local p = {}



function cleanupArgs(argsTable)

	local cleanArgs = {}

	for key, val in pairs(argsTable) do

		if type(val) == 'string' then

			val = val:match('^%s*(.-)%s*$')

			if val ~= '' then

				cleanArgskey = val

			end

		else

			cleanArgskey = val

		end

	end

	return cleanArgs

end



local content = {}



function makeTemplatePattern(template)

	local first = string.sub(template, 1, 1)

	local rest = string.sub(template, 2)

	local pattern = mw.ustring.format('%s[%s%s]%s%s', '%{%{%s*', mw.ustring.upper(first), mw.ustring.lower(first), rest, '%s*|?[^%}]*%}%}')

	return pattern

end



function makeParameterPattern(parameter)

	return mw.ustring.format('%s%s%s%s', '|%s*', parameter, '%s*=%s*', '([^|%}]*)', '%s*[|%}]')

end



function getMatchingTemplateWikitext(content, template, leadOnly)

	if leadOnly then

		content = mw.ustring.gsub(content, "%c%s*==.*","") -- remove first ==Heading== and everything after it

	end

	for templateWikitext in mw.ustring.gmatch(content, '%b{}') do

		local isCorrectTemplate = mw.ustring.match(templateWikitext, makeTemplatePattern(template))

		if isCorrectTemplate then

			return templateWikitext

		end

	end

	return false

end



function getSubjectPageContent(contentNamespaceNumber)

	local namespace = mw.site.namespacescontentNamespaceNumber "name"

	local talkTitle = mw.title.getCurrentTitle()

	if talkTitle.namespace ~= contentNamespaceNumber + 1 then

		return error('Wrong namespace', 0)

	end

	local subjectTitle = mw.title.new(namespace .. ":" .. talkTitle.text)

	return subjectTitle:getContent()

end



-- historical function

--   Looks for {{Historical}} on a Wikipedia_talk: page's related project page.

--   Returns 'yes' if found or '' (empty string) if not found, or an error if used in the wrong namespace.

p.historical = function(frame)

	local parent = frame.getParent(frame)

	local args = cleanupArgs(frame.args)

	local demo = args.demo and true or false

	local content

	if demo then

		local demoText = mw.ustring.gsub(args.demo, '%{%{%!%}%}', '|')

		content = '{{' .. demoText .. '}}'

		if args.demo2 then

			local demo2Text = mw.ustring.gsub(args.demo2, '%{%{%!%}%}', '|')

			content= portalContent  .. '{{' .. demo2Text .. '}}'

		end

	else

		content = getSubjectPageContent(4)

	end



	content = mw.ustring.gsub(content, "<!%-%-.-%-%->","") -- remove HTML comments

	content = mw.ustring.gsub(content, "%c%s*==.*","") -- remove first ==Heading== and everything after it

	content = mw.ustring.gsub(content, "<noinclude>.-</noinclude>", "") -- remove noinclude bits



	local isHistorical = mw.ustring.match(content, makeTemplatePattern('Historical')) and true or false

	return isHistorical and 'yes' or ''

end



-- featured function

--   Looks for {{Featured portal}} on a Portal_talk: page's related portal page.

--   Returns 'yes' if found or '' (empty string) if not found, or an error if used in the wrong namespace.

p.featured = function(frame)

	local parent = frame.getParent(frame)

	local args = cleanupArgs(frame.args)

	local demo = args.demo and true or false

	local content

	if demo then

		local demoText = mw.ustring.gsub(args.demo, '%{%{%!%}%}', '|')

		content = '{{' .. demoText .. '}}'

		if args.demo2 then

			local demo2Text = mw.ustring.gsub(args.demo2, '%{%{%!%}%}', '|')

			content= portalContent  .. '{{' .. demo2Text .. '}}'

		end

	else

		content = getSubjectPageContent(100)

	end



	content = mw.ustring.gsub(content, "<!%-%-.-%-%->","") -- remove HTML comments

	content = mw.ustring.gsub(content, "<noinclude>.-</noinclude>", "") -- remove noinclude bits



	local isFeatured = mw.ustring.match(content, makeTemplatePattern('Featured portal')) and true or false

	return isFeatured and 'yes' or ''

end



-- main function

--   Looks for {{Portal maintenance status}} (or earlier deprecated templates) on a Portal_talk: page's related portal page.

--   Returns an appropriate message string if found or '' (empty string) if not found, or an error if used in the wrong namespace.

p.main = function(frame)

	local parent = frame.getParent(frame)

	local args = cleanupArgs(frame.args)

	local demo = args.demo and true or false

	local portalContent

	if demo then

		local demoText = mw.ustring.gsub(args.demo, '%{%{%!%}%}', '|')

		portalContent = '{{' .. demoText .. '}}'

		if args.demo2 then

			local demo2Text = mw.ustring.gsub(args.demo2, '%{%{%!%}%}', '|')

			portalContent = portalContent  .. '{{' .. demo2Text .. '}}'

		end

	else

		portalContent = getSubjectPageContent(100)

	end



	local status = getMatchingTemplateWikitext(portalContent, 'Portal maintenance status') or getMatchingTemplateWikitext(portalContent, 'Portal flag')

	if not status then

		return ''

	end



	local output = mw.ustring.sub(status, 0, -3) .. '|embed=yes}}' 

	return frame:preprocess(output)

end



return p