local getArgs = require('Module:Arguments').getArgs

local p = {}



function p.dates(frame)

	local returnval;

	local args = getArgs(frame);

	

	if table.getn(args) < 2 then

		if args'1' == nil and args'2' == nil then

			return '';

		elseif args'1' == nil then 

			return args'2'];

		elseif args'2' == nil then 

			return args'1'];

		end

	end

	

	args'1' = args'1']:gsub("&nbsp;"," ");

	args'2' = args'2']:gsub("&nbsp;"," ");

	

	local dmy = false;

	local pr1, m1, d1, y1, su1 = string.match(args'1'], '(.-)(%u%a+)%s(%d+),%s(%d+)(.*)');

	local pr2, m2, d2, y2, su2 = string.match(args'2'], '(.-)(%u%a+)%s(%d+),%s(%d+)(.*)');

	if y1 == nil then

		dmy = true;

		pr1, d1, m1, y1, su1 = string.match(args'1'], '(.-)(%d%d?)%s(%a+)%s(%d+)(.*)');

		pr2, d2, m2, y2, su2 = string.match(args'2'], '(.-)(%d%d?)%s(%a+)%s(%d+)(.*)');

	end

	

	local dash = '&nbsp;– ';

	if y1 ~= nil and y2 ~= nil then

		su1 = su1 or '';

		su2 = su2 or '';

		

		local MONTHS = {January=1, February=2, March=3, April=4, May=5, June=6, July=7, August=8, September=9, October=10, November=11, December=12};

		local diff = os.time({year=y2,month=MONTHSm2],day=d2,hour=0,min=0,sec=0})-os.time({year=y1,month=MONTHSm1],day=d1,hour=0,min=0,sec=0});

		

		if diff < 0 then

			returnval = 'Invalid date range';

		else

			if y1 == y2 then

				if dmy == false then

					returnval = pr1..m1..' '..d1..su1..dash..pr2..m2..' '..d2..', '..y2..su2;

				else

					returnval = pr1..d1..' '..m1..su1..dash..pr2..d2..' '..m2..' '..y2..su2;

				end

			else

				if dmy == false then

					returnval = pr1..m1..' '..d1..', '..y1..su1..dash..pr2..m2..' '..d2..', '..y2..su2;

				else

					returnval = pr1..d1..' '..m1..' '..y1..su1..dash..pr2..d2..' '..m2..' '..y2..su2;

				end

			end

		end

	else

		returnval = args'1'..dash..args'2'];

	end

	

	return returnval;

end



return p