squeezelite-esp32/components/spotify/cspot/bell/main/platform/esp/MDNSService.cpp

#include "MDNSService.h"
#include <arpa/inet.h>
#include <vector>
#include "mdns.h"

using namespace bell;

class implMDNSService : public MDNSService {
private:
    const std::string type;
    const std::string proto;
    void unregisterService() { mdns_service_remove(type.c_str(), proto.c_str()); }

public:
   implMDNSService(std::string type, std::string proto) : type(type), proto(proto) { };                        
};

/**
 * ESP32 implementation of MDNSService
 * @see https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/protocols/mdns.html
 **/

std::unique_ptr<MDNSService> MDNSService::registerService(
    const std::string& serviceName,
    const std::string& serviceType,
    const std::string& serviceProto,
    const std::string& serviceHost,
    int servicePort,
    const std::map<std::string, std::string> txtData
) {
    std::vector<mdns_txt_item_t> txtItems;
    txtItems.reserve(txtData.size());
    for (auto& data : txtData) {
        mdns_txt_item_t item;
        item.key = data.first.c_str();
        item.value = data.second.c_str();
        txtItems.push_back(item);
    }

    mdns_service_add(
        serviceName.c_str(), /* instance_name */
        serviceType.c_str(), /* service_type */
        serviceProto.c_str(), /* proto */
        servicePort, /* port */
        txtItems.data(), /* txt */
        txtItems.size() /* num_items */
    );

    return std::make_unique<implMDNSService>(serviceType, serviceProto);
}