// --- SENDER (Client A) ---
#include <WiFi.h>
#include <PubSubClient.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org"; // Öffentlicher Test-Broker

WiFiClient espClient;
PubSubClient client(espClient);

const int BUTTON_PIN = 15;
bool lastButtonState = HIGH;

void setup() {
  Serial.begin(115200);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  // 1. WiFi Verbindung
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi verbunden!");

  // 2. MQTT Verbindung
  client.setServer(mqtt_server, 1883);
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Verbinde mit MQTT...");
    // Einzigartige ID erzeugen
    if (client.connect("ESP32_Sender_Unique_ID_123")) {
      Serial.println("verbunden!");
    } else {
      delay(5000);
    }
  }
}

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

  // Button Logik
  int reading = digitalRead(BUTTON_PIN);
  if (reading == LOW && lastButtonState == HIGH) {
    Serial.println("Click! Sende Signal...");
    // WICHTIG: Das "Topic" muss eindeutig sein, damit wir uns finden
    client.publish("mein/eigenes/projekt/led", "TOGGLE"); 
    delay(200); // Debounce
  }
  lastButtonState = reading;
}