE DHT22
#define LED_PIN 2
#define BUTTON_PIN 13

DHT dht(DHTPIN, DHTTYPE);

WiFiClient espClient;
PubSubClient client(espClient);

bool systemOn = false;
bool lastButtonState = HIGH;

// TIMERS 
unsigned long previousMillis = 0;
const long interval = 3000;

// Anti-rebond bouton
unsigned long lastDebounceTime = 0;
const long debounceDelay = 200;

// Reconnexion MQTT
unsigned long lastReconnectAttempt = 0;
const long reconnectInterval = 3000;

//  WIFI 
void setup_wifi() {
  WiFi.begin(ssid, password);
  Serial.print("[WIFI] Connexion...");
}

//  CALLBACK MQTT 
void callback(char* topic, byte* payload, unsigned int length) {
  String message = "";

  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  Serial.print("[MQTT] Reçu: ");
  Serial.println(message);

  if (message == "ON") systemOn = true;
  else if (message == "OFF") systemOn = false;
}


void handleMQTT() {
  if (client.connected()) return;

  unsigned long currentMillis = millis();

  if (currentMillis - lastReconnectAttempt >= reconnectInterval) {
    lastReconnectAttempt = currentMillis;

    String clientId = "ESP32-" + String(device_id);

    if (client.connect(clientId.c_str(), mqtt_user, mqtt_pass)) {
      Serial.println("[MQTT] Connecté");
      client.subscribe(topic_rx);
    } else {
      Serial.print("[MQTT] Erreur: ");
      Serial.println(client.state());
    }
  }
}

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

  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  dht.begin();

  setup_wifi();

  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
}

void loop() {

  // WIFI STATUS 
  if (WiFi.status() != WL_CONNECTED) {
    setup_wifi();
  }

  // MQTT 
  handleMQTT();
  client.loop();

  //  BOUTON
  bool currentButtonState = digitalRead(BUTTON_PIN);

  if (lastButtonState == HIGH && currentButtonState == LOW) {
    unsigned long currentMillis = millis();

    if (currentMillis - lastDebounceTime > debounceDelay) {
      systemOn = !systemOn;

      Serial.println(systemOn ? "[SYSTEM] ON (bouton)" : "[SYSTEM] OFF (bouton)");

      lastDebounceTime = currentMillis;
    }
  }

  lastButtonState = currentButtonState;

  //LED 
  digitalWrite(LED_PIN, systemOn ? HIGH : LOW);

  //  ENVOI DHT 
  if (systemOn && client.connected()) {
    unsigned long currentMillis = millis();

    if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis;

      float t = dht.readTemperature();
      float h = dht.readHumidity();

      if (!isnan(t) && !isnan(h)) {

        String payload = "{";
        payload += "\"temperature\":" + String(t) + ",";
        payload += "\"humidite\":" + String(h);
        payload += "}";

        client.publish(topic_tx, payload.c_str());

        Serial.println("[MQTT] Envoyé: " + payload);
      }
    }
  }
}