#include <WiFi.h>
#include <esp_now.h>

// Callback function that will be executed when data is received
void onDataRecv(const esp_now_recv_info_t *recvInfo, const uint8_t *incomingData, int len) {
  char message[len + 1];
  memcpy(message, incomingData, len);
  message[len] = '\0'; // Null-terminate the string
  Serial.print("Received message: ");
  Serial.println(message);

  // Print the sender's MAC address
  char macStr[18];
  snprintf(macStr, sizeof(macStr), "%02X:%02X:%02X:%02X:%02X:%02X",
           recvInfo->src_addr[0], recvInfo->src_addr[1], recvInfo->src_addr[2],
           recvInfo->src_addr[3], recvInfo->src_addr[4], recvInfo->src_addr[5]);
  Serial.print("From MAC: ");
  Serial.println(macStr);
}

void setup() {
  Serial.begin(115200);

  // Set ESP32 to station mode
  WiFi.mode(WIFI_STA);
  Serial.println("ESP-NOW Receiver Initialized");

  // Initialize ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    while (true) {
      delay(1000); // Halt program if ESP-NOW fails
    }
  }

  // Register the receive callback
  esp_now_register_recv_cb(onDataRecv);

  Serial.println("Ready to receive messages");
}

void loop() {
  // Continuously check for connection status
  static unsigned long lastCheck = 0;
  unsigned long now = millis();

  // Check every 5 seconds if ESP-NOW is active
  if (now - lastCheck >= 5000) {
    lastCheck = now;
    if (esp_now_init() != ESP_OK) {
      Serial.println("ESP-NOW not active. Reinitializing...");
      esp_now_deinit(); // Deinitialize and reinitialize ESP-NOW
      if (esp_now_init() == ESP_OK) {
        esp_now_register_recv_cb(onDataRecv);
        Serial.println("ESP-NOW Reinitialized.");
      } else {
        Serial.println("Failed to reinitialize ESP-NOW.");
      }
    }
  }
}

/*

#include <WiFi.h>
#include <esp_wifi.h> // Include ESP-IDF WiFi header for low-level WiFi functions

// Custom MAC address (must follow the MAC address format)
uint8_t customMAC[6] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};

void setup() {
  Serial.begin(115200);

  // Set WiFi to station mode
  WiFi.mode(WIFI_STA);
  Serial.println("ESP32 MAC Address Assignment");

  // Assign the custom MAC address
  if (esp_wifi_set_mac(WIFI_IF_STA, customMAC) == ESP_OK) {
    Serial.println("Custom MAC Address assigned successfully!");
  } else {
    Serial.println("Failed to assign Custom MAC Address.");
  }

  // Print the currently assigned MAC address
  uint8_t currentMAC[6];
  esp_wifi_get_mac(WIFI_IF_STA, currentMAC);

  Serial.print("Current MAC Address: ");
  for (int i = 0; i < 6; i++) {
    Serial.printf("%02X", currentMAC[i]);
    if (i < 5) Serial.print(":");
  }
  Serial.println();
}

void loop() {
  // Nothing to do here
}

*/