coverart

#!/bin/bash
#
# pbrisbin 2010
#
# http://pbrisbin.com/bin/coverart
#
# can use audiotag (+atomicparsley for m4a support) or mpc to read tags;
# make your choice 'round about line 23/25
#
###

# reads the requested tag from a file
read_tag() {
  local sed

  # strip out (Crap) / Disc X / Volume Y
  sed='
  s/(.*) +\([^\)]*\)/\1/g;
  s/(.*) +\(.*/\1/g;
  s/(.*) +\[?[Dd]is[ck].*/\1/g;
  s/(.*) +\[?[Vv]olume.*/\1/g;
  '

  #which audiotag &>/dev/null || return 1
  #audiotag -l "$1" | sed -r '/^=== '"$2"': *(.*)/!d;s//\1/g;'"$sed"
  mpc list ${2,,} any "${1/$mdir\//}" | sed -r "$sed"
}

url_encode() {
  local string="$1" awkscript

  awk='
  $1 == "20"                   { printf("%s", "+"); next } # space becomes plus
  $1 ~  /0[adAD]/              {                    next } # strip newlines
  $2 ~  /^[a-zA-Z0-9.*()\/-]$/ { printf("%s", $2);  next } # pass through what we can
                               { printf("%%%s", $1)      } # take hex value of everything else
  '

  # thanks to Irm for this bit of magic
  echo $string | hexdump -v -e '1/1 "%02x\t"' -e '1/1 "%_c\n"' | LANG=C awk "$awk"
}

# uses my own php page which interfaces with AWS directly to locate a
# direct url to the product's LargeImage -- pretty sweet
fetch() {
  local artist="$1" album="$2" file="$3" url cover_url

  # todo: moved to yesod, no more php, page is gone... fixme?
  #url="http://192.168.0.5/scripts/albumart.php?artist=${artist// /+}&album=${album// /+}"
  #url="http://192.168.0.5/scripts/albumart.php?artist=$(url_encode "$artist")&album=$(url_encode "$album")"
  #cover_url="$(wget -q -O - "$url")"
  cover_url=

  if [[ -z "$cover_url" ]] || [[ "$cover_url" = 'no results' ]]; then
    echo "$artist -- $album: cover url not found" >&2
    return
  fi

  if wget -q -O "$file" "$cover_url"; then
    echo "$artist -- $album: cover retrieved"
  else
    echo "$artist -- $album: error retrieving cover" >&2
    rm -f "$file"
  fi
}

# process any directory not already containing a 'folder.jpg' file
# within it
fetch_covers() {
  local IFS=$'\n' dir file found artist album track

  while read -r dir; do

    file="$dir/$cover"

    [[ -f "$file" ]] && continue

    found=false
    artist=''
    album=''

    # read any one tag and stop
    while read -r track; do
      artist="$(read_tag "$track" 'ARTIST')"
      album="$(read_tag "$track" 'ALBUM')"

      if [[ -n "$artist" ]] && [[ -n "$album" ]]; then
        found=true
        break
      fi
    done < <(find "$dir" -type f -print)

    if ! $found; then
      # we shouldn't get here -- fix your tags slacker
      echo "$(basename "$dir"), no tags read" >&2
      continue
    fi

    # fetch the cover
    fetch "$artist" "$album" "$file"

  done < <(find "$mdir" -type f -exec dirname {} \; | sort -u)
}

# removes any folder.jpgs left by this (or any) script
wipe() { find "$mdir" -name "$cover" -delete; }

mdir="$HOME/Music" # parent directory of your music collection
cover='folder.jpg' # the filename to store the covers as

# pass '--wipe' to do-over
[[ "$1" = '--wipe' ]] && wipe

fetch_covers