// Copyright 2020 Proyectos y Sistemas de Mantenimiento SL (eProsima).

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

/*

 * Host.cpp

 *

 */

#include <utils/Host.hpp>

#if defined(_WIN32)

#include <WinSock2.h> // Avoid conflicts with WinSock of Windows.h

#include <windows.h>

#include <process.h>

#elif defined(__APPLE__)

#include <IOKit/IOKitLib.h>

#else

#include <unistd.h>

#include <fcntl.h>

#endif // if defined(_WIN32)

namespace eprosima {

fastcdr::string_255 Host::compute_machine_id()

{

    #ifdef _WIN32

    char machine_id[255];

    DWORD BufferSize = sizeof(machine_id);

    LONG res = RegGetValueA(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Cryptography", "MachineGuid", RRF_RT_REG_SZ,

                    NULL, machine_id, &BufferSize);

    if (res == 0)

    {

        return machine_id;

    }

    return "";

    #elif defined(__APPLE__)

    io_registry_entry_t ioRegistryRoot = IORegistryEntryFromPath(kIOMainPortDefault, "IOService:/");

    if (!ioRegistryRoot)

    {

        return "";

    }

    CFStringRef uuidCf = (CFStringRef) IORegistryEntryCreateCFProperty(ioRegistryRoot, CFSTR(

                        kIOPlatformUUIDKey), kCFAllocatorDefault, 0);

    IOObjectRelease(ioRegistryRoot);

    if (!uuidCf)

    {

        return "";

    }

    char buf[255];

    if (!CFStringGetCString(uuidCf, buf, sizeof(buf), kCFStringEncodingUTF8))

    {

        return "";

    }

    CFRelease(uuidCf);

    return buf;

    #elif defined(_POSIX_SOURCE)

    int fd = open("/etc/machine-id", O_RDONLY);

    if (fd == -1)

    {

        return "";

    }

    char buffer[33] = {0};

    ssize_t bytes_read = read(fd, buffer, 32);

    close(fd);

    if (bytes_read < 32)

    {

        return "";

    }

    return buffer;

    #else

    return "";

    #endif // if defined(_WIN32)

}

} // eprosima