-- Find Image
-- returns the first filename in the current page
-- checks for [[File:, [[Image:, infobox image, gallery

local p = {}

function p.scan(frame)
	local args = frame.args
	local pargs = frame:getParent().args
	for k, v in pairs(pargs) do
		args[k] = v
	end

	-- first unnamed parameter or |title=
	local title = mw.text.trim(args[1] or args.title or "", "\t\r\n\f %[%]")
	local titleobj
	if title == "" then
		titleobj = mw.title.getCurrentTitle()
	else
		titleobj = mw.title.new(title)
	end

	local pagetxt = titleobj:getContent()
	if not pagetxt then return nil end

	-- look for first [[File:
	local start, last, txt = pagetxt:find("%[%[[Ff]ile:([^|%]]*)")
	-- look for first [[Image:
	local start1, last1, txt1 = pagetxt:find("%[%[[Ii]mage:([^|%]]*)")
	-- look for infobox image
	local start2, last2, txt2 = pagetxt:find("|%s*image%s*=%s*([^.]*.%a*)%A")

	if (start1 or 1e8) < (start or 1e8) then
		start, last, txt = start1, last1, txt1
	end
	if (start2 or 1e8) < (start or 1e8) then
		start, last, txt = start2, last2, txt2
	end

	if not txt then -- look for gallery with Image:
		local start3, last3, txt3 = pagetxt:find("[Ii]mage:%s*([^.]*.%a*)%A")
		if (start3 or 1e8) < (start or 1e8) then
			start, last, txt = start3, last3, txt3
		end
	end

	return txt
end

return p