#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include "HX711.h"

// Blynk credentials
char auth[] = "vfcdAOxUfk5wwpQOhhIlPgNzf70Krjio";
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// Pins
#define TRIG 5
#define ECHO 18
#define MQ2_PIN 34
#define DOUT 19
#define CLK 21
#define METAL_PIN 23

HX711 scale;

void setup() {
  Serial.begin(115200);
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(METAL_PIN, INPUT_PULLUP);

  scale.begin(DOUT, CLK);

  Blynk.begin(auth, ssid, pass);
}

void loop() {
  Blynk.run();

  // --- Fill Level (Ultrasonic) ---
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  long duration = pulseIn(ECHO, HIGH);
  float distance = duration * 0.034 / 2; // cm

  int binHeight = 100; // assume 100cm bin
  int fillLevel = map(distance, 0, binHeight, 100, 0);

  Serial.print("Fill Level: ");
  Serial.println(fillLevel);
  Blynk.virtualWrite(V0, fillLevel);

  // --- Gas Sensor ---
  int gasValue = analogRead(MQ2_PIN);
  Serial.print("Gas: ");
  Serial.println(gasValue);
  Blynk.virtualWrite(V1, gasValue);

  // --- Load Cell ---
  long weight = scale.get_units();
  Serial.print("Weight: ");
  Serial.println(weight);
  Blynk.virtualWrite(V2, weight);

  // --- Metal Detection ---
  int metalDetected = digitalRead(METAL_PIN) == LOW;
  Serial.print("Metal: ");
  Serial.println(metalDetected);
  if (metalDetected) {
    Blynk.virtualWrite(V3, "Metal Detected");
    Blynk.logEvent("metal_alert", "♻️ Metal waste detected");
  } else {
    Blynk.virtualWrite(V3, "No Metal");
  }

  // --- Alerts ---
  if (fillLevel > 80) {
    Blynk.logEvent("bin_full", "⚠️ Bin is nearly full");
  }
  if (gasValue > 500) {
    Blynk.logEvent("gas_alert", "⚠️ Hazardous gas detected");
  }

  delay(2000);
}