dotfiles/.config/mpv/scripts/autload.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
ignore_hidden=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,
  ignore_hidden = 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)
    -- The current file could be a hidden file, ignoring it doesn't load other
    -- files from the current directory.
    if (o.ignore_hidden and not (v == filename) and 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)