/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant 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 2 of the License, or
   (at your option) any later version.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "server.h"

#include "debugging/debugging.h"

#include <map>
#include <vector>
#include "os/path.h"

#include "modulesystem.h"

class RadiantModuleServer : public ModuleServer
{
typedef std::pair<std::string, int> ModuleType;
typedef std::pair<ModuleType, std::string> ModuleKey;
typedef std::map<ModuleKey, Module*> Modules_;
Modules_ m_modules;
bool m_error;

public:
RadiantModuleServer() : m_error( false ){
}

void setError( bool error ){
	m_error = error;
}
bool getError() const {
	return m_error;
}

TextOutputStream& getOutputStream(){
	return globalOutputStream();
}
TextOutputStream& getErrorStream(){
	return globalErrorStream();
}
DebugMessageHandler& getDebugMessageHandler(){
	return globalDebugMessageHandler();
}

void registerModule( const char* type, int version, const char* name, Module& module ){
	ASSERT_NOTNULL( &module );
	if ( !m_modules.insert( Modules_::value_type( ModuleKey( ModuleType( type, version ), name ), &module ) ).second ) {
		globalErrorStream() << "module already registered: type=" << makeQuoted( type ) << " name=" << makeQuoted( name ) << "\n";
	}
	else
	{
		globalOutputStream() << "Module Registered: type=" << makeQuoted( type ) << " version=" << makeQuoted( version ) << " name=" << makeQuoted( name ) << "\n";
	}
}

Module* findModule( const char* type, int version, const char* name ) const {
	auto i = m_modules.find( ModuleKey( ModuleType( type, version ), name ) );
	if ( i != m_modules.end() ) {
		return i->second;
	}
	return nullptr;
}

void foreachModule( const char* type, int version, const Visitor& visitor ){
	for ( Modules_::const_iterator i = m_modules.begin(); i != m_modules.end(); ++i )
	{
		if ( string_equal( ( *i ).first.first.first.c_str(), type ) ) {
			visitor.visit( ( *i ).first.second.c_str(), *( *i ).second );
		}
	}
}
};


#if defined( WIN32 )

#include <windows.h>

#define FORMAT_BUFSIZE 2048
const char* FormatGetLastError(){
	static char buf[FORMAT_BUFSIZE];
	FormatMessage(
		FORMAT_MESSAGE_FROM_SYSTEM |
		FORMAT_MESSAGE_IGNORE_INSERTS,
		NULL,
		GetLastError(),
		MAKELANGID( LANG_NEUTRAL, SUBLANG_DEFAULT ), // Default language
		buf,
		FORMAT_BUFSIZE,
		NULL
		);
	return buf;
}

class DynamicLibrary
{
HMODULE m_library;
public:
typedef int ( __stdcall * FunctionPointer )();

DynamicLibrary( const char* filename ){
	m_library = LoadLibrary( filename );
	if ( m_library == 0 ) {
		globalErrorStream() << "LoadLibrary failed: '" << filename << "'\n";
		globalErrorStream() << "GetLastError: " << FormatGetLastError();
	}
}
~DynamicLibrary(){
	if ( !failed() ) {
		FreeLibrary( m_library );
	}
}
bool failed(){
	return m_library == 0;
}
FunctionPointer findSymbol( const char* symbol ){
	FunctionPointer address = (FunctionPointer) GetProcAddress( m_library, symbol );
	if ( address == 0 ) {
		globalErrorStream() << "GetProcAddress failed: '" << symbol << "'\n";
		globalErrorStream() << "GetLastError: " << FormatGetLastError();
	}
	return address;
}
};

#elif defined( POSIX )

#include <dlfcn.h>

class DynamicLibrary {
	void *m_library;
public:
	using FunctionPointer = int (*)();

	DynamicLibrary(const char *filename)
	{
		m_library = dlopen(filename, RTLD_LOCAL
									 | RTLD_NOW
									 #ifndef __APPLE__
									 | RTLD_DEEPBIND
#endif
		);
		auto error = dlerror();
		if (!m_library || error) {
			globalErrorStream() << "LoadLibrary failed: '" << filename << "'\n";
			globalErrorStream() << "GetLastError: " << error;
		}
	}

	~DynamicLibrary()
	{
		if (!failed()) {
			dlclose(m_library);
		}
	}

	bool failed()
	{
		return m_library == nullptr;
	}

	FunctionPointer findSymbol(const char *symbol)
	{
		if (auto p = reinterpret_cast<FunctionPointer>(dlsym(m_library, symbol))) {
			return p;
		}
		if (auto error = reinterpret_cast<const char *>(dlerror())) {
			globalErrorStream() << error;
		}
		return nullptr;
	}
};

#else
#error "unsupported platform"
#endif

class DynamicLibraryModule {
	typedef void ( RADIANT_DLLIMPORT *RegisterModulesFunc )(ModuleServer &server);

	DynamicLibrary m_library;
	RegisterModulesFunc m_registerModule;
public:
	DynamicLibraryModule(const char *filename)
			: m_library(filename), m_registerModule(nullptr)
	{
		if (!m_library.failed()) {
			m_registerModule = reinterpret_cast<RegisterModulesFunc>( m_library.findSymbol("Radiant_RegisterModules"));
#if 0
            if ( !m_registerModule ) {
                m_registerModule = reinterpret_cast<RegisterModulesFunc>( m_library.findSymbol( "Radiant_RegisterModules@4" ) );
            }
#endif
		}
	}

	bool failed()
	{
		return m_registerModule == nullptr;
	}

	void registerModules(ModuleServer &server)
	{
		m_registerModule(server);
	}
};


class Libraries
{
typedef std::vector<DynamicLibraryModule*> libraries_t;
libraries_t m_libraries;

public:
~Libraries(){
	release();
}
void registerLibrary( const char* filename, ModuleServer& server ){
	DynamicLibraryModule* library = new DynamicLibraryModule( filename );

	if ( library->failed() ) {
		delete library;
	}
	else
	{
		m_libraries.push_back( library );
		library->registerModules( server );
	}
}
void release(){
	for ( libraries_t::iterator i = m_libraries.begin(); i != m_libraries.end(); ++i )
	{
		delete *i;
	}
}
void clear(){
	m_libraries.clear();
}
};


Libraries g_libraries;
RadiantModuleServer g_server;

ModuleServer& GlobalModuleServer_get(){
	return g_server;
}

void GlobalModuleServer_loadModule( const char* filename ){
	g_libraries.registerLibrary( filename, g_server );
}

void GlobalModuleServer_Initialise(){
}

void GlobalModuleServer_Shutdown(){
}