/*
 Copyright (c) 2013 yvt
 
 This file is part of OpenSpades.
 
 OpenSpades 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, either version 3 of the License, or
 (at your option) any later version.
 
 OpenSpades 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 for more details.
 
 You should have received a copy of the GNU General Public License
 along with OpenSpades.  If not, see <http://www.gnu.org/licenses/>.
 
 */

#include <Imports/SDL.h>

#ifdef WIN32

#include "DynamicLibrary.h"
#include "Exception.h"
#include <windows.h>
#include "Debug.h"

namespace spades {

	static std::string errToMsg( DWORD err )
	{
		LPSTR msgBuf = NULL;
		DWORD dwFmt = FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
		size_t size = FormatMessageA(dwFmt, NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&msgBuf, 0, NULL);
		std::string message(msgBuf, size);
		LocalFree(msgBuf);
		return message;
	}

	DynamicLibrary::DynamicLibrary(const char *fn){
		SPADES_MARK_FUNCTION();
		
		name = fn;
		handle = (void *)LoadLibrary(fn);
		if(handle == NULL){
			DWORD err = GetLastError();
			std::string msg = errToMsg( err );
			SPRaise("Failed to dlload '%s': 0x%08x (%s)", fn, (int)err, msg.c_str());
		}
	}
	
	DynamicLibrary::~DynamicLibrary() {
		SPADES_MARK_FUNCTION();
		
		FreeLibrary((HINSTANCE)handle);
	}
	
	void *DynamicLibrary::GetSymbolOrNull(const char *name){
		SPADES_MARK_FUNCTION();
		
		void *addr = (void*)GetProcAddress((HINSTANCE)handle, name);
		return addr;
	}
	
	void *DynamicLibrary::GetSymbol(const char *sname){
		SPADES_MARK_FUNCTION();
		
		void *v = GetSymbolOrNull(sname);
		if(v == NULL){
			DWORD err = GetLastError();
			std::string msg = errToMsg( err );
			SPRaise("Failed to find symbol '%s' in %s: 0x%08x (%s)", sname, name.c_str(), err, msg.c_str());
		}
		return v;
	}
}


#else
#include "DynamicLibrary.h"
#include "Exception.h"
#include <dlfcn.h>
#include "Debug.h"

namespace spades {
	DynamicLibrary::DynamicLibrary(const char *fn){
		SPADES_MARK_FUNCTION();
		
		if(fn == nullptr) {
			SPInvalidArgument("fn");
		}
		
		name = fn;
		handle = dlopen(fn, RTLD_LAZY);
		if(handle == nullptr &&
		   strchr(fn, '/') == nullptr &&
		   strchr(fn, '\\') == nullptr) {
			char *baseDir = SDL_GetBasePath();
			std::string newPath = baseDir;
			newPath += "/";
			newPath += fn;
			handle = dlopen(newPath.c_str(), RTLD_LAZY);
		}
		if(handle == nullptr){
			std::string err = dlerror();
			SPRaise("Failed to dlload '%s': %s", fn, err.c_str());
		}
	}
	
	DynamicLibrary::~DynamicLibrary() {
		SPADES_MARK_FUNCTION();
		
		dlclose(handle);
	}
	
	void *DynamicLibrary::GetSymbolOrNull(const char *name){
		SPADES_MARK_FUNCTION();
		
		void *addr = dlsym(handle, name);
		return addr;
	}
	
	void *DynamicLibrary::GetSymbol(const char *sname){
		SPADES_MARK_FUNCTION();
		
		void *v = GetSymbolOrNull(sname);
		if(v == NULL){
			std::string err = dlerror();
			SPRaise("Failed to find symbol '%s' in %s: %s", sname,
					name.c_str(), err.c_str());
		}
		return v;
	}
}

#endif