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

// --- Configuración de Red y MQTT ---
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "io.adafruit.com";
const int mqtt_port = 1883;
const char* mqtt_user = "mati_xd14";
const char* mqtt_key = "aio_yJdQ27Wrt80ZfHi0JJR5WYsOpFyC";

// --- Pines de Hardware ---
#define POT_PIN 34    // Entrada Analógica (Sensor de Presión 0-10V simulado)
#define BTN_PIN 26    // Entrada Digital (Pulsador con pull-down externo)
#define LED_PIN 2     // Actuador: LED de estado
#define RELAY_PIN 4   // Actuador: Relé para carga industrial

// --- Instancias ---
WiFiClient espClient;
PubSubClient client(espClient);
LiquidCrystal_I2C lcd(0x27, 16, 2);

// --- Variables y Umbrales ---
const float UMBRAL_CRITICO = 80.0; //  80 Bar

void setup_wifi() {
  delay(10);
  lcd.setCursor(0, 0);
  lcd.print("Conectando WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
  lcd.clear();
  lcd.print("WiFi Online");
}

void callback(char* topic, byte* payload, unsigned int length) {
  // Control Remoto del LED desde MQTT
  String message;
  for (int i = 0; i < length; i++) message += (char)payload[i];
  
  if (message == "ON") digitalWrite(LED_PIN, HIGH);
  else if (message == "OFF") digitalWrite(LED_PIN, LOW);
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32_Industria", mqtt_user, mqtt_key)) {
      // Suscripción al tópico de control del LED
      client.subscribe("mati_xd14/feeds/led-control"); 
    } else {
      delay(5000);
    }
  }
}

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(BTN_PIN, INPUT); // 
  
  lcd.init();
  lcd.backlight();
  
  setup_wifi();
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
}

void loop() {
  if (!client.connected()) reconnect();
  client.loop();

  // 1. Lectura y Procesamiento 
  int rawADC = analogRead(POT_PIN);
  // Escalado: 0 a 0-100 Bar
  float presion = (rawADC * 100.0) / 4095.0;

  // 2. Lógica Local (Independiente de Internet)
  if (presion > UMBRAL_CRITICO) {
    digitalWrite(RELAY_PIN, HIGH); // Activa carga industrial
  } else {
    digitalWrite(RELAY_PIN, LOW);
  }

  // 3. Visualización Local LCD
  lcd.setCursor(0, 0);
  lcd.print("Presion: ");
  lcd.print(presion, 1);
  lcd.print(" Bar ");

  lcd.setCursor(0, 1);
  lcd.print(digitalRead(BTN_PIN) ? "STP: ACTIVADO " : "STP: NORMAL   ");

  // 4. Envío de datos a la Nube (MQTT) cada 2 segundos
  static unsigned long lastMsg = 0;
  if (millis() - lastMsg > 2000) {
    lastMsg = millis();
    client.publish("mati_xd14/feeds/presion", String(presion).c_str());
  }
}