// Copyright (C) 2012-2013 ChaosForge / Kornel Kisielewicz
// http://chaosforge.org/
//
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

#include <nv/lua/lua_function.hh>

#include <nv/lua/lua_raw.hh>

using namespace nv;

lua::function_base::function_base( lua_State* a_L, const path& a_path, bool a_global /*= true*/ ) : L(a_L)
{
	if ( !a_path.resolve( L, a_global ) )
	{
		lua_pop( L, 1 );
		throw std::runtime_error("not a valid path - " + a_path.to_string() );
	}

	if ( !lua_isfunction( L, -1 ) ) 
	{
		lua_pop( L, 1 );
		throw std::runtime_error("not a valid function - " + a_path.to_string() );
	}
	m_ref = luaL_ref( L, LUA_REGISTRYINDEX );
}

lua::function_base::function_base( const function_base& func ) : L(func.L)
{
	lua_rawgeti( L, LUA_REGISTRYINDEX, func.m_ref );
	m_ref = luaL_ref( L, LUA_REGISTRYINDEX );
}

lua::function_base::~function_base()
{
	luaL_unref( L, LUA_REGISTRYINDEX, m_ref );
}

lua::function_base& lua::function_base::operator=(const function_base& func)
{
	if ( this != &func ) 
	{
		L = func.L;
		lua_rawgeti( L, LUA_REGISTRYINDEX, func.m_ref );
		m_ref = luaL_ref( L, LUA_REGISTRYINDEX );
	}
	return *this;
}

void lua::function_base::retrieve()
{
	lua_rawgeti( L, LUA_REGISTRYINDEX, m_ref );
}

void lua::function_base::call( int args, int results )
{
	int status = lua_pcall( L, args, results, 0 );
	if ( status != 0 )
	{
		std::string error = lua_tostring( L, -1 );
		lua_pop( L, 1 );
		throw std::runtime_error(error.c_str());
	}
}