-- Based on 4itemnames mod by 4aiman

-- Function to determine if show item name functionality is already implemented
local function show_already_implemented()
	return minetest.get_modpath("unified_inventory") and true or false
end

local wield = {}
local wieldindex = {}
local huds = {}
local dtimes = {}
local dlimit = 3  -- HUD element will be hidden after this many seconds

local hudbars_mod = minetest.get_modpath("hudbars")
local unified_inventory_mod = minetest.get_modpath("unified_inventory")
local stamina_mod = minetest.get_modpath("stamina")

-- Legacy support: Name of the HUD type field for 'hud_add'.
local hud_type_field_name
if minetest.features.hud_def_type_field then
	-- engine version 5.9.0 and later
	hud_type_field_name = "type"
else
	-- All engine versions before 5.9.0
	hud_type_field_name = "hud_elem_type"
end

-- Disable mod if Unified Inventory item names feature is enabled
if unified_inventory_mod and minetest.settings:get_bool("unified_inventory_item_names") ~= false then
	minetest.log("action", "[show_wielded_item] Unified Inventory's item names feature was detected! Running show_wielded_item is pointless now, so it won't do anything")
	return
end

local function set_hud(player)
	if not player:is_player() then return end
	local player_name = player:get_player_name() 
	-- Fixed offset in config file
	local fixed = tonumber(minetest.settings:get("show_wielded_item_y_offset"))
	local off
	if fixed and fixed ~= -1 then
		-- Manual offset
		off = {x=0, y=-fixed}
	else
		-- Default offset
		off = {x=0, y=-101}

		if hudbars_mod then
			-- Tweak offset if hudbars mod was found

			local rows = math.floor((#hb.get_hudbar_identifiers()-1) / 2) + 1
			local vmargin = tonumber(minetest.settings:get("hudbars_vmargin")) or 24
			off.y = -76 - vmargin*rows
		elseif stamina_mod then
			-- Tweak offset if stamina mod was found
			off.y = off.y - 22
		end

		-- Dirty trick to avoid collision with Luanti's status text (e.g. “Volume changed to 0%”)
		if off.y >= -167 and off.y <= -156 then
			off.y = -181
		end
	end

	huds[player_name] = player:hud_add({
		[hud_type_field_name] = "text",
		position = {x=0.5, y=1},
		offset = off,
		alignment = {x=0, y=0},
		number = 0xFFFFFF ,
		text = "",
		z_index = 100,
		style = 1,
	})
end

minetest.register_on_joinplayer(function(player)
	set_hud(player)

	local name = player:get_player_name()
	wield[name] = player:get_wielded_item():get_name()
	wieldindex[name] = player:get_wield_index()
end)

minetest.register_on_leaveplayer(function(player)
	local name = player:get_player_name()
	wield[name] = nil
	wieldindex[name] = nil
end)

local function get_first_line(text)
	-- Cut off text after first newline
	local firstnewline = string.find(text, "\n")
	if firstnewline then
		text = string.sub(text, 1, firstnewline-1)
	end
	return text
end

if not show_already_implemented() then
	minetest.register_globalstep(function(dtime)
		for _, player in pairs(minetest.get_connected_players()) do
			local player_name = player:get_player_name()
			local wstack = player:get_wielded_item()
			local wname = wstack:get_name()
			local windex = player:get_wield_index()

			if dtimes[player_name] and dtimes[player_name] < dlimit then
				dtimes[player_name] = dtimes[player_name] + dtime
				if dtimes[player_name] > dlimit and huds[player_name] then
					player:hud_change(huds[player_name], 'text', "")
				end
			end

			-- Update HUD when wielded item or wielded index changed
			if wname ~= wield[player_name] or windex ~= wieldindex[player_name] then
				wieldindex[player_name] = windex
				wield[player_name] = wname
				dtimes[player_name] = 0

				if huds[player_name] then 

					-- Get description (various fallback checks for old Luanti/Minetest versions)
					local def = minetest.registered_items[wname]
					local desc
					if wstack.get_short_description then
						-- get_short_description()
						desc = wstack:get_short_description()
					end
					if (not desc or desc == "") and wstack.get_description then
						-- get_description()
						desc = wstack:get_description()
						desc = get_first_line(desc)
					end
					if (not desc or desc == "") and not wstack.get_description then
						-- Metadata (old versions only)
						local meta = wstack:get_meta()
						desc = meta:get_string("description")
						desc = get_first_line(desc)
					end
					if not desc or desc == "" then
						-- Item definition
						desc = def.description
						desc = get_first_line(desc)
					end
					if not desc or desc == "" then
						-- Final fallback: itemstring
						desc = wname
					end

					-- Print description
					if desc then
						-- Optionally append the 'technical' itemname
						local tech = minetest.settings:get_bool("show_wielded_item_itemname", false)
						if tech and desc ~= "" then
							desc = desc .. " ["..wname.."]"
						end
						player:hud_change(huds[player_name], 'text', desc)
					end
				end
			end
		end
	end)
end