pp = require("cc.pretty")

pFront = peripheral.wrap("front")
pDown = peripheral.wrap("bottom")

function findItems(item_list, target)
	for i, v in pairs(item_list) do
		if stripModname(v.name) == target then
			return i
		end
	end
	return nil
end

-- uses selected item
function insertForward(slot, count)
	turtle.dropDown(count)
	pFront.pullItems("bottom", 1, 64, slot)
end

function takeForward(slot)
	-- pDown.pullItems("front", slot, 64, 1)
	peripheral.call("bottom", "pullItems", "front", slot or 1)
	turtle.suckDown()
end

function insertDepot(count)
	turtle.dropDown(count)
	peripheral.call("front", "pullItem", "bottom")
end

function takeDepot()
	peripheral.call("front", "pushItem", "bottom")
	turtle.suckDown()
end


function takeItems(type, count)
	local item_list = pFront.list()
	local slot = findItems(item_list, type)

	if slot == nil then
		printError("could not find item " .. type .. " in chest")
		return false
	end

	empty_slot = pFront.size()
	-- todo error if not empty
	pFront.pullItems("front", 1, 64, empty_slot) -- empty first slot
	pFront.pullItems("front", slot, 64, 1) -- get target item to first slot
	pFront.pullItems("front", empty_slot, 64, slot) -- empty last slot for next time
	return turtle.suck(count)
end

function selectItem(name, has_nbt)
	has_nbt = has_nbt or false
	if name == nil or name == "nil" then
		for i = 1,16 do
			if turtle.getItemCount(i) == 0 then
				turtle.select(i)
				return
			end
		end
		printError("no empty slot found")
		return
	end
	for i = 1,16 do
		detail = turtle.getItemDetail(i, true);
		if detail and stripModname(detail.name) == name then
			if has_nbt == (detail.nbt ~= nil) then
				turtle.select(i)
				return
			end
		end
	end
	printError("missing item", name, "nbt=", has_nbt)
end

function getMissing(needed_items)
	missing = {}
	for name,count in pairs(needed_items) do
		missing[name] = count
	end
	target_contents = peripheral.call("front", "list")

	for _, target_item in pairs(target_contents) do
		for name, missing_count in pairs(missing) do
			if stripModname(target_item.name) == name then
				missing[name] = missing_count - target_item.count
				if missing[name] < 1 then
					missing[name] = nil
				end
				break
			end
		end
	end
	pp.pretty_print(missing)
	return missing
end