#define BLYNK_TEMPLATE_ID "TMPL33CiJ--hj"
#define BLYNK_TEMPLATE_NAME "GasSafetyMonitor"
#define BLYNK_AUTH_TOKEN "y4YWCP9rBwBdtTHou7X6aeRId042OSzu"
#include <WiFi.h>
#include <WiFiClient.h>

#include <BlynkSimpleEsp32.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C screen(0x27, 16, 2);

#define SENSOR_PIN 34
#define LED_OK 18
#define LED_DANGER 19
#define ALERT_BUZZER 25
#define BTN_RESET 15

char wifi_ssid[] = "Wokwi-GUEST";
char wifi_pass[] = "";

int gasLimit = 2000;
bool warningTriggered = false;

BLYNK_WRITE(V4) {
  gasLimit = param.asInt();
  screen.setCursor(0, 1);
  screen.print("Limit:");
  screen.print(gasLimit);
  screen.print("   ");
}

void setup() {
  pinMode(LED_OK, OUTPUT);
  pinMode(LED_DANGER, OUTPUT);
  pinMode(ALERT_BUZZER, OUTPUT);
  pinMode(BTN_RESET, INPUT_PULLUP);

  screen.init();
  screen.backlight();
  screen.clear();
  screen.print("Booting...");

  Blynk.begin(BLYNK_AUTH_TOKEN, wifi_ssid, wifi_pass);

  digitalWrite(LED_OK, HIGH);
  digitalWrite(LED_DANGER, LOW);
  digitalWrite(ALERT_BUZZER, LOW);
  delay(1000);
  screen.clear();
}

void loop() {
  Blynk.run();

  int gasReading = analogRead(SENSOR_PIN);
  Blynk.virtualWrite(V1, gasReading);

  screen.setCursor(0, 0);
  screen.print("Gas: ");
  screen.print(gasReading);
  screen.print("    ");

  if (gasReading > gasLimit) {
    if (!warningTriggered) {
      warningTriggered = true;
      digitalWrite(LED_OK, LOW);
      digitalWrite(LED_DANGER, HIGH);
      digitalWrite(ALERT_BUZZER, HIGH);
      screen.setCursor(0, 1);
      screen.print("!! GAS DETECTED !!");
      Blynk.virtualWrite(V2, 1);
      Blynk.logEvent("gas_leak", "Gas concentration above threshold!");
    }
  } else {
    if (!warningTriggered) {
      digitalWrite(LED_OK, HIGH);
      digitalWrite(LED_DANGER, LOW);
      digitalWrite(ALERT_BUZZER, LOW);
      screen.setCursor(0, 1);
      screen.print("Environment Safe ");
      Blynk.virtualWrite(V2, 0);
    }
  }

  // --- Manual reset button (always works) ---
  if (digitalRead(BTN_RESET) == LOW) {
    warningTriggered = false;
    digitalWrite(ALERT_BUZZER, LOW);
    digitalWrite(LED_DANGER, LOW);
    digitalWrite(LED_OK, HIGH);
    screen.setCursor(0, 1);
    screen.print("System Reset   ");
    Blynk.virtualWrite(V2, 0);
    delay(1000); // Debounce delay
  }

  delay(300);
}