technic.compressor_recipes ={}

technic.register_compressor_recipe = function(src, src_count, dst, dst_count)
	technic.compressor_recipes[src] = {src_count = src_count, dst_name = dst, dst_count = dst_count}
	if unified_inventory then
		unified_inventory.register_craft(
		{
			type = "compressing",
			output = dst.." "..dst_count,
			items = {src.." "..src_count},
			width = 0,
		})
	end
end

technic.get_compressor_recipe = function(item)
	if technic.compressor_recipes[item.name] and 
	   item.count >= technic.compressor_recipes[item.name].src_count then
		return technic.compressor_recipes[item.name]
	else
		return nil
	end
end

technic.register_compressor_recipe("default:snowblock",		1,	"default:ice",		1)
technic.register_compressor_recipe("default:sand",		1,	"default:sandstone",	1)
technic.register_compressor_recipe("default:desert_sand",	1,	"default:desert_stone",	1)
technic.register_compressor_recipe("technic:mixed_metal_ingot",	1,	"technic:composite_plate",	1)
technic.register_compressor_recipe("default:copper_ingot",	5,	"technic:copper_plate",	1)
technic.register_compressor_recipe("technic:coal_dust",		4,	"technic:graphite",	1)
technic.register_compressor_recipe("technic:carbon_cloth",	1,	"technic:carbon_plate",	1)


minetest.register_alias("compressor", "technic:compressor")
minetest.register_craft({
	output = 'technic:compressor',
	recipe = {
		{'default:stone',	'default:stone',	'default:stone'},
		{'mesecons:piston',	'technic:motor',	'mesecons:piston'},
		{'default:stone',	'technic:lv_cable',	'default:stone'},
	}
})

minetest.register_craftitem("technic:compressor", {
	description = "Compressor",
	stack_max = 99,
})

local compressor_formspec =
	"invsize[8,9;]"..
	"label[0,0;Compressor]"..
	"list[current_name;src;3,1;1,1;]"..
	"list[current_name;dst;5,1;2,2;]"..
	"list[current_player;main;0,5;8,4;]"

minetest.register_node("technic:compressor", {
	description = "Compressor",
	tiles = {"technic_compressor_top.png", "technic_compressor_bottom.png", "technic_compressor_side.png",
	       "technic_compressor_side.png", "technic_compressor_back.png", "technic_compressor_front.png"},
	paramtype2 = "facedir",
	groups = {cracky=2},
	legacy_facedir_simple = true,
	sounds = default.node_sound_wood_defaults(),
	on_construct = function(pos)
		local meta = minetest.env:get_meta(pos)
		meta:set_string("infotext", "Compressor")
		meta:set_float("technic_power_machine", 1)
		meta:set_string("formspec", compressor_formspec)
		local inv = meta:get_inventory()
		inv:set_size("src", 1)
		inv:set_size("dst", 4)
	end,
	can_dig = function(pos,player)
		local meta = minetest.env:get_meta(pos);
		local inv = meta:get_inventory()
		if not inv:is_empty("src") or not inv:is_empty("dst") 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:compressor_active", {
	description = "Compressor",
	tiles = {"technic_compressor_top.png", "technic_compressor_bottom.png", "technic_compressor_side.png",
	       "technic_compressor_side.png", "technic_compressor_back.png", "technic_compressor_front_active.png"},
	paramtype2 = "facedir",
	groups = {cracky=2,not_in_creative_inventory=1},
	legacy_facedir_simple = true,
	sounds = default.node_sound_wood_defaults(),
	can_dig = function(pos,player)
		local meta = minetest.env:get_meta(pos);
		local inv = meta:get_inventory()
		if not inv:is_empty("src") or not inv:is_empty("dst") 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_abm({
	nodenames = {"technic:compressor","technic:compressor_active"},
	interval = 1,
	chance   = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		-- Run a machine through its states. Takes the same arguments as the ABM action
		-- and adds the machine's states and any extra data which is needed by the machine.
		-- A machine is characterized by running through a set number of states (usually 2:
		-- Idle and active) in some order. A state decides when to move to the next one
		-- and the machine only changes state if it is powered correctly.
		-- The machine will automatically shut down if disconnected from power in some fashion.
		local meta         = minetest.env:get_meta(pos)
		local eu_input     = meta:get_int("LV_EU_input")
		local state        = meta:get_int("state")
		local next_state   = state

		-- Machine information
		local machine_name         = "Compressor"
		local machine_node         = "technic:compressor"
		local machine_state_demand = { 50, 300 }
 
		 -- Setup meta data if it does not exist. state is used as an indicator of this
		if state == 0 then
			meta:set_int("state", 1)
			meta:set_int("LV_EU_demand", machine_state_demand[1])
			meta:set_int("LV_EU_input", 0)
			return
		end
 
		-- Power off automatically if no longer connected to a switching station
		technic.switching_station_timeout_count(pos, "LV")
 
		-- State machine
		if eu_input == 0 then
			-- unpowered - go idle
			hacky_swap_node(pos, machine_node)
			meta:set_string("infotext", machine_name.." Unpowered")
			next_state = 1
		elseif eu_input == machine_state_demand[state] then
			-- Powered - do the state specific actions
			    
			local inv    = meta:get_inventory()
			local empty  = inv:is_empty("src")
			local srcstack  = inv:get_stack("src", 1)
			local src_item = nil
			local recipe = nil
			local result = nil
 
			if srcstack then
				src_item = srcstack:to_table()
			end
			if src_item then
				recipe = technic.get_compressor_recipe(src_item)
			end
			if recipe then
				result = {name=recipe.dst_name, count=recipe.dst_count}
			end 

			if state == 1 then
				hacky_swap_node(pos, machine_node)
				meta:set_string("infotext", machine_name.." Idle")

				if not empty and result and inv:room_for_item("dst",result) then
					meta:set_int("src_time", 0)
					next_state = 2
				end
			elseif state == 2 then
				hacky_swap_node(pos, machine_node.."_active")
				meta:set_string("infotext", machine_name.." Active")

				if empty then
					next_state = 1
				else
					meta:set_int("src_time", meta:get_int("src_time") + 1)
					if meta:get_int("src_time") == 4 then 
						-- 4 ticks per output
						-- check if there's room for output in "dst" list

						meta:set_int("src_time", 0)
						if recipe and inv:room_for_item("dst",result) then
							-- take stuff from "src" list
							srcstack:take_item(recipe.src_count)
							inv:set_stack("src", 1, srcstack)
							-- Put result in "dst" list
							inv:add_item("dst", result)
						else
							-- all full: go idle
							next_state = 1
						end
					end
				end
			end
		end
		-- Change state?
		if next_state ~= state then
			meta:set_int("LV_EU_demand", machine_state_demand[next_state])
			meta:set_int("state", next_state)
		end
	end
})

technic.register_LV_machine ("technic:compressor","RE")
technic.register_LV_machine ("technic:compressor_active","RE")