--[[

	TechAge
	=======

	Copyright (C) 2020 Joachim Stolberg

	AGPL v3
	See LICENSE.txt for more information

	Configured inventory lib
	Assuming the inventory has the name "conf"
	Otherwise the name has to be provided as argument

]]--

local StackName = ... or "conf"

-- for lazy programmers
local M = minetest.get_meta

local inv_lib = {}

function inv_lib.preassigned_stacks(pos, xsize, ysize)
	local inv = M(pos):get_inventory()
	local tbl = {}
	for idx = 1, xsize * ysize do
		local item_name = inv:get_stack(StackName, idx):get_name()
		if item_name ~= "" then
			local x = (idx - 1) % xsize
			local y = math.floor((idx - 1) / xsize)
			tbl[#tbl+1] = "item_image["..x..","..y..";1,1;"..item_name.."]"
		end
	end
	return table.concat(tbl, "")
end

function inv_lib.item_filter(pos, size)
	local inv = M(pos):get_inventory()
	local filter = {}
	for idx = 1, size do
		local item_name = inv:get_stack(StackName, idx):get_name()
		if item_name == "" then item_name = "unconfigured" end
		if not filter[item_name] then
			filter[item_name] = {}
		end
		table.insert(filter[item_name], idx)
	end
	return filter
end

function inv_lib.allow_conf_inv_put(pos, listname, index, stack, player)
	local inv = M(pos):get_inventory()
	local list = inv:get_list(listname)

	if list[index]:get_count() == 0 then
		stack:set_count(1)
		inv:set_stack(listname, index, stack)
		return 0
	end
	return 0
end

function inv_lib.allow_conf_inv_take(pos, listname, index, stack, player)
	local inv = M(pos):get_inventory()
	inv:set_stack(listname, index, nil)
	return 0
end

function inv_lib.allow_conf_inv_move(pos, from_list, from_index, to_list, to_index, count, player)
	local inv = minetest.get_meta(pos):get_inventory()
	local stack = inv:get_stack(to_list, to_index)

	if stack:get_count() == 0 then
		return 1
	else
		return 0
	end
end

function inv_lib.put_items(pos, inv, listname, item, stacks, idx)
	local name = item:get_name()
	local count = item:get_count()
	for _, i in ipairs(stacks or {}) do
		if not idx or idx == i then
			local stack = inv:get_stack(listname, i)
			local leftover = stack:add_item({name = name, count = count})
			count = leftover:get_count()
			inv:set_stack(listname, i, stack)
			if count == 0 then
				return true
			end
		end
	end
	if count > 0 then
		return ItemStack({name = name, count = count})
	end
	return false
end

function inv_lib.take_item(pos, inv, listname, num, stacks)
	local mem = techage.get_mem(pos)
	mem.ta_startpos = mem.ta_startpos or 1
	local size = #(stacks or {})
	for i = 1, size do
		local idx = stacks[((i + mem.ta_startpos) % size) + 1]
		local stack = inv:get_stack(listname, idx)
		local taken = stack:take_item(num)
		if taken:get_count() > 0 then
			inv:set_stack(listname, idx, stack)
			mem.ta_startpos = mem.ta_startpos + i
			return taken
		end
	end
end


return inv_lib