--- a/src/lib/Bbcode.luan	Sun Jul 03 22:01:23 2022 -0600
+++ b/src/lib/Bbcode.luan	Sun Jul 03 23:59:41 2022 -0600
@@ -3,13 +3,19 @@
 local type = Luan.type or error()
 local ipairs = Luan.ipairs or error()
 local stringify = Luan.stringify or error()
+local Io = require "luan:Io.luan"
+local output_of = Io.output_of or error()
 local Parsers = require "luan:Parsers.luan"
 local bbcode_parse = Parsers.bbcode_parse or error()
 local Html = require "luan:Html.luan"
 local html_encode = Html.encode or error()
 local Table = require "luan:Table.luan"
 local is_list = Table.is_list or error()
+local String = require "luan:String.luan"
+local gsub = String.gsub or error()
 local User = require "site:/lib/User.luan"
+local Shared = require "site:/lib/Shared.luan"
+local list_to_set = Shared.list_to_set or error()
 local Logging = require "luan:logging/Logging.luan"
 local logger = Logging.logger "Bbcode"
 
@@ -111,4 +117,47 @@
 	%><div post><% to_html(bbcode) %></div><%
 end
 
+
+local doesnt_nest = list_to_set{
+	"url"
+	"code"
+	"img"
+	"video"
+}
+
+local function preprocess(bbcode)
+	if type(bbcode) == "string" then
+		bbcode = gsub( bbcode, [[(^|\s)(https?://\S+)]], "$1[url]$2[/url]" )
+		%><%= bbcode %><%
+	else
+		type(bbcode) == "table" or error()
+		if is_list(bbcode) then
+			for _, v in ipairs(bbcode) do
+				preprocess(v)
+			end
+		else
+			local name = bbcode.name
+			local param = bbcode.param
+			%>[<%=name%><%
+			if param ~= nil then
+				%>=<%=param%><%
+			end
+			%>]<%
+			if doesnt_nest[name] then
+				%><%=bbcode.contents%><%
+			else
+				preprocess(bbcode.contents)
+			end
+			%>[/<%=name%>]<%
+		end
+	end
+end
+
+function Bbcode.preprocess(bbcode)
+	bbcode = bbcode_parse(bbcode)
+	return output_of(function()
+		preprocess(bbcode)
+	end)
+end
+
 return Bbcode