#!/bin/bash
# Desc: Download albums from bandcamp. Accepts either artist page, or album page as argv. then proceeds to a repl mode
# Usage: bandcampdl.sh ARTIST_URL
# Example: bandcampdl.sh https://paperceilings.bandcamp.com/


#set -x
# /* FUNC DEF */ ---------------------------------------------------------------
msg(){ printf -- "%s\n" "$@"; }
emsg(){ printf -- "%s\n" "$@" >&2; }
bail(){ emsg "$@"; usage; exit 1; }
usage(){ awk -F '# ' 'NR>2{print $2};$0==""{exit}' <"$0"; }
slide(){ eval "set -- \$$# $*"; printf -- "%s" "$@"; }

bandrip(){
  album="$(curl -s "$1" | awk -F'(<|>)' '/<title>/{gsub(/[^[:alnum:] ]/, "", $3);print $3}')"
      mkdir "$album" 
      (
        cd "$album" || return
        printf -- "downloading: %s\n" "$album"
        awk '/^[download]/{print $0}' < <(youtube-dl -R infinite --sleep-interval 20 -i -x "$1")
      )
}

bandwalk(){
  local url="${1}"
  if awk '/href=.\/album\//{exit}' <<<"$(curl -sL "$url")"; then
    mapfile -t discog < <(curl -s "${url}/music" | awk -v artist="$url" -F'"' '/href=.\/album\//{printf("%s%s\n", artist,$2)}')
    for link in "${discog[@]}"; do
      # NOTE: Cant disown or `wait` wont work. derp.
      (bandrip "$link")  &
      sleep 5s
    done
  else
    (bandrip "$link")&
  fi
}


# /* INIT */ ------------------------------------------------------------------
test "$1" == "--help" && { usage; exit; }


# /* MAIN */ ------------------------------------------------------------------
while (($#)); do
  bandwalk "$1"
  shift
  sleep 0.2s
done

wait

sleep 2s
printf -- "starting read eval loop. press ^D to exit.\n"
while read -p 'enter url: ' entry; do
  bandwalk "$entry"
done