#include <WiFi.h>
#include <HTTPClient.h>

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

// ==================== PINOS ====================
#define PIN_GAS     34   // AOUT do sensor MQ
#define LED_VERDE   0
#define LED_VERM    2
#define BUZZER      15

// ==================== LIMITES ====================
#define GAS_ON   750   // entra em alarme
#define GAS_OFF  650   // sai do alarme

// ==================== VARIÁVEIS ====================
bool gasAlarm = false;
bool messageSent = false;

// ==================== PROTÓTIPOS ====================
void sendWhatsAppAlert();
int readGasFiltered();

// ==================== SETUP ====================
void setup() {
  Serial.begin(115200);

  // WiFi
  WiFi.begin(ssid, password);
  Serial.print("Conectando ao WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi conectado!");

  // ADC ESP32
  analogSetAttenuation(ADC_11db);

  // GPIOs
  pinMode(LED_VERDE, OUTPUT);
  pinMode(LED_VERM, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  // Estado inicial
  digitalWrite(LED_VERDE, HIGH);
  digitalWrite(LED_VERM, LOW);
  digitalWrite(BUZZER, LOW);
}

// ==================== LOOP ====================
void loop() {
  int gasValue = readGasFiltered();

  Serial.print("Gás (PPM): ");
  Serial.println(gasValue);

  // ===== ENTRA EM ALARME =====
  if (!gasAlarm && gasValue >= GAS_ON) {
    gasAlarm = true;

    Serial.println("⚠️ ALERTA: Vazamento de Gás");

    digitalWrite(LED_VERDE, LOW);
    digitalWrite(LED_VERM, HIGH);
    digitalWrite(BUZZER, HIGH);

    if (!messageSent) {
      sendWhatsAppAlert();
      messageSent = true;
    }
  }

  // ===== SAI DO ALARME =====
  else if (gasAlarm && gasValue <= GAS_OFF) {
    gasAlarm = false;
    messageSent = false;

    Serial.println("✅ Ambiente Seguro");

    digitalWrite(LED_VERDE, HIGH);
    digitalWrite(LED_VERM, LOW);
    digitalWrite(BUZZER, LOW);
  }

  delay(2000);
}

// ==================== FILTRO ADC ====================
int readGasFiltered() {
  const int samples = 20;
  long sum = 0;

  for (int i = 0; i < samples; i++) {
    sum += analogRead(PIN_GAS);
    delay(5);
  }

  return sum / samples;
}

// ==================== WHATSAPP ====================
void sendWhatsAppAlert() {
  if (WiFi.status() != WL_CONNECTED) return;

  HTTPClient http;

  String url = "https://api.callmebot.com/whatsapp.php?";
  url += "phone=554896956965";
  url += "&text=ALERTA:+Vazamento+de+Gás!";
  url += "&apikey=6349684";

  http.begin(url);
  int httpCode = http.GET();

  if (httpCode == 200) {
    Serial.println("📨 Mensagem enviada com sucesso!");
  } else {
    Serial.print("❌ Erro HTTP: ");
    Serial.println(httpCode);
  }

  http.end();
}