local p = {}

--Returns the target of ((Category redirect)), if it exists, else returns the original cat.
function p.rtarget( cat )
	if (mw.ustring.match( cat, '[{}!|]') ~= nil ) then
		return cat	
	end
	local catcontent = mw.title.new( cat or '', 'Category' ):getContent()
	if string.match( catcontent or '', '(( *[Cc]at' ) then
		local getRegex = require('Module:Template redirect regex').main
		local tregex = getRegex('Category redirect')
		for _, v in pairs (tregex) do
			local rtarget = mw.ustring.match( catcontent, v..'%s*|%s*([^|{))]+)' )
			if rtarget then
				rtarget = mw.ustring.gsub(rtarget, '^1%s*=%s*', '')
				rtarget = string.gsub(rtarget, '^[Cc]ategory:', '')
				return rtarget
			end
		end
	end
	return cat
end

function p.main( frame )
	local args = frame:getParent().args
	local cat  = args[1]
	
	if (cat == '') or (cat == nil) then
		return ''
	end
	return p.rtarget( cat )
end

return p
Categories