dotfiles/multimedia/.config/mpv/scripts/autoload.lua

-- This script automatically loads playlist entries before and after the
-- the currently played file. It does so by scanning the directory a file is
-- located in when starting playback. It sorts the directory entries
-- alphabetically, and adds entries before and after the current file to
-- the internal playlist. (It stops if it would add an already existing
-- playlist entry at the same position - this makes it "stable".)
-- Add at most 5000 * 2 files when starting a file (before + after).

--[[
To configure this script use file autoload.conf in directory script-opts (the "script-opts"
directory must be in the mpv configuration directory, typically ~/.config/mpv/).

Example configuration would be:

disabled=no
images=no
videos=yes
audio=yes

--]]

MAXENTRIES = 5000

local msg = require("mp.msg")
local options = require("mp.options")
local utils = require("mp.utils")

o = {
	disabled = false,
	images = true,
	videos = true,
	audio = true,
}
options.read_options(o)

function Set(t)
	local set = {}
	for _, v in pairs(t) do
		set[v] = true
	end
	return set
end

function SetUnion(a, b)
	local res = {}
	for k in pairs(a) do
		res[k] = true
	end
	for k in pairs(b) do
		res[k] = true
	end
	return res
end

EXTENSIONS_VIDEO = Set({
	"mkv",
	"avi",
	"mp4",
	"ogv",
	"webm",
	"rmvb",
	"flv",
	"wmv",
	"mpeg",
	"mpg",
	"m4v",
	"3gp",
})

EXTENSIONS_AUDIO = Set({
	"mp3",
	"wav",
	"ogm",
	"flac",
	"m4a",
	"wma",
	"ogg",
	"opus",
})

EXTENSIONS_IMAGES = Set({
	"jpg",
	"jpeg",
	"png",
	"tif",
	"tiff",
	"gif",
	"webp",
	"svg",
	"bmp",
})

EXTENSIONS = Set({})
if o.videos then
	EXTENSIONS = SetUnion(EXTENSIONS, EXTENSIONS_VIDEO)
end
if o.audio then
	EXTENSIONS = SetUnion(EXTENSIONS, EXTENSIONS_AUDIO)
end
if o.images then
	EXTENSIONS = SetUnion(EXTENSIONS, EXTENSIONS_IMAGES)
end

function add_files_at(index, files)
	index = index - 1
	local oldcount = mp.get_property_number("playlist-count", 1)
	for i = 1, #files do
		mp.commandv("loadfile", files[i], "append")
		mp.commandv("playlist-move", oldcount + i - 1, index + i - 1)
	end
end

function get_extension(path)
	match = string.match(path, "%.([^%.]+)$")
	if match == nil then
		return "nomatch"
	else
		return match
	end
end

table.filter = function(t, iter)
	for i = #t, 1, -1 do
		if not iter(t[i]) then
			table.remove(t, i)
		end
	end
end

-- splitbynum and alnumcomp from alphanum.lua (C) Andre Bogus
-- Released under the MIT License
-- http://www.davekoelle.com/files/alphanum.lua

-- split a string into a table of number and string values
function splitbynum(s)
	local result = {}
	for x, y in (s or ""):gmatch("(%d*)(%D*)") do
		if x ~= "" then
			table.insert(result, tonumber(x))
		end
		if y ~= "" then
			table.insert(result, y)
		end
	end
	return result
end

function clean_key(k)
	k = (" " .. k .. " "):gsub("%s+", " "):sub(2, -2):lower()
	return splitbynum(k)
end

-- compare two strings
function alnumcomp(x, y)
	local xt, yt = clean_key(x), clean_key(y)
	for i = 1, math.min(#xt, #yt) do
		local xe, ye = xt[i], yt[i]
		if type(xe) == "string" then
			ye = tostring(ye)
		elseif type(ye) == "string" then
			xe = tostring(xe)
		end
		if xe ~= ye then
			return xe < ye
		end
	end
	return #xt < #yt
end

local autoloaded = nil

function find_and_add_entries()
	local path = mp.get_property("path", "")
	local dir, filename = utils.split_path(path)
	msg.trace(("dir: %s, filename: %s"):format(dir, filename))
	if o.disabled then
		msg.verbose("stopping: autoload disabled")
		return
	elseif #dir == 0 then
		msg.verbose("stopping: not a local path")
		return
	end

	local pl_count = mp.get_property_number("playlist-count", 1)
	-- check if this is a manually made playlist
	if
		(pl_count > 1 and autoloaded == nil)
		or (pl_count == 1 and EXTENSIONS[string.lower(get_extension(filename))] == nil)
	then
		msg.verbose("stopping: manually made playlist")
		return
	else
		autoloaded = true
	end

	local pl = mp.get_property_native("playlist", {})
	local pl_current = mp.get_property_number("playlist-pos-1", 1)
	msg.trace(("playlist-pos-1: %s, playlist: %s"):format(pl_current, utils.to_string(pl)))

	local files = utils.readdir(dir, "files")
	if files == nil then
		msg.verbose("no other files in directory")
		return
	end
	table.filter(files, function(v, k)
		if string.match(v, "^%.") then
			return false
		end
		local ext = get_extension(v)
		if ext == nil then
			return false
		end
		return EXTENSIONS[string.lower(ext)]
	end)
	table.sort(files, alnumcomp)

	if dir == "." then
		dir = ""
	end

	-- Find the current pl entry (dir+"/"+filename) in the sorted dir list
	local current
	for i = 1, #files do
		if files[i] == filename then
			current = i
			break
		end
	end
	if current == nil then
		return
	end
	msg.trace("current file position in files: " .. current)

	local append = { [-1] = {}, [1] = {} }
	for direction = -1, 1, 2 do -- 2 iterations, with direction = -1 and +1
		for i = 1, MAXENTRIES do
			local file = files[current + i * direction]
			local pl_e = pl[pl_current + i * direction]
			if file == nil or file[1] == "." then
				break
			end

			local filepath = dir .. file
			if pl_e then
				-- If there's a playlist entry, and it's the same file, stop.
				msg.trace(pl_e.filename .. " == " .. filepath .. " ?")
				if pl_e.filename == filepath then
					break
				end
			end

			if direction == -1 then
				if pl_current == 1 then -- never add additional entries in the middle
					msg.info("Prepending " .. file)
					table.insert(append[-1], 1, filepath)
				end
			else
				msg.info("Adding " .. file)
				table.insert(append[1], filepath)
			end
		end
	end

	add_files_at(pl_current + 1, append[1])
	add_files_at(pl_current, append[-1])
end

mp.register_event("start-file", find_and_add_entries)