#include "os.hpp"

#include <filesystem>

#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
    #include <mutex>
    #include <dlfcn.h>
    #include <pthread.h>
#elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
// TODO
#endif

namespace fs = std::filesystem;

namespace mijin
{

//
// internal defines
//

//
// internal constants
//

//
// internal types
//

//
// internal variables
//

#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
namespace
{
std::mutex gDlErrorMutex; // dlerror may not be thread-safe
}
#endif // MIJIN_TARGET_OS == MIJIN_OS_LINUX

//
// internal functions
//

//
// public functions
//

Result<LibraryHandle> openSharedLibrary(std::string_view libraryFile) noexcept
{
#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
    const std::unique_lock dlErrorLock(gDlErrorMutex);
    dlerror(); // NOLINT(concurrency-mt-unsafe) we take care of that

    const fs::path libraryPath = fs::absolute(libraryFile);
    void* ptr = dlopen(libraryPath.c_str(), RTLD_NOW);
    if (ptr == nullptr)
    {
        return ResultError(dlerror()); // NOLINT(concurrency-mt-unsafe) we take care of that
    }
    return LibraryHandle{.data = dlopen(libraryPath.c_str(), RTLD_NOW)};
#elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
	// TODO
	(void) libraryFile;
	return {};
#endif
}

bool closeSharedLibrary(const LibraryHandle library) noexcept
{
#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
    return dlclose(library.data) == 0;
#elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
    (void) library;
    return true;
#endif
}

void* loadSymbolFromLibrary(const LibraryHandle library, const char* symbolName) noexcept
{
#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
    return dlsym(library.data, symbolName);
#elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
	(void) library;
	(void) symbolName;
	return nullptr;
#endif
}

void setCurrentThreadName(const char* threadName) noexcept
{
#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
    pthread_setname_np(pthread_self(), threadName);
#elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
	(void) threadName;
#endif
}

[[nodiscard]] std::string makeLibraryFilename(std::string_view libraryName) noexcept
{
#if MIJIN_TARGET_OS == MIJIN_OS_LINUX
    return "lib" + std::string(libraryName) + ".so";
#elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
    return std::string(libraryName) + ".dll";
#else

#endif
}

} // namespace mijin