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

// --- Configurações de WiFi ---
const char* ssid = "Wokwi-GUEST"; 
const char* password = "";

// --- Configurações MQTT ---
const char* mqttserver = "test.mosquitto.org"; 
const int mqttport = 1883;

// --- Tópicos ---
#define TOPIC_PREFIX  "eduardo_esp32_lcd" 

WiFiClient espClient;
PubSubClient client(espClient);

// --- Configuração dos PINOS I2C (Manual) ---
#define I2C_SDA 16 
#define I2C_SCL 17

// --- Configuração do LCD I2C (20x4) ---
LiquidCrystal_I2C lcd(0x27, 20, 4); 

// --- Pinos do Hardware ---
#define LED1_PIN 13
#define LED2_PIN 12
#define POT_PIN 33
#define LDR_PIN 35    
#define DHT_PIN 32      
#define DHTTYPE DHT22  
#define BTN1_PIN 14
#define BTN2_PIN 27

// --- NOVOS PINOS: ULTRASSONICO ---
#define TRIG_PIN 26
#define ECHO_PIN 25

DHT dht(DHT_PIN, DHTTYPE);

// --- Variáveis de Controle ---
unsigned long lastMsg = 0;
const long interval = 2000; 
int lastBtn1State = HIGH; 
int lastBtn2State = HIGH;

// --- Protótipos ---
void setup_wifi();
void callback(char* topic, byte* payload, unsigned int length);
void reconnect();
void checkButtons();
long readUltrasonicDistance(); // Nova função

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

  // Inicia I2C nos pinos manuais
  Wire.begin(I2C_SDA, I2C_SCL);

  // Inicialização do LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0); 
  lcd.print("Inicializando...");
  
  // Configuração dos Pinos
  pinMode(LED1_PIN, OUTPUT);
  pinMode(LED2_PIN, OUTPUT);
  pinMode(POT_PIN, INPUT);
  pinMode(LDR_PIN, INPUT); 
  pinMode(BTN1_PIN, INPUT_PULLUP);
  pinMode(BTN2_PIN, INPUT_PULLUP);
  
  // Configuração do Ultrassônico
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  dht.begin();
  
  setup_wifi();
  
  client.setServer(mqttserver, mqttport);
  client.setCallback(callback);

  lcd.clear();
}

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

  checkButtons();

  unsigned long now = millis();
  if (now - lastMsg > interval) {
    lastMsg = now;

    // 1. Sensores Analógicos
    int potValue = analogRead(POT_PIN);
    float potPorcentagem = (potValue / 4095.0) * 100.0;

    int ldrValue = analogRead(LDR_PIN);
    float ldrPorcentagem = (ldrValue / 4095.0) * 100.0;

    // 2. Sensor DHT
    float h = dht.readHumidity();
    float t = dht.readTemperature();

    // 3. Sensor Ultrassônico (NOVO)
    long distanciaCM = readUltrasonicDistance();

    if (isnan(h) || isnan(t)) {
      Serial.println("Falha sensor DHT!");
      return; 
    }
    
    // --- Publicando MQTT ---
    client.publish(TOPIC_PREFIX "/pot", String(potPorcentagem, 0).c_str());
    client.publish(TOPIC_PREFIX "/ldr", String(ldrPorcentagem, 0).c_str()); 
    client.publish(TOPIC_PREFIX "/temp", String(t, 1).c_str());
    client.publish(TOPIC_PREFIX "/hum", String(h, 1).c_str());
    client.publish(TOPIC_PREFIX "/dist", String(distanciaCM).c_str()); // Publica dist

    // --- Atualizando LCD (Dashboard) ---
    // Linha 0: Temp e Umidade
    lcd.setCursor(0, 0);
    lcd.print("T:" + String(t, 1) + "C H:" + String(h, 0) + "%   ");

    // Linha 1: Pot e LDR
    lcd.setCursor(0, 1);
    lcd.print("P:" + String((int)potPorcentagem) + "% L:" + String((int)ldrPorcentagem) + "%   ");

    // Linha 2: Distância
    lcd.setCursor(0, 2);
    lcd.print("Distancia: " + String(distanciaCM) + " cm   ");

    // Linha 3: Reservada para MSG recebida (não limpamos aqui para persistir a msg)

    Serial.printf("Dados: T=%.1f D=%ld cm\n", t, distanciaCM);
  }
}

// --- Função para ler o HC-SR04 ---
long readUltrasonicDistance() {
  // Limpa o Trigger
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  
  // Envia pulso de 10us
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  // Lê o tempo de resposta (timeout de 30ms para evitar travar o WiFi)
  long duration = pulseIn(ECHO_PIN, HIGH, 30000);
  
  // Calcula a distância: Distancia = (Tempo * VelocidadeSom) / 2
  // Velocidade do som no ar ~= 0.034 cm/us
  long distance = duration * 0.034 / 2;
  
  return distance;
}

void checkButtons() {
  int currentBtn1 = digitalRead(BTN1_PIN);
  int currentBtn2 = digitalRead(BTN2_PIN);

  if (currentBtn1 != lastBtn1State) {
    lastBtn1State = currentBtn1;
    String status = (currentBtn1 == LOW) ? "PRESSIONADO" : "SOLTO";
    client.publish(TOPIC_PREFIX "/btn1", status.c_str());
    delay(50); 
  }

  if (currentBtn2 != lastBtn2State) {
    lastBtn2State = currentBtn2;
    String status = (currentBtn2 == LOW) ? "PRESSIONADO" : "SOLTO";
    client.publish(TOPIC_PREFIX "/btn2", status.c_str());
    delay(50); 
  }
}

void setup_wifi() {
  delay(10);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message;
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  
  // Exibe mensagem recebida na Linha 3
  if (String(topic) == TOPIC_PREFIX "/display") {
    lcd.setCursor(0, 3);
    // Preenche com espaços antes para limpar lixo antigo
    lcd.print("                    "); 
    lcd.setCursor(0, 3);
    lcd.print(message); 
  }

  // Comandos de LED
  if (String(topic) == TOPIC_PREFIX "/led1") {
    if (message == "1" || message == "on" || message == "ON") digitalWrite(LED1_PIN, HIGH);
    else if (message == "0" || message == "off" || message == "OFF") digitalWrite(LED1_PIN, LOW);
  }
  if (String(topic) == TOPIC_PREFIX "/led2") {
    if (message == "1" || message == "on" || message == "ON") digitalWrite(LED2_PIN, HIGH);
    else if (message == "0" || message == "off" || message == "OFF") digitalWrite(LED2_PIN, LOW);
  }
}

void reconnect() {
  while (!client.connected()) {
    // Escreve na linha de mensagens que está tentando conectar
    lcd.setCursor(0, 3);
    lcd.print("MQTT: Conectando...");
    
    String clientId = "ESP32-" + String(random(0xffff), HEX);

    if (client.connect(clientId.c_str())) {
      client.publish(TOPIC_PREFIX "/status", "Online");
      client.subscribe(TOPIC_PREFIX "/led1");
      client.subscribe(TOPIC_PREFIX "/led2");
      client.subscribe(TOPIC_PREFIX "/display"); 

      lcd.setCursor(0, 3);
      lcd.print("MQTT: Online!       ");
      
    } else {
      delay(5000);
    }
  }
}