Tube capability for tool workshop

Tool workshop can now accept tools to repair via tube.  It has upgrade
slots.  Battery upgrade reduces its power consumption.  Tube upgrade
makes it eject fully-repaired (or unrepairable) items via tube.

technic/machines/MV/tool_workshop.lua

@@ -14,10 +14,15 @@ minetest.register_craft({
 	}
 })
 
+local workshop_demand = {5000, 3500, 2000}
+
 local workshop_formspec =
 	"invsize[8,9;]"..
 	"list[current_name;src;3,1;1,1;]"..
 	"label[0,0;"..S("%s Tool Workshop"):format("MV").."]"..
+	"list[current_name;upgrade1;1,3;1,1;]"..
+	"list[current_name;upgrade2;2,3;1,1;]"..
+	"label[1,4;"..S("Upgrade Slots").."]"..
 	"list[current_player;main;0,5;8,4;]"
 
 local run = function(pos, node)
@@ -26,15 +31,16 @@ local run = function(pos, node)
 	local eu_input     = meta:get_int("MV_EU_input")
 	local machine_name = S("%s Tool Workshop"):format("MV")
 	local machine_node = "technic:tool_workshop"
-	local demand       = 5000
 
 	-- Setup meta data if it does not exist.
 	if not eu_input then
-		meta:set_int("MV_EU_demand", demand)
+		meta:set_int("MV_EU_demand", workshop_demand[1])
 		meta:set_int("MV_EU_input", 0)
 		return
 	end
 
+	local EU_upgrade, tube_upgrade = technic.handle_machine_upgrades(meta)
+
 	local repairable = false
 	local srcstack = inv:get_stack("src", 1)
 	if not srcstack:is_empty() then
@@ -46,27 +52,32 @@ local run = function(pos, node)
 			repairable = true
 		end
 	end
+	technic.handle_machine_pipeworks(pos, tube_upgrade, function (pos, x_velocity, z_velocity)
+		if not repairable then
+			technic.send_items(pos, x_velocity, z_velocity, "src")
+		end
+	end)
 	if not repairable then
 		meta:set_string("infotext", S("%s Idle"):format(machine_name))
 		meta:set_int("MV_EU_demand", 0)
 		return
 	end
 	
-	if eu_input < demand then
+	if eu_input < workshop_demand[EU_upgrade+1] then
 		meta:set_string("infotext", S("%s Unpowered"):format(machine_name))
-	elseif eu_input >= demand then
+	elseif eu_input >= workshop_demand[EU_upgrade+1] then
 		meta:set_string("infotext", S("%s Active"):format(machine_name))
 		srcstack:add_wear(-1000)
 		inv:set_stack("src", 1, srcstack)
 	end
-	meta:set_int("MV_EU_demand", demand)
+	meta:set_int("MV_EU_demand", workshop_demand[EU_upgrade+1])
 end
 
 minetest.register_node("technic:tool_workshop", {
 	description = S("%s Tool Workshop"):format("MV"),
 	tiles = {"technic_workshop_top.png", "technic_machine_bottom.png", "technic_workshop_side.png",
 	         "technic_workshop_side.png", "technic_workshop_side.png", "technic_workshop_side.png"},
-	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2, technic_machine=1},
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2, technic_machine=1, tubedevice=1, tubedevice_receiver=1},
 	sounds = default.node_sound_wood_defaults(),
 	on_construct = function(pos)
 		local meta = minetest.get_meta(pos)
@@ -74,10 +85,21 @@ minetest.register_node("technic:tool_workshop", {
 		meta:set_string("formspec", workshop_formspec)
 		local inv = meta:get_inventory()
 		inv:set_size("src", 1)
+		inv:set_size("upgrade1", 1)
+		inv:set_size("upgrade2", 1)
 	end,	
 	can_dig = technic.machine_can_dig,
 	allow_metadata_inventory_put = technic.machine_inventory_put,
 	allow_metadata_inventory_take = technic.machine_inventory_take,
+	tube = {
+		can_insert = function (pos, node, stack, direction)
+			return minetest.get_meta(pos):get_inventory():room_for_item("src", stack)
+		end,
+		insert_object = function (pos, node, stack, direction)
+			return minetest.get_meta(pos):get_inventory():add_item("src", stack)
+		end,
+		connect_sides = {left = 1, right = 1, back = 1, top = 1, bottom = 1},
+	},
 	technic_run = run,
 })