local wallpaper = {}

wallpaper.active = -1

-- How many minutes have passed since 00:00
wallpaper.timenow = function()
	local time = {}

	for t in string.gmatch(os.date("%H:%M"), "[^:]+") do
		table.insert(time, t)
	end

	return (tonumber(time[1]) * 60) + tonumber(time[2])
end


-- Return wallpaper's start time in minutes since 00:00
wallpaper.get_start_time = function(entry)
	return (entry.start_time[1] * 60) + entry.start_time[2]
end


-- Set the ith wallpaper
wallpaper.set = function(i)
	local path = beautiful.wallpaper[i].file
	wallpaper.active = i

	-- Set wallpaper maximized on each display
	for s in screen do
		gears.wallpaper.maximized(path, s)
	end
end


-- Which image should be scheduled now?
wallpaper.current = function()
	for i = #beautiful.wallpaper, 1, -1 do
		if wallpaper.get_start_time(beautiful.wallpaper[i]) <= wallpaper.timenow() then
			return i
		end
	end
end


wallpaper.update = function()
	local current = wallpaper.current()

	if current ~= wallpaper.active then
		wallpaper.set(current)
	end

	return true
end


wallpaper.start = function()
	window.timer = gears.timer.start_new(10, wallpaper.update)
end

return wallpaper