#include <WiFi.h>
#include <PubSubClient.h>

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

// MQTT broker
const char* mqtt_server = "broker.hivemq.com";
const char* topic = "wokwi/coal-weight-sensor";

// WiFi and MQTT client objects
WiFiClient espClient;
PubSubClient client(espClient);

float baseWeight = 5000.0; // Base weight of coal in kg
long lastMsg = 0;

void setup_wifi() {
  delay(10);
  Serial.println("Connecting to Wi-Fi...");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Wi-Fi connected!");
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client")) {
      Serial.println("Connected to MQTT broker!");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" trying again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);

  Serial.println("Weight simulation ready!");
}

float generateWeight() {
  // Simulate normal weight fluctuation
  float weight = baseWeight + random(-5, 5);

  // Introduce occasional significant drops to simulate theft
  if (random(100) < 5) { // 5% chance of theft event
    weight -= random(50, 200); // Simulate a drop
    Serial.println("Warning: Sudden drop detected!");
  }

  return weight;
}

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

  // Generate and publish simulated weight data
  float weight = generateWeight();
  Serial.print("Simulated Weight: ");
  Serial.println(weight);

  // Publish weight to MQTT
  String weightStr = String(weight);
  client.publish(topic, weightStr.c_str());

  delay(1000); // Delay between readings
}