/*
 * Copyright (C) 2013  Patrick "P. J." McDermott
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 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; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
#include "../logging.h"
#include "../scripting/ffi.h"
#include "script.h"
#include "resource.h"

/* LUA_OK is defined in Lua 5.2 but not 5.1. */
#ifndef LUA_OK
#define LUA_OK 0
#endif

static struct resource_table script_res;

struct script *
script_get(const char *path)
{
	struct script *s;

	s = (struct script *) resource_get(&script_res, path);
	if (s != NULL) {
		resource_use((struct resource *) s);
		return s;
	}

	s = resource_alloc(path, sizeof(*s));

	/* Load the script. */
	s->lua_state = luaL_newstate();
	luaL_openlibs(s->lua_state);
	if (luaL_loadfile(s->lua_state, path) != LUA_OK) {
		err(1, "Error loading script: %s\n",
				lua_tostring(s->lua_state, -1));
	}

	/* Run the script once to let it define functions. */
	if (lua_pcall(s->lua_state, 0, 0, 0) != LUA_OK) {
		err(1, "Error running script: %s\n",
				lua_tostring(s->lua_state, -1));
	}

	ffi_register_functions(s);

	resource_use((struct resource *) s);
	resource_add(&script_res, path, (struct resource *) s);

	return s;
}

void
script_free(struct script *script)
{
	lua_State *data;

	if (script == NULL) {
		return;
	}

	data = script->lua_state;
	if (resource_free(&script_res, (struct resource *) script)) {
		lua_close(data);
	}
}