/*
 * sharedlibrary.cpp
 *
 *  Created on: Apr 19, 2014
 *      Author: gregor
 */

#if defined WIN32
#include <sstream>
#endif

#if defined LINUX || defined ANDROID
#include <dlfcn.h>
#endif

#include <GLTB/exception.h>
#include <GLTB/sharedlibrary.h>

namespace gltb {
	SharedLibrary::SharedLibrary(std::string libraryName)
	: libraryName(libraryName)
	{
#if defined WIN32
		// TODO reimplement this using LoadLibraryEx
		library = LoadLibraryA(libraryName.c_str());
		if(library == NULL) {
			std::ostringstream message;
			message << "LoadLibrary failed with error code " << GetLastError();
			throw Exception(message.str(), "gltb::SharedLibrary::SharedLibrary()");
		}
#else
		library = dlopen(libraryName.c_str(), RTLD_NOW);
		if(library == 0) {
			throw Exception("dlopen failed: " + std::string(dlerror()), "gltb::SharedLibrary::SharedLibrary()");
		}
#endif
	}

	SharedLibrary::~SharedLibrary()
	{
#if defined WIN32
		FreeLibrary(library);
#else
		dlclose(library);
#endif
	}

	void *SharedLibrary::getSymbol(std::string name)
	{
#if defined WIN32
		void *result = GetProcAddress(library, name.c_str());
		if(result == NULL) {
			std::ostringstream message;
			message << "GetProcAddress failed with error code " << GetLastError();
			throw Exception(message.str(), "gltb::SharedLibrary::SharedLibrary()");
		}

		return result;
#else
		dlerror(); // clear any previous error
		void *result = dlsym(library, name.c_str()); // dlsym returning NULL may be ok
		char *error = dlerror(); // check dlerror again for actual errors
		if(error != 0) {
			throw Exception("dlsym failed: " + std::string(error), "gltb::SharedLibrary::getSymbol()");
		}

		return result;
#endif
	}
}