transcode all FLAC files to 16bit 44.1 kHz with sox

Transcoder.hs

module Main where

import Core
import System.Directory
import System.FilePath
import System.Process
import Data.Maybe
import Data.List

main :: IO ()
main = do
  let allDirs = ("/home/shae/Music" </> ) <$> dirList
  print allDirs
  eachFoo <- mapM listDirectory' allDirs
  let flacsOnly = filter (("calf" ==) . take 4 . reverse) <$> eachFoo
      singles = filter ((1 ==) . length) flacsOnly
      flacsOnly' = filter ((1 <) . length) flacsOnly
      transCode = concatMap (fmap transcodeCommand) (newNames <$> flacsOnly')
  print $ "singles are " <> show singles
  mapM_ callCommand transCode

wrapFile :: FilePath -> FilePath
wrapFile f = "\"" <> f <> "\""

transcodeCommand :: (String, String) -> String
transcodeCommand (old,new) =
    mconcat [", sox --show-progress --no-clobber "
            , wrapFile old
            , " -r 44100 -b 16 "
            , wrapFile $ replaceFileName old new
            ]

listDirectory' :: FilePath -> IO [FilePath]
listDirectory' dir = do
    fs <- listDirectory dir
    pure $ (dir </>) <$> fs

prefexes :: [[Char]]
prefexes = [[a,b,'-'] | a <- letrs, b <- letrs]
    where letrs = ['A' .. 'Z']

newNames :: [FilePath] -> [(FilePath,FilePath)]
newNames oops@[_] = error $ "newNames breaks with one input " <> show oops
newNames paths = zip (sort paths) $ zipWith (<>) prefexes newPaths
    where cp = commonPrefix paths :: FilePath
          newPaths = sort $ drop (length cp) <$> paths

the :: Eq a => [a] -> Maybe a
the [] = Nothing
the (x:xs)
  | all (==x) xs = Just x
  | otherwise = Nothing

commonPrefix :: Eq a => [[a]] -> [a]
commonPrefix = catMaybes . takeWhile isJust . map the . transpose

commonPref (a:as) (b:bs) theSame =
    if a == b
    then commonPref as bs (theSame <> a)
    else theSame

data MyMaybe a where
    MyJust :: a -> MyMaybe a
    MyNothing :: MyMaybe a

{-
input is a list of directory names
1. get a list of all the *.flac files in that directory
2. find the longest common prefix
   replace that with 'A' .. 'Z' in order for the output name
3. call ", sox --show-progress --no-clobber " inputFile " -r 44100 -b 16 " thisLetter outputFile
(- 127 66)
 -}

dirList :: [FilePath]
dirList = [ -- "beats_antique/2010_Dia_de_los_Muertos"
          -- , "beats_antique/2012_Mayans_vs_Aliens"
          -- , "beats_antique/2019_Bhangra_Saanj" -- has only one file!
            -- "beats_antique/2019_The_Grand_Bizarre"
          --   "beats_antique/2021_Singles"
          -- , "chinese_man/2015_Sho-Bro"
          -- , "chinese_man/2017_Shikantaza"
          -- , "chinese_man/2018_Shikantaza_Remix"
          -- , "danger/2014_July-2013"
          -- , "danger/2017_drum"
          -- , "danger/2019_origins"
          -- , "danheim/2018_runagaldr"
          -- , "danheim/2021_domadagr"
          -- , "danheim/singles"
          -- , "dead-end/2019-pure-vanilla"
          -- , "draper/2018_Paro"
          -- , "draper/2019_Kudoclasm"
          -- , "einar_selvik/2017_snake_pit_poetry"
          -- , "einar_selvik/2020_assassins_creed"
          -- , "evian_christ/2014_Waterfall"
          -- , "glitch_mob/2017_the_clouds_breathe_for_you"

          --   "glitch_mob/2018_see_without_eyes"
          -- , "glitch_mob/2018_see_without_eyes_deluxe"
          -- , "glitch_mob/2019_singles"
          -- , "glitch_mob/2020_chemicals"
          -- , "godspeed_you_black_emperor/1993_all_lights_fucked_on_the_hairy_amp_drooling"
          -- , "godspeed_you_black_emperor/2017_luciferian_towers"
          -- , "heilung/2018_Lifa"
          -- , "hudson_mohawke/2015_lantern"
          -- , "hudson_mohawke/2020_black_cherry" -- ONE FILE
            "kraddy/2009_Freakshow"
          , "kraddy/2011_Anthems_of_the_Hero"
          , "oliver_coates/2020_skins_n_slime"
          , "onhell/2020_grime_beats_vol_1"
          , "onhell/2022_grime_beats_vol_2"
          , "outer_wilds/2022-outer-wilds-deluxe"
          , "pantyraid/2016_AfterGlow"
          -- "pine_hill_haints/2020_13"
          , "proleter/2012_curses-from-past-times-bonus"
          , "proleter/2014_tribute-to-the-mastkers-vol-1"
          , "proleter/2015_tribute-to-the-mastkers-vol-2"
          , "proleter/2017_life-playing-tricks"
          , "proleter/2018_curses_from_past_times"
          , "rachika_nayar/2022_heaven_come_crashing"
          , "sleigh_bells/2021_texis"
          , "super_onze/2016_jo_kanga_djiribi"
          , "super_onze/2020-yehia-samak-ngoni-by-night"
          , "the_modern_savage/2015_unfazed"
          , "tipper/2019_jettison_mind_hatch"
          , "tipper/2021_insolito"
          , "tipper/2022_marble_hunting"
          , "too_many_zooz/2014_09_fanimals"
          , "too_many_zooz/2014_11_brasshouse_volume_1"
          , "too_many_zooz/2015_the_internet"
          , "too_many_zooz/2016_subway_gawdz"
          , "too_many_zooz/2018_very_too_many_zooz_xmas"
          , "too_many_zooz/2019_zombiEP"
          , "too_many_zooz/singles"
          , "williamson/2016_backesto_park"
          , "wintergatan/2017_21_instruments"
          , "wintergatan/2020_wintergatan_singles"
          ]