local function hasItemsInStorage(storage)
	for _, _ in pairs(storage.list()) do
		return true
	end

	return false
end

local function hasItemsInTurtle()
	for ii = 1, 16 do
		if turtle.getItemCount(ii) > 0 then
			return true
		end
	end

	return false
end

local function fillTurtle()
	local success = true
	turtle.select(1)
	while success do
		success = turtle.suck()
	end
end

local function emptyTurtle()
	for ii = 1, 16 do
		turtle.select(ii)
		turtle.drop()
	end
end

local function getSpecialCategoryIndex(state, item_name)
	for idx, categ in pairs(state.categories) do
		for _, pattern in pairs(categ) do
			if string.match(item_name, pattern) then
				return idx
			end
		end
	end

	return 0
end

local function hasIdenticalItemsInStorage(state, storage, slot)
	local item = turtle.getItemDetail(slot)
	if item == nil then
		return false
	end

	local itemSpecialCat = getSpecialCategoryIndex(state, item.name)
	local chestSpecialCat = 0

	for _, other in pairs(storage.list()) do
		if other.name == item.name then
			return true
		end

		if itemSpecialCat > 0 and chestSpecialCat == 0 then
			chestSpecialCat = getSpecialCategoryIndex(state, other.name)

			if itemSpecialCat == chestSpecialCat then
				return true
			end
		end
	end

	return false
end

local function storeIdenticalItemsInStorage(state)
	local storage = peripheral.wrap("front")
	for ii = 1, 16 do
		if hasIdenticalItemsInStorage(state, storage, ii) then
			turtle.select(ii)
			turtle.drop()
		end
	end
end

local function getEmptySlotInStorage(storage)
	return 5 -- TODO
end

local function swapSlotsInStorage(storage, slotA, slotB)
	local emptySlot = getEmptySlotInStorage(storage)
	storage.pushItems(peripheral.getName(storage), slotA, nil, emptySlot)
	storage.pushItems(peripheral.getName(storage), slotB, nil, slotA)
	storage.pushItems(peripheral.getName(storage), emptySlot, nil, slotB)
end


return { getSpecialCategoryIndex = getSpecialCategoryIndex, hasItemsInStorage = hasItemsInStorage, hasItemsInTurtle = hasItemsInTurtle, fillTurtle = fillTurtle, emptyTurtle = emptyTurtle, hadIdenticalItemsInStorage = hasIdenticalItemsInStorage, storeIdenticalItemsInStorage = storeIdenticalItemsInStorage, swapSlotsInStorage = swapSlotsInStorage }