local S = minetest.get_translator("lzr_level_select")
local F = minetest.formspec_escape

lzr_level_select = {}

local current_level_selection = nil
local current_custom_level_selection = nil
local custom_levels

local no_levels_form = function(player, message)
	return "formspec_version[4]size[8,3.5]"..
	"textarea[0.5,0.5;7,1.8;;;"..F(message).."]"..
	"button_exit[3,2.5;2,0.6;okay;"..F(S("OK")).."]"
end

lzr_level_select.open_dialog = function(player, level_set)
	local caption
	if level_set == "core" then
		caption = S("Select level:")
	elseif level_set == "custom" then
		caption = S("Select custom level:")
	else
		minetest.log("error", "[lzr_level_select] open_dialog called with unknown level_set!")
		return false
	end
	local form = "formspec_version[4]size[6,10]"..
		"label[0.5,0.4;"..F(caption).."]"..
		"button_exit[1.5,8.5;3,1;okay;"..F(S("Start")).."]"..
		"tablecolumns[color;text]"..
		"table[0.5,0.8;5,7.5;levellist;"
	local list = {}
	local entry_header = ""
	local first_uncompleted_level = nil
	if level_set == "core" then
		-- Built-in level set
		local completed_levels = lzr_levels.get_completed_levels()
		for l=1, lzr_levels.LAST_LEVEL do
			if completed_levels[l] then
				entry_header = "#00FF00"
			else
				if not first_uncompleted_level then
					first_uncompleted_level = l
				end
				entry_header  = ""
			end
			table.insert(list, entry_header..","..F(lzr_levels.get_level_name(l, nil, true)))
		end
		if not first_uncompleted_level then
			first_uncompleted_level = 1
		end
		current_level_selection = first_uncompleted_level
	else
		-- Custom level set (editor levels)
		local list_levels = lzr_editor.get_custom_levels()
		custom_levels = {}
		for l=1, #list_levels do
			local levelname = list_levels[l]
			-- Hide the autosave level because it's not meant
			-- for playing
			if levelname ~= lzr_globals.AUTOSAVE_NAME then
				table.insert(custom_levels, levelname)

				local proper_name = lzr_editor.get_custom_level_name(levelname, true)
				table.insert(list, entry_header..","..F(proper_name))
			end
		end
		first_uncompleted_level = 1
		current_custom_level_selection = 1
	end
	if not first_uncompleted_level then
		first_uncompleted_level = 1
	end
	local list_str = table.concat(list, ",")
	form = form .. list_str .. ";"..first_uncompleted_level.."]"
	local formname
	if level_set == "core" then
		if #list == 0 then
			form = no_levels_form(player, S("There are no levels."))
		end
		formname = "lzr_level_select:levellist"
	else
		if #list == 0 then
			form = no_levels_form(player,
				S("There are no custom levels.").."\n"..
				S("Install levels from your friends or use the level editor to build your own."))
		end
		formname = "lzr_level_select:levellist_custom"
	end
	minetest.show_formspec(player:get_player_name(), formname, form)
end

local load_custom_level = function(level, player)
	minetest.log("action", "[lzr_level_select] Player selects custom level: "..level)
	local csv = minetest.get_worldpath().."/levels/"..level..".csv"
	local levels_path = minetest.get_worldpath().."/levels"

	local custom_level_data = lzr_levels.analyze_levels(csv, levels_path)
	if custom_level_data then
		-- Load level with metadata (preferred)
		lzr_levels.start_level(1, custom_level_data)
	else
		-- Fallback when CSV file could not be read
		custom_level_data = lzr_levels.create_fallback_level_data(level, levels_path)
		lzr_levels.start_level(1, custom_level_data)
		minetest.log("action", "[lzr_level_select] No CSV file found for custom level: "..tostring(level)..". Using fallback")
	end
end

minetest.register_on_player_receive_fields(function(player, formname, fields)
	if formname == "lzr_level_select:levellist" then
		if fields.okay then
			if current_level_selection then
				lzr_levels.start_level(current_level_selection)
			end
		elseif fields.levellist then
			local expl = minetest.explode_table_event(fields.levellist)
			if expl.type == "CHG" then
				current_level_selection = expl.row
			elseif expl.type == "DCL" then
				current_level_selection = expl.row
				lzr_levels.start_level(current_level_selection)
				minetest.close_formspec(player:get_player_name(), "lzr_level_select:levellist")
			elseif expl.type == "INV" then
				current_level_selection = nil
			end
		end
	elseif formname == "lzr_level_select:levellist_custom" then
		if fields.okay then
			if custom_levels and current_custom_level_selection then
				local level = custom_levels[current_custom_level_selection]
				if level then
					load_custom_level(level, player)
				end
			end
		elseif fields.levellist then
			local expl = minetest.explode_table_event(fields.levellist)
			if expl.type == "CHG" then
				current_custom_level_selection = expl.row
			elseif expl.type == "DCL" then
				current_custom_level_selection = expl.row
				if custom_levels then
					local level = custom_levels[current_custom_level_selection]
					if level then
						load_custom_level(level, player)
					end
				end
				minetest.close_formspec(player:get_player_name(), "lzr_level_select:levellist_custom")
			elseif expl.type == "INV" then
				current_custom_level_selection = nil
			end
		end
	end
end)

minetest.register_chatcommand("level", {
	privs = { server = true },
	description = S("Go to level"),
	params = S("<level>"),
	func = function(name, param)
		local level = tonumber(param)
		if not level then
			return false
		end
		if level < 1 or level > lzr_levels.LAST_LEVEL then
			return false, S("Invalid level!")
		end
		lzr_levels.start_level(level)
		return true
	end,

})