View source for Module:Autolink

--
-- implements {{Autolink}}, {{Unlink}}, and {{Formatted link}}
--

require('Module:No globals')
local p = {}

-- removes all special formatting from a string
local function unprettify( s )
	return s:gsub( '""', '' )
		:gsub( "'''?", '' )
		:gsub( '[# ]##?', ' ' ) --lmao
		:gsub( '  ', ' ' )
end

-- formats a link
local function prettify_link( target, label )
	if not target or target == '' then
		return ''
	end
	
	if not label or label == '' then
		label = target
	end
	
	local plain_target = unprettify( target )
	local plain_label = unprettify( label )
	local prettified_label = label:gsub( '""', '"' ):gsub( '([^&# ])#([^#])', '%1 §&nbsp;%2' ):gsub( '##', '#' )
	
	local link = ''
	if plain_target == prettified_label then
		-- no formatting
		link = ('[[%s]]'):format( plain_target )
	elseif plain_target == plain_label then
		local start, _end = prettified_label:find( plain_target, 1, true )
		if start then
			-- only formatting is on the link boundaries (`''Foo Bar''`)
			link = ('%s[[%s]]%s'):format( prettified_label:sub( 1, start - 1 ), plain_target, prettified_label:sub( _end + 1 ) )
		else
			-- formatting within the link (`''Foo Bar'' (Quux)`)
			link = ('[[%s|%s]]'):format( plain_target, prettified_label )
		end
	else
		if plain_label == prettified_label then
			-- no formatting
			link = ('[[%s|%s]]'):format( plain_target, prettified_label )
		else
			local start, _end = prettified_label:find( plain_label, 1, true )
			if start then
				-- only formatting is on the text boundaries (`[[Foo Bar Baz|''Foo Bar'']]`)
				link = ('%s[[%s|%s]]%s'):format( prettified_label:sub( 1, start - 1 ), plain_target, prettified_label:sub( start, _end ), prettified_label:sub( _end + 1 ) )
			else
				-- formatting within the text (`[[Foo Bar Baz|''Foo'' Bar]]`)
				link = ('[[%s|%s]]'):format( plain_target, prettified_label )
			end
		end
	end
	return link
end

-- there's several things this doesn't do that it probably could/should:
-- * supporting mixed lists (currently it assumes that whatever list type is used by the first item is the same as all other items)
-- ** similarly, supporting sublists
-- * allowing multiple items to be linked/formatted via multiple parameters, instead of just via a list in the first parameter
-- * supporting multiline link syntax (probably most likely from SMW annotations with multiline values, though file embeds can have multiline descriptions too)
-- * allowing text to be removed from the link for display (e.g. excluding the dabtag in `Dark Magician (manga)`)
function p.link( frame )
	local args = frame == mw.getCurrentFrame() and frame:getParent().args or frame

	-- the gsub() is a dumb hack for the encoded apostrophe test case(s)
	local items = args[1] and args[1]:gsub( '&amp;', '&' ) or ''
	
	-- remove any empty lines/list items from the input
	local lines = {}
	for item in mw.text.gsplit( items, '\n' ) do
		item = mw.text.trim( item:match( '^[*#;:]?(.*)$' ) )
		if item ~= '' then
			table.insert( lines, item )
		end
	end

	-- if there's more than one line, grab the list character (with a fallback if there is none)
	local listtype = ''
	if #lines > 1 then
		listtype = (items:match( '^%s*([*#;:])' ) or '*') .. ' '
	end
	
	-- format, link, and return
	local prettified_lines = {}
	local result = ''
	for _, line in ipairs( lines ) do
		if line:find( '[[', 1, true ) then
			local prettified_line = {}
			local post = line
			while post:find( '[[', 1, true ) do
				local pre, annotation, target, label
				if post:match( '^[^%[]*%[%[[^|%]]+::' ) then
					-- don't format SMW annotations
					pre, annotation = post:match( '^([^%[]*)(%[%[[^%]]+%]%])' )
				else
					pre, target, label = post:match( '^([^%[]*)%[%[ *([^|%]]+) *|? *([^%]]-) *%]%]' )
				end
				table.insert( prettified_line, ('%s%s'):format( pre and pre:gsub( '""', '"' ) or '', target and prettify_link( target, label ) or annotation ) )
				post = post:match( '%]%](.*)$' )
			end
			result = ('%s%s'):format( table.concat( prettified_line ), post:gsub( '""', '"' ) )
		elseif line:find( '\127', 1, true ) then
			-- input is unlinked but has a ref tag
			-- \127 (DEL) is the start/end character of strip markers
			-- technically this will match any stripped content, not just ref tags
			local link, ref = line:match( '^([^\127]+)(\127.*)$' )
			result = ('%s%s'):format( prettify_link( link ), ref )
		else
			result = prettify_link( line )
		end
		
		table.insert( prettified_lines, ('%s%s'):format( listtype, result ) )
	end
	
	prettified_lines = table.concat( prettified_lines, '\n' )
		:gsub( '%[%[[Cc][Aa][Tt][Ee][Gg][Oo][Rr][Yy]:', '[[:Category:' )
		:gsub( '%[%[[Ff][Ii][Ll][Ee]:', '[[:File:' )
		:gsub( '%[%[[Ii][Mm][Aa][Gg][Ee]:', '[[:File:' )
		
	return prettified_lines
end

-- returns the target of the first link in text
-- to return the entire text without any links instead, see {{Delink}}
function p.unlink( frame )
	local txt = frame == mw.getCurrentFrame() and frame:getParent().args[1] or frame[1]
	return txt and ( txt:match( '%[%[:?(.-)[|%]]' ) or mw.text.trim( txt ) )
end

return p