Remove zip release files, move mod to root, exclude assets from Makefile (#92)

16 files changed, 1152 insertions, 0 deletions

diff --git a/advtrains_luaautomation/README.txt b/advtrains_luaautomation/README.txt
new file mode 100644
index 0000000..f2219bf
--- /dev/null
+++ b/advtrains_luaautomation/README.txt
@@ -0,0 +1,165 @@
+
+#### Advtrains - Lua Automation features
+
+This mod offers components that run LUA code and interface with each other through a global environment. It makes complex automated railway systems possible.
+
+### atlatc
+The mod is sometimes abbreviated as 'atlatc'. This stands for AdvTrainsLuaATC. This short name has been chosen for user convenience, since the name of this mod ('advtrains_luaautomation') is very long.
+
+### Privilege
+To perform any operations using this mod (except executing operation panels), players need the "atlatc" privilege.
+This privilege should never be granted to anyone except trusted administrators. Even though the LUA environment is sandboxed, it is still possible to DoS the server by coding infinite loops or requesting expotentially growing interrupts. 
+
+### Active and passive
+Active components are these who have LUA code running in them. They are triggered on specific events. Passive components are dumb, they only have a state and can be set to another state, they can't perform actions themselves.
+
+### Environments
+
+Each active component is assigned to an environment. This is where all data are held. Components in different environments can't inferface with each other.
+This system allows multiple independent automation systems to run simultaneously without polluting each other's environment.
+
+/env_create <env_name>
+Create environment with the given name. To be able to do anything, you first need to create an environment. Choose the name wisely, you can't change it afterwards.
+
+/env_setup <env_name>
+Invoke the form to edit the environment's initialization code. For more information, see the section on active components. You can also delete an environment from here.
+
+### Active components
+
+The code of every active component is run on specific events which are explained soon. When run, every variable written that is not local and is no function or userdata is saved over code re-runs and over server restarts. Additionally, the following global variables are defined:
+
+# event
+The variable 'event' contains a table with information on the current event. How this table can look is explained below.
+
+# S
+The variable 'S' contains a table which is shared between all components of the environment. Its contents are persistent over server restarts. May not contain functions, every other value is allowed.
+Example:
+Component 1: S.stuff="foo"
+Component 2: print(S.stuff)
+-> foo
+
+# F
+The variable 'F' also contains a table which is shared between all components of the environment. Its contents are discarded on server shutdown or when the init code gets re-run. Every data type is allowed, even functions.
+The purpose of this table is not to save data, but to provide static value and function definitions. The table should be populated by the init code.
+
+# Standard Lua functions
+The following standard Lua libraries are available:
+string, math, table, os
+The following standard Lua functions are available:
+assert, error, ipairs, pairs, next, select, tonumber, tostring, type, unpack
+
+Every attempt to overwrite any of the predefined values results in an error.
+
+# LuaAutomation-specific global functions
+
+POS(x,y,z)
+Shorthand function to create a position vector {x=?, y=?, z=?} with less characters
+
+getstate(pos)
+Get the state of the passive component at position 'pos'. See section on passive components for more info.
+pos can be either a position vector (created by POS()) or a string, the name of this passive component.
+
+setstate(pos, newstate)
+Set the state of the passive component at position 'pos'.
+pos can be either a position vector (created by POS()) or a string, the name of this passive component.
+
+interrupt(time, message)
+Cause LuaAutomation to trigger an 'int' event on this component after the given time in seconds with the specified 'message' field. 'message' can be of any Lua data type.
+Not available in init code!
+
+interrupt_pos(pos, message)
+Immediately trigger an 'ext_int' event on the active component at position pos. 'message' is like in interrupt().
+USE WITH CARE, or better don't use! Incorrect use can result in expotential growth of interrupts.
+
+## Components and events
+
+The event table is a table of the following format:
+{
+	type = "<type>",
+	<type> = true,
+	... additional content ...
+}
+You can check for the event type by either using
+if event.type == "wanted" then ...do stuff... end
+or
+if event.wanted then ...do stuff... end
+(if 'wanted' is the event type to check for)
+
+# Init code
+The initialization code is not a component as such, but rather a part of the whole environment. It can (and should) be used to make definitions that other components can refer to.
+Examples:
+A function to define behavior for trains in subway stations:
+function F.station()
+	if event.train then atc_send("B0WOL") end
+	if event.int and event.message="depart" then atc_send("OCD1SM") end
+end
+
+The init code is run whenever the F table needs to be refilled with data. This is the case on server startup and whenever the init code is changed and you choose to run it.
+Functions are run in the environment of the currently active node, regardless of where they were defined. So, the 'event' table always reflects the state of the calling node.
+
+The 'event' table of the init code is always {type="init", init=true}.
+
+# ATC rails
+The Lua-controlled ATC rails are the only components that can actually interface with trains. The following event types are generated:
+
+{type="train", train=true, id="<train_id>"}
+This event is fired when a train enters the rail. The field 'id' is the unique train ID, which is a long string (generated by concatenating os.time() and os.clock() at creation time). The Itrainmap mod displays the last 4 digits of this ID.
+
+{type="int", int=true, message=<message>}
+Fired when an interrupt set by the 'interrupt' function runs out. 'message' is the message passed to the interrupt function.
+{type="ext_int", ext_int=true, message=<message>}
+Fired when another node called 'interrupt_pos' on this position. 'message' is the message passed to the interrupt_pos function.
+
+In addition to the default environment functions, the following functions are available:
+
+atc_send(<atc_command>)
+	Sends the specified ATC command to the train and returns true. If there is no train, returns false and does nothing.
+atc_reset()
+	Resets the train's current ATC command. If there is no train, returns false and does nothing.
+atc_arrow
+	Boolean, true when the train is driving in the direction of the arrows of the ATC rail. Nil if there is no train.
+atc_id
+	Train ID of the train currently passing the controller. Nil if there's no train.
+atc_speed
+	Speed of the train, or nil if there is no train.
+atc_set_text_outside(text)
+	Set text shown on the outside of the train. Pass nil to show no text.
+atc_set_text_inside(text)
+	Set text shown to train passengers. Pass nil to show no text.
+
+# Operator panel
+This simple node executes its actions when punched. It can be used to change a switch and update the corresponding signals or similar applications.
+
+The event fired is {type="punch", punch=true} by default. In case of an interrupt, the events are similar to the ones of the ATC rail.
+
+### Passive components
+
+All passive components can be interfaced with the setstate and getstate functions(see above).
+Below, each apperance is mapped to the "state" of that node.
+
+## Signals
+The light signals are interfaceable, the analog signals are not.
+"green" - Signal shows green light
+"red" - Signal shows red light
+
+## Switches
+All default rail switches are interfaceable, independent of orientation.
+"cr" - The switch is set in the direction that is not straight.
+"st" - The switch is set in the direction that is straight.
+
+## Mesecon Switch
+The Mesecon switch can be switched using LuaAutomation. Note that this is not possible on levers, only the full-node 'Switch' block.
+"on" - the switch is switched on
+"off" - the switch is switched off
+
+##Andrew's Cross
+"on" - it blinks
+"off" - it does not blink
+
+### Passive component naming
+You can assign names to passive components using the Passive Component Naming tool.
+Once you set a name for any component, you can reference it by that name in the getstate() and setstate() functions, like this:
+(Imagine a signal that you have named "Stn_P1_out" at position (1,2,3) )
+setstate("Stn_P1_out", "green") instead of setstate(POS(1,2,3), "green")
+This way, you don't need to memorize positions.
+
diff --git a/advtrains_luaautomation/active_common.lua b/advtrains_luaautomation/active_common.lua
new file mode 100644
index 0000000..8c910c6
--- /dev/null
+++ b/advtrains_luaautomation/active_common.lua
@@ -0,0 +1,134 @@
+
+
+local ac = {nodes={}}
+
+function ac.load(data)
+	if data then
+		ac.nodes=data.nodes
+	end
+end
+function ac.save()
+	return {nodes = ac.nodes}
+end
+
+function ac.after_place_node(pos, player)
+	advtrains.ndb.update(pos)
+	local meta=minetest.get_meta(pos)
+	meta:set_string("formspec", ac.getform(pos, meta))
+	meta:set_string("infotext", "LuaAutomation component, unconfigured.")
+	local ph=minetest.pos_to_string(pos)
+	--just get first available key!
+	for en,_ in pairs(atlatc.envs) do
+		ac.nodes[ph]={env=en}
+		return
+	end
+end
+function ac.getform(pos, meta_p)
+	local meta = meta_p or minetest.get_meta(pos)
+	local envs_asvalues={}
+	
+	local ph=minetest.pos_to_string(pos)
+	local nodetbl = ac.nodes[ph]
+	local env, code, err = nil, "", ""
+	if nodetbl then
+		code=nodetbl.code or ""
+		err=nodetbl.err or ""
+		env=nodetbl.env or ""
+	end
+	local sel = 1
+	for n,_ in pairs(atlatc.envs) do
+		envs_asvalues[#envs_asvalues+1]=n
+		if n==env then
+			sel=#envs_asvalues
+		end
+	end
+	local form = "size[10,10]dropdown[0,0;3;env;"..table.concat(envs_asvalues, ",")..";"..sel.."]"
+		.."button[4,0;2,1;save;Save]button[7,0;2,1;cle;Clear local env] textarea[0.2,1;10,10;code;Code;"..minetest.formspec_escape(code).."]"
+		.."label[0,9.8;"..err.."]"
+	return form
+end
+
+function ac.after_dig_node(pos, node, player)
+	advtrains.invalidate_all_paths(pos)
+	advtrains.ndb.clear(pos)
+	local ph=minetest.pos_to_string(pos)
+	ac.nodes[ph]=nil
+end
+
+function ac.on_receive_fields(pos, formname, fields, player)
+	if not minetest.check_player_privs(player:get_player_name(), {atlatc=true}) then
+		minetest.chat_send_player(player:get_player_name(), "Missing privilege: atlatc - Operation cancelled!")
+		return
+	end
+	
+	local meta=minetest.get_meta(pos)
+	local ph=minetest.pos_to_string(pos)
+	local nodetbl = ac.nodes[ph] or {}
+	--if fields.quit then return end
+	if fields.env then
+		nodetbl.env=fields.env
+	end
+	if fields.code then
+		nodetbl.code=fields.code
+	end
+	if fields.save then
+		nodetbl.err=nil
+	end
+	if fields.cle then
+		nodetbl.data={}
+	end
+	
+	ac.nodes[ph]=nodetbl
+	
+	meta:set_string("formspec", ac.getform(pos, meta))
+	if nodetbl.env then
+		meta:set_string("infotext", "LuaAutomation component, assigned to environment '"..nodetbl.env.."'")
+	else
+		meta:set_string("infotext", "LuaAutomation component, invalid enviroment set!")
+	end
+end
+
+function ac.run_in_env(pos, evtdata, customfct_p)
+	local ph=minetest.pos_to_string(pos)
+	local nodetbl = ac.nodes[ph]
+	if not nodetbl then
+		atwarn("LuaAutomation component at",ph,": Data not in memory! Please visit component and click 'Save'!")
+		return
+	end
+	
+	local meta
+	if minetest.get_node_or_nil(pos) then
+		meta=minetest.get_meta(pos)
+	end
+	
+	if not nodetbl.env or not atlatc.envs[nodetbl.env] then
+		atwarn("LuaAutomation component at",ph,": Not an existing environment: "..(nodetbl.env or "<nil>"))
+		return false
+	end
+	if not nodetbl.code or nodetbl.code=="" then
+		atwarn("LuaAutomation component at",ph,": No code to run! (insert -- to suppress warning)")
+		return false
+	end
+	
+	local customfct=customfct_p or {}
+	customfct.interrupt=function(t, imesg)
+		atlatc.interrupt.add(t, pos, {type="int", int=true, message=imesg})
+	end
+	
+	local datain=nodetbl.data or {}
+	local succ, dataout = atlatc.envs[nodetbl.env]:execute_code(datain, nodetbl.code, evtdata, customfct)
+	if succ then
+		atlatc.active.nodes[ph].data=atlatc.remove_invalid_data(dataout)
+	else
+		atlatc.active.nodes[ph].err=dataout
+		atwarn("LuaAutomation ATC interface rail at",ph,": LUA Error:",dataout)
+		if meta then
+			meta:set_string("infotext", "LuaAutomation ATC interface rail, ERROR:"..dataout)
+		end
+	end
+	if meta then
+		meta:set_string("formspec", ac.getform(pos, meta))
+	end
+end
+
+atlatc.active=ac
diff --git a/advtrains_luaautomation/atc_rail.lua b/advtrains_luaautomation/atc_rail.lua
new file mode 100644
index 0000000..3ec82c8
--- /dev/null
+++ b/advtrains_luaautomation/atc_rail.lua
@@ -0,0 +1,124 @@
+-- atc_rail.lua
+-- registers and handles the ATC rail. Active component.
+-- This is the only component that can interface with trains, so train interface goes here too.
+
+--Using subtable
+local r={}
+
+function r.fire_event(pos, evtdata)
+	
+	local ph=minetest.pos_to_string(pos)
+	local railtbl = atlatc.active.nodes[ph]
+	
+	if not railtbl then
+		atwarn("LuaAutomation ATC interface rail at",ph,": Data not in memory! Please visit position and click 'Save'!")
+		return
+	end
+	
+	
+	local arrowconn = railtbl.arrowconn
+	if not arrowconn then
+		atwarn("LuaAutomation ATC interface rail at",ph,": Incomplete Data! Please visit position and click 'Save'!")
+		return
+	end
+	
+	--prepare ingame API for ATC. Regenerate each time since pos needs to be known
+	--If no train, then return false.
+	local train_id=advtrains.detector.on_node[ph]
+	local train, atc_arrow, tvel
+	if train_id then train=advtrains.trains[train_id] end
+	if train then 
+		if not train.path then
+			--we happened to get in between an invalidation step
+			--delay
+			atlatc.interrupt.add(0,pos,evtdata)
+			return
+		end
+		for index, ppos in pairs(train.path) do
+			if vector.equals(advtrains.round_vector_floor_y(ppos), pos) then
+				atc_arrow =
+						vector.equals(
+								advtrains.dirCoordSet(pos, arrowconn),
+								advtrains.round_vector_floor_y(train.path[index+train.movedir])
+						)
+			end
+		end
+		if atc_arrow==nil then
+			atwarn("LuaAutomation ATC rail at", pos, ": Rail not on train's path! Can't determine arrow direction. Assuming +!")
+			atc_arrow=true
+		end
+		tvel=train.velocity
+	end
+	local customfct={
+		atc_send = function(cmd)
+			if not train_id then return false end
+			assertt(cmd, "string")
+			advtrains.atc.train_reset_command(train_id)
+			train.atc_command=cmd
+			train.atc_arrow=atc_arrow
+			return true
+		end,
+		atc_reset = function(cmd)
+			if not train_id then return false end
+			assertt(cmd, "string")
+			advtrains.atc.train_reset_command(train_id)
+			return true
+		end,
+		atc_arrow = atc_arrow,
+		atc_id = train_id,
+		atc_speed = tvel,
+		atc_set_text_outside = function(text)
+			if not train_id then return false end
+			if text then assertt(text, "string") end
+			advtrains.trains[train_id].text_outside=text
+			return true
+		end,
+		atc_set_text_inside = function(text)
+			if not train_id then return false end
+			if text then assertt(text, "string") end
+			advtrains.trains[train_id].text_inside=text
+			return true
+		end,
+	}
+	
+	atlatc.active.run_in_env(pos, evtdata, customfct)
+	
+end
+
+advtrains.register_tracks("default", {
+	nodename_prefix="advtrains_luaautomation:dtrack",
+	texture_prefix="advtrains_dtrack_atc",
+	models_prefix="advtrains_dtrack",
+	models_suffix=".b3d",
+	shared_texture="advtrains_dtrack_shared_atc.png",
+	description=atltrans("LuaAutomation ATC Rail"),
+	formats={},
+	get_additional_definiton = function(def, preset, suffix, rotation)
+		return {
+			after_place_node = atlatc.active.after_place_node,
+			after_dig_node = atlatc.active.after_dig_node,
+
+			on_receive_fields = function(pos, ...)
+				atlatc.active.on_receive_fields(pos, ...)
+				
+				--set arrowconn (for ATC)
+				local ph=minetest.pos_to_string(pos)
+				local _, conn1=advtrains.get_rail_info_at(pos, advtrains.all_tracktypes)
+				atlatc.active.nodes[ph].arrowconn=conn1
+			end,
+
+			advtrains = {
+				on_train_enter = function(pos, train_id)
+					--do async. Event is fired in train steps
+					atlatc.interrupt.add(0, pos, {type="train", train=true, id=train_id})
+				end,
+			},
+			luaautomation = {
+				fire_event=r.fire_event
+			}
+		}
+	end
+}, advtrains.trackpresets.t_30deg_straightonly)
+
+
+atlatc.rail = r
diff --git a/advtrains_luaautomation/chatcmds.lua b/advtrains_luaautomation/chatcmds.lua
new file mode 100644
index 0000000..2d0c69d
--- /dev/null
+++ b/advtrains_luaautomation/chatcmds.lua
@@ -0,0 +1,84 @@
+--chatcmds.lua
+--Registers commands to modify the init and step code for LuaAutomation
+
+--position helper.
+--punching a node will result in that position being saved and inserted into a text field on the top of init form.
+local punchpos={}
+
+minetest.register_on_punchnode(function(pos, node, player, pointed_thing)
+	local pname=player:get_player_name()
+	punchpos[pname]=pos
+end)
+
+local function get_init_form(env, pname)
+	local err = env.init_err or ""
+	local code = env.init_code or ""
+	local ppos=punchpos[pname]
+	local pp=""
+	if ppos then
+		pp="POS"..minetest.pos_to_string(ppos)
+	end
+	local form = "size[10,10]button[0,0;2,1;run;Run InitCode]button[2,0;2,1;cls;Clear S]"
+		.."button[4,0;2,1;save;Save] button[6,0;2,1;del;Delete Env.] field[8.1,0.5;2,1;punchpos;Last punched position;"..pp.."]"
+		.."textarea[0.2,1;10,10;code;Environment initialization code;"..minetest.formspec_escape(code).."]"
+		.."label[0,9.8;"..err.."]"
+	return form
+end
+
+core.register_chatcommand("env_setup", {
+	params = "<environment name>",
+	description = "Set up and modify AdvTrains LuaAutomation environment",
+	privs = {atlatc=true},
+	func = function(name, param)
+		local env=atlatc.envs[param]
+		if not env then return false,"Invalid environment name!" end
+		minetest.show_formspec(name, "atlatc_envsetup_"..param, get_init_form(env, name))
+		return true
+	end,
+})
+
+core.register_chatcommand("env_create", {
+	params = "<environment name>",
+	description = "Create an AdvTrains LuaAutomation environment",
+	privs = {atlatc=true},
+	func = function(name, param)
+		if not param or param=="" then return false, "Name required!" end
+		if atlatc.envs[param] then return false, "Environment already exists!" end
+		atlatc.envs[param] = atlatc.env_new(param)
+		return true, "Created environment '"..param.."'. Use '/env_setup "..param.."' to define global initialization code, or start building LuaATC components!"
+	end,
+})
+
+
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	
+	local pname=player:get_player_name()
+	if not minetest.check_player_privs(pname, {atlatc=true}) then return end
+	
+	local envname=string.match(formname, "^atlatc_delconfirm_(.+)$")
+	if envname and fields.sure=="YES" then
+		atlatc.envs[envname]=nil
+		minetest.chat_send_player(pname, "Environment deleted!")
+		return
+	end
+	
+	envname=string.match(formname, "^atlatc_envsetup_(.+)$")
+	if not envname then return end
+	
+	local env=atlatc.envs[envname]
+	if not env then return end
+	
+	if fields.del then
+		minetest.show_formspec(pname, "atlatc_delconfirm_"..envname, "field[sure;"..minetest.formspec_escape("SURE TO DELETE ENVIRONMENT "..envname.."? Type YES (all uppercase) to continue or just quit form to cancel.")..";]")
+		return
+	end
+	
+	env.init_err=nil
+	if fields.code then
+		env.init_code=fields.code
+	end
+	if fields.run then
+		env:run_initcode()
+		minetest.show_formspec(pname, formname, get_init_form(env, pname))
+	end
+end)
diff --git a/advtrains_luaautomation/depends.txt b/advtrains_luaautomation/depends.txt
new file mode 100644
index 0000000..602cf47
--- /dev/null
+++ b/advtrains_luaautomation/depends.txt
@@ -0,0 +1,2 @@
+advtrains
+mesecons_switch?
\ No newline at end of file
diff --git a/advtrains_luaautomation/environment.lua b/advtrains_luaautomation/environment.lua
new file mode 100644
index 0000000..0b25e87
--- /dev/null
+++ b/advtrains_luaautomation/environment.lua
@@ -0,0 +1,275 @@
+-------------
+-- lua sandboxed environment
+
+-- function to cross out functions and userdata.
+-- modified from dump()
+function atlatc.remove_invalid_data(o, nested)
+	if o==nil then return nil end
+	local valid_dt={["nil"]=true, boolean=true, number=true, string=true}
+	if type(o) ~= "table" then
+		--check valid data type
+		if not valid_dt[type(o)] then
+			return nil
+		end
+		return o
+	end
+	-- Contains table -> true/nil of currently nested tables
+	nested = nested or {}
+	if nested[o] then
+		return nil
+	end
+	nested[o] = true
+	for k, v in pairs(o) do
+		v = atlatc.remove_invalid_data(v, nested)
+	end
+	nested[o] = nil
+	return o
+end
+
+
+local env_proto={
+	load = function(self, envname, data)
+		self.name=envname
+		self.sdata=data.sdata and atlatc.remove_invalid_data(data.sdata) or {}
+		self.fdata={}
+		self.init_code=data.init_code or ""
+		self.step_code=data.step_code or ""
+	end,
+	save = function(self)
+		-- throw any function values out of the sdata table
+		self.sdata = atlatc.remove_invalid_data(self.sdata)
+		return {sdata = self.sdata, init_code=self.init_code, step_code=self.step_code}
+	end,
+}
+
+--Environment
+--Code modified from mesecons_luacontroller (credit goes to Jeija and mesecons contributors)
+
+local safe_globals = {
+	"assert", "error", "ipairs", "next", "pairs", "select",
+	"tonumber", "tostring", "type", "unpack", "_VERSION"
+}
+
+--print is actually minetest.chat_send_all()
+--using advtrains.print_concat_table because it's cool
+local function safe_print(t, ...)
+	local str=advtrains.print_concat_table({t, ...})
+	minetest.log("action", "[atlatc] "..str)
+	minetest.chat_send_all(str)
+end
+
+local function safe_date()
+	return(os.date("*t",os.time()))
+end
+
+-- string.rep(str, n) with a high value for n can be used to DoS
+-- the server. Therefore, limit max. length of generated string.
+local function safe_string_rep(str, n)
+	if #str * n > 2000 then
+		debug.sethook() -- Clear hook
+		error("string.rep: string length overflow", 2)
+	end
+
+	return string.rep(str, n)
+end
+
+-- string.find with a pattern can be used to DoS the server.
+-- Therefore, limit string.find to patternless matching.
+-- Note: Disabled security since there are enough security leaks and this would be unneccessary anyway to DoS the server
+local function safe_string_find(...)
+	--if (select(4, ...)) ~= true then
+	--	debug.sethook() -- Clear hook
+	--	error("string.find: 'plain' (fourth parameter) must always be true for security reasons.")
+	--end
+
+	return string.find(...)
+end
+
+local mp=minetest.get_modpath("advtrains_luaautomation")
+local p_api_getstate, p_api_setstate = dofile(mp.."/passive.lua")
+
+local static_env = {
+	--core LUA functions
+	print = safe_print,
+	string = {
+		byte = string.byte,
+		char = string.char,
+		format = string.format,
+		len = string.len,
+		lower = string.lower,
+		upper = string.upper,
+		rep = safe_string_rep,
+		reverse = string.reverse,
+		sub = string.sub,
+		find = safe_string_find,
+	},
+	math = {
+		abs = math.abs,
+		acos = math.acos,
+		asin = math.asin,
+		atan = math.atan,
+		atan2 = math.atan2,
+		ceil = math.ceil,
+		cos = math.cos,
+		cosh = math.cosh,
+		deg = math.deg,
+		exp = math.exp,
+		floor = math.floor,
+		fmod = math.fmod,
+		frexp = math.frexp,
+		huge = math.huge,
+		ldexp = math.ldexp,
+		log = math.log,
+		log10 = math.log10,
+		max = math.max,
+		min = math.min,
+		modf = math.modf,
+		pi = math.pi,
+		pow = math.pow,
+		rad = math.rad,
+		random = math.random,
+		sin = math.sin,
+		sinh = math.sinh,
+		sqrt = math.sqrt,
+		tan = math.tan,
+		tanh = math.tanh,
+	},
+	table = {
+		concat = table.concat,
+		insert = table.insert,
+		maxn = table.maxn,
+		remove = table.remove,
+		sort = table.sort,
+	},
+	os = {
+		clock = os.clock,
+		difftime = os.difftime,
+		time = os.time,
+		date = safe_date,
+	},
+	POS = function(x,y,z) return {x=x, y=y, z=z} end,
+	getstate = p_api_getstate,
+	setstate = p_api_setstate,
+	--interrupts are handled per node, position unknown.
+	--however external interrupts can be set here.
+	interrupt_pos = function(pos, imesg)
+		if not type(pos)=="table" or not pos.x or not pos.y or not pos.z then
+			debug.sethook()
+			error("Invalid position supplied to interrupt_pos")
+		end
+		atlatc.interrupt.add(0, pos, {type="ext_int", ext_int=true, message=imesg})
+	end,
+}
+
+for _, name in pairs(safe_globals) do
+	static_env[name] = _G[name]
+end
+
+
+--The environment all code calls get is a table that has set static_env as metatable.
+--In general, every variable is local to a single code chunk, but kept persistent over code re-runs. Data is also saved, but functions and userdata and circular references are removed
+--Init code and step code's environments are not saved
+-- S - Table that can contain any save data global to the environment. Will be saved statically. Can't contain functions or userdata or circular references.
+-- F - Table global to the environment, can contain volatile data that is deleted when server quits.
+--     The init code should populate this table with functions and other definitions.
+
+local proxy_env={}
+--proxy_env gets a new metatable in every run, but is the shared environment of all functions ever defined.
+
+-- returns: true, fenv if successful; nil, error if error 
+function env_proto:execute_code(localenv, code, evtdata, customfct)
+	local metatbl ={
+		__index = function(t, i)
+			if i=="S" then
+				return self.sdata
+			elseif i=="F" then
+				return self.fdata
+			elseif i=="event" then
+				return evtdata
+			elseif customfct and customfct[i] then
+				return customfct[i]
+			elseif localenv and localenv[i] then
+				return localenv[i]
+			end
+			return static_env[i]
+		end,
+		__newindex = function(t, i, v)
+			if i=="S" or i=="F" or i=="event" or (customfct and customfct[i]) or static_env[i] then
+				debug.sethook()
+				error("Trying to overwrite environment contents")
+			end
+			localenv[i]=v
+		end,
+	}
+	setmetatable(proxy_env, metatbl)
+	local fun, err=loadstring(code)
+	if not fun then
+		return false, err
+	end
+	
+	setfenv(fun, proxy_env)
+	local succ, data = pcall(fun)
+	if succ then
+		data=localenv
+	end
+	return succ, data
+end
+
+function env_proto:run_initcode()
+	if self.init_code and self.init_code~="" then
+		local old_fdata=self.fdata
+		self.fdata = {}
+		atprint("[atlatc]Running initialization code for environment '"..self.name.."'")
+		local succ, err = self:execute_code({}, self.init_code, {type="init", init=true})
+		if not succ then
+			atwarn("[atlatc]Executing InitCode for '"..self.name.."' failed:"..err)
+			self.init_err=err
+			if old_fdata then
+				self.fdata=old_fdata
+				atwarn("[atlatc]The 'F' table has been restored to the previous state.")
+			end
+		end
+	end
+end
+function env_proto:run_stepcode()
+	if self.step_code and self.step_code~="" then
+		local succ, err = self:execute_code({}, self.step_code, nil, {})
+		if not succ then
+			--TODO
+		end
+	end
+end
+
+--- class interface
+
+function atlatc.env_new(name)
+	local newenv={
+		name=name,
+		init_code="",
+		step_code="",
+		sdata={}
+	}
+	setmetatable(newenv, {__index=env_proto})
+	return newenv
+end
+function atlatc.env_load(name, data)
+	local newenv={}
+	setmetatable(newenv, {__index=env_proto})
+	newenv:load(name, data)
+	return newenv
+end
+
+function atlatc.run_initcode()
+	for envname, env in pairs(atlatc.envs) do
+		env:run_initcode()
+	end
+end
+function atlatc.run_stepcode()
+	for envname, env in pairs(atlatc.envs) do
+		env:run_stepcode()
+	end
+end
+
+
+
+
diff --git a/advtrains_luaautomation/init.lua b/advtrains_luaautomation/init.lua
new file mode 100644
index 0000000..0257aef
--- /dev/null
+++ b/advtrains_luaautomation/init.lua
@@ -0,0 +1,110 @@
+-- advtrains_luaautomation/init.lua
+-- Lua automation features for advtrains
+-- Uses global table 'atlatc' (AdvTrains_LuaATC)
+
+-- Boilerplate to support localized strings if intllib mod is installed.
+if minetest.get_modpath("intllib") then
+    atltrans = intllib.Getter()
+else
+    atltrans = function(s,a,...)a={a,...}return s:gsub("@(%d+)",function(n)return a[tonumber(n)]end)end
+end
+
+--Privilege
+--Only trusted players should be enabled to build stuff which can break the server.
+
+atlatc = { envs = {}}
+
+minetest.register_privilege("atlatc", { description = "Player can place and modify LUA ATC components. Grant with care! Allows to execute bad LUA code.", give_to_singleplayer = false, default= false })
+
+--assertt helper. error if a variable is not of a type
+function assertt(var, typ)
+	if type(var)~=typ then
+		error("Assertion failed, variable has to be of type "..typ)
+	end
+end
+
+local mp=minetest.get_modpath("advtrains_luaautomation")
+if not mp then
+	error("Mod name error: Mod folder is not named 'advtrains_luaautomation'!")
+end
+dofile(mp.."/environment.lua")
+dofile(mp.."/interrupt.lua")
+dofile(mp.."/active_common.lua")
+dofile(mp.."/atc_rail.lua")
+dofile(mp.."/operation_panel.lua")
+dofile(mp.."/pcnaming.lua")
+if mesecon then
+	dofile(mp.."/p_mesecon_iface.lua")
+end
+dofile(mp.."/chatcmds.lua")
+
+
+local filename=minetest.get_worldpath().."/advtrains_luaautomation"
+
+function atlatc.load()
+	local file, err = io.open(filename, "r")
+	if not file then
+		minetest.log("error", " Failed to read advtrains_luaautomation save data from file "..filename..": "..(err or "Unknown Error"))
+	else
+		atprint("luaautomation reading file:",filename)
+		local tbl = minetest.deserialize(file:read("*a"))
+		if type(tbl) == "table" then
+			if tbl.version==1 then
+				for envname, data in pairs(tbl.envs) do
+					atlatc.envs[envname]=atlatc.env_load(envname, data)
+				end
+				atlatc.active.load(tbl.active)
+				atlatc.interrupt.load(tbl.interrupt)
+				atlatc.pcnaming.load(tbl.pcnaming)
+			end
+		else
+			minetest.log("error", " Failed to read advtrains_luaautomation save data from file "..filename..": Not a table!")
+		end
+		file:close()
+	end
+	-- run init code of all environments
+	atlatc.run_initcode()
+end
+
+
+atlatc.save = function()
+	--versions:
+	-- 1 - Initial save format.
+	
+	local envdata={}
+	for envname, env in pairs(atlatc.envs) do
+		envdata[envname]=env:save()
+	end
+	local save_tbl={
+		version = 1,
+		envs=envdata,
+		active = atlatc.active.save(),
+		interrupt = atlatc.interrupt.save(),
+		pcnaming = atlatc.pcnaming.save(),
+	}
+	
+	local datastr = minetest.serialize(save_tbl)
+	if not datastr then
+		minetest.log("error", " Failed to save advtrains_luaautomation save data to file "..filename..": Can't serialize!")
+		return
+	end
+	local file, err = io.open(filename, "w")
+	if err then
+		minetest.log("error", " Failed to save advtrains_luaautomation save data to file "..filename..": "..(err or "Unknown Error"))
+		return
+	end
+	file:write(datastr)
+	file:close()
+end
+
+
+-- globalstep for step code
+local timer, step_int=0, 2
+
+function atlatc.mainloop_stepcode(dtime)
+	timer=timer+dtime
+	if timer>step_int then
+		timer=0
+		atlatc.run_stepcode()
+	end
+end
diff --git a/advtrains_luaautomation/interrupt.lua b/advtrains_luaautomation/interrupt.lua
new file mode 100644
index 0000000..718b8c7
--- /dev/null
+++ b/advtrains_luaautomation/interrupt.lua
@@ -0,0 +1,46 @@
+-- interrupt.lua
+-- implements interrupt queue
+
+--to be saved: pos and evtdata
+local iq={}
+local queue={}
+local timer=0
+local run=false
+
+function iq.load(data)
+	local d=data or {}
+	queue = d.queue or {}
+	timer = d.timer or 0
+end
+function iq.save()
+	return {queue = queue, timer=timer}
+end
+
+function iq.add(t, pos, evtdata)
+	queue[#queue+1]={t=t+timer, p=pos, e=evtdata}
+	run=true
+end
+
+function iq.mainloop(dtime)
+	timer=timer + math.min(dtime, 0.2)
+	for i=1,#queue do
+		local qe=queue[i]
+		if not qe then
+			table.remove(queue, i)
+			i=i-1
+		elseif timer>qe.t then
+			local pos, evtdata=queue[i].p, queue[i].e
+			local node=advtrains.ndb.get_node(pos)
+			local ndef=minetest.registered_nodes[node.name]
+			if ndef and ndef.luaautomation and ndef.luaautomation.fire_event then
+				ndef.luaautomation.fire_event(pos, evtdata)
+			end
+			table.remove(queue, i)
+			i=i-1
+		end
+	end
+end
+
+
+
+atlatc.interrupt=iq
diff --git a/advtrains_luaautomation/operation_panel.lua b/advtrains_luaautomation/operation_panel.lua
new file mode 100644
index 0000000..1d585f7
--- /dev/null
+++ b/advtrains_luaautomation/operation_panel.lua
@@ -0,0 +1,23 @@
+
+local function on_punch(pos, player)
+	atlatc.interrupt.add(0, pos, {type="punch", punch=true})
+end
+
+
+minetest.register_node("advtrains_luaautomation:oppanel", {
+	drawtype = "normal",
+	tiles={"atlatc_oppanel.png"},
+	description = "LuaAutomation operation panel",
+	groups = {
+		choppy = 1,
+		save_in_nodedb=1,
+	},
+	after_place_node = atlatc.active.after_place_node,
+	after_dig_node = atlatc.active.after_dig_node,
+	on_receive_fields = atlatc.active.on_receive_fields,
+	on_punch = on_punch,
+	luaautomation = {
+		fire_event=atlatc.active.run_in_env
+	}
+	
+})
diff --git a/advtrains_luaautomation/p_display.lua b/advtrains_luaautomation/p_display.lua
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/advtrains_luaautomation/p_display.lua
diff --git a/advtrains_luaautomation/p_mesecon_iface.lua b/advtrains_luaautomation/p_mesecon_iface.lua
new file mode 100644
index 0000000..95e5d8a
--- /dev/null
+++ b/advtrains_luaautomation/p_mesecon_iface.lua
@@ -0,0 +1,53 @@
+-- p_mesecon_iface.lua
+-- Mesecons interface by overriding the switch
+
+if not mesecon then return end
+
+minetest.override_item("mesecons_switch:mesecon_switch_off", {
+	groups = {
+		dig_immediate=2,
+		save_in_nodedb=1,
+	},
+	on_rightclick = function (pos, node)
+		advtrains.ndb.swap_node(pos, {name="mesecons_switch:mesecon_switch_on", param2=node.param2})
+		mesecon.receptor_on(pos)
+		minetest.sound_play("mesecons_switch", {pos=pos})
+	end,
+	on_updated_from_nodedb = function(pos, node)
+		mesecon.receptor_off(pos)
+	end,
+	luaautomation = {
+		getstate = "off",
+		setstate = function(pos, node, newstate)
+			if newstate=="on" then
+				advtrains.ndb.swap_node(pos, {name="mesecons_switch:mesecon_switch_on", param2=node.param2})
+				mesecon.receptor_on(pos)
+			end
+		end,
+	},
+})
+
+minetest.override_item("mesecons_switch:mesecon_switch_on", {
+	groups = {
+		dig_immediate=2,
+		save_in_nodedb=1,
+		not_in_creative_inventory=1,
+	},
+	on_rightclick = function (pos, node)
+		advtrains.ndb.swap_node(pos, {name="mesecons_switch:mesecon_switch_off", param2=node.param2})
+		mesecon.receptor_off(pos)
+		minetest.sound_play("mesecons_switch", {pos=pos})
+	end,
+	on_updated_from_nodedb = function(pos, node)
+		mesecon.receptor_on(pos)
+	end,
+	luaautomation = {
+		getstate = "on",
+		setstate = function(pos, node, newstate)
+			if newstate=="off" then
+				advtrains.ndb.swap_node(pos, {name="mesecons_switch:mesecon_switch_off", param2=node.param2})
+				mesecon.receptor_off(pos)
+			end
+		end,
+	},
+})
diff --git a/advtrains_luaautomation/passive.lua b/advtrains_luaautomation/passive.lua
new file mode 100644
index 0000000..774df8a
--- /dev/null
+++ b/advtrains_luaautomation/passive.lua
@@ -0,0 +1,39 @@
+-- passive.lua
+-- API to passive components, as described in passive_api.txt
+
+local function getstate(parpos)
+	local pos=atlatc.pcnaming.resolve_pos(parpos)
+	if type(pos)~="table" or (not pos.x or not pos.y or not pos.z) then
+		debug.sethook()
+		error("Invalid position supplied to getstate")
+	end
+	local node=advtrains.ndb.get_node(pos)
+	local ndef=minetest.registered_nodes[node.name]
+	if ndef and ndef.luaautomation and ndef.luaautomation.getstate then
+		local st=ndef.luaautomation.getstate
+		if type(st)=="function" then
+			return st(pos, node)
+		else
+			return st
+		end
+	end
+	return nil
+end
+
+local function setstate(parpos, newstate)
+	local pos=atlatc.pcnaming.resolve_pos(parpos)
+	if type(pos)~="table" or (not pos.x or not pos.y or not pos.z) then
+		debug.sethook()
+		error("Invalid position supplied to setstate")
+	end
+	local node=advtrains.ndb.get_node(pos)
+	local ndef=minetest.registered_nodes[node.name]
+	if ndef and ndef.luaautomation and ndef.luaautomation.setstate then
+		local st=ndef.luaautomation.setstate
+		st(pos, node, newstate)
+	end
+end
+
+-- gets called from environment.lua
+-- return the values here to keep them local
+return getstate, setstate
diff --git a/advtrains_luaautomation/passive_api.txt b/advtrains_luaautomation/passive_api.txt
new file mode 100644
index 0000000..a735208
--- /dev/null
+++ b/advtrains_luaautomation/passive_api.txt
@@ -0,0 +1,23 @@
+Lua Automation - Passive Component API
+
+Passive components are nodes that do not have code running in them. However, active components can query these and request actions from them. Examples:
+Switches
+Signals
+Displays
+Mesecon Transmitter
+
+All passive components have a table called 'luaautomation' in their node definition and have the group 'save_in_nodedb' set, so they work in unloaded chunks.
+Example for a switch:
+luaautomation = {
+	getstate = function(pos, node)
+		return "st"
+	end,
+	-- OR
+	getstate = "st",
+
+	setstate = function(pos, node, newstate)
+		if newstate=="cr" then
+			advtrains.ndb.swap_node(pos, <corresponding switch alt>)
+		end
+	end
+}
\ No newline at end of file
diff --git a/advtrains_luaautomation/pcnaming.lua b/advtrains_luaautomation/pcnaming.lua
new file mode 100644
index 0000000..56ed2d6
--- /dev/null
+++ b/advtrains_luaautomation/pcnaming.lua
@@ -0,0 +1,74 @@
+--pcnaming.lua
+--a.k.a Passive component naming
+--Allows to assign names to passive components, so they can be called like:
+--setstate("iamasignal", "green")
+atlatc.pcnaming={name_map={}}
+function atlatc.pcnaming.load(stuff)
+	if type(stuff)=="table" then
+		atlatc.pcnaming.name_map=stuff
+	end
+end
+function atlatc.pcnaming.save()
+	return atlatc.pcnaming.name_map
+end
+
+function atlatc.pcnaming.resolve_pos(posorname)
+	if type(posorname)=="table" then return posorname end
+	return atlatc.pcnaming.name_map[posorname]
+end
+
+minetest.register_craftitem("advtrains_luaautomation:pcnaming",{
+	description = attrans("Passive Component Naming Tool\n\nRight-click to name a passive component."),
+	groups = {cracky=1}, -- key=name, value=rating; rating=1..3.
+	inventory_image = "atlatc_pcnaming.png",
+	wield_image = "atlatc_pcnaming.png",
+	stack_max = 1,
+	on_place = function(itemstack, placer, pointed_thing)
+		local pname = placer:get_player_name()
+		if not pname then
+			return
+		end
+		if not minetest.check_player_privs(pname, {atlatc=true}) then
+			minetest.chat_send_player(pname, "Missing privilege: atlatc")
+			return
+		end
+		if pointed_thing.type=="node" then
+			local pos=pointed_thing.under
+			if advtrains.is_protected(pos, pname) then
+				minetest.record_protection_violation(pos, pname)
+				return
+			end
+			local node=minetest.get_node(pos)
+			local ndef=minetest.registered_nodes[node.name]
+			if ndef then
+				if ndef.luaautomation then
+					--look if this one already has a name
+					local pn=""
+					for name, npos in pairs(atlatc.pcnaming.name_map) do
+						if vector.equals(npos, pos) then
+							pn=name
+						end
+					end
+					minetest.show_formspec(pname, "atlatc_naming_"..minetest.pos_to_string(pos), "field[pn;Set name of component (empty to clear);"..pn.."]")
+				end
+			end
+		end
+	end,
+})
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	local pts=string.match(formname, "^atlatc_naming_(.+)")
+	if pts then
+		local pos=minetest.string_to_pos(pts)
+		if fields.pn then
+			--first remove all occurences
+			for name, npos in pairs(atlatc.pcnaming.name_map) do
+				if vector.equals(npos, pos) then
+					atlatc.pcnaming.name_map[name]=nil
+				end
+			end
+			if fields.pn~="" then
+				atlatc.pcnaming.name_map[fields.pn]=pos
+			end
+		end
+	end
+end)
diff --git a/advtrains_luaautomation/textures/atlatc_oppanel.png b/advtrains_luaautomation/textures/atlatc_oppanel.png
new file mode 100644
index 0000000..96eb30e
--- /dev/null
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diff --git a/advtrains_luaautomation/textures/atlatc_pcnaming.png b/advtrains_luaautomation/textures/atlatc_pcnaming.png
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