#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

// ================= CONFIGURACIÓN =================
#define DHTPIN 2
#define DHTTYPE DHT22
#define COOLING_PIN 8
#define LED_ON_PIN 9
#define LED_OFF_PIN 10

// Umbrales de temperatura
#define UMBRAL_ALTO 28.0
#define UMBRAL_BAJO 20.0
#define HISTERESIS 1.0

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Ajusta la dirección I2C si es necesario

bool coolingState = false;

void setup() {
  Serial.begin(9600);   
  // Inicializar hardware
  lcd.init();
  lcd.backlight();
  dht.begin();  
  pinMode(COOLING_PIN, OUTPUT);
  pinMode(LED_ON_PIN, OUTPUT);
  pinMode(LED_OFF_PIN, OUTPUT);
  
  digitalWrite(COOLING_PIN, LOW);
  digitalWrite(LED_ON_PIN, LOW);
  digitalWrite(LED_OFF_PIN, HIGH);  // Inicia apagado
  
  // Mensaje inicial
  lcd.setCursor(0, 0);
  lcd.print("Iniciando...");
  delay(2000);
  lcd.clear();
}

void loop() {
  static unsigned long lastRead = 0;
  
  if(millis() - lastRead >= 2000) {  // Lectura cada 2 segundos
    lastRead = millis();
    
    // Verificar sensor
    if(checkSensorError()) return;
    
    // Leer valores
    float temperature = dht.readTemperature();
    float humidity = dht.readHumidity();
    
    // Mostrar en LCD (formato: "T:23.5°C H:45.0%")
    lcd.setCursor(0, 0);
    lcd.print("T:");
    lcd.print(temperature, 1);
    lcd.print((char)223);  // Símbolo grado
    lcd.print("C ");
    
    lcd.setCursor(9, 0);
    lcd.print("H:");
    lcd.print(humidity, 1);
    lcd.print("%");
    
    // Controlar enfriamiento (siempre muestra "Enfriar: ON/OFF")
    lcd.setCursor(0, 1);
    lcd.print("Enfriar: ");
    lcd.print(coolingState ? "ON " : "OFF");
    
    // Lógica de control
    if (temperature > (UMBRAL_ALTO + (coolingState ? -HISTERESIS : 0))) {
      setCooling(true);
    } 
    else if (temperature < (UMBRAL_BAJO + (coolingState ? HISTERESIS : 0))) {
      setCooling(false);
    }
  }
}

bool checkSensorError() {
  if(isnan(dht.readTemperature())) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Error sensor DHT!");
    lcd.setCursor(0, 1);
    lcd.print("Verificar conexion");
    
    // Parpadear LEDs en error
    digitalWrite(LED_ON_PIN, LOW);
    for(int i=0; i<5; i++) {
      digitalWrite(LED_OFF_PIN, !digitalRead(LED_OFF_PIN));
      delay(300);
    }
    return true;
  }
  return false;
}

void setCooling(bool state) {
  if(coolingState != state) {
    coolingState = state;
    digitalWrite(COOLING_PIN, state ? HIGH : LOW);
    digitalWrite(LED_ON_PIN, state ? HIGH : LOW);
    digitalWrite(LED_OFF_PIN, state ? LOW : HIGH);
    
    // Log por serial
    Serial.print("Enfriamiento ");
    Serial.println(state ? "ACTIVADO" : "DESACTIVADO");
  }
}