local randomModule = require('Module:Random')



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



function isAffirmed(val)

	if not(val) then return false end

	local affirmedWords = ' add added affirm affirmed include included on true yes y '

	return string.find(affirmedWords, ' '..string.lower(val)..' ', 1, true ) and true or false

end



function makeOutput(allItems, maxItems, more, notRandom)

	local output

	if notRandom then

		output = ''

		local itemIndex = 1

		local maxCount = math.min(#allItems, maxItems)

		while itemIndex <= maxCount do

			output = output .. allItemsitemIndex .. '\n'

			itemIndex = itemIndex + 1

		end

	else

		local randomiseArgs = {

			't' = allItems,

			'limit' = maxItems

		}

		local randomisedItems = randomModule.main('array', randomiseArgs )

		output = table.concat(randomisedItems, '\n')

	end

	if more then

		output = output .. more

	end

	return mw.text.trim(output)

end



function cleanForPatternMatching(wikitext)

	-- remove wikilink brackets

	local cleaned = mw.ustring.gsub(wikitext, "%[%[(.-)%]%]","%1")

	-- remove pipes that would have been in piped links

	cleaned = mw.ustring.gsub(cleaned, "%|"," ")

	-- remove external links

	cleaned = mw.ustring.gsub(cleaned, "%[.-%]"," ")

	return cleaned

end



function makeCollapsed(outerText, innerText)

	return "{{Hidden begin | titlestyle = font-weight:normal | title = " .. outerText .. "}}" .. innerText .. "{{Hidden end}}"

end





-- Get current events for a "YYYY Month D" date. Returns a table of list items.

function getRecentAdditions(subpage, keepPatterns, skipPatterns, showWikitext)

	local title = mw.title.new('Wikipedia:Recent additions' .. subpage)

	local raw = title:getContent()

	local itemPattern = '%*%s?%.%.%.[%S ]*'

	local items = {}

	for item in mw.ustring.gmatch(raw, itemPattern) do

		local keep = false

		local skip = false

		local isListItem = ( string.sub(item, 0, 1) == '*' )

		if isListItem then

			local text = cleanForPatternMatching(item)

			for ii, keepPatt in pairs(keepPatterns) do

				if not keep and mw.ustring.find(text, keepPatt) then

					keep = true

				end

			end

			if #skipPatterns > 0 then

				for iii, skipPatt in pairs(skipPatterns) do

					if not skip and mw.ustring.find(text, skipPatt) then

						skip = true			

					end

				end

			end

		end

		if keep and not skip then

			-- remove (pictured) inline note

			local cleanItem = mw.ustring.gsub(item, "%s*''%(.-pictured.-%)''", "")

			-- remove (illustrated) inline note

			cleanItem = mw.ustring.gsub(cleanItem, "%s*''%(.-illustrated.-%)''", "")

			if showWikitext then

				-- remove html comments

				cleanItem = mw.ustring.gsub(cleanItem, "%<%!%-%-(.-)%-%-%>", "")

				local itemWikitext = "<pre>" .. mw.text.nowiki( cleanItem ) .. "</pre>"

				cleanItem = makeCollapsed(cleanItem, itemWikitext)

			end

			table.insert(items, cleanItem)

		end

	end

	return items

end



function getItems(maxMonths, patterns, skipPatterns, showWikitext)

	local allItems = {}

	local lang = mw.language.new('en')

	local currentYear  = tonumber(lang:formatDate('Y', 'now'))

	local currentMonth = tonumber(lang:formatDate('n', 'now'))

	local monthsAgo = 0

	while monthsAgo < maxMonths do

		local subpage

		if monthsAgo == 0 then

			subpage = ''

		else

			local year = currentYear - math.modf( (monthsAgo+12-currentMonth)/12 ) 

			local month = math.fmod(12 + currentMonth - math.fmod(monthsAgo, 12), 12)

			month = ( month ~= 0 ) and month or 12

			subpage = lang:formatDate('/Y/F', year .. '-' .. month)

		end

		local monthlyItems = getRecentAdditions(subpage, patterns, skipPatterns, showWikitext)

		for i, item in ipairs(monthlyItems) do

			table.insert(allItems, item)

		end

		monthsAgo = monthsAgo + 1

	end

	return allItems

end



function getPatterns(args, prefix)

	local patterns = {}

	local ii = 1

	while argsprefix and prefix..ii or ii do

		patternsii = argsprefix and prefix..ii or ii

		ii = ii + 1

	end

	return patterns

end



local p = {}



p.main = function(frame)

	local parent = frame.getParent(frame)

	local parentArgs = parent.args

	local args = cleanupArgs(parentArgs)



	if args'not' and not args'not1' then

		args'not1' = args'not'

	end

	

	local patterns = getPatterns(args)

	if #patterns < 1 then

		return error("Search pattern not set")

	end



	local skipPatterns = getPatterns(args, 'not')



	local months = tonumber(args.months) or 30

	

	local showWikitext = isAffirmed(args.wikitext)



	local allItems = getItems(months, patterns, skipPatterns, showWikitext)

	if #allItems < 1 then

		return args.header and '' or args.none or 'No recent additions'

	end



	local maxItems = tonumber(args.max) or 6



	local more = args.more

	if isAffirmed(args.more) then

		more = "'''[[Wikipedia:Recent additions|More recent additions...]]'''"

	end



	local nonRandom = isAffirmed(args.latest)



	local output = makeOutput(allItems, maxItems, more, nonRandom)

	if args.header then

		output = args.header .. '\n' .. output .. '\n' .. (args.footer or '{{Box-footer}}')

	end

	local needsExpansion = mw.ustring.find(output, '{{', 0, true)	

	if needsExpansion then

		return frame:preprocess(output)

	else 

		return output

	end

end



return p