local mp = require 'mp'
local mp_options = require 'mp.options'

local enabled = false
local catching_up = false

local target = 1
local brick = 0

function on_pause_change(name, value)
	if not enabled then return end

	if value == true then
		mp.osd_message("resetting catchup info on pausing", 1)
		local catching_up = false
		mp.set_property('speed', 1)
	end
end

function do_process_timer()
	if not enabled then return end

	local pause = mp.get_property('pause')
	local rem = tonumber(mp.get_property('time-remaining') or 0)

	if pause == 'no' then
		local cspeed = tonumber(mp.get_property('speed') or 1)

		if rem > target + 0.8 + brick and not catching_up then
			mp.osd_message("catchup", 1)
			catching_up = true
			mp.set_property('speed', 1.5)
		elseif (rem < target - 0.1 + brick and catching_up) or rem < target - 0.4 + brick and cspeed > 1 then
			mp.osd_message("done catching up", 1)
			catching_up = false
			mp.set_property('speed', 1)
		end

		if catching_up and cspeed == 1 then
			catching_up = false
		end
	end
end

function on_keybind()
	if enabled then
		mp.osd_message("disabling catchup features", 3)
		enabled = false

		if catching_up then
			catching_up = false
			mp.set_property('speed', 1)
		end
	else
		mp.osd_message("enabling catchup features", 3)
		enabled = true
	end
end

function increase_target()
	target = target + 0.1
	mp.osd_message("target: " .. target, 1)
end

function decrease_target()
	target = target - 0.1
	mp.osd_message("target: " .. target, 1)
end

function increase_brick()
	brick = brick + 0.1
	mp.osd_message("brick: " .. brick, 1)
end

function decrease_brick()
	brick = brick - 0.1
	mp.osd_message("brick: " .. brick, 1)
end

mp.observe_property("pause", "bool", on_pause_change)
mp.add_periodic_timer(0.07, do_process_timer)
mp.add_key_binding("Shift+c", "catchup-toggle", on_keybind)

mp.add_key_binding("Ctrl+Down", "catchup-decrease-target", decrease_target)
mp.add_key_binding("Ctrl+Up", "catchup-increase-target", increase_target)
mp.add_key_binding("Ctrl+Left", "catchup-decrease-brick", decrease_brick)
mp.add_key_binding("Ctrl+Right", "catchup-increase-brick", increase_brick)

local options = {
	enable = false
}

mp_options.read_options(options, "catchup")

enabled = not options.enable
on_keybind()