Module:DailyFeatured

---

local p = {}

local function getPool()
	local content = mw.getCurrentFrame():expandTemplate{ title = "Featured pool" }
	local pages = {}

	for line in mw.text.gsplit(content or "", "\n", true) do
		line = mw.text.trim(line)

		line = line:gsub("<!%-%-.-%-%->", "")
		line = mw.text.trim(line)

		if line ~= "" then
			line = line:gsub("^%*%s*", "")
			line = mw.text.trim(line)

			local linkedTitle = line:match("^%[%[([^%]|]+)|?.-%]%]$")
			if linkedTitle then
				line = linkedTitle
			end

			if line ~= "" then
				table.insert(pages, line)
			end
		end
	end

	return pages
end

local function cleanWikitext(s)
	if not s or s == "" then
		return ""
	end

	s = s:gsub("<!%-%-.-%-%->", "")
	s = s:gsub("<ref[^>/]-/>", "")
	s = s:gsub("<ref.->.-</ref>", "")
	s = s:gsub("<ref.->", "")
	s = s:gsub("%[%[File:.-%]%]", "")
	s = s:gsub("%[%[Image:.-%]%]", "")
	s = s:gsub("%{%b{}%}", "")
	s = s:gsub("'''", "")
	s = s:gsub("''", "")
	s = s:gsub("%[%[([^%]|]+)|([^%]]+)%]%]", "%2")
	s = s:gsub("%[%[([^%]]+)%]%]", "%1")
	s = s:gsub("\r", "")
	s = s:gsub("[ \t]+", " ")

	return mw.text.trim(s)
end

local function shorten(s)
	if mw.ustring.len(s) > 200 then
		return mw.ustring.sub(s, 1, 197) .. "…"
	end

	return s
end

local function extractHeadlineFromContent(wikitext)
	if not wikitext or wikitext == "" then
		return ""
	end

	for line in mw.text.gsplit(wikitext, "\n", true) do
		local raw = line
		local cleaned = cleanWikitext(line)

		if raw:match("^==+%s*[^=].-==+%s*$") then
			break
		end

		if cleaned ~= ""
			and not cleaned:match("^__%u+__$")
			and not cleaned:match("^%[%[[Cc]ategory:") then
			return shorten(cleaned)
		end
	end

	for line in mw.text.gsplit(wikitext, "\n", true) do
		local cleaned = cleanWikitext(line)

		if cleaned:match("^==+%s*[^=].-==+%s*$") then
			cleaned = cleaned:gsub("^=+%s*", ""):gsub("%s*=+$", "")
			cleaned = mw.text.trim(cleaned)

			if cleaned ~= "" then
				return shorten(cleaned)
			end
		end
	end

	for line in mw.text.gsplit(wikitext, "\n", true) do
		local cleaned = cleanWikitext(line)

		if cleaned ~= ""
			and not cleaned:match("^__%u+__$")
			and not cleaned:match("^%[%[[Cc]ategory:") then
			return shorten(cleaned)
		end
	end

	return ""
end

function p.main(frame)
	local pages = getPool()

	if #pages == 0 then
		return "No featured pages defined."
	end

	local day = tonumber(os.date("%j")) or 1
	local index = ((day - 1) % #pages) + 1
	local title = pages[index]

	local args = (frame and frame.args) or {}

	if args.titleonly == "1" then
		return title
	end

	local page = mw.title.new(title)
	local headline = ""

	if page and page.exists then
		local content = page:getContent() or ""
		headline = extractHeadlineFromContent(content)
	end

	if headline == "" then
		headline = "Featured page for " .. os.date("%d %B %Y") .. "."
	end

	return string.format(
		"'''[[%s]]'''<div style=\"margin-top:0.35em;\"><small>%s</small></div>",
		title,
		headline
	)
end

return p