technic/technic/machines/hv/nuclear_reactor.lua

-- The enriched uranium rod driven EU generator.
-- A very large and advanced machine providing vast amounts of power.
-- Very efficient but also expensive to run as it needs uranium. (10000EU 86400 ticks (24h))
-- Provides HV EUs that can be down converted as needed.
--
-- The nuclear reactor core needs water and a protective shield to work.
-- This is checked now and then and if the machine is tampered with... BOOM!

local burn_ticks   = 24*60                      -- [minutes]. How many minutes does the power plant burn per serving?
local power_supply = 10000                      -- [HV] EUs
local fuel_type    = "technic:enriched_uranium" -- The reactor burns this stuff


-- FIXME: recipe must make more sense like a rod recepticle, steam chamber, HV generator?
minetest.register_craft({
	output = 'technic:hv_nuclear_reactor_core',
	recipe = {
		{'technic:stainless_steel_ingot', 'technic:stainless_steel_ingot', 'technic:stainless_steel_ingot'},
		{'technic:stainless_steel_ingot',                              '', 'technic:stainless_steel_ingot'},
		{'technic:stainless_steel_ingot',              'technic:hv_cable', 'technic:stainless_steel_ingot'},
	}
})

minetest.register_craftitem("technic:hv_nuclear_reactor_core",{
	description = "Uranium Rod Driven HV Reactor",
	stack_max = 1,
}) 

local generator_formspec =
	"invsize[8,9;]"..
	--"image[0,0;5,5;technic_generator_menu.png]"..
	"label[0,0;Nuclear Reactor Rod Compartment]"..
	"list[current_name;src;2,1;3,2;]"..
	"list[current_player;main;0,5;8,4;]"

-- "Boxy sphere"
local nodebox = {
	{ -0.353, -0.353, -0.353, 0.353, 0.353, 0.353 }, -- Box
	{ -0.495, -0.064, -0.064, 0.495, 0.064, 0.064 }, -- Circle +-x
	{ -0.483, -0.128, -0.128, 0.483, 0.128, 0.128 },
	{ -0.462, -0.191, -0.191, 0.462, 0.191, 0.191 },
	{ -0.433, -0.249, -0.249, 0.433, 0.249, 0.249 },
	{ -0.397, -0.303, -0.303, 0.397, 0.303, 0.303 },
	{ -0.305, -0.396, -0.305, 0.305, 0.396, 0.305 }, -- Circle +-y
	{ -0.250, -0.432, -0.250, 0.250, 0.432, 0.250 },
	{ -0.191, -0.461, -0.191, 0.191, 0.461, 0.191 },
	{ -0.130, -0.482, -0.130, 0.130, 0.482, 0.130 },
	{ -0.066, -0.495, -0.066, 0.066, 0.495, 0.066 },
	{ -0.064, -0.064, -0.495, 0.064, 0.064, 0.495 }, -- Circle +-z
	{ -0.128, -0.128, -0.483, 0.128, 0.128, 0.483 },
	{ -0.191, -0.191, -0.462, 0.191, 0.191, 0.462 },
	{ -0.249, -0.249, -0.433, 0.249, 0.249, 0.433 },
	{ -0.303, -0.303, -0.397, 0.303, 0.303, 0.397 },
}

minetest.register_node("technic:hv_nuclear_reactor_core", {
	description = "Nuclear Reactor",
	tiles = {"technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png",
	         "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png",
	         "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png"},
	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2},
	legacy_facedir_simple = true,
	sounds = default.node_sound_wood_defaults(),
	drawtype="nodebox",
	paramtype = "light",
	node_box = {
		type = "fixed",
		fixed = nodebox
	},
	on_construct = function(pos)
		local meta = minetest.env:get_meta(pos)
		meta:set_string("infotext", "Nuclear Reactor Core")
		meta:set_float("technic_hv_power_machine", 1)
		meta:set_int("HV_EU_supply", 0)
		meta:set_int("HV_EU_from_fuel", 1) -- Signal to the switching station that this device burns some sort of fuel and needs special handling
		meta:set_int("burn_time", 0)
		meta:set_string("formspec", generator_formspec)
		local inv = meta:get_inventory()
		inv:set_size("src", 6)
	end,	
	can_dig = function(pos,player)
		local meta = minetest.env:get_meta(pos);
		local inv = meta:get_inventory()
		if not inv:is_empty("src") then
			minetest.chat_send_player(player:get_player_name(), "Machine cannot be removed because it is not empty");
			return false
		else
			return true
		end
	end,
})

minetest.register_node("technic:hv_nuclear_reactor_core_active", {
	description = "Uranium Rod Driven HV Reactor",
	tiles = {"technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png",
	         "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png",
		 "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png"},
	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2, not_in_creative_inventory=1},
	legacy_facedir_simple = true,
	sounds = default.node_sound_wood_defaults(),
	drop="technic:hv_nuclear_reactor_core",
	drawtype="nodebox",
	light_source = 15,
	paramtype = "light",
	node_box = {
		type = "fixed",
		fixed = nodebox
	},
	can_dig = function(pos,player)
		local meta = minetest.env:get_meta(pos);
		local inv = meta:get_inventory()
		if not inv:is_empty("src") then
			minetest.chat_send_player(player:get_player_name(), "Machine cannot be removed because it is not empty");
			return false
		else
			return true
		end
	end,
})

local check_reactor_structure = function(pos)
	-- The reactor consists of an 11x11x11 cube structure
	-- A cross section through the middle:
	--  CCCCC CCCCC
	--  CCCCC CCCCC
	--  CCSSS SSSCC
	--  CCSCC CCSCC
	--  CCSCWWWCSCC
	--  CCSCW#WCSCC
	--  CCSCW|WCSCC
	--  CCSCC|CCSCC
	--  CCSSS|SSSCC
	--  CCCCC|CCCCC
	--  C = Concrete, S = Stainless Steel, W = water node (not floating), #=reactor core, |=HV cable
	--  The man-hole and the HV cable is only in the middle
	--  The man-hole is optional

	local source_water_nodes = minetest.find_nodes_in_area(
		{x=pos.x-1, y=pos.y-1, z=pos.z-1},
		{x=pos.x+1, y=pos.y+1, z=pos.z+1},
		"default:water_source")
	local flowing_water_nodes = minetest.find_nodes_in_area(
		{x=pos.x-1, y=pos.y-1, z=pos.z-1},
		{x=pos.x+1, y=pos.y+1, z=pos.z+1},
		"default:water_flowing")
	if not ((#source_water_nodes + #flowing_water_nodes) >= 25) then
		return false
	end

	local inner_shield_nodes = minetest.find_nodes_in_area(
		{x=pos.x-2, y=pos.y-2, z=pos.z-2},
		{x=pos.x+2, y=pos.y+2, z=pos.z+2},
		"technic:concrete")
	if not (#inner_shield_nodes >= 96) then
		return false
	end

	local steel_shield_nodes = minetest.find_nodes_in_area(
		{x=pos.x-3, y=pos.y-3, z=pos.z-3},
		{x=pos.x+3, y=pos.y+3, z=pos.z+3},
		"default:steelblock")
	if not (#steel_shield_nodes >= 216) then
		return false
	end

	local outer_shield_nodes = minetest.find_nodes_in_area(
		{x=pos.x-5, y=pos.y-5, z=pos.z-5},
		{x=pos.x+5, y=pos.y+5, z=pos.z+5},
		"technic:concrete")
	if not (#outer_shield_nodes >= (984 + #inner_shield_nodes)) then
		return false
	end
	return true
end

local explode_reactor = function(pos)
	print("BOOM A reactor exploded!")
end

minetest.register_abm({
	nodenames = {"technic:hv_nuclear_reactor_core", "technic:hv_nuclear_reactor_core_active"},
	interval = 1,
	chance   = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		local meta = minetest.env:get_meta(pos)
		local burn_time = meta:get_int("burn_time")

		-- If more to burn and the energy produced was used: produce some more
		if burn_time > 0 then
			if not check_reactor_structure(pos) then
				explode_reactor(pos)
			end
			if meta:get_int("HV_EU_supply") == 0 then
				-- We did not use the power
				meta:set_int("HV_EU_supply", power_supply)
			else
				burn_time = burn_time - 1
				meta:set_int("burn_time", burn_time)
				local percent = math.floor(burn_time / (burn_ticks * 60) * 100)
				meta:set_string("infotext", "Nuclear Reactor Core ("..percent.."%)")
			end
		end

		-- Burn another piece of coal
		if burn_time <= 0 then
			local inv = meta:get_inventory()
			local correct_fuel_count = 0
			if not inv:is_empty("src") then 
				local srclist = inv:get_list("src")
				for _, srcstack in pairs(srclist) do
					if srcstack then
						local src_item=srcstack:to_table()
						if src_item and src_item["name"] == fuel_type then
							correct_fuel_count = correct_fuel_count + 1
						end
					end
				end
				-- Check that the reactor is complete as well as the correct number of correct fuel
				if correct_fuel_count == 6 then
					if not check_reactor_structure(pos) then
						burn_time = burn_ticks * 60
						meta:set_int("burn_time", burn_time)
						hacky_swap_node (pos,"technic:hv_nuclear_reactor_core_active") 
						meta:set_int("HV_EU_supply", power_supply)
						for idx, srcstack in pairs(srclist) do
							srcstack:take_item()
							inv:set_stack("src", idx, srcstack)
						end
					end
				else
					meta:set_int("HV_EU_supply", 0)
				end
			end
		end

		-- Nothing left to burn
		if burn_time == 0 then
			meta:set_string("infotext", "Nuclear Reactor Core (idle)")
			hacky_swap_node(pos,"technic:hv_nuclear_reactor_core")
		end
	end
})

technic.register_HV_machine ("technic:hv_nuclear_reactor_core","PR")
technic.register_HV_machine ("technic:hv_nuclear_reactor_core_active","PR")