local S = minetest.get_translator("mcl_compass")

mcl_compass = {}

local compass_frames = 32

local default_spawn_settings = minetest.settings:get("static_spawnpoint")

-- Timer for random compass spinning
local random_timer = 0
local random_timer_trigger = 0.5 -- random compass spinning tick in seconds. Increase if there are performance problems

local random_frame = math.random(0, compass_frames-1)

minetest.register_globalstep(function(dtime)
	random_timer = random_timer + dtime
	local players  = minetest.get_connected_players()

	if random_timer >= random_timer_trigger then
		random_frame = (random_frame + math.random(-1, 1)) % compass_frames
		random_timer = 0
	end
	for i,player in ipairs(players) do
		local function has_compass(player)
			for _,stack in ipairs(player:get_inventory():get_list("main")) do
				if minetest.get_item_group(stack:get_name(), "compass") ~= 0 then
					return true
				end
			end
			return false
		end
		if has_compass(player) then
			local pos = player:get_pos()
			local dim = mcl_worlds.pos_to_dimension(pos)
			local compass_image
			-- Compasses do not work in certain zones
			if not mcl_worlds.compass_works(pos) then
				compass_image = random_frame
			else
				local spawn = {x=0,y=0,z=0}
				local ssp = minetest.setting_get_pos("static_spawnpoint")
				if ssp then
					spawn = ssp
					if type(spawn) ~= "table" or type(spawn.x) ~= "number" or type(spawn.y) ~= "number" or type(spawn.z) ~= "number" then
						spawn = {x=0,y=0,z=0}
					end
				end
				local dir = player:get_look_horizontal()
				local angle_north = math.deg(math.atan2(spawn.x - pos.x, spawn.z - pos.z))
				if angle_north < 0 then angle_north = angle_north + 360 end
				local angle_dir = -math.deg(dir)
				local angle_relative = (angle_north - angle_dir + 180) % 360
				compass_image = math.floor((angle_relative/11.25) + 0.5) % compass_frames
			end

			for j,stack in ipairs(player:get_inventory():get_list("main")) do
				if minetest.get_item_group(stack:get_name(), "compass") ~= 0 and
						minetest.get_item_group(stack:get_name(), "compass")-1 ~= compass_image then
					local itemname = "mcl_compass:"..compass_image
					stack:set_name(itemname)
					player:get_inventory():set_stack("main", j, stack)
				end
			end
		end
	end
end)

local images = {}
for frame = 0, compass_frames-1 do
	local s = string.format("%02d", frame)
	table.insert(images, "mcl_compass_compass_"..s..".png")
end

local doc_mod = minetest.get_modpath("doc") ~= nil

local stereotype_frame = 18
for i,img in ipairs(images) do
	local inv = 1
	if i == stereotype_frame then
		inv = 0
	end
	local use_doc, longdesc, usagehelp, tt
	use_doc = i == stereotype_frame
	if use_doc then
		tt = S("Points to the world origin")
		longdesc = S("Compasses are tools which point to the world origin (X=0, Z=0) or the spawn point in the Overworld.")
	end
	local itemstring = "mcl_compass:"..(i-1)
	minetest.register_craftitem(itemstring, {
		description = S("Compass"),
		_tt_help = tt,
		_doc_items_create_entry = use_doc,
		_doc_items_longdesc = longdesc,
		_doc_items_usagehelp = usagehelp,
		inventory_image = img,
		wield_image = img,
		stack_max = 64,
		groups = {not_in_creative_inventory=inv, compass=i, tool=1, disable_repair=1 }
	})

	-- Help aliases. Makes sure the lookup tool works correctly
	if not use_doc and doc_mod then
		doc.add_entry_alias("craftitems", "mcl_compass:"..(stereotype_frame-1), "craftitems", itemstring)
	end
end

minetest.register_craft({
	output = 'mcl_compass:'..stereotype_frame,
	recipe = {
		{'', 'mcl_core:iron_ingot', ''},
		{'mcl_core:iron_ingot', 'mesecons:redstone', 'mcl_core:iron_ingot'},
		{'', 'mcl_core:iron_ingot', ''}
	}
})

minetest.register_alias("mcl_compass:compass", "mcl_compass:"..stereotype_frame)

-- Export stereotype item for other mods to use
mcl_compass.stereotype = "mcl_compass:"..tostring(stereotype_frame)