local p = {}



local function isnotempty(s)

	return s and s:match( '^%s*(.-)%s*$' ) ~= ''

end

 

function p.table(frame)

	local args = (frame.args1 ~= nil) and frame.args or frame:getParent().args

	local cols

	if isnotempty(args'4thcoltitle']) and isnotempty(args'3rdcoltitle']) then

		cols = 4

	elseif isnotempty(args'3rdcoltitle']) then cols = 3

	else cols = 2

	end



	-- compute the maximum cell index

	local cellcount = 0

	for k, v in pairs( args ) do

		if type( k ) == 'number' and isnotempty(v) then

			cellcount = math.max(cellcount, k)

		end

	end

	-- compute the number of rows

	local rows = math.ceil(cellcount / cols)



	-- create the root table

	local root = mw.html.create('table')

	root

		:addClass('wikitable')

		:addClass('sortable')

		:css('font-size', '95%')



	-- add the header row

	local row = root:tag('tr')

	local cell= row:tag('th')

	cell:wikitext('Airlines')

	cell= row:tag('th')

	cell:addClass('unsortable')

	cell:wikitext('Destinations')

	if (isnotempty(args'3rdcoltitle'])) then

		cell= row:tag('th')

		cell:css('width','10%')

		if (isnotempty(args'3rdcolunsortable'])) then

			cell:addClass('unsortable')

		end

		cell:wikitext(args'3rdcoltitle'])

	end

	if (isnotempty(args'4thcoltitle'])) then

		cell= row:tag('th')

		if (isnotempty(args'4thcolunsortable'])) then

			cell:addClass('unsortable')

		end

		cell:wikitext(args'4thcoltitle'])

	end

	-- loop over rows

	for j=1,rows do

		row = root:tag('tr')

		for i=1,cols do

			cell= row:tag('td')

			if (i > 2) then cell:css('text-align','center') end

			cell:wikitext(argscols*(j - 1) + i or '')

		end

	end

	-- return the root table

	return tostring(root)

end



return p