Make the quarry consume struts

sparkmachine/lua/quarry.lua

@@ -36,6 +36,23 @@ local function try_drain_energy(target_pos, amount) ---
 	end
 end
 
+local function try_remove_item(target_pos, listname, itemname, amount)
+	local inv = minetest.get_inventory({type="node", pos=target_pos})
+	local stack = ItemStack(itemname)
+	local amount = amount or 1
+	stack:set_count(amount)
+
+	local result = inv:remove_item(listname, stack)
+
+	if result:get_count() ~= amount then
+		inv:add_item(listname, result)
+	else
+		return true
+	end
+	
+	return false
+end
+
 local function on_construct(pos, player)
 	player:get_meta():set_string(NAME .. ":quarry_pos" , minetest.pos_to_string(pos))
 
@@ -133,13 +150,19 @@ end
 
 local function place_strut(position, quarrypos)
 	if minetest.get_node(position).name == "air" then
-		if try_drain_energy(quarrypos, ENERGYCOST.static_strut) then
+		minetest.debug("PLACE")
-			minetest.set_node(position, { name = NAME .. ":static_strut"})
+		if try_remove_item(quarrypos, "quarry", NAME .. ":static_strut") then
+			minetest.debug("ENERGY")
+			if try_drain_energy(quarrypos, ENERGYCOST.static_strut) then
+				minetest.debug("CONFIRM")
+				minetest.set_node(position, { name = NAME .. ":static_strut"})
+			else
+				-- Restore items
+			end
 		end
 		return true
-	else
-		return false
 	end
+	return false
 end