/*
	Copyright (C) 2016 - 2021
	Part of the Battle for Wesnoth Project https://www.wesnoth.org/

	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; either version 2 of the License, or
	(at your option) any later version.
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY.

	See the COPYING file for more details.
*/

#include "scripting/lua_preferences.hpp"

#include "config.hpp"
#include "lua/lua.h"
#include "lua/lauxlib.h"
#include "preferences/general.hpp"
#include "scripting/lua_common.hpp"

/**
 * The __index metamethod.
 * Parameter 1: the preference table.
 * Parameter 2: preference name, must be a string.
 * Returns: preference value. If there isn't such a preference, returns nil.
 */
static int impl_preferences_get(lua_State* L)
{
	std::string preference_name = luaL_checkstring(L, 2);
	luaW_pushscalar(L, preferences::get_as_attribute(preference_name));
	return 1;
}

/**
 * The __newindex metamethod.
 * Parameter 1: the preference table.
 * Parameter 2: preference name, must be a string.
 * Parameter 3: preference value.
 * Returns nothing.
 */
static int impl_preferences_set(lua_State* L)
{
	std::string preference_name = luaL_checkstring(L, 2);
	config::attribute_value value;
	luaW_toscalar(L, 3, value);
	preferences::set(preference_name, value);
	return 0;
}

namespace lua_preferences
{
	std::string register_table(lua_State* L)
	{
		// Push the wesnoth table to the stack
		lua_getglobal(L, "wesnoth");

		// Create the preferences table
		lua_newtable(L);
		lua_pushcfunction(L, impl_preferences_get);
		lua_setfield(L, -2, "__index");
		lua_pushcfunction(L, impl_preferences_set);
		lua_setfield(L, -2, "__newindex");
		lua_pushstring(L, "src/scripting/lua_preferences.cpp");
		lua_setfield(L, -2, "__metatable");

		// Set the table as its own metatable
		lua_pushvalue(L, -1);
		lua_setmetatable(L, -2);

		// Assign the table to wesnoth.preferences
		lua_setfield(L, -2, "preferences");

		// Pop the wesnoth table from the stack
		lua_pop(L, 1);

		return "Adding preferences table...\n";
	}
}