#include <WiFi.h>
#include <WiFiUdp.h>
#define SSDP_MULTICAST_IP IPAddress("239.255.255.250")
#define SSDP_PORT 1900
#define UPNP_HTTP_PORT 5000 // Most routers use 5000, but it can vary
#define SEARCH_TIMEOUT 5000  // 2 seconds timeout

class CUpnpClient {
private:
    IPAddress routerIP;
    String    routerIPString;
    uint16_t  routerPort;

    IPAddress publicIP;
    uint16_t publicPort;
    
    uint32_t lastDiscoveryTime;
    String routerLocation;
    String controlURL;
    char buffer[1024]; // Stack-based buffer for responses

public:
    CUpnpClient() : publicPort(0), lastDiscoveryTime(0) {}

    bool registerUPnP(uint32_t *pip, uint16_t *pport);

private:
    String fetchUPnPDescription(const String &location);
    String parseXML(const String &xml);
    int sendSoapRequest(const char *request, char *response, size_t responseSize);

    bool discoverUPnP();
    bool requestPortMappingEntry();
    bool requestPortForwarding();
    bool requestExternalIP();
    bool requestExternalPort();
};