-- LUALOCALS < ---------------------------------------------------------
local minetest, pairs, string, table, type
    = minetest, pairs, string, table, type
local string_gmatch, string_match, string_sub, table_concat
    = string.gmatch, string.match, string.sub, table.concat
-- LUALOCALS > ---------------------------------------------------------

local modname = minetest.get_current_modname()

local keepinteract = minetest.settings:get_bool(modname .. "_keep_interact")
local keepshout = minetest.settings:get_bool(modname .. "_keep_shout")

local function hasprivs(player, ...)
	if type(player) == "string" then
		player = minetest.get_player_by_name(player)
	end
	if not (player and player.is_player and player:is_player()) then return end
	return minetest.check_player_privs(player, ...)
end
local function isstealth(player) return hasprivs(player, "stealth") end

local saved = {}
local function nonzero(t)
	for _, v in pairs(t) do if v ~= 0 then return true end end
end
local function updatevisible(player)
	local props = player:get_properties()
	if not props then return end
	local pname = player:get_player_name()
	local atts = player:get_nametag_attributes()

	local isvis = nonzero(props.visual_size)
	or props.pointable
	or atts.color.a > 0
	or props.makes_footstep_sound

	if isvis and not saved[pname] then
		saved[pname] = {p = props, a = atts}
	end
	local needvis = not isstealth(player)
	if isvis == needvis then return end

	player:set_properties({
			visual_size = needvis and saved[pname].p.visual_size or {x = 0, y = 0},
			pointable = needvis and saved[pname].p.pointable or false,
			makes_footstep_sound = needvis and saved[pname].p.makes_footstep_sound or false
		})
	player:set_nametag_attributes({
			color = needvis and saved[pname].a.color or {r = 0, g = 0, b = 0, a = 0}
		})
	minetest.after(0, function() return updatevisible(player) end)
end

local function grantrevoke(pname)
	return minetest.after(0, function()
			local player = minetest.get_player_by_name(pname)
			if player then return updatevisible(player) end
		end)
end

minetest.register_privilege("stealth", {
		description = "Invisibility",
		give_to_singleplayer = false,
		give_to_admin = false,
		on_grant = grantrevoke,
		on_revoke = grantrevoke
	})

local function auto_remove_priv(player, priv)
	if hasprivs(player, {stealth = true, [priv] = true, privs = true}) then
		local cc = minetest.registered_chatcommands.revoke
		if cc and cc.func then
			local pname = player:get_player_name()
			minetest.after(0, function()
					cc.func(pname, pname .. " " .. priv)
				end)
		end
	end
end

minetest.register_on_joinplayer(function(player)
		if not keepinteract then auto_remove_priv(player, "interact") end
		if not keepshout then auto_remove_priv(player, "shout") end
		return updatevisible(player)
	end)

local timer = 0
minetest.register_globalstep(function(dtime)
		timer = timer - dtime
		if timer <= 0 then
			for _, player in pairs(minetest.get_connected_players()) do
				if isstealth(player) then updatevisible(player) end
			end
			timer = 1
		end
	end)

minetest.after(0, function()
		local oldjoin = minetest.send_join_message
		function minetest.send_join_message(pname, ...)
			if not minetest.check_player_privs(pname, "stealth") then
				return oldjoin(pname, ...)
			end
		end
		local oldleave = minetest.send_leave_message
		function minetest.send_leave_message(pname, ...)
			if not minetest.check_player_privs(pname, "stealth") then
				return oldleave(pname, ...)
			end
		end
	end)

local function stripfirstline(msg)
	local pref, clients, suff = string_match(msg, "^(.*clients[^%w_]+)([^}]*)(.*)$")
	if not clients then return msg end
	local clist = {}
	for pname in string_gmatch(clients, "%S+") do
		if string_sub(pname, -1) == "," then
			pname = string_sub(pname, 1, #pname - 1)
		end
		if not isstealth(pname) then
			clist[#clist + 1] = pname
		end
	end
	msg = pref .. table_concat(clist, ", ") .. suff
	return msg
end
local function stripstatus(rawmsg, ...)
	local lines = rawmsg:split("\n")
	lines[1] = stripfirstline(lines[1])
	return table_concat(lines, "\n"), ...
end
local oldstatus = minetest.get_server_status
function minetest.get_server_status(...)
	return stripstatus(oldstatus(...))
end