local expansion = {}
local origArgs

function has_arg(name)
	-- The argument can exist and be empty or not exist at all
	return string.len(origArgs[name] or '') > 0
end

function arg(name)
	return origArgs[name]
end

function expansion.set_val(prop, val)
	expansion.frame:preprocess('{{#set: ' .. prop .. '=' .. val .. '}}')	
end


function single_entry(box, argn)
	if has_arg(argn) then
		box:tag('div'):attr('style', 'min-width: 250px; display: inline-block;'):wikitext("'''" .. argn .. ":''' " .. arg(argn))
	end
end

function expansion.expansion(frame)

	expansion.frame = frame
    if frame == mw.getCurrentFrame() then
        origArgs = frame:getParent().args
    else
        origArgs = frame
    end

    local entry = mw.html.create('div')

    entry
        :attr('style', 'background:#f9f9f9; margin: 10px 2px 10px 2px; padding: 5px; border: 1px solid #a7d7f9; min-width: 100px;')
        
    if not has_arg('type') then
    	return "* ERROR: '''WRONG <code>type</code> parameter!'''"	
	end
	
	if arg('type') == 'PCIe' then
		return 	expansion.pcie(entry)
	end
   
   return entry     
end

function expansion.pcie(box)
	local tbl = mw.html.create('table')
	local t = tbl:tag('tr')
	local n = (has_arg('pcie revision') and 1)
				+ (has_arg('pcie lanes') and 1)
				+ (has_arg('pcie config') and 1) 
	
	t:tag('td'):attr('rowspan', n):wikitext("'''PCIe'''")
	
	t:tag('td'):wikitext("'''Revision:''' " .. arg('pcie revision'))
	
	if has_arg('pcie lanes') then
		tbl:tag('tr'):tag('td'):wikitext("'''Max Lanes:''' " .. arg('pcie lanes'))
		expansion.set_val('max pcie lanes', arg('pcie lanes'))
	end
	
	if has_arg('pcie config') then
		local pcieconf = tbl:tag('tr'):tag('td')
		pcieconf:wikitext("'''Configuration:''' " .. arg('pcie config'))
		
		for i = 2, 10 do
			if has_arg('pcie config ' .. i) then
				pcieconf:wikitext(', ' .. arg('pcie config ' .. i))
			end
		end
	end
	
	return box:tag('div'):attr('style', 'min-width: 250px; display: inline-block;'):node(tbl)
end

return expansion