-- sponsorblock-minimal.lua
-- source: https://codeberg.org/jouni/mpv_sponsorblock_minimal
--
-- This script skips sponsored segments of YouTube videos
-- using data from https://github.com/ajayyy/SponsorBlock

local opt = require 'mp.options'
local utils = require 'mp.utils'

local ON = false
local ranges = nil

local options = {
	server = "https://sponsor.ajay.app/api/skipSegments",

	-- Categories to fetch and skip
	categories = '"sponsor"',

	-- Set this to "true" to use sha256HashPrefix instead of videoID
	hash = ""
}

opt.read_options(options)

function get_ranges(youtube_id, url)
	local luacurl_available, cURL = pcall(require,'cURL')

	local res = nil
	if not(luacurl_available) then -- if Lua-cURL is not available on this system
		local sponsors = mp.command_native{
			name = "subprocess",
			capture_stdout = true,
			playback_only = false,
			args = {"curl", "-L", "-s", "-g", url}
		}
		res = sponsors.stdout
	else -- otherwise use Lua-cURL (binding to libcurl)
		local buf={}
		local c = cURL.easy_init()
		c:setopt_followlocation(1)
		c:setopt_url(url)
		c:setopt_writefunction(function(chunk) table.insert(buf,chunk); return true; end)
		c:perform()
		res = table.concat(buf)
	end

	if res then
		local json = utils.parse_json(res)
		if type(json) == "table" then
			if options.hash == "true" then
				for _, i in pairs(json) do
					if i.videoID == youtube_id then
						return i.segments
					end
				end
			else
				return json
			end
		end
	end

	return nil
end

function skip_ads(name,pos)
	if pos then
		for _, i in pairs(ranges) do
			v = i.segment[2]
			if i.segment[1] <= pos and v > pos then
				--this message may sometimes be wrong
				--it only seems to be a visual thing though
				mp.osd_message(("[sponsorblock] skipping forward %ds"):format(math.floor(v-mp.get_property("time-pos"))))
				--need to do the +0.01 otherwise mpv will start spamming skip sometimes
				--example: https://www.youtube.com/watch?v=4ypMJzeNooo
				mp.set_property("time-pos",v+0.01)
				return
			end
		end
	end
end

function file_loaded()
	local video_path = mp.get_property("path", "")
	local video_referer = string.match(mp.get_property("http-header-fields", ""), "Referer:([^,]+)") or ""

	local urls = {
		"ytdl://youtu%.be/([%w-_]+).*",
		"ytdl://w?w?w?%.?youtube%.com/v/([%w-_]+).*",
		"https?://youtu%.be/([%w-_]+).*",
		"https?://w?w?w?%.?youtube%.com/v/([%w-_]+).*",
		"/watch.*[?&]v=([%w-_]+).*",
		"/embed/([%w-_]+).*",
		"^ytdl://([%w-_]+)$",
		"-([%w-_]+)%."
	}
	local youtube_id = nil
	local purl = mp.get_property("metadata/by-key/PURL", "")
	for i,url in ipairs(urls) do
		youtube_id = youtube_id or string.match(video_path, url) or string.match(video_referer, url) or string.match(purl, url)
		if youtube_id then break end
	end

	if not youtube_id or string.len(youtube_id) < 11 then return end
	youtube_id = string.sub(youtube_id, 1, 11)

	local url = ""
	if options.hash == "true" then
		local sha = mp.command_native{
			name = "subprocess",
			capture_stdout = true,
			args = {"sha256sum"},
			stdin_data = youtube_id
		}
		url = ("%s/%s?categories=[%s]"):format(options.server, string.sub(sha.stdout, 0, 4), options.categories)
	else
		url = ("%s?videoID=%s&categories=[%s]"):format(options.server, youtube_id, options.categories)
	end

	ranges = get_ranges(youtube_id, url)
	if ranges then
		ON = true
		mp.add_key_binding("b","sponsorblock",toggle)
		mp.observe_property("time-pos", "native", skip_ads)
	end
end

function end_file()
	if not ON then return end
	mp.unobserve_property(skip_ads)
	ranges = nil
	ON = false
end

function toggle()
	if ON then
		mp.unobserve_property(skip_ads)
		mp.osd_message("[sponsorblock] off")
		ON = false
	else
		mp.observe_property("time-pos", "native", skip_ads)
		mp.osd_message("[sponsorblock] on")
		ON = true
	end
end

mp.register_event("file-loaded", file_loaded)
mp.register_event("end-file", end_file)
