mpv script for sending notifications on track change

notify-send.lua

local mp = require("mp")
local utils = require("mp.utils")
local msg = require("mp.msg")
local home = os.getenv("HOME")
-- local mpv_cache = home .. "/.cache/mpv"
local mpv_cache = "/tmp"
local title = ""
local origin = ""
local thumbnail = home .. "/Pictures/icons/Guyman-Helmet-Music-512.png"

table.unpack = table.unpack or unpack -- 5.1 compatibility

local function shell_escape(inputString)
	if inputString == nil then
		return "Station ID"
	end

	-- Characters to escape: $ ` "
	local escapedString = string.gsub(inputString, '([$`"])', "\\%1")

	-- Preserve newline characters
	escapedString = string.gsub(escapedString, "\\n", "\n")

	return escapedString
end

local function notify(summary, body, options)
	local option_args = {}
	for key, value in pairs(options or {}) do
		-- local info = key .. " = " .. value
		-- msg.log("info", "DEBUG: " .. info)
		table.insert(option_args, string.format("--%s=%s", key, value))
	end
	msg.log("info", "summary:", summary)
	msg.log("info", "body:", body)
	return pcall(mp.command_native, {
		"run",
		"notify-send",
		table.unpack(option_args),
		shell_escape(summary),
		shell_escape(body),
	})
end

local function notify_media()
	return notify(title, origin, {
		-- For some inscrutable reason, GNOME 3.24.2
		-- nondeterministically fails to pick up the notification icon
		-- if either of these two parameters are present.
		--
		-- urgency = "low",
		-- ["app-name"] = "mpv",

		-- ...and this one makes notifications nondeterministically
		-- fail to appear altogether.
		--
		-- hint = "string:desktop-entry:mpv",

		icon = thumbnail,
		--["replaces-process"] = "mpv-notification",
		--["replace-file"] = mpv_cache .. "/mpv_notification",
	})
end

local function set_data(metadata)
	local function tag(name)
		return metadata[string.upper(name)] or metadata[name]
	end

	local function parse_data(data)
		local t = {}
		-- TODO: Address multiple hyphen

		for s in string.gmatch(data, "[^-]+") do
			table.insert(t, s)
		end

		if t[2] ~= nil then
			t[2] = t[2]:gsub("^%s+", "")
		end

		return t
	end

	local function update_origin(meta)
		return string.format("%s\\n%s", origin, meta)
	end

	local ice = tag("icy-title")

	if ice then
		local data = parse_data(ice)
		origin = data[1]
		title = data[2]
		local icy_name = tag("icy-name")
		origin = update_origin(icy_name)
	else
		title = tag("title") or title
		origin = tag("artist_credit") or tag("artist") or origin

		local album = tag("album")
		if album then
			origin = update_origin(album)
		end

		local year = tag("original_year") or tag("year")
		if year then
			origin = update_origin(year)
		else
			local date = tag("date")
			if date then
				origin = update_origin(date)
			end
		end
	end

	return title, origin
end

local function initialize_data_from_filename()
	local path = mp.get_property_native("path")
	local dir, file = utils.split_path(path)

	-- TODO: handle embedded covers and videos?
	-- potential options: mpv's take_screenshot, ffprobe/ffmpeg, ...
	-- hooking off existing desktop thumbnails would be good too
	-- local thumbnail = find_cover(dir)

	title = file
	origin = dir
end

local function dump_cover()
	if mp.get_property("track-list/1/albumart") == "yes" then
		msg.log("info", "Cover art found. Dumping cover art...")

		local path = mp.get_property_native("path")
		local cover = mpv_cache .. "/mpv.jpg"

		mp.command_native({
			"run",
			"ffmpeg",
			"-loglevel",
			"quiet",
			"-y",
			"-i",
			path,
			"-map",
			"0:v",
			"-map",
			"-0:V",
			"-c",
			"copy",
			cover,
		})

		msg.log("info", "Command finished. Cover art dumped to " .. cover)
		thumbnail = cover
	end
end

local function update_data()
	initialize_data_from_filename()
	dump_cover()
end

local function notify_metadata_updated(_, metadata)
	if metadata then
		-- for name,val in pairs(metadata) do
		--   msg.log("info", name, ": ", val)
		-- end
		title, origin = set_data(metadata)
	end

	if title ~= "" then
		msg.log("info", "Sending notification...")
		-- return notify_media(title, origin, thumbnail)
		return notify_media()
	end
end

mp.add_hook("on_preloaded", 50, update_data)
mp.observe_property("metadata", "native", notify_metadata_updated)