mesecons/mesecons_luacontroller/init.lua

--        ______
--       |
--       |
--       |        __       ___  _   __         _  _
-- |   | |       |  | |\ |  |  |_| |  | |  |  |_ |_|
-- |___| |______ |__| | \|  |  | \ |__| |_ |_ |_ |\
-- |
-- |
--

-- Reference
-- ports = get_real_port_states(pos): gets if inputs are powered from outside
-- newport = merge_port_states(state1, state2): just does result = state1 or state2 for every port
-- set_port(pos, rule, state): activates/deactivates the mesecons according to the port states
-- set_port_states(pos, ports): Applies new port states to a Luacontroller at pos
-- run_inner(pos, code, event): runs code on the controller at pos and event
-- reset_formspec(pos, code, errmsg): installs new code and prints error messages, without resetting LCID
-- reset_meta(pos, code, errmsg): performs a software-reset, installs new code and prints error message
-- run(pos, event): a wrapper for run_inner which gets code & handles errors via reset_meta
-- resetn(pos): performs a hardware reset, turns off all ports
--
-- The Sandbox
-- The whole code of the controller runs in a sandbox,
-- a very restricted environment.
-- Actually the only way to damage the server is to
-- use too much memory from the sandbox.
-- You can add more functions to the environment
-- (see where local env is defined)
-- Something nice to play is is appending minetest.env to it.

local BASENAME = "mesecons_luacontroller:luacontroller"

local rules = {
	a = {x = -1, y = 0, z =  0, name="A"},
	b = {x =  0, y = 0, z =  1, name="B"},
	c = {x =  1, y = 0, z =  0, name="C"},
	d = {x =  0, y = 0, z = -1, name="D"},
}


------------------
-- Action stuff --
------------------
-- These helpers are required to set the port states of the luacontroller

local function update_real_port_states(pos, rule_name, new_state)
	local meta = minetest.get_meta(pos)
	if rule_name == nil then
		meta:set_int("real_portstates", 1)
		return
	end
	local n = meta:get_int("real_portstates") - 1
	local L = {}
	for i = 1, 4 do
		L[i] = n % 2
		n = math.floor(n / 2)
	end
	--                   (0,-1) (-1,0)      (1,0) (0,1)
	local pos_to_side = {  4,     1,   nil,   3,    2 }
	if rule_name.x == nil then
		for _, rname in ipairs(rule_name) do
			local port = pos_to_side[rname.x + (2 * rname.z) + 3]
			L[port] = (newstate == "on") and 1 or 0
		end
	else
		local port = pos_to_side[rule_name.x + (2 * rule_name.z) + 3]
		L[port] = (new_state == "on") and 1 or 0
	end
	meta:set_int("real_portstates",
		1 +
		1 * L[1] +
		2 * L[2] +
		4 * L[3] +
		8 * L[4])
end


local port_names = {"a", "b", "c", "d"}

local function get_real_port_states(pos)
	-- Determine if ports are powered (by itself or from outside)
	local meta = minetest.get_meta(pos)
	local L = {}
	local n = meta:get_int("real_portstates") - 1
	for _, name in ipairs(port_names) do
		L[name] = ((n % 2) == 1)
		n = math.floor(n / 2)
	end
	return L
end


local function merge_port_states(ports, vports)
	return {
		a = ports.a or vports.a,
		b = ports.b or vports.b,
		c = ports.c or vports.c,
		d = ports.d or vports.d,
	}
end

local function generate_name(ports)
	local d = ports.d and 1 or 0
	local c = ports.c and 1 or 0
	local b = ports.b and 1 or 0
	local a = ports.a and 1 or 0
	return BASENAME..d..c..b..a
end


local function set_port(pos, rule, state)
	if state then
		mesecon.receptor_on(pos, {rule})
	else
		mesecon.receptor_off(pos, {rule})
	end
end


local function clean_port_states(ports)
	ports.a = ports.a and true or false
	ports.b = ports.b and true or false
	ports.c = ports.c and true or false
	ports.d = ports.d and true or false
end


local function set_port_states(pos, ports)
	local node = minetest.get_node(pos)
	local name = node.name
	clean_port_states(ports)
	local vports = minetest.registered_nodes[name].virtual_portstates
	local new_name = generate_name(ports)

	if name ~= new_name and vports then
		-- Problem:
		-- We need to place the new node first so that when turning
		-- off some port, it won't stay on because the rules indicate
		-- there is an onstate output port there.
		-- When turning the output off then, it will however cause feedback
		-- so that the luacontroller will receive an "off" event by turning
		-- its output off.
		-- Solution / Workaround:
		-- Remember which output was turned off and ignore next "off" event.
		local meta = minetest.get_meta(pos)
		local ign = minetest.deserialize(meta:get_string("ignore_offevents"), true) or {}
		if ports.a and not vports.a and not mesecon.is_powered(pos, rules.a) then ign.A = true end
		if ports.b and not vports.b and not mesecon.is_powered(pos, rules.b) then ign.B = true end
		if ports.c and not vports.c and not mesecon.is_powered(pos, rules.c) then ign.C = true end
		if ports.d and not vports.d and not mesecon.is_powered(pos, rules.d) then ign.D = true end
		meta:set_string("ignore_offevents", minetest.serialize(ign))

		minetest.swap_node(pos, {name = new_name, param2 = node.param2})

		if ports.a ~= vports.a then set_port(pos, rules.a, ports.a) end
		if ports.b ~= vports.b then set_port(pos, rules.b, ports.b) end
		if ports.c ~= vports.c then set_port(pos, rules.c, ports.c) end
		if ports.d ~= vports.d then set_port(pos, rules.d, ports.d) end
	end
end


-----------------
-- Overheating --
-----------------
local function burn_controller(pos)
	local node = minetest.get_node(pos)
	node.name = BASENAME.."_burnt"
	minetest.swap_node(pos, node)
	minetest.get_meta(pos):set_string("lc_memory", "");
	-- Wait for pending operations
	minetest.after(0.2, mesecon.receptor_off, pos, mesecon.rules.flat)
end

local function overheat(pos, meta)
	if mesecon.do_overheat(pos) then -- If too hot
		burn_controller(pos)
		return true
	end
end

------------------------
-- Ignored off events --
------------------------

local function ignore_event(event, meta)
	if event.type ~= "off" then return false end
	local ignore_offevents = minetest.deserialize(meta:get_string("ignore_offevents"), true) or {}
	if ignore_offevents[event.pin.name] then
		ignore_offevents[event.pin.name] = nil
		meta:set_string("ignore_offevents", minetest.serialize(ignore_offevents))
		return true
	end
end

-------------------------
-- Parsing and running --
-------------------------

local function save_memory(pos, meta, memstring)
	local memsize_max = mesecon.setting("luacontroller_memsize", 100000)

	if (#memstring <= memsize_max) then
		meta:set_string("lc_memory", memstring)
		meta:mark_as_private("lc_memory")
	else
		print("Error: Luacontroller memory overflow. "..memsize_max.." bytes available, "
				..#memstring.." required. Controller overheats.")
		burn_controller(pos)
	end
end

-- Returns success (boolean), errmsg (string)
-- run (as opposed to run_inner) is responsible for setting up meta according to this output
local function run_inner(pos, code, event)
	local meta = minetest.get_meta(pos)
	-- Note: These return success, presumably to avoid changing LC ID.
	if overheat(pos) then return true, "" end
	if ignore_event(event, meta) then return true, "" end

	local vports = minetest.registered_nodes[minetest.get_node(pos).name].virtual_portstates
	local vports_copy = {}
	for k, v in pairs(vports) do vports_copy[k] = v end
	local rports = get_real_port_states(pos)
	local pin = merge_port_states(vports, rports)
	local port = vports_copy

	-- Load code & mem from meta
	local mem = meta:get_string("lc_memory")
	local code = meta:get_string("code")
	local success, port, mem = mesecons_sandbox.run(pin, port, mem, code)
	if not success then return false, port end

	set_port_states(pos, port)
	save_memory(pos, meta, mem)

	return true
end

local function reset_formspec(meta, code, errmsg)
	meta:set_string("code", code)
	meta:mark_as_private("code")
	code = minetest.formspec_escape(code or "")
	errmsg = minetest.formspec_escape(tostring(errmsg or ""))
	meta:set_string("formspec", "size[12,10]"
		.."background[-0.2,-0.25;12.4,10.75;jeija_luac_background.png]"
		.."label[0.1,8.3;"..errmsg.."]"
		.."textarea[0.2,0.2;12.2,9.5;code;;"..code.."]"
		.."image_button[4.75,8.75;2.5,1;jeija_luac_runbutton.png;program;]"
		.."image_button_exit[11.72,-0.25;0.425,0.4;jeija_close_window.png;exit;]"
		)
end

local function reset_meta(pos, code, errmsg)
	local meta = minetest.get_meta(pos)
	reset_formspec(meta, code, errmsg)
	meta:set_int("luac_id", math.random(1, 65535))
end

-- Wraps run_inner with LC-reset-on-error
local function run(pos, event)
	local meta = minetest.get_meta(pos)
	local code = meta:get_string("code")
	local ok, errmsg = run_inner(pos, code, event)
	if not ok then
		reset_meta(pos, code, errmsg)
	else
		reset_formspec(meta, code, errmsg)
	end
	return ok, errmsg
end

local function reset(pos)
	set_port_states(pos, {a=false, b=false, c=false, d=false})
end

local function node_timer(pos)
	if minetest.registered_nodes[minetest.get_node(pos).name].is_burnt then
		return false
	end
	run(pos, {type="interrupt"})
	return false
end

-----------------------
-- A.Queue callbacks --
-----------------------

mesecon.queue:add_function("lc_interrupt", function (pos, luac_id, iid)
	-- There is no luacontroller anymore / it has been reprogrammed / replaced / burnt
	if (minetest.get_meta(pos):get_int("luac_id") ~= luac_id) then return end
	if (minetest.registered_nodes[minetest.get_node(pos).name].is_burnt) then return end
	run(pos, {type="interrupt", iid = iid})
end)

mesecon.queue:add_function("lc_digiline_relay", function (pos, channel, luac_id, msg)
	if not digiline then return end
	-- This check is only really necessary because in case of server crash, old actions can be thrown into the future
	if (minetest.get_meta(pos):get_int("luac_id") ~= luac_id) then return end
	if (minetest.registered_nodes[minetest.get_node(pos).name].is_burnt) then return end
	-- The actual work
	digiline:receptor_send(pos, digiline.rules.default, channel, msg)
end)

-----------------------
-- Node Registration --
-----------------------

local output_rules = {}
local input_rules = {}

local node_box = {
	type = "fixed",
	fixed = {
		{-8/16, -8/16, -8/16, 8/16, -7/16, 8/16}, -- Bottom slab
		{-5/16, -7/16, -5/16, 5/16, -6/16, 5/16}, -- Circuit board
		{-3/16, -6/16, -3/16, 3/16, -5/16, 3/16}, -- IC
	}
}

local selection_box = {
	type = "fixed",
	fixed = { -8/16, -8/16, -8/16, 8/16, -5/16, 8/16 },
}

local digiline = {
	receptor = {},
	effector = {
		action = function(pos, node, channel, msg)
			msg = clean_and_weigh_digiline_message(msg)
			run(pos, {type = "digiline", channel = channel, msg = msg})
		end
	}
}

local function get_program(pos)
	local meta = minetest.get_meta(pos)
	return meta:get_string("code")
end

local function set_program(pos, code)
	reset(pos)
	reset_meta(pos, code)
	return run(pos, {type="program"})
end

local function on_receive_fields(pos, form_name, fields, sender)
	if not fields.program then
		return
	end
	local name = sender:get_player_name()
	if minetest.is_protected(pos, name) and not minetest.check_player_privs(name, {protection_bypass=true}) then
		minetest.record_protection_violation(pos, name)
		return
	end
	local ok, err = set_program(pos, fields.code)
	if not ok then
		-- it's not an error from the server perspective
		minetest.log("action", "Lua controller programming error: " .. tostring(err))
	end
end

for a = 0, 1 do -- 0 = off  1 = on
for b = 0, 1 do
for c = 0, 1 do
for d = 0, 1 do
	local cid = tostring(d)..tostring(c)..tostring(b)..tostring(a)
	local node_name = BASENAME..cid
	local top = "jeija_luacontroller_top.png"
	if a == 1 then
		top = top.."^jeija_luacontroller_LED_A.png"
	end
	if b == 1 then
		top = top.."^jeija_luacontroller_LED_B.png"
	end
	if c == 1 then
		top = top.."^jeija_luacontroller_LED_C.png"
	end
	if d == 1 then
		top = top.."^jeija_luacontroller_LED_D.png"
	end

	local groups
	if a + b + c + d ~= 0 then
		groups = {dig_immediate=2, not_in_creative_inventory=1, overheat = 1}
	else
		groups = {dig_immediate=2, overheat = 1}
	end

	output_rules[cid] = {}
	input_rules[cid] = {}
	if a == 1 then table.insert(output_rules[cid], rules.a) end
	if b == 1 then table.insert(output_rules[cid], rules.b) end
	if c == 1 then table.insert(output_rules[cid], rules.c) end
	if d == 1 then table.insert(output_rules[cid], rules.d) end

	if a == 0 then table.insert( input_rules[cid], rules.a) end
	if b == 0 then table.insert( input_rules[cid], rules.b) end
	if c == 0 then table.insert( input_rules[cid], rules.c) end
	if d == 0 then table.insert( input_rules[cid], rules.d) end

	local mesecons = {
		effector = {
			rules = input_rules[cid],
			action_change = function (pos, _, rule_name, new_state)
				update_real_port_states(pos, rule_name, new_state)
				run(pos, {type=new_state, pin=rule_name})
			end,
		},
		receptor = {
			state = mesecon.state.on,
			rules = output_rules[cid]
		},
		luacontroller = {
			get_program = get_program,
			set_program = set_program,
		},
	}

	minetest.register_node(node_name, {
		description = "Luacontroller",
		drawtype = "nodebox",
		tiles = {
			top,
			"jeija_microcontroller_bottom.png",
			"jeija_microcontroller_sides.png",
			"jeija_microcontroller_sides.png",
			"jeija_microcontroller_sides.png",
			"jeija_microcontroller_sides.png"
		},
		inventory_image = top,
		paramtype = "light",
		is_ground_content = false,
		groups = groups,
		drop = BASENAME.."0000",
		sunlight_propagates = true,
		selection_box = selection_box,
		node_box = node_box,
		on_construct = reset_meta,
		on_receive_fields = on_receive_fields,
		sounds = default.node_sound_stone_defaults(),
		mesecons = mesecons,
		digiline = digiline,
		-- Virtual portstates are the ports that
		-- the node shows as powered up (light up).
		virtual_portstates = {
			a = a == 1,
			b = b == 1,
			c = c == 1,
			d = d == 1,
		},
		after_dig_node = function (pos, node)
			mesecon.do_cooldown(pos)
			mesecon.receptor_off(pos, output_rules)
		end,
		is_luacontroller = true,
		on_timer = node_timer,
		on_blast = mesecon.on_blastnode,
	})
end
end
end
end

------------------------------
-- Overheated Luacontroller --
------------------------------

minetest.register_node(BASENAME .. "_burnt", {
	drawtype = "nodebox",
	tiles = {
		"jeija_luacontroller_burnt_top.png",
		"jeija_microcontroller_bottom.png",
		"jeija_microcontroller_sides.png",
		"jeija_microcontroller_sides.png",
		"jeija_microcontroller_sides.png",
		"jeija_microcontroller_sides.png"
	},
	inventory_image = "jeija_luacontroller_burnt_top.png",
	is_burnt = true,
	paramtype = "light",
	is_ground_content = false,
	groups = {dig_immediate=2, not_in_creative_inventory=1},
	drop = BASENAME.."0000",
	sunlight_propagates = true,
	selection_box = selection_box,
	node_box = node_box,
	on_construct = reset_meta,
	on_receive_fields = on_receive_fields,
	sounds = default.node_sound_stone_defaults(),
	virtual_portstates = {a = false, b = false, c = false, d = false},
	mesecons = {
		effector = {
			rules = mesecon.rules.flat,
			action_change = function(pos, _, rule_name, new_state)
				update_real_port_states(pos, rule_name, new_state)
			end,
		},
	},
	on_blast = mesecon.on_blastnode,
})

------------------------
-- Craft Registration --
------------------------

minetest.register_craft({
	output = BASENAME.."0000 2",
	recipe = {
		{'mesecons_materials:silicon', 'mesecons_materials:silicon', 'group:mesecon_conductor_craftable'},
		{'mesecons_materials:silicon', 'mesecons_materials:silicon', 'group:mesecon_conductor_craftable'},
		{'group:mesecon_conductor_craftable', 'group:mesecon_conductor_craftable', ''},
	}
})