// Copyright (C) 2003-2008 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

#include <string.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <dlfcn.h>
#include <stdio.h>
#endif

#include "Common.h"
#include "StringUtil.h"
#include "DynamicLibrary.h"

DynamicLibrary::DynamicLibrary()
{
	library = 0;
}

#ifdef _WIN32
std::string GetLastErrorAsString()
{
	LPVOID lpMsgBuf = 0;
	DWORD error = GetLastError();
	FormatMessage( 
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
		NULL,
		error,
		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
		(LPTSTR) &lpMsgBuf,
		0, NULL);
	std::string s;
	if (lpMsgBuf)
	{
		s = ((char *)lpMsgBuf);
		LocalFree(lpMsgBuf);
	} else {
		s = StringFromFormat("(unknown error %08x)", error);
	}
	return s;
}
#endif

bool DynamicLibrary::Load(const char* filename)
{
	if (!filename || strlen(filename) == 0)
	{
		LOG(MASTER_LOG, "Missing filename of dynamic library to load");
		return false;
	}
	LOG(MASTER_LOG, "Trying to load library %s", filename);

	if (IsLoaded())
	{
		LOG(MASTER_LOG, "Trying to load already loaded library %s", filename);
		return false;
	}

#ifdef _WIN32
	library = LoadLibrary(filename);
	if (!library) {
		LOG(MASTER_LOG, "Error loading DLL %s: %s", filename, GetLastErrorAsString().c_str());
		return false;
	}
#else
	library = dlopen(filename, RTLD_NOW | RTLD_LOCAL);
	if (!library)
	{
		#ifdef LOGGING
		LOG(MASTER_LOG, "Error loading DLL %s: %s", filename, dlerror());
		#else
		printf("Error loading DLL %s: %s", filename, dlerror());
		#endif
		return false;
	}
#endif
	library_file = filename;
	return true;
}


void DynamicLibrary::Unload()
{
	if (!IsLoaded())
	{
		PanicAlert("Trying to unload non-loaded library");
		return;
	}

#ifdef _WIN32
	FreeLibrary(library);
#else
	dlclose(library);
#endif
	library = 0;
}


void* DynamicLibrary::Get(const char* funcname) const
{
	void* retval;
#ifdef _WIN32
	if (!library)
	{
		PanicAlert("Can't find function %s - Library not loaded.");
	}
	retval = GetProcAddress(library, funcname);
	//if (!retval)
	//{
	//	PanicAlert("Did not find function %s in library %s.", funcname, library_file.c_str());
	//}
#else
	retval = dlsym(library, funcname);

	if (!retval)
	{
		printf("Symbol %s missing in %s (error: %s)\n", funcname, library_file.c_str(), dlerror());
	}
#endif
	return retval;
}