-- LUALOCALS < ---------------------------------------------------------
local ipairs, minetest
    = ipairs, minetest
-- LUALOCALS > ---------------------------------------------------------

local modname = minetest.get_current_modname()
local lib = _G[modname]

minetest.register_privilege("watch", "Player can watch other players")

local huds = {}
local function handlehud(player)
	local data = lib.dataget(player) or {}
	local text = ""
	if data.target then text = "Watching: " .. data.target end
	if data.watchall then text = text .. "\n(Hotkey Cycling)" end
	local pname = player:get_player_name()
	local tip = huds[pname]
	if tip then
		if text ~= tip.text then
			player:hud_change(tip.id, "text", text)
			tip.text = text
		end
		return
	end
	if text == "" then return end
	huds[pname] = {
		id = player:hud_add({
				hud_elem_type = "text",
				position = {x = 0.5, y = 0.25},
				text = text,
				number = 0xFFFFFF,
				alignment = {x = 0, y = 0},
				offset = {x = 0, y = 0},
			}),
		text = text
	}
end

local function everyone(func)
	for _, p in ipairs(minetest.get_connected_players()) do
		func(p)
	end
end

local function handlewatchall(p)
	if not (lib.dataget(p) or {}).watchall then return end
	local pn = p:get_player_name()
	local n = p:get_wield_index()
	everyone(function(q)
			local qn = q:get_player_name()
			if qn ~= pn then
				n = n - 1
				if n == 0 then
					lib.start(p, q)
				else
					lib.stop(p, q)
				end
			end
		end)
end

minetest.register_globalstep(function(dt)
		everyone(function(p)
				handlewatchall(p)
				lib.restore(dt, p)
				if p:get_armor_groups().immortal then
					p:set_breath(11)
				end
				return handlehud(p)
			end)
	end)

minetest.register_on_joinplayer(function(player)
		return lib.stop(player)
	end)

minetest.register_on_leaveplayer(function(player)
		lib.stop(player)
		everyone(function(p) lib.stop(p, player) end)
		huds[player:get_player_name()] = nil
	end)

minetest.register_chatcommand("watch", {
		params = "<to_name>",
		description = "watch a given player",
		privs = {watch = true},
		func = lib.start
	})

minetest.register_chatcommand("unwatch", {
		description = "unwatch a player",
		privs = {watch = true},
		func = function(p, ...)
			local player = minetest.get_player_by_name(p)
			if player then
				local data = lib.dataget(player) or {}
				data.watchall = nil
				lib.dataset(player, data)
			end
			return lib.stop(p, ...)
		end
	})

minetest.register_chatcommand("watchall", {
		description = "cycle watching all players",
		privs = {watch = true},
		func = function(name)
			local player = minetest.get_player_by_name(name)
			if not player then return end
			local data = lib.dataget(player) or {}
			data.watchall = true
			lib.dataset(player, data)
		end
	})