minetest/src/scriptapi.cpp

/*
Minetest-c55
Copyright (C) 2011 celeron55, Perttu Ahola <celeron55@gmail.com>

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

#include "scriptapi.h"

#include <iostream>
#include <list>
extern "C" {
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
}

#include "log.h"
#include "server.h"
#include "porting.h"
#include "filesys.h"
#include "serverobject.h"
#include "script.h"
//#include "luna.h"
#include "luaentity_common.h"
#include "content_sao.h" // For LuaEntitySAO
#include "itemdef.h"
#include "nodedef.h"
#include "craftdef.h"
#include "main.h" // For g_settings
#include "settings.h" // For accessing g_settings
#include "nodemetadata.h"
#include "mapblock.h" // For getNodeBlockPos
#include "content_nodemeta.h"
#include "utility.h"
#include "tool.h"

static void stackDump(lua_State *L, std::ostream &o)
{
  int i;
  int top = lua_gettop(L);
  for (i = 1; i <= top; i++) {  /* repeat for each level */
	int t = lua_type(L, i);
	switch (t) {

	  case LUA_TSTRING:  /* strings */
	  	o<<"\""<<lua_tostring(L, i)<<"\"";
		break;

	  case LUA_TBOOLEAN:  /* booleans */
		o<<(lua_toboolean(L, i) ? "true" : "false");
		break;

	  case LUA_TNUMBER:  /* numbers */ {
	  	char buf[10];
		snprintf(buf, 10, "%g", lua_tonumber(L, i));
		o<<buf;
		break; }

	  default:  /* other values */
		o<<lua_typename(L, t);
		break;

	}
	o<<" ";
  }
  o<<std::endl;
}

static void realitycheck(lua_State *L)
{
	int top = lua_gettop(L);
	if(top >= 30){
		dstream<<"Stack is over 30:"<<std::endl;
		stackDump(L, dstream);
		script_error(L, "Stack is over 30 (reality check)");
	}
}

class StackUnroller
{
private:
	lua_State *m_lua;
	int m_original_top;
public:
	StackUnroller(lua_State *L):
		m_lua(L),
		m_original_top(-1)
	{
		m_original_top = lua_gettop(m_lua); // store stack height
	}
	~StackUnroller()
	{
		lua_settop(m_lua, m_original_top); // restore stack height
	}
};

class ModNameStorer
{
private:
	lua_State *L;
public:
	ModNameStorer(lua_State *L_, const std::string modname):
		L(L_)
	{
		// Store current modname in registry
		lua_pushstring(L, modname.c_str());
		lua_setfield(L, LUA_REGISTRYINDEX, "minetest_current_modname");
	}
	~ModNameStorer()
	{
		// Clear current modname in registry
		lua_pushnil(L);
		lua_setfield(L, LUA_REGISTRYINDEX, "minetest_current_modname");
	}
};

/*
	Getters for stuff in main tables
*/

static Server* get_server(lua_State *L)
{
	// Get server from registry
	lua_getfield(L, LUA_REGISTRYINDEX, "minetest_server");
	Server *server = (Server*)lua_touserdata(L, -1);
	lua_pop(L, 1);
	return server;
}

static ServerEnvironment* get_env(lua_State *L)
{
	// Get environment from registry
	lua_getfield(L, LUA_REGISTRYINDEX, "minetest_env");
	ServerEnvironment *env = (ServerEnvironment*)lua_touserdata(L, -1);
	lua_pop(L, 1);
	return env;
}

static void objectref_get(lua_State *L, u16 id)
{
	// Get minetest.object_refs[i]
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "object_refs");
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_pushnumber(L, id);
	lua_gettable(L, -2);
	lua_remove(L, -2); // object_refs
	lua_remove(L, -2); // minetest
}

static void luaentity_get(lua_State *L, u16 id)
{
	// Get minetest.luaentities[i]
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "luaentities");
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_pushnumber(L, id);
	lua_gettable(L, -2);
	lua_remove(L, -2); // luaentities
	lua_remove(L, -2); // minetest
}

/*
	Table field getters
*/

static bool getstringfield(lua_State *L, int table,
		const char *fieldname, std::string &result)
{
	lua_getfield(L, table, fieldname);
	bool got = false;
	if(lua_isstring(L, -1)){
		size_t len = 0;
		const char *ptr = lua_tolstring(L, -1, &len);
		result.assign(ptr, len);
		got = true;
	}
	lua_pop(L, 1);
	return got;
}

static bool getintfield(lua_State *L, int table,
		const char *fieldname, int &result)
{
	lua_getfield(L, table, fieldname);
	bool got = false;
	if(lua_isnumber(L, -1)){
		result = lua_tonumber(L, -1);
		got = true;
	}
	lua_pop(L, 1);
	return got;
}

static bool getfloatfield(lua_State *L, int table,
		const char *fieldname, float &result)
{
	lua_getfield(L, table, fieldname);
	bool got = false;
	if(lua_isnumber(L, -1)){
		result = lua_tonumber(L, -1);
		got = true;
	}
	lua_pop(L, 1);
	return got;
}

static bool getboolfield(lua_State *L, int table,
		const char *fieldname, bool &result)
{
	lua_getfield(L, table, fieldname);
	bool got = false;
	if(lua_isboolean(L, -1)){
		result = lua_toboolean(L, -1);
		got = true;
	}
	lua_pop(L, 1);
	return got;
}

static std::string checkstringfield(lua_State *L, int table,
		const char *fieldname)
{
	lua_getfield(L, table, fieldname);
	std::string s = luaL_checkstring(L, -1);
	lua_pop(L, 1);
	return s;
}

static std::string getstringfield_default(lua_State *L, int table,
		const char *fieldname, const std::string &default_)
{
	std::string result = default_;
	getstringfield(L, table, fieldname, result);
	return result;
}

static int getintfield_default(lua_State *L, int table,
		const char *fieldname, int default_)
{
	int result = default_;
	getintfield(L, table, fieldname, result);
	return result;
}

static float getfloatfield_default(lua_State *L, int table,
		const char *fieldname, float default_)
{
	float result = default_;
	getfloatfield(L, table, fieldname, result);
	return result;
}

static bool getboolfield_default(lua_State *L, int table,
		const char *fieldname, bool default_)
{
	bool result = default_;
	getboolfield(L, table, fieldname, result);
	return result;
}

struct EnumString
{
	int num;
	const char *str;
};

static bool string_to_enum(const EnumString *spec, int &result,
		const std::string &str)
{
	const EnumString *esp = spec;
	while(esp->str){
		if(str == std::string(esp->str)){
			result = esp->num;
			return true;
		}
		esp++;
	}
	return false;
}

/*static bool enum_to_string(const EnumString *spec, std::string &result,
		int num)
{
	const EnumString *esp = spec;
	while(esp){
		if(num == esp->num){
			result = esp->str;
			return true;
		}
		esp++;
	}
	return false;
}*/

static int getenumfield(lua_State *L, int table,
		const char *fieldname, const EnumString *spec, int default_)
{
	int result = default_;
	string_to_enum(spec, result,
			getstringfield_default(L, table, fieldname, ""));
	return result;
}

static void setintfield(lua_State *L, int table,
		const char *fieldname, int value)
{
	lua_pushinteger(L, value);
	if(table < 0)
		table -= 1;
	lua_setfield(L, table, fieldname);
}

static void setfloatfield(lua_State *L, int table,
		const char *fieldname, float value)
{
	lua_pushnumber(L, value);
	if(table < 0)
		table -= 1;
	lua_setfield(L, table, fieldname);
}

static void setboolfield(lua_State *L, int table,
		const char *fieldname, bool value)
{
	lua_pushboolean(L, value);
	if(table < 0)
		table -= 1;
	lua_setfield(L, table, fieldname);
}

static void warn_if_field_exists(lua_State *L, int table,
		const char *fieldname, const std::string &message)
{
	lua_getfield(L, table, fieldname);
	if(!lua_isnil(L, -1)){
		infostream<<script_get_backtrace(L)<<std::endl;
		infostream<<"WARNING: field \""<<fieldname<<"\": "
				<<message<<std::endl;
	}
	lua_pop(L, 1);
}

/*
	EnumString definitions
*/

struct EnumString es_ItemType[] =
{
	{ITEM_NONE, "none"},
	{ITEM_NODE, "node"},
	{ITEM_CRAFT, "craft"},
	{ITEM_TOOL, "tool"},
	{0, NULL},
};

struct EnumString es_DrawType[] =
{
	{NDT_NORMAL, "normal"},
	{NDT_AIRLIKE, "airlike"},
	{NDT_LIQUID, "liquid"},
	{NDT_FLOWINGLIQUID, "flowingliquid"},
	{NDT_GLASSLIKE, "glasslike"},
	{NDT_ALLFACES, "allfaces"},
	{NDT_ALLFACES_OPTIONAL, "allfaces_optional"},
	{NDT_TORCHLIKE, "torchlike"},
	{NDT_SIGNLIKE, "signlike"},
	{NDT_PLANTLIKE, "plantlike"},
	{NDT_FENCELIKE, "fencelike"},
	{NDT_RAILLIKE, "raillike"},
	{0, NULL},
};

struct EnumString es_ContentParamType[] =
{
	{CPT_NONE, "none"},
	{CPT_LIGHT, "light"},
	{0, NULL},
};

struct EnumString es_ContentParamType2[] =
{
	{CPT2_NONE, "none"},
	{CPT2_FULL, "full"},
	{CPT2_FLOWINGLIQUID, "flowingliquid"},
	{CPT2_FACEDIR, "facedir"},
	{CPT2_WALLMOUNTED, "wallmounted"},
	{0, NULL},
};

struct EnumString es_LiquidType[] =
{
	{LIQUID_NONE, "none"},
	{LIQUID_FLOWING, "flowing"},
	{LIQUID_SOURCE, "source"},
	{0, NULL},
};

struct EnumString es_NodeBoxType[] =
{
	{NODEBOX_REGULAR, "regular"},
	{NODEBOX_FIXED, "fixed"},
	{NODEBOX_WALLMOUNTED, "wallmounted"},
	{0, NULL},
};

/*
	C struct <-> Lua table converter functions
*/

static void push_v3f(lua_State *L, v3f p)
{
	lua_newtable(L);
	lua_pushnumber(L, p.X);
	lua_setfield(L, -2, "x");
	lua_pushnumber(L, p.Y);
	lua_setfield(L, -2, "y");
	lua_pushnumber(L, p.Z);
	lua_setfield(L, -2, "z");
}

static v2s16 read_v2s16(lua_State *L, int index)
{
	v2s16 p;
	luaL_checktype(L, index, LUA_TTABLE);
	lua_getfield(L, index, "x");
	p.X = lua_tonumber(L, -1);
	lua_pop(L, 1);
	lua_getfield(L, index, "y");
	p.Y = lua_tonumber(L, -1);
	lua_pop(L, 1);
	return p;
}

static v2f read_v2f(lua_State *L, int index)
{
	v2f p;
	luaL_checktype(L, index, LUA_TTABLE);
	lua_getfield(L, index, "x");
	p.X = lua_tonumber(L, -1);
	lua_pop(L, 1);
	lua_getfield(L, index, "y");
	p.Y = lua_tonumber(L, -1);
	lua_pop(L, 1);
	return p;
}

static v3f read_v3f(lua_State *L, int index)
{
	v3f pos;
	luaL_checktype(L, index, LUA_TTABLE);
	lua_getfield(L, index, "x");
	pos.X = lua_tonumber(L, -1);
	lua_pop(L, 1);
	lua_getfield(L, index, "y");
	pos.Y = lua_tonumber(L, -1);
	lua_pop(L, 1);
	lua_getfield(L, index, "z");
	pos.Z = lua_tonumber(L, -1);
	lua_pop(L, 1);
	return pos;
}

static v3f check_v3f(lua_State *L, int index)
{
	v3f pos;
	luaL_checktype(L, index, LUA_TTABLE);
	lua_getfield(L, index, "x");
	pos.X = luaL_checknumber(L, -1);
	lua_pop(L, 1);
	lua_getfield(L, index, "y");
	pos.Y = luaL_checknumber(L, -1);
	lua_pop(L, 1);
	lua_getfield(L, index, "z");
	pos.Z = luaL_checknumber(L, -1);
	lua_pop(L, 1);
	return pos;
}

static void pushFloatPos(lua_State *L, v3f p)
{
	p /= BS;
	push_v3f(L, p);
}

static v3f checkFloatPos(lua_State *L, int index)
{
	return check_v3f(L, index) * BS;
}

static void push_v3s16(lua_State *L, v3s16 p)
{
	lua_newtable(L);
	lua_pushnumber(L, p.X);
	lua_setfield(L, -2, "x");
	lua_pushnumber(L, p.Y);
	lua_setfield(L, -2, "y");
	lua_pushnumber(L, p.Z);
	lua_setfield(L, -2, "z");
}

static v3s16 read_v3s16(lua_State *L, int index)
{
	// Correct rounding at <0
	v3f pf = read_v3f(L, index);
	return floatToInt(pf, 1.0);
}

static v3s16 check_v3s16(lua_State *L, int index)
{
	// Correct rounding at <0
	v3f pf = check_v3f(L, index);
	return floatToInt(pf, 1.0);
}

static void pushnode(lua_State *L, const MapNode &n, INodeDefManager *ndef)
{
	lua_newtable(L);
	lua_pushstring(L, ndef->get(n).name.c_str());
	lua_setfield(L, -2, "name");
	lua_pushnumber(L, n.getParam1());
	lua_setfield(L, -2, "param1");
	lua_pushnumber(L, n.getParam2());
	lua_setfield(L, -2, "param2");
}

static MapNode readnode(lua_State *L, int index, INodeDefManager *ndef)
{
	lua_getfield(L, index, "name");
	const char *name = luaL_checkstring(L, -1);
	lua_pop(L, 1);
	u8 param1;
	lua_getfield(L, index, "param1");
	if(lua_isnil(L, -1))
		param1 = 0;
	else
		param1 = lua_tonumber(L, -1);
	lua_pop(L, 1);
	u8 param2;
	lua_getfield(L, index, "param2");
	if(lua_isnil(L, -1))
		param2 = 0;
	else
		param2 = lua_tonumber(L, -1);
	lua_pop(L, 1);
	return MapNode(ndef, name, param1, param2);
}

static video::SColor readARGB8(lua_State *L, int index)
{
	video::SColor color;
	luaL_checktype(L, index, LUA_TTABLE);
	lua_getfield(L, index, "a");
	if(lua_isnumber(L, -1))
		color.setAlpha(lua_tonumber(L, -1));
	lua_pop(L, 1);
	lua_getfield(L, index, "r");
	color.setRed(lua_tonumber(L, -1));
	lua_pop(L, 1);
	lua_getfield(L, index, "g");
	color.setGreen(lua_tonumber(L, -1));
	lua_pop(L, 1);
	lua_getfield(L, index, "b");
	color.setBlue(lua_tonumber(L, -1));
	lua_pop(L, 1);
	return color;
}

static core::aabbox3d<f32> read_aabbox3df32(lua_State *L, int index, f32 scale)
{
	core::aabbox3d<f32> box;
	if(lua_istable(L, -1)){
		lua_rawgeti(L, -1, 1);
		box.MinEdge.X = lua_tonumber(L, -1) * scale;
		lua_pop(L, 1);
		lua_rawgeti(L, -1, 2);
		box.MinEdge.Y = lua_tonumber(L, -1) * scale;
		lua_pop(L, 1);
		lua_rawgeti(L, -1, 3);
		box.MinEdge.Z = lua_tonumber(L, -1) * scale;
		lua_pop(L, 1);
		lua_rawgeti(L, -1, 4);
		box.MaxEdge.X = lua_tonumber(L, -1) * scale;
		lua_pop(L, 1);
		lua_rawgeti(L, -1, 5);
		box.MaxEdge.Y = lua_tonumber(L, -1) * scale;
		lua_pop(L, 1);
		lua_rawgeti(L, -1, 6);
		box.MaxEdge.Z = lua_tonumber(L, -1) * scale;
		lua_pop(L, 1);
	}
	return box;
}

#if 0
/*
	MaterialProperties
*/

static MaterialProperties read_material_properties(
		lua_State *L, int table)
{
	MaterialProperties prop;
	prop.diggability = (Diggability)getenumfield(L, -1, "diggability",
			es_Diggability, DIGGABLE_NORMAL);
	getfloatfield(L, -1, "constant_time", prop.constant_time);
	getfloatfield(L, -1, "weight", prop.weight);
	getfloatfield(L, -1, "crackiness", prop.crackiness);
	getfloatfield(L, -1, "crumbliness", prop.crumbliness);
	getfloatfield(L, -1, "cuttability", prop.cuttability);
	getfloatfield(L, -1, "flammability", prop.flammability);
	return prop;
}
#endif

/*
	Groups
*/
static void read_groups(lua_State *L, int index,
		std::map<std::string, int> &result)
{
	result.clear();
	lua_pushnil(L);
	if(index < 0)
		index -= 1;
	while(lua_next(L, index) != 0){
		// key at index -2 and value at index -1
		std::string name = luaL_checkstring(L, -2);
		int rating = luaL_checkinteger(L, -1);
		result[name] = rating;
		// removes value, keeps key for next iteration
		lua_pop(L, 1);
	}
}

/*
	ToolCapabilities
*/

static ToolCapabilities read_tool_capabilities(
		lua_State *L, int table)
{
	ToolCapabilities toolcap;
	getfloatfield(L, table, "full_punch_interval", toolcap.full_punch_interval);
	getintfield(L, table, "max_drop_level", toolcap.max_drop_level);
	lua_getfield(L, table, "groupcaps");
	if(lua_istable(L, -1)){
		int table_groupcaps = lua_gettop(L);
		lua_pushnil(L);
		while(lua_next(L, table_groupcaps) != 0){
			// key at index -2 and value at index -1
			std::string groupname = luaL_checkstring(L, -2);
			if(lua_istable(L, -1)){
				int table_groupcap = lua_gettop(L);
				// This will be created
				ToolGroupCap groupcap;
				// Read simple parameters
				getfloatfield(L, table_groupcap, "maxwear", groupcap.maxwear);
				getintfield(L, table_groupcap, "maxlevel", groupcap.maxlevel);
				// Read "times" table
				lua_getfield(L, table_groupcap, "times");
				if(lua_istable(L, -1)){
					int table_times = lua_gettop(L);
					lua_pushnil(L);
					while(lua_next(L, table_times) != 0){
						// key at index -2 and value at index -1
						int rating = luaL_checkinteger(L, -2);
						float time = luaL_checknumber(L, -1);
						groupcap.times[rating] = time;
						// removes value, keeps key for next iteration
						lua_pop(L, 1);
					}
				}
				lua_pop(L, 1);
				// Insert groupcap into toolcap
				toolcap.groupcaps[groupname] = groupcap;
			}
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);
	return toolcap;
}

static void set_tool_capabilities(lua_State *L, int table,
		const ToolCapabilities &toolcap)
{
	setfloatfield(L, table, "full_punch_interval", toolcap.full_punch_interval);
	setintfield(L, table, "max_drop_level", toolcap.max_drop_level);
	// Create groupcaps table
	lua_newtable(L);
	// For each groupcap
	for(std::map<std::string, ToolGroupCap>::const_iterator
			i = toolcap.groupcaps.begin(); i != toolcap.groupcaps.end(); i++){
		// Create groupcap table
		lua_newtable(L);
		const std::string &name = i->first;
		const ToolGroupCap &groupcap = i->second;
		// Create subtable "times"
		lua_newtable(L);
		for(std::map<int, float>::const_iterator
				i = groupcap.times.begin(); i != groupcap.times.end(); i++){
			int rating = i->first;
			float time = i->second;
			lua_pushinteger(L, rating);
			lua_pushnumber(L, time);
			lua_settable(L, -3);
		}
		// Set subtable "times"
		lua_setfield(L, -2, "times");
		// Set simple parameters
		setfloatfield(L, -1, "maxwear", groupcap.maxwear);
		setintfield(L, -1, "maxlevel", groupcap.maxlevel);
		// Insert groupcap table into groupcaps table
		lua_setfield(L, -2, name.c_str());
	}
	// Set groupcaps table
	lua_setfield(L, -2, "groupcaps");
}

static void push_tool_capabilities(lua_State *L,
		const ToolCapabilities &prop)
{
	lua_newtable(L);
	set_tool_capabilities(L, -1, prop);
}

/*
	DigParams
*/

static void set_dig_params(lua_State *L, int table,
		const DigParams &params)
{
	setboolfield(L, table, "diggable", params.diggable);
	setfloatfield(L, table, "time", params.time);
	setintfield(L, table, "wear", params.wear);
}

static void push_dig_params(lua_State *L,
		const DigParams &params)
{
	lua_newtable(L);
	set_dig_params(L, -1, params);
}

/*
	HitParams
*/

static void set_hit_params(lua_State *L, int table,
		const HitParams &params)
{
	setintfield(L, table, "hp", params.hp);
	setintfield(L, table, "wear", params.wear);
}

static void push_hit_params(lua_State *L,
		const HitParams &params)
{
	lua_newtable(L);
	set_hit_params(L, -1, params);
}

/*
	PointedThing
*/

static void push_pointed_thing(lua_State *L, const PointedThing& pointed)
{
	lua_newtable(L);
	if(pointed.type == POINTEDTHING_NODE)
	{
		lua_pushstring(L, "node");
		lua_setfield(L, -2, "type");
		push_v3s16(L, pointed.node_undersurface);
		lua_setfield(L, -2, "under");
		push_v3s16(L, pointed.node_abovesurface);
		lua_setfield(L, -2, "above");
	}
	else if(pointed.type == POINTEDTHING_OBJECT)
	{
		lua_pushstring(L, "object");
		lua_setfield(L, -2, "type");
		objectref_get(L, pointed.object_id);
		lua_setfield(L, -2, "ref");
	}
	else
	{
		lua_pushstring(L, "nothing");
		lua_setfield(L, -2, "type");
	}
}

/*
	ItemDefinition
*/

static ItemDefinition read_item_definition(lua_State *L, int index)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	// Read the item definition
	ItemDefinition def;

	def.type = (ItemType)getenumfield(L, index, "type",
			es_ItemType, ITEM_NONE);
	getstringfield(L, index, "name", def.name);
	getstringfield(L, index, "description", def.description);
	getstringfield(L, index, "inventory_image", def.inventory_image);
	getstringfield(L, index, "wield_image", def.wield_image);

	lua_getfield(L, index, "wield_scale");
	if(lua_istable(L, -1)){
		def.wield_scale = check_v3f(L, -1);
	}
	lua_pop(L, 1);

	def.stack_max = getintfield_default(L, index, "stack_max", def.stack_max);
	if(def.stack_max == 0)
		def.stack_max = 1;

	lua_getfield(L, index, "on_use");
	def.usable = lua_isfunction(L, -1);
	lua_pop(L, 1);

	getboolfield(L, index, "liquids_pointable", def.liquids_pointable);

	warn_if_field_exists(L, index, "tool_digging_properties",
			"deprecated: use tool_capabilities");
	
	lua_getfield(L, index, "tool_capabilities");
	if(lua_istable(L, -1)){
		def.tool_capabilities = new ToolCapabilities(
				read_tool_capabilities(L, -1));
	}

	// If name is "" (hand), ensure there are ToolCapabilities
	// because it will be looked up there whenever any other item has
	// no ToolCapabilities
	if(def.name == "" && def.tool_capabilities == NULL){
		def.tool_capabilities = new ToolCapabilities();
	}

	lua_getfield(L, index, "groups");
	read_groups(L, -1, def.groups);
	lua_pop(L, 1);

	return def;
}

/*
	ContentFeatures
*/

static ContentFeatures read_content_features(lua_State *L, int index)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	ContentFeatures f;
	/* Name */
	getstringfield(L, index, "name", f.name);

	/* Groups */
	lua_getfield(L, index, "groups");
	read_groups(L, -1, f.groups);
	lua_pop(L, 1);

	/* Visual definition */

	f.drawtype = (NodeDrawType)getenumfield(L, index, "drawtype", es_DrawType,
			NDT_NORMAL);
	getfloatfield(L, index, "visual_scale", f.visual_scale);

	lua_getfield(L, index, "tile_images");
	if(lua_istable(L, -1)){
		int table = lua_gettop(L);
		lua_pushnil(L);
		int i = 0;
		while(lua_next(L, table) != 0){
			// key at index -2 and value at index -1
			if(lua_isstring(L, -1))
				f.tname_tiles[i] = lua_tostring(L, -1);
			else
				f.tname_tiles[i] = "";
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
			i++;
			if(i==6){
				lua_pop(L, 1);
				break;
			}
		}
		// Copy last value to all remaining textures
		if(i >= 1){
			std::string lastname = f.tname_tiles[i-1];
			while(i < 6){
				f.tname_tiles[i] = lastname;
				i++;
			}
		}
	}
	lua_pop(L, 1);

	lua_getfield(L, index, "special_materials");
	if(lua_istable(L, -1)){
		int table = lua_gettop(L);
		lua_pushnil(L);
		int i = 0;
		while(lua_next(L, table) != 0){
			// key at index -2 and value at index -1
			int smtable = lua_gettop(L);
			std::string tname = getstringfield_default(
					L, smtable, "image", "");
			bool backface_culling = getboolfield_default(
					L, smtable, "backface_culling", true);
			MaterialSpec mspec(tname, backface_culling);
			f.mspec_special[i] = mspec;
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
			i++;
			if(i==6){
				lua_pop(L, 1);
				break;
			}
		}
	}
	lua_pop(L, 1);

	f.alpha = getintfield_default(L, index, "alpha", 255);

	/* Other stuff */
	
	lua_getfield(L, index, "post_effect_color");
	if(!lua_isnil(L, -1))
		f.post_effect_color = readARGB8(L, -1);
	lua_pop(L, 1);

	f.param_type = (ContentParamType)getenumfield(L, index, "paramtype",
			es_ContentParamType, CPT_NONE);
	f.param_type_2 = (ContentParamType2)getenumfield(L, index, "paramtype2",
			es_ContentParamType2, CPT2_NONE);

	// Warn about some deprecated fields
	warn_if_field_exists(L, index, "wall_mounted",
			"deprecated: use paramtype2 = 'wallmounted'");
	warn_if_field_exists(L, index, "light_propagates",
			"deprecated: determined from paramtype");
	warn_if_field_exists(L, index, "dug_item",
			"deprecated: use 'drop' field");
	warn_if_field_exists(L, index, "extra_dug_item",
			"deprecated: use 'drop' field");
	warn_if_field_exists(L, index, "extra_dug_item_rarity",
			"deprecated: use 'drop' field");
	
	// True for all ground-like things like stone and mud, false for eg. trees
	getboolfield(L, index, "is_ground_content", f.is_ground_content);
	f.light_propagates = (f.param_type == CPT_LIGHT);
	getboolfield(L, index, "sunlight_propagates", f.sunlight_propagates);
	// This is used for collision detection.
	// Also for general solidness queries.
	getboolfield(L, index, "walkable", f.walkable);
	// Player can point to these
	getboolfield(L, index, "pointable", f.pointable);
	// Player can dig these
	getboolfield(L, index, "diggable", f.diggable);
	// Player can climb these
	getboolfield(L, index, "climbable", f.climbable);
	// Player can build on these
	getboolfield(L, index, "buildable_to", f.buildable_to);
	// Metadata name of node (eg. "furnace")
	getstringfield(L, index, "metadata_name", f.metadata_name);
	// Whether the node is non-liquid, source liquid or flowing liquid
	f.liquid_type = (LiquidType)getenumfield(L, index, "liquidtype",
			es_LiquidType, LIQUID_NONE);
	// If the content is liquid, this is the flowing version of the liquid.
	getstringfield(L, index, "liquid_alternative_flowing",
			f.liquid_alternative_flowing);
	// If the content is liquid, this is the source version of the liquid.
	getstringfield(L, index, "liquid_alternative_source",
			f.liquid_alternative_source);
	// Viscosity for fluid flow, ranging from 1 to 7, with
	// 1 giving almost instantaneous propagation and 7 being
	// the slowest possible
	f.liquid_viscosity = getintfield_default(L, index,
			"liquid_viscosity", f.liquid_viscosity);
	// Amount of light the node emits
	f.light_source = getintfield_default(L, index,
			"light_source", f.light_source);
	f.damage_per_second = getintfield_default(L, index,
			"damage_per_second", f.damage_per_second);
	
	lua_getfield(L, index, "selection_box");
	if(lua_istable(L, -1)){
		f.selection_box.type = (NodeBoxType)getenumfield(L, -1, "type",
				es_NodeBoxType, NODEBOX_REGULAR);

		lua_getfield(L, -1, "fixed");
		if(lua_istable(L, -1))
			f.selection_box.fixed = read_aabbox3df32(L, -1, BS);
		lua_pop(L, 1);

		lua_getfield(L, -1, "wall_top");
		if(lua_istable(L, -1))
			f.selection_box.wall_top = read_aabbox3df32(L, -1, BS);
		lua_pop(L, 1);

		lua_getfield(L, -1, "wall_bottom");
		if(lua_istable(L, -1))
			f.selection_box.wall_bottom = read_aabbox3df32(L, -1, BS);
		lua_pop(L, 1);

		lua_getfield(L, -1, "wall_side");
		if(lua_istable(L, -1))
			f.selection_box.wall_side = read_aabbox3df32(L, -1, BS);
		lua_pop(L, 1);
	}
	lua_pop(L, 1);

	// Set to true if paramtype used to be 'facedir_simple'
	getboolfield(L, index, "legacy_facedir_simple", f.legacy_facedir_simple);
	// Set to true if wall_mounted used to be set to true
	getboolfield(L, index, "legacy_wallmounted", f.legacy_wallmounted);

	return f;
}

/*
	Inventory stuff
*/

static ItemStack read_item(lua_State *L, int index);

static void inventory_set_list_from_lua(Inventory *inv, const char *name,
		lua_State *L, int tableindex, int forcesize=-1)
{
	dstream<<"inventory_set_list_from_lua\n";
	if(tableindex < 0)
		tableindex = lua_gettop(L) + 1 + tableindex;
	// If nil, delete list
	if(lua_isnil(L, tableindex)){
		inv->deleteList(name);
		return;
	}
	// Otherwise set list
	std::vector<ItemStack> items;
	luaL_checktype(L, tableindex, LUA_TTABLE);
	lua_pushnil(L);
	while(lua_next(L, tableindex) != 0){
		// key at index -2 and value at index -1
		items.push_back(read_item(L, -1));
		// removes value, keeps key for next iteration
		lua_pop(L, 1);
	}
	int listsize = (forcesize != -1) ? forcesize : items.size();
	InventoryList *invlist = inv->addList(name, listsize);
	int index = 0;
	for(std::vector<ItemStack>::const_iterator
			i = items.begin(); i != items.end(); i++){
		if(forcesize != -1 && index == forcesize)
			break;
		invlist->changeItem(index, *i);
		index++;
	}
	while(forcesize != -1 && index < forcesize){
		invlist->deleteItem(index);
		index++;
	}
	dstream<<"inventory_set_list_from_lua done\n";
}

static void inventory_get_list_to_lua(Inventory *inv, const char *name,
		lua_State *L)
{
	InventoryList *invlist = inv->getList(name);
	if(invlist == NULL){
		lua_pushnil(L);
		return;
	}
	// Get the table insert function
	lua_getglobal(L, "table");
	lua_getfield(L, -1, "insert");
	int table_insert = lua_gettop(L);
	// Create and fill table
	lua_newtable(L);
	int table = lua_gettop(L);
	for(u32 i=0; i<invlist->getSize(); i++){
		ItemStack item = invlist->getItem(i);
		lua_pushvalue(L, table_insert);
		lua_pushvalue(L, table);
		lua_pushstring(L, item.getItemString().c_str());
		if(lua_pcall(L, 2, 0, 0))
			script_error(L, "error: %s", lua_tostring(L, -1));
	}
}

/*
	Helpful macros for userdata classes
*/

#define method(class, name) {#name, class::l_##name}

/*
	LuaItemStack
*/

class LuaItemStack
{
private:
	ItemStack m_stack;

	static const char className[];
	static const luaL_reg methods[];

	// Exported functions
	
	// garbage collector
	static int gc_object(lua_State *L)
	{
		LuaItemStack *o = *(LuaItemStack **)(lua_touserdata(L, 1));
		delete o;
		return 0;
	}

	// is_empty(self) -> true/false
	static int l_is_empty(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		lua_pushboolean(L, item.empty());
		return 1;
	}

	// get_name(self) -> string
	static int l_get_name(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		lua_pushstring(L, item.name.c_str());
		return 1;
	}

	// get_count(self) -> number
	static int l_get_count(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		lua_pushinteger(L, item.count);
		return 1;
	}

	// get_wear(self) -> number
	static int l_get_wear(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		lua_pushinteger(L, item.wear);
		return 1;
	}

	// get_metadata(self) -> string
	static int l_get_metadata(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		lua_pushlstring(L, item.metadata.c_str(), item.metadata.size());
		return 1;
	}

	// clear(self) -> true
	static int l_clear(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		o->m_stack.clear();
		lua_pushboolean(L, true);
		return 1;
	}

	// replace(self, itemstack or itemstring or table or nil) -> true
	static int l_replace(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		o->m_stack = read_item(L, 2);
		lua_pushboolean(L, true);
		return 1;
	}

	// to_string(self) -> string
	static int l_to_string(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		std::string itemstring = o->m_stack.getItemString();
		lua_pushstring(L, itemstring.c_str());
		return 1;
	}

	// to_table(self) -> table or nil
	static int l_to_table(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		const ItemStack &item = o->m_stack;
		if(item.empty())
		{
			lua_pushnil(L);
		}
		else
		{
			lua_newtable(L);
			lua_pushstring(L, item.name.c_str());
			lua_setfield(L, -2, "name");
			lua_pushinteger(L, item.count);
			lua_setfield(L, -2, "count");
			lua_pushinteger(L, item.wear);
			lua_setfield(L, -2, "wear");
			lua_pushlstring(L, item.metadata.c_str(), item.metadata.size());
			lua_setfield(L, -2, "metadata");
		}
		return 1;
	}

	// get_stack_max(self) -> number
	static int l_get_stack_max(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		lua_pushinteger(L, item.getStackMax(get_server(L)->idef()));
		return 1;
	}

	// get_free_space(self) -> number
	static int l_get_free_space(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		lua_pushinteger(L, item.freeSpace(get_server(L)->idef()));
		return 1;
	}

	// is_known(self) -> true/false
	// Checks if the item is defined.
	static int l_is_known(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		bool is_known = item.isKnown(get_server(L)->idef());
		lua_pushboolean(L, is_known);
		return 1;
	}

	// get_definition(self) -> table
	// Returns the item definition table from minetest.registered_items,
	// or a fallback one (name="unknown")
	static int l_get_definition(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;

		// Get minetest.registered_items[name]
		lua_getglobal(L, "minetest");
		lua_getfield(L, -1, "registered_items");
		luaL_checktype(L, -1, LUA_TTABLE);
		lua_getfield(L, -1, item.name.c_str());
		if(lua_isnil(L, -1))
		{
			lua_pop(L, 1);
			lua_getfield(L, -1, "unknown");
		}
		return 1;
	}

	// get_tool_capabilities(self) -> table
	// Returns the effective tool digging properties.
	// Returns those of the hand ("") if this item has none associated.
	static int l_get_tool_capabilities(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		const ToolCapabilities &prop =
			item.getToolCapabilities(get_server(L)->idef());
		push_tool_capabilities(L, prop);
		return 1;
	}

	// add_wear(self, amount) -> true/false
	// The range for "amount" is [0,65535]. Wear is only added if the item
	// is a tool. Adding wear might destroy the item.
	// Returns true if the item is (or was) a tool.
	static int l_add_wear(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		int amount = lua_tointeger(L, 2);
		bool result = item.addWear(amount, get_server(L)->idef());
		lua_pushboolean(L, result);
		return 1;
	}

	// add_item(self, itemstack or itemstring or table or nil) -> itemstack
	// Returns leftover item stack
	static int l_add_item(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		ItemStack newitem = read_item(L, 2);
		ItemStack leftover = item.addItem(newitem, get_server(L)->idef());
		create(L, leftover);
		return 1;
	}

	// item_fits(self, itemstack or itemstring or table or nil) -> true/false, itemstack
	// First return value is true iff the new item fits fully into the stack
	// Second return value is the would-be-left-over item stack
	static int l_item_fits(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		ItemStack newitem = read_item(L, 2);
		ItemStack restitem;
		bool fits = item.itemFits(newitem, &restitem, get_server(L)->idef());
		lua_pushboolean(L, fits);  // first return value
		create(L, restitem);       // second return value
		return 2;
	}

	// take_item(self, takecount=1) -> itemstack
	static int l_take_item(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		u32 takecount = 1;
		if(!lua_isnone(L, 2))
			takecount = lua_tointeger(L, 2);
		ItemStack taken = item.takeItem(takecount);
		create(L, taken);
		return 1;
	}

	// peek_item(self, peekcount=1) -> itemstack
	static int l_peek_item(lua_State *L)
	{
		LuaItemStack *o = checkobject(L, 1);
		ItemStack &item = o->m_stack;
		u32 peekcount = 1;
		if(!lua_isnone(L, 2))
			peekcount = lua_tointeger(L, 2);
		ItemStack peekaboo = item.peekItem(peekcount);
		create(L, peekaboo);
		return 1;
	}

public:
	LuaItemStack(const ItemStack &item):
		m_stack(item)
	{
	}

	~LuaItemStack()
	{
	}

	const ItemStack& getItem() const
	{
		return m_stack;
	}
	ItemStack& getItem()
	{
		return m_stack;
	}
	
	// LuaItemStack(itemstack or itemstring or table or nil)
	// Creates an LuaItemStack and leaves it on top of stack
	static int create_object(lua_State *L)
	{
		ItemStack item = read_item(L, 1);
		LuaItemStack *o = new LuaItemStack(item);
		*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
		luaL_getmetatable(L, className);
		lua_setmetatable(L, -2);
		return 1;
	}
	// Not callable from Lua
	static int create(lua_State *L, const ItemStack &item)
	{
		LuaItemStack *o = new LuaItemStack(item);
		*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
		luaL_getmetatable(L, className);
		lua_setmetatable(L, -2);
		return 1;
	}

	static LuaItemStack* checkobject(lua_State *L, int narg)
	{
		luaL_checktype(L, narg, LUA_TUSERDATA);
		void *ud = luaL_checkudata(L, narg, className);
		if(!ud) luaL_typerror(L, narg, className);
		return *(LuaItemStack**)ud;  // unbox pointer
	}

	static void Register(lua_State *L)
	{
		lua_newtable(L);
		int methodtable = lua_gettop(L);
		luaL_newmetatable(L, className);
		int metatable = lua_gettop(L);

		lua_pushliteral(L, "__metatable");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);  // hide metatable from Lua getmetatable()

		lua_pushliteral(L, "__index");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);

		lua_pushliteral(L, "__gc");
		lua_pushcfunction(L, gc_object);
		lua_settable(L, metatable);

		lua_pop(L, 1);  // drop metatable

		luaL_openlib(L, 0, methods, 0);  // fill methodtable
		lua_pop(L, 1);  // drop methodtable

		// Can be created from Lua (LuaItemStack(itemstack or itemstring or table or nil))
		lua_register(L, className, create_object);
	}
};
const char LuaItemStack::className[] = "ItemStack";
const luaL_reg LuaItemStack::methods[] = {
	method(LuaItemStack, is_empty),
	method(LuaItemStack, get_name),
	method(LuaItemStack, get_count),
	method(LuaItemStack, get_wear),
	method(LuaItemStack, get_metadata),
	method(LuaItemStack, clear),
	method(LuaItemStack, replace),
	method(LuaItemStack, to_string),
	method(LuaItemStack, to_table),
	method(LuaItemStack, get_stack_max),
	method(LuaItemStack, get_free_space),
	method(LuaItemStack, is_known),
	method(LuaItemStack, get_definition),
	method(LuaItemStack, get_tool_capabilities),
	method(LuaItemStack, add_wear),
	method(LuaItemStack, add_item),
	method(LuaItemStack, item_fits),
	method(LuaItemStack, take_item),
	method(LuaItemStack, peek_item),
	{0,0}
};

static ItemStack read_item(lua_State *L, int index)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	if(lua_isnil(L, index))
	{
		return ItemStack();
	}
	else if(lua_isuserdata(L, index))
	{
		// Convert from LuaItemStack
		LuaItemStack *o = LuaItemStack::checkobject(L, index);
		return o->getItem();
	}
	else if(lua_isstring(L, index))
	{
		// Convert from itemstring
		std::string itemstring = lua_tostring(L, index);
		IItemDefManager *idef = get_server(L)->idef();
		try
		{
			ItemStack item;
			item.deSerialize(itemstring, idef);
			return item;
		}
		catch(SerializationError &e)
		{
			infostream<<"WARNING: unable to create item from itemstring"
					<<": "<<itemstring<<std::endl;
			return ItemStack();
		}
	}
	else if(lua_istable(L, index))
	{
		// Convert from table
		IItemDefManager *idef = get_server(L)->idef();
		std::string name = getstringfield_default(L, index, "name", "");
		int count = getintfield_default(L, index, "count", 1);
		int wear = getintfield_default(L, index, "wear", 0);
		std::string metadata = getstringfield_default(L, index, "metadata", "");
		return ItemStack(name, count, wear, metadata, idef);
	}
	else
	{
		throw LuaError(L, "Expecting itemstack, itemstring, table or nil");
	}
}

/*
	InvRef
*/

class InvRef
{
private:
	InventoryLocation m_loc;

	static const char className[];
	static const luaL_reg methods[];

	static InvRef *checkobject(lua_State *L, int narg)
	{
		luaL_checktype(L, narg, LUA_TUSERDATA);
		void *ud = luaL_checkudata(L, narg, className);
		if(!ud) luaL_typerror(L, narg, className);
		return *(InvRef**)ud;  // unbox pointer
	}
	
	static Inventory* getinv(lua_State *L, InvRef *ref)
	{
		return get_server(L)->getInventory(ref->m_loc);
	}

	static InventoryList* getlist(lua_State *L, InvRef *ref,
			const char *listname)
	{
		Inventory *inv = getinv(L, ref);
		if(!inv)
			return NULL;
		return inv->getList(listname);
	}

	static void reportInventoryChange(lua_State *L, InvRef *ref)
	{
		// Inform other things that the inventory has changed
		get_server(L)->setInventoryModified(ref->m_loc);
	}
	
	// Exported functions
	
	// garbage collector
	static int gc_object(lua_State *L) {
		InvRef *o = *(InvRef **)(lua_touserdata(L, 1));
		delete o;
		return 0;
	}

	// get_size(self, listname)
	static int l_get_size(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		InventoryList *list = getlist(L, ref, listname);
		if(list){
			lua_pushinteger(L, list->getSize());
		} else {
			lua_pushinteger(L, 0);
		}
		return 1;
	}

	// set_size(self, listname, size)
	static int l_set_size(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		int newsize = luaL_checknumber(L, 3);
		Inventory *inv = getinv(L, ref);
		if(newsize == 0){
			inv->deleteList(listname);
			reportInventoryChange(L, ref);
			return 0;
		}
		InventoryList *list = inv->getList(listname);
		if(list){
			list->setSize(newsize);
		} else {
			list = inv->addList(listname, newsize);
		}
		reportInventoryChange(L, ref);
		return 0;
	}

	// get_stack(self, listname, i) -> itemstack
	static int l_get_stack(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		int i = luaL_checknumber(L, 3) - 1;
		InventoryList *list = getlist(L, ref, listname);
		ItemStack item;
		if(list != NULL && i >= 0 && i < (int) list->getSize())
			item = list->getItem(i);
		LuaItemStack::create(L, item);
		return 1;
	}

	// set_stack(self, listname, i, stack) -> true/false
	static int l_set_stack(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		int i = luaL_checknumber(L, 3) - 1;
		ItemStack newitem = read_item(L, 4);
		InventoryList *list = getlist(L, ref, listname);
		if(list != NULL && i >= 0 && i < (int) list->getSize()){
			list->changeItem(i, newitem);
			reportInventoryChange(L, ref);
			lua_pushboolean(L, true);
		} else {
			lua_pushboolean(L, false);
		}
		return 1;
	}

	// get_list(self, listname) -> list or nil
	static int l_get_list(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		Inventory *inv = getinv(L, ref);
		inventory_get_list_to_lua(inv, listname, L);
		return 1;
	}

	// set_list(self, listname, list)
	static int l_set_list(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		Inventory *inv = getinv(L, ref);
		InventoryList *list = inv->getList(listname);
		if(list)
			inventory_set_list_from_lua(inv, listname, L, 3,
					list->getSize());
		else
			inventory_set_list_from_lua(inv, listname, L, 3);
		reportInventoryChange(L, ref);
		return 0;
	}

	// add_item(self, listname, itemstack or itemstring or table or nil) -> itemstack
	// Returns the leftover stack
	static int l_add_item(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		ItemStack item = read_item(L, 3);
		InventoryList *list = getlist(L, ref, listname);
		if(list){
			ItemStack leftover = list->addItem(item);
			if(leftover.count != item.count)
				reportInventoryChange(L, ref);
			LuaItemStack::create(L, leftover);
		} else {
			LuaItemStack::create(L, item);
		}
		return 1;
	}

	// room_for_item(self, listname, itemstack or itemstring or table or nil) -> true/false
	// Returns true if the item completely fits into the list
	static int l_room_for_item(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		ItemStack item = read_item(L, 3);
		InventoryList *list = getlist(L, ref, listname);
		if(list){
			lua_pushboolean(L, list->roomForItem(item));
		} else {
			lua_pushboolean(L, false);
		}
		return 1;
	}

	// contains_item(self, listname, itemstack or itemstring or table or nil) -> true/false
	// Returns true if the list contains the given count of the given item name
	static int l_contains_item(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		ItemStack item = read_item(L, 3);
		InventoryList *list = getlist(L, ref, listname);
		if(list){
			lua_pushboolean(L, list->containsItem(item));
		} else {
			lua_pushboolean(L, false);
		}
		return 1;
	}

	// remove_item(self, listname, itemstack or itemstring or table or nil) -> itemstack
	// Returns the items that were actually removed
	static int l_remove_item(lua_State *L)
	{
		InvRef *ref = checkobject(L, 1);
		const char *listname = luaL_checkstring(L, 2);
		ItemStack item = read_item(L, 3);
		InventoryList *list = getlist(L, ref, listname);
		if(list){
			ItemStack removed = list->removeItem(item);
			if(!removed.empty())
				reportInventoryChange(L, ref);
			LuaItemStack::create(L, removed);
		} else {
			LuaItemStack::create(L, ItemStack());
		}
		return 1;
	}

public:
	InvRef(const InventoryLocation &loc):
		m_loc(loc)
	{
	}

	~InvRef()
	{
	}

	// Creates an InvRef and leaves it on top of stack
	// Not callable from Lua; all references are created on the C side.
	static void create(lua_State *L, const InventoryLocation &loc)
	{
		InvRef *o = new InvRef(loc);
		*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
		luaL_getmetatable(L, className);
		lua_setmetatable(L, -2);
	}
	static void createPlayer(lua_State *L, Player *player)
	{
		InventoryLocation loc;
		loc.setPlayer(player->getName());
		create(L, loc);
	}
	static void createNodeMeta(lua_State *L, v3s16 p)
	{
		InventoryLocation loc;
		loc.setNodeMeta(p);
		create(L, loc);
	}

	static void Register(lua_State *L)
	{
		lua_newtable(L);
		int methodtable = lua_gettop(L);
		luaL_newmetatable(L, className);
		int metatable = lua_gettop(L);

		lua_pushliteral(L, "__metatable");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);  // hide metatable from Lua getmetatable()

		lua_pushliteral(L, "__index");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);

		lua_pushliteral(L, "__gc");
		lua_pushcfunction(L, gc_object);
		lua_settable(L, metatable);

		lua_pop(L, 1);  // drop metatable

		luaL_openlib(L, 0, methods, 0);  // fill methodtable
		lua_pop(L, 1);  // drop methodtable

		// Cannot be created from Lua
		//lua_register(L, className, create_object);
	}
};
const char InvRef::className[] = "InvRef";
const luaL_reg InvRef::methods[] = {
	method(InvRef, get_size),
	method(InvRef, set_size),
	method(InvRef, get_stack),
	method(InvRef, set_stack),
	method(InvRef, get_list),
	method(InvRef, set_list),
	method(InvRef, add_item),
	method(InvRef, room_for_item),
	method(InvRef, contains_item),
	method(InvRef, remove_item),
	{0,0}
};

/*
	NodeMetaRef
*/

class NodeMetaRef
{
private:
	v3s16 m_p;
	ServerEnvironment *m_env;

	static const char className[];
	static const luaL_reg methods[];

	static NodeMetaRef *checkobject(lua_State *L, int narg)
	{
		luaL_checktype(L, narg, LUA_TUSERDATA);
		void *ud = luaL_checkudata(L, narg, className);
		if(!ud) luaL_typerror(L, narg, className);
		return *(NodeMetaRef**)ud;  // unbox pointer
	}
	
	static NodeMetadata* getmeta(NodeMetaRef *ref)
	{
		NodeMetadata *meta = ref->m_env->getMap().getNodeMetadata(ref->m_p);
		return meta;
	}

	/*static IGenericNodeMetadata* getgenericmeta(NodeMetaRef *ref)
	{
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL)
			return NULL;
		if(meta->typeId() != NODEMETA_GENERIC)
			return NULL;
		return (IGenericNodeMetadata*)meta;
	}*/

	static void reportMetadataChange(NodeMetaRef *ref)
	{
		// Inform other things that the metadata has changed
		v3s16 blockpos = getNodeBlockPos(ref->m_p);
		MapEditEvent event;
		event.type = MEET_BLOCK_NODE_METADATA_CHANGED;
		event.p = blockpos;
		ref->m_env->getMap().dispatchEvent(&event);
		// Set the block to be saved
		MapBlock *block = ref->m_env->getMap().getBlockNoCreateNoEx(blockpos);
		if(block)
			block->raiseModified(MOD_STATE_WRITE_NEEDED,
					"NodeMetaRef::reportMetadataChange");
	}
	
	// Exported functions
	
	// garbage collector
	static int gc_object(lua_State *L) {
		NodeMetaRef *o = *(NodeMetaRef **)(lua_touserdata(L, 1));
		delete o;
		return 0;
	}

	// get_type(self)
	static int l_get_type(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL){
			lua_pushnil(L);
			return 1;
		}
		// Do it
		lua_pushstring(L, meta->typeName());
		return 1;
	}

	// allows_text_input(self)
	static int l_allows_text_input(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		lua_pushboolean(L, meta->allowsTextInput());
		return 1;
	}

	// set_text(self, text)
	static int l_set_text(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string text = luaL_checkstring(L, 2);
		meta->setText(text);
		reportMetadataChange(ref);
		return 0;
	}

	// get_text(self)
	static int l_get_text(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string text = meta->getText();
		lua_pushstring(L, text.c_str());
		return 1;
	}

	// get_owner(self)
	static int l_get_owner(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string owner = meta->getOwner();
		lua_pushstring(L, owner.c_str());
		return 1;
	}

	// set_owner(self, string)
	static int l_set_owner(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string owner = luaL_checkstring(L, 2);
		meta->setOwner(owner);
		reportMetadataChange(ref);
		return 1;
	}

	// get_allow_removal(self)
	static int l_get_allow_removal(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL){
			lua_pushboolean(L, true);
			return 1;
		}
		// Do it
		lua_pushboolean(L, !meta->nodeRemovalDisabled());
		return 1;
	}

	/* IGenericNodeMetadata interface */
	
	// set_infotext(self, text)
	static int l_set_infotext(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string text = luaL_checkstring(L, 2);
		meta->setInfoText(text);
		reportMetadataChange(ref);
		return 0;
	}

	// get_inventory(self)
	static int l_get_inventory(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		InvRef::createNodeMeta(L, ref->m_p);
		return 1;
	}

	// set_inventory_draw_spec(self, text)
	static int l_set_inventory_draw_spec(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string text = luaL_checkstring(L, 2);
		meta->setInventoryDrawSpec(text);
		reportMetadataChange(ref);
		return 0;
	}

	// set_allow_text_input(self, text)
	static int l_set_allow_text_input(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		bool b = lua_toboolean(L, 2);
		meta->setAllowTextInput(b);
		reportMetadataChange(ref);
		return 0;
	}

	// set_allow_removal(self, text)
	static int l_set_allow_removal(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		bool b = lua_toboolean(L, 2);
		meta->setRemovalDisabled(!b);
		reportMetadataChange(ref);
		return 0;
	}

	// set_enforce_owner(self, text)
	static int l_set_enforce_owner(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		bool b = lua_toboolean(L, 2);
		meta->setEnforceOwner(b);
		reportMetadataChange(ref);
		return 0;
	}

	// is_inventory_modified(self)
	static int l_is_inventory_modified(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		lua_pushboolean(L, meta->isInventoryModified());
		return 1;
	}

	// reset_inventory_modified(self)
	static int l_reset_inventory_modified(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		meta->resetInventoryModified();
		reportMetadataChange(ref);
		return 0;
	}

	// is_text_modified(self)
	static int l_is_text_modified(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		lua_pushboolean(L, meta->isTextModified());
		return 1;
	}

	// reset_text_modified(self)
	static int l_reset_text_modified(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		meta->resetTextModified();
		reportMetadataChange(ref);
		return 0;
	}

	// set_string(self, name, var)
	static int l_set_string(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string name = luaL_checkstring(L, 2);
		size_t len = 0;
		const char *s = lua_tolstring(L, 3, &len);
		std::string str(s, len);
		meta->setString(name, str);
		reportMetadataChange(ref);
		return 0;
	}

	// get_string(self, name)
	static int l_get_string(lua_State *L)
	{
		NodeMetaRef *ref = checkobject(L, 1);
		NodeMetadata *meta = getmeta(ref);
		if(meta == NULL) return 0;
		// Do it
		std::string name = luaL_checkstring(L, 2);
		std::string str = meta->getString(name);
		lua_pushlstring(L, str.c_str(), str.size());
		return 1;
	}

public:
	NodeMetaRef(v3s16 p, ServerEnvironment *env):
		m_p(p),
		m_env(env)
	{
	}

	~NodeMetaRef()
	{
	}

	// Creates an NodeMetaRef and leaves it on top of stack
	// Not callable from Lua; all references are created on the C side.
	static void create(lua_State *L, v3s16 p, ServerEnvironment *env)
	{
		NodeMetaRef *o = new NodeMetaRef(p, env);
		//infostream<<"NodeMetaRef::create: o="<<o<<std::endl;
		*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
		luaL_getmetatable(L, className);
		lua_setmetatable(L, -2);
	}

	static void Register(lua_State *L)
	{
		lua_newtable(L);
		int methodtable = lua_gettop(L);
		luaL_newmetatable(L, className);
		int metatable = lua_gettop(L);

		lua_pushliteral(L, "__metatable");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);  // hide metatable from Lua getmetatable()

		lua_pushliteral(L, "__index");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);

		lua_pushliteral(L, "__gc");
		lua_pushcfunction(L, gc_object);
		lua_settable(L, metatable);

		lua_pop(L, 1);  // drop metatable

		luaL_openlib(L, 0, methods, 0);  // fill methodtable
		lua_pop(L, 1);  // drop methodtable

		// Cannot be created from Lua
		//lua_register(L, className, create_object);
	}
};
const char NodeMetaRef::className[] = "NodeMetaRef";
const luaL_reg NodeMetaRef::methods[] = {
	method(NodeMetaRef, get_type),
	method(NodeMetaRef, allows_text_input),
	method(NodeMetaRef, set_text),
	method(NodeMetaRef, get_text),
	method(NodeMetaRef, get_owner),
	method(NodeMetaRef, set_owner),
	method(NodeMetaRef, get_allow_removal),
	method(NodeMetaRef, set_infotext),
	method(NodeMetaRef, get_inventory),
	method(NodeMetaRef, set_inventory_draw_spec),
	method(NodeMetaRef, set_allow_text_input),
	method(NodeMetaRef, set_allow_removal),
	method(NodeMetaRef, set_enforce_owner),
	method(NodeMetaRef, is_inventory_modified),
	method(NodeMetaRef, reset_inventory_modified),
	method(NodeMetaRef, is_text_modified),
	method(NodeMetaRef, reset_text_modified),
	method(NodeMetaRef, set_string),
	method(NodeMetaRef, get_string),
	{0,0}
};

/*
	ObjectRef
*/

class ObjectRef
{
private:
	ServerActiveObject *m_object;

	static const char className[];
	static const luaL_reg methods[];

	static ObjectRef *checkobject(lua_State *L, int narg)
	{
		luaL_checktype(L, narg, LUA_TUSERDATA);
		void *ud = luaL_checkudata(L, narg, className);
		if(!ud) luaL_typerror(L, narg, className);
		return *(ObjectRef**)ud;  // unbox pointer
	}
	
	static ServerActiveObject* getobject(ObjectRef *ref)
	{
		ServerActiveObject *co = ref->m_object;
		return co;
	}
	
	static LuaEntitySAO* getluaobject(ObjectRef *ref)
	{
		ServerActiveObject *obj = getobject(ref);
		if(obj == NULL)
			return NULL;
		if(obj->getType() != ACTIVEOBJECT_TYPE_LUAENTITY)
			return NULL;
		return (LuaEntitySAO*)obj;
	}
	
	static ServerRemotePlayer* getplayer(ObjectRef *ref)
	{
		ServerActiveObject *obj = getobject(ref);
		if(obj == NULL)
			return NULL;
		if(obj->getType() != ACTIVEOBJECT_TYPE_PLAYER)
			return NULL;
		return static_cast<ServerRemotePlayer*>(obj);
	}
	
	// Exported functions
	
	// garbage collector
	static int gc_object(lua_State *L) {
		ObjectRef *o = *(ObjectRef **)(lua_touserdata(L, 1));
		//infostream<<"ObjectRef::gc_object: o="<<o<<std::endl;
		delete o;
		return 0;
	}

	// remove(self)
	static int l_remove(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		verbosestream<<"ObjectRef::l_remove(): id="<<co->getId()<<std::endl;
		co->m_removed = true;
		return 0;
	}
	
	// getpos(self)
	// returns: {x=num, y=num, z=num}
	static int l_getpos(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		v3f pos = co->getBasePosition() / BS;
		lua_newtable(L);
		lua_pushnumber(L, pos.X);
		lua_setfield(L, -2, "x");
		lua_pushnumber(L, pos.Y);
		lua_setfield(L, -2, "y");
		lua_pushnumber(L, pos.Z);
		lua_setfield(L, -2, "z");
		return 1;
	}
	
	// setpos(self, pos)
	static int l_setpos(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		//LuaEntitySAO *co = getluaobject(ref);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		// pos
		v3f pos = checkFloatPos(L, 2);
		// Do it
		co->setPos(pos);
		// Move player if applicable
		ServerRemotePlayer *player = getplayer(ref);
		if(player != NULL)
			get_server(L)->SendMovePlayer(player);
		return 0;
	}
	
	// moveto(self, pos, continuous=false)
	static int l_moveto(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		//LuaEntitySAO *co = getluaobject(ref);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		// pos
		v3f pos = checkFloatPos(L, 2);
		// continuous
		bool continuous = lua_toboolean(L, 3);
		// Do it
		co->moveTo(pos, continuous);
		return 0;
	}

	// punch(self, puncher, tool_capabilities, direction, time_from_last_punch)
	static int l_punch(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ObjectRef *puncher_ref = checkobject(L, 2);
		ServerActiveObject *co = getobject(ref);
		ServerActiveObject *puncher = getobject(puncher_ref);
		if(co == NULL) return 0;
		if(puncher == NULL) return 0;
		ToolCapabilities toolcap = read_tool_capabilities(L, 3);
		v3f dir = read_v3f(L, 4);
		float time_from_last_punch = 1000000;
		if(lua_isnumber(L, 5))
			time_from_last_punch = lua_tonumber(L, 5);
		// Do it
		puncher->punch(dir, &toolcap, puncher, time_from_last_punch);
		return 0;
	}

	// right_click(self, clicker); clicker = an another ObjectRef
	static int l_right_click(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ObjectRef *ref2 = checkobject(L, 2);
		ServerActiveObject *co = getobject(ref);
		ServerActiveObject *co2 = getobject(ref2);
		if(co == NULL) return 0;
		if(co2 == NULL) return 0;
		// Do it
		co->rightClick(co2);
		return 0;
	}

	// set_hp(self, hp)
	// hp = number of hitpoints (2 * number of hearts)
	// returns: nil
	static int l_set_hp(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		luaL_checknumber(L, 2);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		int hp = lua_tonumber(L, 2);
		/*infostream<<"ObjectRef::l_set_hp(): id="<<co->getId()
				<<" hp="<<hp<<std::endl;*/
		// Do it
		co->setHP(hp);
		// Return
		return 0;
	}

	// get_hp(self)
	// returns: number of hitpoints (2 * number of hearts)
	// 0 if not applicable to this type of object
	static int l_get_hp(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		int hp = co->getHP();
		/*infostream<<"ObjectRef::l_get_hp(): id="<<co->getId()
				<<" hp="<<hp<<std::endl;*/
		// Return
		lua_pushnumber(L, hp);
		return 1;
	}

	// get_inventory(self)
	static int l_get_inventory(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		// Do it
		InventoryLocation loc = co->getInventoryLocation();
		if(get_server(L)->getInventory(loc) != NULL)
			InvRef::create(L, loc);
		else
			lua_pushnil(L);
		return 1;
	}

	// get_wield_list(self)
	static int l_get_wield_list(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		// Do it
		lua_pushstring(L, co->getWieldList().c_str());
		return 1;
	}

	// get_wield_index(self)
	static int l_get_wield_index(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		// Do it
		lua_pushinteger(L, co->getWieldIndex() + 1);
		return 1;
	}

	// get_wielded_item(self)
	static int l_get_wielded_item(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		// Do it
		LuaItemStack::create(L, co->getWieldedItem());
		return 1;
	}

	// set_wielded_item(self, itemstack or itemstring or table or nil)
	static int l_set_wielded_item(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerActiveObject *co = getobject(ref);
		if(co == NULL) return 0;
		// Do it
		ItemStack item = read_item(L, 2);
		bool success = co->setWieldedItem(item);
		lua_pushboolean(L, success);
		return 1;
	}

	/* LuaEntitySAO-only */

	// setvelocity(self, {x=num, y=num, z=num})
	static int l_setvelocity(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// pos
		v3f pos = checkFloatPos(L, 2);
		// Do it
		co->setVelocity(pos);
		return 0;
	}
	
	// getvelocity(self)
	static int l_getvelocity(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		v3f v = co->getVelocity();
		pushFloatPos(L, v);
		return 1;
	}
	
	// setacceleration(self, {x=num, y=num, z=num})
	static int l_setacceleration(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// pos
		v3f pos = checkFloatPos(L, 2);
		// Do it
		co->setAcceleration(pos);
		return 0;
	}
	
	// getacceleration(self)
	static int l_getacceleration(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		v3f v = co->getAcceleration();
		pushFloatPos(L, v);
		return 1;
	}
	
	// setyaw(self, radians)
	static int l_setyaw(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// pos
		float yaw = luaL_checknumber(L, 2) * core::RADTODEG;
		// Do it
		co->setYaw(yaw);
		return 0;
	}
	
	// getyaw(self)
	static int l_getyaw(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		float yaw = co->getYaw() * core::DEGTORAD;
		lua_pushnumber(L, yaw);
		return 1;
	}
	
	// settexturemod(self, mod)
	static int l_settexturemod(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		std::string mod = luaL_checkstring(L, 2);
		co->setTextureMod(mod);
		return 0;
	}
	
	// setsprite(self, p={x=0,y=0}, num_frames=1, framelength=0.2,
	//           select_horiz_by_yawpitch=false)
	static int l_setsprite(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		v2s16 p(0,0);
		if(!lua_isnil(L, 2))
			p = read_v2s16(L, 2);
		int num_frames = 1;
		if(!lua_isnil(L, 3))
			num_frames = lua_tonumber(L, 3);
		float framelength = 0.2;
		if(!lua_isnil(L, 4))
			framelength = lua_tonumber(L, 4);
		bool select_horiz_by_yawpitch = false;
		if(!lua_isnil(L, 5))
			select_horiz_by_yawpitch = lua_toboolean(L, 5);
		co->setSprite(p, num_frames, framelength, select_horiz_by_yawpitch);
		return 0;
	}

	// set_armor_groups(self, groups)
	static int l_set_armor_groups(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		ItemGroupList groups;
		read_groups(L, 2, groups);
		co->setArmorGroups(groups);
		return 0;
	}

	// DEPRECATED
	// get_entity_name(self)
	static int l_get_entity_name(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		std::string name = co->getName();
		lua_pushstring(L, name.c_str());
		return 1;
	}
	
	// get_luaentity(self)
	static int l_get_luaentity(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		LuaEntitySAO *co = getluaobject(ref);
		if(co == NULL) return 0;
		// Do it
		luaentity_get(L, co->getId());
		return 1;
	}
	
	/* Player-only */
	
	// get_player_name(self)
	static int l_get_player_name(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerRemotePlayer *player = getplayer(ref);
		if(player == NULL){
			lua_pushnil(L);
			return 1;
		}
		// Do it
		lua_pushstring(L, player->getName());
		return 1;
	}
	
	// get_look_dir(self)
	static int l_get_look_dir(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerRemotePlayer *player = getplayer(ref);
		if(player == NULL) return 0;
		// Do it
		float pitch = player->getRadPitch();
		float yaw = player->getRadYaw();
		v3f v(cos(pitch)*cos(yaw), sin(pitch), cos(pitch)*sin(yaw));
		push_v3f(L, v);
		return 1;
	}

	// get_look_pitch(self)
	static int l_get_look_pitch(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerRemotePlayer *player = getplayer(ref);
		if(player == NULL) return 0;
		// Do it
		lua_pushnumber(L, player->getRadPitch());
		return 1;
	}

	// get_look_yaw(self)
	static int l_get_look_yaw(lua_State *L)
	{
		ObjectRef *ref = checkobject(L, 1);
		ServerRemotePlayer *player = getplayer(ref);
		if(player == NULL) return 0;
		// Do it
		lua_pushnumber(L, player->getRadYaw());
		return 1;
	}

public:
	ObjectRef(ServerActiveObject *object):
		m_object(object)
	{
		//infostream<<"ObjectRef created for id="<<m_object->getId()<<std::endl;
	}

	~ObjectRef()
	{
		/*if(m_object)
			infostream<<"ObjectRef destructing for id="
					<<m_object->getId()<<std::endl;
		else
			infostream<<"ObjectRef destructing for id=unknown"<<std::endl;*/
	}

	// Creates an ObjectRef and leaves it on top of stack
	// Not callable from Lua; all references are created on the C side.
	static void create(lua_State *L, ServerActiveObject *object)
	{
		ObjectRef *o = new ObjectRef(object);
		//infostream<<"ObjectRef::create: o="<<o<<std::endl;
		*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
		luaL_getmetatable(L, className);
		lua_setmetatable(L, -2);
	}

	static void set_null(lua_State *L)
	{
		ObjectRef *o = checkobject(L, -1);
		o->m_object = NULL;
	}
	
	static void Register(lua_State *L)
	{
		lua_newtable(L);
		int methodtable = lua_gettop(L);
		luaL_newmetatable(L, className);
		int metatable = lua_gettop(L);

		lua_pushliteral(L, "__metatable");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);  // hide metatable from Lua getmetatable()

		lua_pushliteral(L, "__index");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);

		lua_pushliteral(L, "__gc");
		lua_pushcfunction(L, gc_object);
		lua_settable(L, metatable);

		lua_pop(L, 1);  // drop metatable

		luaL_openlib(L, 0, methods, 0);  // fill methodtable
		lua_pop(L, 1);  // drop methodtable

		// Cannot be created from Lua
		//lua_register(L, className, create_object);
	}
};
const char ObjectRef::className[] = "ObjectRef";
const luaL_reg ObjectRef::methods[] = {
	// ServerActiveObject
	method(ObjectRef, remove),
	method(ObjectRef, getpos),
	method(ObjectRef, setpos),
	method(ObjectRef, moveto),
	method(ObjectRef, punch),
	method(ObjectRef, right_click),
	method(ObjectRef, set_hp),
	method(ObjectRef, get_hp),
	method(ObjectRef, get_inventory),
	method(ObjectRef, get_wield_list),
	method(ObjectRef, get_wield_index),
	method(ObjectRef, get_wielded_item),
	method(ObjectRef, set_wielded_item),
	// LuaEntitySAO-only
	method(ObjectRef, setvelocity),
	method(ObjectRef, getvelocity),
	method(ObjectRef, setacceleration),
	method(ObjectRef, getacceleration),
	method(ObjectRef, setyaw),
	method(ObjectRef, getyaw),
	method(ObjectRef, settexturemod),
	method(ObjectRef, setsprite),
	method(ObjectRef, set_armor_groups),
	method(ObjectRef, get_entity_name),
	method(ObjectRef, get_luaentity),
	// Player-only
	method(ObjectRef, get_player_name),
	method(ObjectRef, get_look_dir),
	method(ObjectRef, get_look_pitch),
	method(ObjectRef, get_look_yaw),
	{0,0}
};

// Creates a new anonymous reference if id=0
static void objectref_get_or_create(lua_State *L,
		ServerActiveObject *cobj)
{
	if(cobj->getId() == 0){
		ObjectRef::create(L, cobj);
	} else {
		objectref_get(L, cobj->getId());
	}
}

/*
	EnvRef
*/

class EnvRef
{
private:
	ServerEnvironment *m_env;

	static const char className[];
	static const luaL_reg methods[];

	static EnvRef *checkobject(lua_State *L, int narg)
	{
		luaL_checktype(L, narg, LUA_TUSERDATA);
		void *ud = luaL_checkudata(L, narg, className);
		if(!ud) luaL_typerror(L, narg, className);
		return *(EnvRef**)ud;  // unbox pointer
	}
	
	// Exported functions

	// EnvRef:add_node(pos, node)
	// pos = {x=num, y=num, z=num}
	static int l_add_node(lua_State *L)
	{
		//infostream<<"EnvRef::l_add_node()"<<std::endl;
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// pos
		v3s16 pos = read_v3s16(L, 2);
		// content
		MapNode n = readnode(L, 3, env->getGameDef()->ndef());
		// Do it
		bool succeeded = env->getMap().addNodeWithEvent(pos, n);
		lua_pushboolean(L, succeeded);
		return 1;
	}

	// EnvRef:remove_node(pos)
	// pos = {x=num, y=num, z=num}
	static int l_remove_node(lua_State *L)
	{
		//infostream<<"EnvRef::l_remove_node()"<<std::endl;
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// pos
		v3s16 pos = read_v3s16(L, 2);
		// Do it
		bool succeeded = env->getMap().removeNodeWithEvent(pos);
		lua_pushboolean(L, succeeded);
		return 1;
	}

	// EnvRef:get_node(pos)
	// pos = {x=num, y=num, z=num}
	static int l_get_node(lua_State *L)
	{
		//infostream<<"EnvRef::l_get_node()"<<std::endl;
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// pos
		v3s16 pos = read_v3s16(L, 2);
		// Do it
		MapNode n = env->getMap().getNodeNoEx(pos);
		// Return node
		pushnode(L, n, env->getGameDef()->ndef());
		return 1;
	}

	// EnvRef:get_node_or_nil(pos)
	// pos = {x=num, y=num, z=num}
	static int l_get_node_or_nil(lua_State *L)
	{
		//infostream<<"EnvRef::l_get_node()"<<std::endl;
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// pos
		v3s16 pos = read_v3s16(L, 2);
		// Do it
		try{
			MapNode n = env->getMap().getNode(pos);
			// Return node
			pushnode(L, n, env->getGameDef()->ndef());
			return 1;
		} catch(InvalidPositionException &e)
		{
			lua_pushnil(L);
			return 1;
		}
	}

	// EnvRef:get_node_light(pos, timeofday)
	// pos = {x=num, y=num, z=num}
	// timeofday: nil = current time, 0 = night, 0.5 = day
	static int l_get_node_light(lua_State *L)
	{
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// Do it
		v3s16 pos = read_v3s16(L, 2);
		u32 time_of_day = env->getTimeOfDay();
		if(lua_isnumber(L, 3))
			time_of_day = 24000.0 * lua_tonumber(L, 3);
		time_of_day %= 24000;
		u32 dnr = time_to_daynight_ratio(time_of_day);
		MapNode n = env->getMap().getNodeNoEx(pos);
		try{
			MapNode n = env->getMap().getNode(pos);
			INodeDefManager *ndef = env->getGameDef()->ndef();
			lua_pushinteger(L, n.getLightBlend(dnr, ndef));
			return 1;
		} catch(InvalidPositionException &e)
		{
			lua_pushnil(L);
			return 1;
		}
	}

	// EnvRef:add_entity(pos, entityname) -> ObjectRef or nil
	// pos = {x=num, y=num, z=num}
	static int l_add_entity(lua_State *L)
	{
		//infostream<<"EnvRef::l_add_entity()"<<std::endl;
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// pos
		v3f pos = checkFloatPos(L, 2);
		// content
		const char *name = luaL_checkstring(L, 3);
		// Do it
		ServerActiveObject *obj = new LuaEntitySAO(env, pos, name, "");
		int objectid = env->addActiveObject(obj);
		// If failed to add, return nothing (reads as nil)
		if(objectid == 0)
			return 0;
		// Return ObjectRef
		objectref_get_or_create(L, obj);
		return 1;
	}

	// EnvRef:add_item(pos, itemstack or itemstring or table) -> ObjectRef or nil
	// pos = {x=num, y=num, z=num}
	static int l_add_item(lua_State *L)
	{
		//infostream<<"EnvRef::l_add_item()"<<std::endl;
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// pos
		v3f pos = checkFloatPos(L, 2);
		// item
		ItemStack item = read_item(L, 3);
		if(item.empty() || !item.isKnown(get_server(L)->idef()))
			return 0;
		// Do it
		ServerActiveObject *obj = createItemSAO(env, pos, item.getItemString());
		int objectid = env->addActiveObject(obj);
		// If failed to add, return nothing (reads as nil)
		if(objectid == 0)
			return 0;
		// Return ObjectRef
		objectref_get_or_create(L, obj);
		return 1;
	}

	// EnvRef:add_rat(pos)
	// pos = {x=num, y=num, z=num}
	static int l_add_rat(lua_State *L)
	{
		infostream<<"EnvRef::l_add_rat(): C++ mobs have been removed."
				<<" Doing nothing."<<std::endl;
		return 0;
	}

	// EnvRef:add_firefly(pos)
	// pos = {x=num, y=num, z=num}
	static int l_add_firefly(lua_State *L)
	{
		infostream<<"EnvRef::l_add_firefly(): C++ mobs have been removed."
				<<" Doing nothing."<<std::endl;
		return 0;
	}

	// EnvRef:get_meta(pos)
	static int l_get_meta(lua_State *L)
	{
		//infostream<<"EnvRef::l_get_meta()"<<std::endl;
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// Do it
		v3s16 p = read_v3s16(L, 2);
		NodeMetaRef::create(L, p, env);
		return 1;
	}

	// EnvRef:get_player_by_name(name)
	static int l_get_player_by_name(lua_State *L)
	{
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// Do it
		const char *name = luaL_checkstring(L, 2);
		ServerRemotePlayer *player =
				static_cast<ServerRemotePlayer*>(env->getPlayer(name));
		if(player == NULL){
			lua_pushnil(L);
			return 1;
		}
		// Put player on stack
		objectref_get_or_create(L, player);
		return 1;
	}

	// EnvRef:get_objects_inside_radius(pos, radius)
	static int l_get_objects_inside_radius(lua_State *L)
	{
		// Get the table insert function
		lua_getglobal(L, "table");
		lua_getfield(L, -1, "insert");
		int table_insert = lua_gettop(L);
		// Get environemnt
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// Do it
		v3f pos = checkFloatPos(L, 2);
		float radius = luaL_checknumber(L, 3) * BS;
		std::set<u16> ids = env->getObjectsInsideRadius(pos, radius);
		lua_newtable(L);
		int table = lua_gettop(L);
		for(std::set<u16>::const_iterator
				i = ids.begin(); i != ids.end(); i++){
			ServerActiveObject *obj = env->getActiveObject(*i);
			// Insert object reference into table
			lua_pushvalue(L, table_insert);
			lua_pushvalue(L, table);
			objectref_get_or_create(L, obj);
			if(lua_pcall(L, 2, 0, 0))
				script_error(L, "error: %s", lua_tostring(L, -1));
		}
		return 1;
	}

	// EnvRef:set_timeofday(val)
	// val = 0...1
	static int l_set_timeofday(lua_State *L)
	{
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// Do it
		float timeofday_f = luaL_checknumber(L, 2);
		assert(timeofday_f >= 0.0 && timeofday_f <= 1.0);
		int timeofday_mh = (int)(timeofday_f * 24000.0);
		// This should be set directly in the environment but currently
		// such changes aren't immediately sent to the clients, so call
		// the server instead.
		//env->setTimeOfDay(timeofday_mh);
		get_server(L)->setTimeOfDay(timeofday_mh);
		return 0;
	}

	// EnvRef:get_timeofday() -> 0...1
	static int l_get_timeofday(lua_State *L)
	{
		EnvRef *o = checkobject(L, 1);
		ServerEnvironment *env = o->m_env;
		if(env == NULL) return 0;
		// Do it
		int timeofday_mh = env->getTimeOfDay();
		float timeofday_f = (float)timeofday_mh / 24000.0;
		lua_pushnumber(L, timeofday_f);
		return 1;
	}

	static int gc_object(lua_State *L) {
		EnvRef *o = *(EnvRef **)(lua_touserdata(L, 1));
		delete o;
		return 0;
	}

public:
	EnvRef(ServerEnvironment *env):
		m_env(env)
	{
		//infostream<<"EnvRef created"<<std::endl;
	}

	~EnvRef()
	{
		//infostream<<"EnvRef destructing"<<std::endl;
	}

	// Creates an EnvRef and leaves it on top of stack
	// Not callable from Lua; all references are created on the C side.
	static void create(lua_State *L, ServerEnvironment *env)
	{
		EnvRef *o = new EnvRef(env);
		//infostream<<"EnvRef::create: o="<<o<<std::endl;
		*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
		luaL_getmetatable(L, className);
		lua_setmetatable(L, -2);
	}

	static void set_null(lua_State *L)
	{
		EnvRef *o = checkobject(L, -1);
		o->m_env = NULL;
	}
	
	static void Register(lua_State *L)
	{
		lua_newtable(L);
		int methodtable = lua_gettop(L);
		luaL_newmetatable(L, className);
		int metatable = lua_gettop(L);

		lua_pushliteral(L, "__metatable");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);  // hide metatable from Lua getmetatable()

		lua_pushliteral(L, "__index");
		lua_pushvalue(L, methodtable);
		lua_settable(L, metatable);

		lua_pushliteral(L, "__gc");
		lua_pushcfunction(L, gc_object);
		lua_settable(L, metatable);

		lua_pop(L, 1);  // drop metatable

		luaL_openlib(L, 0, methods, 0);  // fill methodtable
		lua_pop(L, 1);  // drop methodtable

		// Cannot be created from Lua
		//lua_register(L, className, create_object);
	}
};
const char EnvRef::className[] = "EnvRef";
const luaL_reg EnvRef::methods[] = {
	method(EnvRef, add_node),
	method(EnvRef, remove_node),
	method(EnvRef, get_node),
	method(EnvRef, get_node_or_nil),
	method(EnvRef, get_node_light),
	method(EnvRef, add_entity),
	method(EnvRef, add_item),
	method(EnvRef, add_rat),
	method(EnvRef, add_firefly),
	method(EnvRef, get_meta),
	method(EnvRef, get_player_by_name),
	method(EnvRef, get_objects_inside_radius),
	method(EnvRef, set_timeofday),
	method(EnvRef, get_timeofday),
	{0,0}
};

/*
	Global functions
*/

class LuaABM : public ActiveBlockModifier
{
private:
	lua_State *m_lua;
	int m_id;

	std::set<std::string> m_trigger_contents;
	std::set<std::string> m_required_neighbors;
	float m_trigger_interval;
	u32 m_trigger_chance;
public:
	LuaABM(lua_State *L, int id,
			const std::set<std::string> &trigger_contents,
			const std::set<std::string> &required_neighbors,
			float trigger_interval, u32 trigger_chance):
		m_lua(L),
		m_id(id),
		m_trigger_contents(trigger_contents),
		m_required_neighbors(required_neighbors),
		m_trigger_interval(trigger_interval),
		m_trigger_chance(trigger_chance)
	{
	}
	virtual std::set<std::string> getTriggerContents()
	{
		return m_trigger_contents;
	}
	virtual std::set<std::string> getRequiredNeighbors()
	{
		return m_required_neighbors;
	}
	virtual float getTriggerInterval()
	{
		return m_trigger_interval;
	}
	virtual u32 getTriggerChance()
	{
		return m_trigger_chance;
	}
	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n,
			u32 active_object_count, u32 active_object_count_wider)
	{
		lua_State *L = m_lua;
	
		realitycheck(L);
		assert(lua_checkstack(L, 20));
		StackUnroller stack_unroller(L);

		// Get minetest.registered_abms
		lua_getglobal(L, "minetest");
		lua_getfield(L, -1, "registered_abms");
		luaL_checktype(L, -1, LUA_TTABLE);
		int registered_abms = lua_gettop(L);

		// Get minetest.registered_abms[m_id]
		lua_pushnumber(L, m_id);
		lua_gettable(L, registered_abms);
		if(lua_isnil(L, -1))
			assert(0);
		
		// Call action
		luaL_checktype(L, -1, LUA_TTABLE);
		lua_getfield(L, -1, "action");
		luaL_checktype(L, -1, LUA_TFUNCTION);
		push_v3s16(L, p);
		pushnode(L, n, env->getGameDef()->ndef());
		lua_pushnumber(L, active_object_count);
		lua_pushnumber(L, active_object_count_wider);
		if(lua_pcall(L, 4, 0, 0))
			script_error(L, "error: %s", lua_tostring(L, -1));
	}
};

// debug(text)
// Writes a line to dstream
static int l_debug(lua_State *L)
{
	std::string text = lua_tostring(L, 1);
	dstream << text << std::endl;
	return 0;
}

// log([level,] text)
// Writes a line to the logger.
// The one-argument version logs to infostream.
// The two-argument version accept a log level: error, action, info, or verbose.
static int l_log(lua_State *L)
{
	std::string text;
	LogMessageLevel level = LMT_INFO;
	if(lua_isnone(L, 2))
	{
		text = lua_tostring(L, 1);
	}
	else
	{
		std::string levelname = lua_tostring(L, 1);
		text = lua_tostring(L, 2);
		if(levelname == "error")
			level = LMT_ERROR;
		else if(levelname == "action")
			level = LMT_ACTION;
		else if(levelname == "verbose")
			level = LMT_VERBOSE;
	}
	log_printline(level, text);
	return 0;
}

// register_item_raw({lots of stuff})
static int l_register_item_raw(lua_State *L)
{
	luaL_checktype(L, 1, LUA_TTABLE);
	int table = 1;

	// Get the writable item and node definition managers from the server
	IWritableItemDefManager *idef =
			get_server(L)->getWritableItemDefManager();
	IWritableNodeDefManager *ndef =
			get_server(L)->getWritableNodeDefManager();

	// Check if name is defined
	lua_getfield(L, table, "name");
	if(lua_isstring(L, -1)){
		std::string name = lua_tostring(L, -1);
		verbosestream<<"register_item_raw: "<<name<<std::endl;
	} else {
		throw LuaError(L, "register_item_raw: name is not defined or not a string");
	}

	// Check if on_use is defined

	// Read the item definition and register it
	ItemDefinition def = read_item_definition(L, table);
	idef->registerItem(def);

	// Read the node definition (content features) and register it
	if(def.type == ITEM_NODE)
	{
		ContentFeatures f = read_content_features(L, table);
		ndef->set(f.name, f);
	}

	return 0; /* number of results */
}

// register_alias_raw(name, convert_to_name)
static int l_register_alias_raw(lua_State *L)
{
	std::string name = luaL_checkstring(L, 1);
	std::string convert_to = luaL_checkstring(L, 2);

	// Get the writable item definition manager from the server
	IWritableItemDefManager *idef =
			get_server(L)->getWritableItemDefManager();
	
	idef->registerAlias(name, convert_to);
	
	return 0; /* number of results */
}

// helper for register_craft
static bool read_craft_recipe_shaped(lua_State *L, int index,
		int &width, std::vector<std::string> &recipe)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	if(!lua_istable(L, index))
		return false;

	lua_pushnil(L);
	int rowcount = 0;
	while(lua_next(L, index) != 0){
		int colcount = 0;
		// key at index -2 and value at index -1
		if(!lua_istable(L, -1))
			return false;
		int table2 = lua_gettop(L);
		lua_pushnil(L);
		while(lua_next(L, table2) != 0){
			// key at index -2 and value at index -1
			if(!lua_isstring(L, -1))
				return false;
			recipe.push_back(lua_tostring(L, -1));
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
			colcount++;
		}
		if(rowcount == 0){
			width = colcount;
		} else {
			if(colcount != width)
				return false;
		}
		// removes value, keeps key for next iteration
		lua_pop(L, 1);
		rowcount++;
	}
	return width != 0;
}

// helper for register_craft
static bool read_craft_recipe_shapeless(lua_State *L, int index,
		std::vector<std::string> &recipe)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	if(!lua_istable(L, index))
		return false;

	lua_pushnil(L);
	while(lua_next(L, index) != 0){
		// key at index -2 and value at index -1
		if(!lua_isstring(L, -1))
			return false;
		recipe.push_back(lua_tostring(L, -1));
		// removes value, keeps key for next iteration
		lua_pop(L, 1);
	}
	return true;
}

// helper for register_craft
static bool read_craft_replacements(lua_State *L, int index,
		CraftReplacements &replacements)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	if(!lua_istable(L, index))
		return false;

	lua_pushnil(L);
	while(lua_next(L, index) != 0){
		// key at index -2 and value at index -1
		if(!lua_istable(L, -1))
			return false;
		lua_rawgeti(L, -1, 1);
		if(!lua_isstring(L, -1))
			return false;
		std::string replace_from = lua_tostring(L, -1);
		lua_pop(L, 1);
		lua_rawgeti(L, -1, 2);
		if(!lua_isstring(L, -1))
			return false;
		std::string replace_to = lua_tostring(L, -1);
		lua_pop(L, 1);
		replacements.pairs.push_back(
				std::make_pair(replace_from, replace_to));
		// removes value, keeps key for next iteration
		lua_pop(L, 1);
	}
	return true;
}
// register_craft({output=item, recipe={{item00,item10},{item01,item11}})
static int l_register_craft(lua_State *L)
{
	//infostream<<"register_craft"<<std::endl;
	luaL_checktype(L, 1, LUA_TTABLE);
	int table = 1;

	// Get the writable craft definition manager from the server
	IWritableCraftDefManager *craftdef =
			get_server(L)->getWritableCraftDefManager();
	
	std::string type = getstringfield_default(L, table, "type", "shaped");

	/*
		CraftDefinitionShaped
	*/
	if(type == "shaped"){
		std::string output = getstringfield_default(L, table, "output", "");
		if(output == "")
			throw LuaError(L, "Crafting definition is missing an output");

		int width = 0;
		std::vector<std::string> recipe;
		lua_getfield(L, table, "recipe");
		if(lua_isnil(L, -1))
			throw LuaError(L, "Crafting definition is missing a recipe"
					" (output=\"" + output + "\")");
		if(!read_craft_recipe_shaped(L, -1, width, recipe))
			throw LuaError(L, "Invalid crafting recipe"
					" (output=\"" + output + "\")");

		CraftReplacements replacements;
		lua_getfield(L, table, "replacements");
		if(!lua_isnil(L, -1))
		{
			if(!read_craft_replacements(L, -1, replacements))
				throw LuaError(L, "Invalid replacements"
						" (output=\"" + output + "\")");
		}

		CraftDefinition *def = new CraftDefinitionShaped(
				output, width, recipe, replacements);
		craftdef->registerCraft(def);
	}
	/*
		CraftDefinitionShapeless
	*/
	else if(type == "shapeless"){
		std::string output = getstringfield_default(L, table, "output", "");
		if(output == "")
			throw LuaError(L, "Crafting definition (shapeless)"
					" is missing an output");

		std::vector<std::string> recipe;
		lua_getfield(L, table, "recipe");
		if(lua_isnil(L, -1))
			throw LuaError(L, "Crafting definition (shapeless)"
					" is missing a recipe"
					" (output=\"" + output + "\")");
		if(!read_craft_recipe_shapeless(L, -1, recipe))
			throw LuaError(L, "Invalid crafting recipe"
					" (output=\"" + output + "\")");

		CraftReplacements replacements;
		lua_getfield(L, table, "replacements");
		if(!lua_isnil(L, -1))
		{
			if(!read_craft_replacements(L, -1, replacements))
				throw LuaError(L, "Invalid replacements"
						" (output=\"" + output + "\")");
		}

		CraftDefinition *def = new CraftDefinitionShapeless(
				output, recipe, replacements);
		craftdef->registerCraft(def);
	}
	/*
		CraftDefinitionToolRepair
	*/
	else if(type == "toolrepair"){
		float additional_wear = getfloatfield_default(L, table,
				"additional_wear", 0.0);

		CraftDefinition *def = new CraftDefinitionToolRepair(
				additional_wear);
		craftdef->registerCraft(def);
	}
	/*
		CraftDefinitionCooking
	*/
	else if(type == "cooking"){
		std::string output = getstringfield_default(L, table, "output", "");
		if(output == "")
			throw LuaError(L, "Crafting definition (cooking)"
					" is missing an output");

		std::string recipe = getstringfield_default(L, table, "recipe", "");
		if(recipe == "")
			throw LuaError(L, "Crafting definition (cooking)"
					" is missing a recipe"
					" (output=\"" + output + "\")");

		float cooktime = getfloatfield_default(L, table, "cooktime", 3.0);

		CraftDefinition *def = new CraftDefinitionCooking(
				output, recipe, cooktime);
		craftdef->registerCraft(def);
	}
	/*
		CraftDefinitionFuel
	*/
	else if(type == "fuel"){
		std::string recipe = getstringfield_default(L, table, "recipe", "");
		if(recipe == "")
			throw LuaError(L, "Crafting definition (fuel)"
					" is missing a recipe");

		float burntime = getfloatfield_default(L, table, "burntime", 1.0);

		CraftDefinition *def = new CraftDefinitionFuel(
				recipe, burntime);
		craftdef->registerCraft(def);
	}
	else
	{
		throw LuaError(L, "Unknown crafting definition type: \"" + type + "\"");
	}

	lua_pop(L, 1);
	return 0; /* number of results */
}

// setting_get(name)
static int l_setting_get(lua_State *L)
{
	const char *name = luaL_checkstring(L, 1);
	try{
		std::string value = g_settings->get(name);
		lua_pushstring(L, value.c_str());
	} catch(SettingNotFoundException &e){
		lua_pushnil(L);
	}
	return 1;
}

// setting_getbool(name)
static int l_setting_getbool(lua_State *L)
{
	const char *name = luaL_checkstring(L, 1);
	try{
		bool value = g_settings->getBool(name);
		lua_pushboolean(L, value);
	} catch(SettingNotFoundException &e){
		lua_pushnil(L);
	}
	return 1;
}

// chat_send_all(text)
static int l_chat_send_all(lua_State *L)
{
	const char *text = luaL_checkstring(L, 1);
	// Get server from registry
	Server *server = get_server(L);
	// Send
	server->notifyPlayers(narrow_to_wide(text));
	return 0;
}

// chat_send_player(name, text)
static int l_chat_send_player(lua_State *L)
{
	const char *name = luaL_checkstring(L, 1);
	const char *text = luaL_checkstring(L, 2);
	// Get server from registry
	Server *server = get_server(L);
	// Send
	server->notifyPlayer(name, narrow_to_wide(text));
	return 0;
}

// get_player_privs(name, text)
static int l_get_player_privs(lua_State *L)
{
	const char *name = luaL_checkstring(L, 1);
	// Get server from registry
	Server *server = get_server(L);
	// Do it
	lua_newtable(L);
	int table = lua_gettop(L);
	u64 privs_i = server->getPlayerEffectivePrivs(name);
	std::set<std::string> privs_s = privsToSet(privs_i);
	for(std::set<std::string>::const_iterator
			i = privs_s.begin(); i != privs_s.end(); i++){
		lua_pushboolean(L, true);
		lua_setfield(L, table, i->c_str());
	}
	lua_pushvalue(L, table);
	return 1;
}

// get_inventory(location)
static int l_get_inventory(lua_State *L)
{
	InventoryLocation loc;

	std::string type = checkstringfield(L, 1, "type");
	if(type == "player"){
		std::string name = checkstringfield(L, 1, "name");
		loc.setPlayer(name);
	} else if(type == "node"){
		lua_getfield(L, 1, "pos");
		v3s16 pos = check_v3s16(L, -1);
		loc.setNodeMeta(pos);
	}
	
	if(get_server(L)->getInventory(loc) != NULL)
		InvRef::create(L, loc);
	else
		lua_pushnil(L);
	return 1;
}

// get_dig_params(groups, tool_capabilities[, time_from_last_punch])
static int l_get_dig_params(lua_State *L)
{
	std::map<std::string, int> groups;
	read_groups(L, 1, groups);
	ToolCapabilities tp = read_tool_capabilities(L, 2);
	if(lua_isnoneornil(L, 3))
		push_dig_params(L, getDigParams(groups, &tp));
	else
		push_dig_params(L, getDigParams(groups, &tp,
					luaL_checknumber(L, 3)));
	return 1;
}

// get_hit_params(groups, tool_capabilities[, time_from_last_punch])
static int l_get_hit_params(lua_State *L)
{
	std::map<std::string, int> groups;
	read_groups(L, 1, groups);
	ToolCapabilities tp = read_tool_capabilities(L, 2);
	if(lua_isnoneornil(L, 3))
		push_hit_params(L, getHitParams(groups, &tp));
	else
		push_hit_params(L, getHitParams(groups, &tp,
					luaL_checknumber(L, 3)));
	return 1;
}

// get_current_modname()
static int l_get_current_modname(lua_State *L)
{
	lua_getfield(L, LUA_REGISTRYINDEX, "minetest_current_modname");
	return 1;
}

// get_modpath(modname)
static int l_get_modpath(lua_State *L)
{
	const char *modname = luaL_checkstring(L, 1);
	// Do it
	const ModSpec *mod = get_server(L)->getModSpec(modname);
	if(!mod){
		lua_pushnil(L);
		return 1;
	}
	lua_pushstring(L, mod->path.c_str());
	return 1;
}

// get_worldpath()
static int l_get_worldpath(lua_State *L)
{
	std::string worldpath = get_server(L)->getWorldPath();
	lua_pushstring(L, worldpath.c_str());
	return 1;
}

static const struct luaL_Reg minetest_f [] = {
	{"debug", l_debug},
	{"log", l_log},
	{"register_item_raw", l_register_item_raw},
	{"register_alias_raw", l_register_alias_raw},
	{"register_craft", l_register_craft},
	{"setting_get", l_setting_get},
	{"setting_getbool", l_setting_getbool},
	{"chat_send_all", l_chat_send_all},
	{"chat_send_player", l_chat_send_player},
	{"get_player_privs", l_get_player_privs},
	{"get_inventory", l_get_inventory},
	{"get_dig_params", l_get_dig_params},
	{"get_hit_params", l_get_hit_params},
	{"get_current_modname", l_get_current_modname},
	{"get_modpath", l_get_modpath},
	{"get_worldpath", l_get_worldpath},
	{NULL, NULL}
};

/*
	Main export function
*/

void scriptapi_export(lua_State *L, Server *server)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	verbosestream<<"scriptapi_export()"<<std::endl;
	StackUnroller stack_unroller(L);

	// Store server as light userdata in registry
	lua_pushlightuserdata(L, server);
	lua_setfield(L, LUA_REGISTRYINDEX, "minetest_server");

	// Register global functions in table minetest
	lua_newtable(L);
	luaL_register(L, NULL, minetest_f);
	lua_setglobal(L, "minetest");
	
	// Get the main minetest table
	lua_getglobal(L, "minetest");

	// Add tables to minetest
	
	lua_newtable(L);
	lua_setfield(L, -2, "object_refs");
	lua_newtable(L);
	lua_setfield(L, -2, "luaentities");

	// Register wrappers
	LuaItemStack::Register(L);
	InvRef::Register(L);
	NodeMetaRef::Register(L);
	ObjectRef::Register(L);
	EnvRef::Register(L);
}

bool scriptapi_loadmod(lua_State *L, const std::string &scriptpath,
		const std::string &modname)
{
	ModNameStorer modnamestorer(L, modname);

	if(!string_allowed(modname, "abcdefghijklmnopqrstuvwxyz"
			"0123456789_")){
		errorstream<<"Error loading mod \""<<modname
				<<"\": modname does not follow naming conventions: "
				<<"Only chararacters [a-z0-9_] are allowed."<<std::endl;
		return false;
	}
	
	bool success = false;

	try{
		success = script_load(L, scriptpath.c_str());
	}
	catch(LuaError &e){
		errorstream<<"Error loading mod \""<<modname
				<<"\": "<<e.what()<<std::endl;
	}

	return success;
}

void scriptapi_add_environment(lua_State *L, ServerEnvironment *env)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	verbosestream<<"scriptapi_add_environment"<<std::endl;
	StackUnroller stack_unroller(L);

	// Create EnvRef on stack
	EnvRef::create(L, env);
	int envref = lua_gettop(L);

	// minetest.env = envref
	lua_getglobal(L, "minetest");
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_pushvalue(L, envref);
	lua_setfield(L, -2, "env");

	// Store environment as light userdata in registry
	lua_pushlightuserdata(L, env);
	lua_setfield(L, LUA_REGISTRYINDEX, "minetest_env");

	/*
		Add ActiveBlockModifiers to environment
	*/

	// Get minetest.registered_abms
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_abms");
	luaL_checktype(L, -1, LUA_TTABLE);
	int registered_abms = lua_gettop(L);
	
	if(lua_istable(L, registered_abms)){
		int table = lua_gettop(L);
		lua_pushnil(L);
		while(lua_next(L, table) != 0){
			// key at index -2 and value at index -1
			int id = lua_tonumber(L, -2);
			int current_abm = lua_gettop(L);

			std::set<std::string> trigger_contents;
			lua_getfield(L, current_abm, "nodenames");
			if(lua_istable(L, -1)){
				int table = lua_gettop(L);
				lua_pushnil(L);
				while(lua_next(L, table) != 0){
					// key at index -2 and value at index -1
					luaL_checktype(L, -1, LUA_TSTRING);
					trigger_contents.insert(lua_tostring(L, -1));
					// removes value, keeps key for next iteration
					lua_pop(L, 1);
				}
			} else if(lua_isstring(L, -1)){
				trigger_contents.insert(lua_tostring(L, -1));
			}
			lua_pop(L, 1);

			std::set<std::string> required_neighbors;
			lua_getfield(L, current_abm, "neighbors");
			if(lua_istable(L, -1)){
				int table = lua_gettop(L);
				lua_pushnil(L);
				while(lua_next(L, table) != 0){
					// key at index -2 and value at index -1
					luaL_checktype(L, -1, LUA_TSTRING);
					required_neighbors.insert(lua_tostring(L, -1));
					// removes value, keeps key for next iteration
					lua_pop(L, 1);
				}
			} else if(lua_isstring(L, -1)){
				required_neighbors.insert(lua_tostring(L, -1));
			}
			lua_pop(L, 1);

			float trigger_interval = 10.0;
			getfloatfield(L, current_abm, "interval", trigger_interval);

			int trigger_chance = 50;
			getintfield(L, current_abm, "chance", trigger_chance);

			LuaABM *abm = new LuaABM(L, id, trigger_contents,
					required_neighbors, trigger_interval, trigger_chance);
			
			env->addActiveBlockModifier(abm);

			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);
}

#if 0
// Dump stack top with the dump2 function
static void dump2(lua_State *L, const char *name)
{
	// Dump object (debug)
	lua_getglobal(L, "dump2");
	luaL_checktype(L, -1, LUA_TFUNCTION);
	lua_pushvalue(L, -2); // Get previous stack top as first parameter
	lua_pushstring(L, name);
	if(lua_pcall(L, 2, 0, 0))
		script_error(L, "error: %s", lua_tostring(L, -1));
}
#endif

/*
	object_reference
*/

void scriptapi_add_object_reference(lua_State *L, ServerActiveObject *cobj)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_add_object_reference: id="<<cobj->getId()<<std::endl;
	StackUnroller stack_unroller(L);

	// Create object on stack
	ObjectRef::create(L, cobj); // Puts ObjectRef (as userdata) on stack
	int object = lua_gettop(L);

	// Get minetest.object_refs table
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "object_refs");
	luaL_checktype(L, -1, LUA_TTABLE);
	int objectstable = lua_gettop(L);
	
	// object_refs[id] = object
	lua_pushnumber(L, cobj->getId()); // Push id
	lua_pushvalue(L, object); // Copy object to top of stack
	lua_settable(L, objectstable);
}

void scriptapi_rm_object_reference(lua_State *L, ServerActiveObject *cobj)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_rm_object_reference: id="<<cobj->getId()<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.object_refs table
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "object_refs");
	luaL_checktype(L, -1, LUA_TTABLE);
	int objectstable = lua_gettop(L);
	
	// Get object_refs[id]
	lua_pushnumber(L, cobj->getId()); // Push id
	lua_gettable(L, objectstable);
	// Set object reference to NULL
	ObjectRef::set_null(L);
	lua_pop(L, 1); // pop object

	// Set object_refs[id] = nil
	lua_pushnumber(L, cobj->getId()); // Push id
	lua_pushnil(L);
	lua_settable(L, objectstable);
}

bool scriptapi_on_chat_message(lua_State *L, const std::string &name,
		const std::string &message)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	// Get minetest.registered_on_chat_messages
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_on_chat_messages");
	luaL_checktype(L, -1, LUA_TTABLE);
	int table = lua_gettop(L);
	// Foreach
	lua_pushnil(L);
	while(lua_next(L, table) != 0){
		// key at index -2 and value at index -1
		luaL_checktype(L, -1, LUA_TFUNCTION);
		// Call function
		lua_pushstring(L, name.c_str());
		lua_pushstring(L, message.c_str());
		if(lua_pcall(L, 2, 1, 0))
			script_error(L, "error: %s", lua_tostring(L, -1));
		bool ate = lua_toboolean(L, -1);
		lua_pop(L, 1);
		if(ate)
			return true;
		// value removed, keep key for next iteration
	}
	return false;
}

/*
	misc
*/

void scriptapi_on_newplayer(lua_State *L, ServerActiveObject *player)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	// Get minetest.registered_on_newplayers
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_on_newplayers");
	luaL_checktype(L, -1, LUA_TTABLE);
	int table = lua_gettop(L);
	// Foreach
	lua_pushnil(L);
	while(lua_next(L, table) != 0){
		// key at index -2 and value at index -1
		luaL_checktype(L, -1, LUA_TFUNCTION);
		// Call function
		objectref_get_or_create(L, player);
		if(lua_pcall(L, 1, 0, 0))
			script_error(L, "error: %s", lua_tostring(L, -1));
		// value removed, keep key for next iteration
	}
}

void scriptapi_on_dieplayer(lua_State *L, ServerActiveObject *player)
{
    realitycheck(L);
    assert(lua_checkstack(L, 20));
    StackUnroller stack_unroller(L);
    
    // Get minetest.registered_on_dieplayers
    lua_getglobal(L, "minetest");
    lua_getfield(L, -1, "registered_on_dieplayers");
    luaL_checktype(L, -1, LUA_TTABLE);
    int table = lua_gettop(L);
    // Foreach
    lua_pushnil(L);
    while(lua_next(L, table) != 0){
        // key at index -2 and value at index -1
       luaL_checktype(L, -1, LUA_TFUNCTION);
        // Call function
       objectref_get_or_create(L, player);
        if(lua_pcall(L, 1, 0, 0))
            script_error(L, "error: %s", lua_tostring(L, -1));
        // value removed, keep key for next iteration
    }
}


bool scriptapi_on_respawnplayer(lua_State *L, ServerActiveObject *player)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	dstream<<"player: "<<player<<"   id: "<<player->getId()<<std::endl;

	bool positioning_handled_by_some = false;

	// Get minetest.registered_on_respawnplayers
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_on_respawnplayers");
	luaL_checktype(L, -1, LUA_TTABLE);
	int table = lua_gettop(L);
	// Foreach
	lua_pushnil(L);
	while(lua_next(L, table) != 0){
		// key at index -2 and value at index -1
		luaL_checktype(L, -1, LUA_TFUNCTION);
		// Call function
		objectref_get_or_create(L, player);
		if(lua_pcall(L, 1, 1, 0))
			script_error(L, "error: %s", lua_tostring(L, -1));
		bool positioning_handled = lua_toboolean(L, -1);
		lua_pop(L, 1);
		if(positioning_handled)
			positioning_handled_by_some = true;
		// value removed, keep key for next iteration
	}
	return positioning_handled_by_some;
}

void scriptapi_get_creative_inventory(lua_State *L, ServerRemotePlayer *player)
{
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "creative_inventory");
	luaL_checktype(L, -1, LUA_TTABLE);
	inventory_set_list_from_lua(&player->inventory, "main", L, -1,
			PLAYER_INVENTORY_SIZE);
}

/*
	item callbacks and node callbacks
*/

// Retrieves minetest.registered_items[name][callbackname]
// If that is nil or on error, return false and stack is unchanged
// If that is a function, returns true and pushes the
// function onto the stack
static bool get_item_callback(lua_State *L,
		const char *name, const char *callbackname)
{
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_items");
	lua_remove(L, -2);
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_getfield(L, -1, name);
	lua_remove(L, -2);
	// Should be a table
	if(lua_type(L, -1) != LUA_TTABLE)
	{
		errorstream<<"Item \""<<name<<"\" not defined"<<std::endl;
		lua_pop(L, 1);
		return false;
	}
	lua_getfield(L, -1, callbackname);
	lua_remove(L, -2);
	// Should be a function or nil
	if(lua_type(L, -1) == LUA_TFUNCTION)
	{
		return true;
	}
	else if(lua_isnil(L, -1))
	{
		lua_pop(L, 1);
		return false;
	}
	else
	{
		errorstream<<"Item \""<<name<<"\" callback \""
			<<callbackname<<" is not a function"<<std::endl;
		lua_pop(L, 1);
		return false;
	}
}

bool scriptapi_item_on_drop(lua_State *L, ItemStack &item,
		ServerActiveObject *dropper, v3f pos)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	// Push callback function on stack
	if(!get_item_callback(L, item.name.c_str(), "on_drop"))
		return false;

	// Call function
	LuaItemStack::create(L, item);
	objectref_get_or_create(L, dropper);
	pushFloatPos(L, pos);
	if(lua_pcall(L, 3, 1, 0))
		script_error(L, "error: %s", lua_tostring(L, -1));
	if(!lua_isnil(L, -1))
		item = read_item(L, -1);
	return true;
}

bool scriptapi_item_on_place(lua_State *L, ItemStack &item,
		ServerActiveObject *placer, const PointedThing &pointed)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	// Push callback function on stack
	if(!get_item_callback(L, item.name.c_str(), "on_place"))
		return false;

	// Call function
	LuaItemStack::create(L, item);
	objectref_get_or_create(L, placer);
	push_pointed_thing(L, pointed);
	if(lua_pcall(L, 3, 1, 0))
		script_error(L, "error: %s", lua_tostring(L, -1));
	if(!lua_isnil(L, -1))
		item = read_item(L, -1);
	return true;
}

bool scriptapi_item_on_use(lua_State *L, ItemStack &item,
		ServerActiveObject *user, const PointedThing &pointed)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	// Push callback function on stack
	if(!get_item_callback(L, item.name.c_str(), "on_use"))
		return false;

	// Call function
	LuaItemStack::create(L, item);
	objectref_get_or_create(L, user);
	push_pointed_thing(L, pointed);
	if(lua_pcall(L, 3, 1, 0))
		script_error(L, "error: %s", lua_tostring(L, -1));
	if(!lua_isnil(L, -1))
		item = read_item(L, -1);
	return true;
}

bool scriptapi_node_on_punch(lua_State *L, v3s16 pos, MapNode node,
		ServerActiveObject *puncher)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	INodeDefManager *ndef = get_server(L)->ndef();

	// Push callback function on stack
	if(!get_item_callback(L, ndef->get(node).name.c_str(), "on_punch"))
		return false;

	// Call function
	push_v3s16(L, pos);
	pushnode(L, node, ndef);
	objectref_get_or_create(L, puncher);
	if(lua_pcall(L, 3, 0, 0))
		script_error(L, "error: %s", lua_tostring(L, -1));
	return true;
}

bool scriptapi_node_on_dig(lua_State *L, v3s16 pos, MapNode node,
		ServerActiveObject *digger)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	StackUnroller stack_unroller(L);

	INodeDefManager *ndef = get_server(L)->ndef();

	// Push callback function on stack
	if(!get_item_callback(L, ndef->get(node).name.c_str(), "on_dig"))
		return false;

	// Call function
	push_v3s16(L, pos);
	pushnode(L, node, ndef);
	objectref_get_or_create(L, digger);
	if(lua_pcall(L, 3, 0, 0))
		script_error(L, "error: %s", lua_tostring(L, -1));
	return true;
}

/*
	environment
*/

void scriptapi_environment_step(lua_State *L, float dtime)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_environment_step"<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.registered_globalsteps
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_globalsteps");
	luaL_checktype(L, -1, LUA_TTABLE);
	int table = lua_gettop(L);
	// Foreach
	lua_pushnil(L);
	while(lua_next(L, table) != 0){
		// key at index -2 and value at index -1
		luaL_checktype(L, -1, LUA_TFUNCTION);
		// Call function
		lua_pushnumber(L, dtime);
		if(lua_pcall(L, 1, 0, 0))
			script_error(L, "error: %s", lua_tostring(L, -1));
		// value removed, keep key for next iteration
	}
}

void scriptapi_environment_on_generated(lua_State *L, v3s16 minp, v3s16 maxp)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_environment_on_generated"<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.registered_on_generateds
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_on_generateds");
	luaL_checktype(L, -1, LUA_TTABLE);
	int table = lua_gettop(L);
	// Foreach
	lua_pushnil(L);
	while(lua_next(L, table) != 0){
		// key at index -2 and value at index -1
		luaL_checktype(L, -1, LUA_TFUNCTION);
		// Call function
		push_v3s16(L, minp);
		push_v3s16(L, maxp);
		if(lua_pcall(L, 2, 0, 0))
			script_error(L, "error: %s", lua_tostring(L, -1));
		// value removed, keep key for next iteration
	}
}

/*
	luaentity
*/

bool scriptapi_luaentity_add(lua_State *L, u16 id, const char *name)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	verbosestream<<"scriptapi_luaentity_add: id="<<id<<" name=\""
			<<name<<"\""<<std::endl;
	StackUnroller stack_unroller(L);
	
	// Get minetest.registered_entities[name]
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "registered_entities");
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_pushstring(L, name);
	lua_gettable(L, -2);
	// Should be a table, which we will use as a prototype
	//luaL_checktype(L, -1, LUA_TTABLE);
	if(lua_type(L, -1) != LUA_TTABLE){
		errorstream<<"LuaEntity name \""<<name<<"\" not defined"<<std::endl;
		return false;
	}
	int prototype_table = lua_gettop(L);
	//dump2(L, "prototype_table");
	
	// Create entity object
	lua_newtable(L);
	int object = lua_gettop(L);

	// Set object metatable
	lua_pushvalue(L, prototype_table);
	lua_setmetatable(L, -2);
	
	// Add object reference
	// This should be userdata with metatable ObjectRef
	objectref_get(L, id);
	luaL_checktype(L, -1, LUA_TUSERDATA);
	if(!luaL_checkudata(L, -1, "ObjectRef"))
		luaL_typerror(L, -1, "ObjectRef");
	lua_setfield(L, -2, "object");

	// minetest.luaentities[id] = object
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "luaentities");
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_pushnumber(L, id); // Push id
	lua_pushvalue(L, object); // Copy object to top of stack
	lua_settable(L, -3);
	
	return true;
}

void scriptapi_luaentity_activate(lua_State *L, u16 id,
		const std::string &staticdata)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	verbosestream<<"scriptapi_luaentity_activate: id="<<id<<std::endl;
	StackUnroller stack_unroller(L);
	
	// Get minetest.luaentities[id]
	luaentity_get(L, id);
	int object = lua_gettop(L);
	
	// Get on_activate function
	lua_pushvalue(L, object);
	lua_getfield(L, -1, "on_activate");
	if(!lua_isnil(L, -1)){
		luaL_checktype(L, -1, LUA_TFUNCTION);
		lua_pushvalue(L, object); // self
		lua_pushlstring(L, staticdata.c_str(), staticdata.size());
		// Call with 2 arguments, 0 results
		if(lua_pcall(L, 2, 0, 0))
			script_error(L, "error running function on_activate: %s\n",
					lua_tostring(L, -1));
	}
}

void scriptapi_luaentity_rm(lua_State *L, u16 id)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	verbosestream<<"scriptapi_luaentity_rm: id="<<id<<std::endl;

	// Get minetest.luaentities table
	lua_getglobal(L, "minetest");
	lua_getfield(L, -1, "luaentities");
	luaL_checktype(L, -1, LUA_TTABLE);
	int objectstable = lua_gettop(L);
	
	// Set luaentities[id] = nil
	lua_pushnumber(L, id); // Push id
	lua_pushnil(L);
	lua_settable(L, objectstable);
	
	lua_pop(L, 2); // pop luaentities, minetest
}

std::string scriptapi_luaentity_get_staticdata(lua_State *L, u16 id)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_luaentity_get_staticdata: id="<<id<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.luaentities[id]
	luaentity_get(L, id);
	int object = lua_gettop(L);
	
	// Get get_staticdata function
	lua_pushvalue(L, object);
	lua_getfield(L, -1, "get_staticdata");
	if(lua_isnil(L, -1))
		return "";
	
	luaL_checktype(L, -1, LUA_TFUNCTION);
	lua_pushvalue(L, object); // self
	// Call with 1 arguments, 1 results
	if(lua_pcall(L, 1, 1, 0))
		script_error(L, "error running function get_staticdata: %s\n",
				lua_tostring(L, -1));
	
	size_t len=0;
	const char *s = lua_tolstring(L, -1, &len);
	return std::string(s, len);
}

void scriptapi_luaentity_get_properties(lua_State *L, u16 id,
		LuaEntityProperties *prop)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_luaentity_get_properties: id="<<id<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.luaentities[id]
	luaentity_get(L, id);
	//int object = lua_gettop(L);

	/* Read stuff */
	
	prop->hp_max = getintfield_default(L, -1, "hp_max", 10);

	getboolfield(L, -1, "physical", prop->physical);

	getfloatfield(L, -1, "weight", prop->weight);

	lua_getfield(L, -1, "collisionbox");
	if(lua_istable(L, -1))
		prop->collisionbox = read_aabbox3df32(L, -1, 1.0);
	lua_pop(L, 1);

	getstringfield(L, -1, "visual", prop->visual);
	
	lua_getfield(L, -1, "visual_size");
	if(lua_istable(L, -1))
		prop->visual_size = read_v2f(L, -1);
	lua_pop(L, 1);

	lua_getfield(L, -1, "textures");
	if(lua_istable(L, -1)){
		prop->textures.clear();
		int table = lua_gettop(L);
		lua_pushnil(L);
		while(lua_next(L, table) != 0){
			// key at index -2 and value at index -1
			if(lua_isstring(L, -1))
				prop->textures.push_back(lua_tostring(L, -1));
			else
				prop->textures.push_back("");
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);
	
	lua_getfield(L, -1, "spritediv");
	if(lua_istable(L, -1))
		prop->spritediv = read_v2s16(L, -1);
	lua_pop(L, 1);

	lua_getfield(L, -1, "initial_sprite_basepos");
	if(lua_istable(L, -1))
		prop->initial_sprite_basepos = read_v2s16(L, -1);
	lua_pop(L, 1);
}

void scriptapi_luaentity_step(lua_State *L, u16 id, float dtime)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.luaentities[id]
	luaentity_get(L, id);
	int object = lua_gettop(L);
	// State: object is at top of stack
	// Get step function
	lua_getfield(L, -1, "on_step");
	if(lua_isnil(L, -1))
		return;
	luaL_checktype(L, -1, LUA_TFUNCTION);
	lua_pushvalue(L, object); // self
	lua_pushnumber(L, dtime); // dtime
	// Call with 2 arguments, 0 results
	if(lua_pcall(L, 2, 0, 0))
		script_error(L, "error running function 'on_step': %s\n", lua_tostring(L, -1));
}

// Calls entity:on_punch(ObjectRef puncher, time_from_last_punch,
//                       tool_capabilities, direction)
void scriptapi_luaentity_punch(lua_State *L, u16 id,
		ServerActiveObject *puncher, float time_from_last_punch,
		const ToolCapabilities *toolcap, v3f dir)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.luaentities[id]
	luaentity_get(L, id);
	int object = lua_gettop(L);
	// State: object is at top of stack
	// Get function
	lua_getfield(L, -1, "on_punch");
	if(lua_isnil(L, -1))
		return;
	luaL_checktype(L, -1, LUA_TFUNCTION);
	lua_pushvalue(L, object); // self
	objectref_get_or_create(L, puncher); // Clicker reference
	lua_pushnumber(L, time_from_last_punch);
	push_tool_capabilities(L, *toolcap);
	push_v3f(L, dir);
	// Call with 5 arguments, 0 results
	if(lua_pcall(L, 5, 0, 0))
		script_error(L, "error running function 'on_punch': %s\n", lua_tostring(L, -1));
}

// Calls entity:on_rightclick(ObjectRef clicker)
void scriptapi_luaentity_rightclick(lua_State *L, u16 id,
		ServerActiveObject *clicker)
{
	realitycheck(L);
	assert(lua_checkstack(L, 20));
	//infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
	StackUnroller stack_unroller(L);

	// Get minetest.luaentities[id]
	luaentity_get(L, id);
	int object = lua_gettop(L);
	// State: object is at top of stack
	// Get function
	lua_getfield(L, -1, "on_rightclick");
	if(lua_isnil(L, -1))
		return;
	luaL_checktype(L, -1, LUA_TFUNCTION);
	lua_pushvalue(L, object); // self
	objectref_get_or_create(L, clicker); // Clicker reference
	// Call with 2 arguments, 0 results
	if(lua_pcall(L, 2, 0, 0))
		script_error(L, "error running function 'on_rightclick': %s\n", lua_tostring(L, -1));
}