Module:Category main article

---

-- This module implements {{Category main article}}.
-- Tweaked by User:Rickert

local mHatnote = require('Module:Hatnote')
local mFormatLink = require('Module:Format link')
local yesno = require('Module:Yesno')
local mTableTools -- lazily initialise
local mArguments -- lazily initialise

local p = {}

-- Helper: true if the page is in Template: or Module: namespace
local function isTemplateOrModule(title)
	local t = (type(title) == 'string' and title) or (title and title.prefixedText) or ''
	if t == '' then return false end
	local ok, tt = pcall(mw.title.new, t)
	if not ok or not tt then return false end
	local ns = tt.namespace
	return ns == 10 or ns == 828
end

function p.catMain(frame)
	mTableTools = require('Module:TableTools')
	mArguments = require('Module:Arguments')

	-- Grab args
	local args = mArguments.getArgs(frame, { wrappers = 'Template:Category main article' })
	local pages = mTableTools.compressSparseArray(args)
	local options = {
		article = args.article,
		selfref = args.selfref,
	}

	-- Determine the outer page (the page using the template)
	local thisTitle = mw.title.getCurrentTitle()
	local text = p._catMain(options, thisTitle, unpack(pages))

	if isTemplateOrModule(thisTitle.prefixedText) then return text end

	if thisTitle.namespace ~= 14 then text = text .. '\n[[Category:Pages misusing Category main article]]' end

	return text
end

function p._catMain(options, thisTitle, ...)
	options = options or {}
	local pages = { ... }

	thisTitle = thisTitle or mw.title.getCurrentTitle()
	local fullTitle = thisTitle and thisTitle.prefixedText or ''
	local thisText = thisTitle and thisTitle.text or (pages[1] or '')

	local isTemplate = isTemplateOrModule(fullTitle)

	-- Red link detection
	local rawLinks = mFormatLink.formatPages({
		categorizeMissing = not isTemplate and 'Categories with hatnote templates targeting a non-existent page' or nil,
	}, pages)

	-- Convert to plain strings
	local links = {}
	for i, link in ipairs(rawLinks or {}) do
		links[i] = tostring(link)
	end

	-- Auto-fill if empty
	local firstOutputLink = nil
	local usedAutoFill = false

	if not links[1] or links[1] == '' then
		local title = mw.title.new(thisText)
		if title and title.isRedirect then title = title.redirectTarget end
		firstOutputLink = title and title.text or thisText
		usedAutoFill = true
		links[1] = tostring(mFormatLink._formatLink {
			link = firstOutputLink,
			categorizeMissing = not isTemplate and 'Categories with hatnote templates targeting a non-existent page'
				or nil,
		})
		pages = { firstOutputLink }
	else
		local visible = links[1]
		visible = visible:gsub("^'''", ''):gsub("'''$", '')
		visible = visible:gsub('%[%[', ''):gsub('%]%]', '')
		visible = visible:gsub('|.*$', '')
		visible = visible:gsub('#.*$', '')
		firstOutputLink = visible
		usedAutoFill = false
	end

	-- Bold links
	for i, link in ipairs(links) do
		links[i] = string.format("'''%s'''", link)
	end

	-- Determine pagetype
	local pagetype
	if options.article ~= nil then
		pagetype = yesno(options.article) ~= false and 'article' or 'page'
	elseif pages and pages[1] then
		local page = pages[1]:gsub('|.*', '')
		local tt = mw.title.new(page)
		pagetype = tt and tt.namespace == 0 and 'article' or 'page'
	else
		pagetype = 'article'
	end

	-- Work out whether we need to be singular or plural
	local stringToFormat
	if #links > 1 then
		stringToFormat = 'The main %ss for this category are %s.'
	else
		stringToFormat = 'The main %s for this category is %s.'
	end

	-- Build hatnote text
	local text = string.format(stringToFormat, pagetype, mw.text.listToText(links))

	-- Pass through Module:Hatnote
	local hnOptions = { selfref = yesno(options.selfref) == true }
	text = mHatnote._hatnote(text, hnOptions)

	return text, firstOutputLink, usedAutoFill
end

return p