#!/bin/sh
# qndl-artist — 아티스트 폴더/메타데이터 통일 헬퍼
export LC_ALL="${LC_ALL:-C.UTF-8}"

MUSIC="${XDG_MUSIC_DIR:-$HOME/Music}"
ALIASES="${QNDL_ALIASES:-${XDG_DOTFILES_DIR:-$HOME/.dotfiles}/global/Music/artist-aliases.tsv}"

# 이름 → 표준명. 맵 정확일치 → 기존 폴더 대소문자무시 매칭 → 원본.
cmd_normalize() {
  _name="$1"
  if [ -f "$ALIASES" ]; then
    _c="$(awk -F'\t' -v n="$_name" '/^#/ || NF < 2 { next } $1 == n { print $2; exit }' "$ALIASES")"
    [ -n "$_c" ] && { printf '%s\n' "$_c"; return 0; }
  fi
  if [ -d "$MUSIC" ]; then
    _m="$(find "$MUSIC" -mindepth 1 -maxdepth 1 -type d -printf '%f\n' 2>/dev/null |
      awk -v n="$_name" 'tolower($0) == tolower(n) { print; exit }')"
    [ -n "$_m" ] && { printf '%s\n' "$_m"; return 0; }
  fi
  printf '%s\n' "$_name"
}

# mp3 1개를 표준 폴더로 이동(필요시) + album_artist 설정.
cmd_apply() {
  _fp="$1"; _canon="$2"
  [ -f "$_fp" ] || { printf 'apply: no such file: %s\n' "$_fp" >&2; return 1; }
  case "$_fp" in
  "$MUSIC"/*) : ;;
  *) printf 'apply: not under %s: %s\n' "$MUSIC" "$_fp" >&2; return 1 ;;
  esac
  _rel="${_fp#"$MUSIC"/}"
  _artist_seg="${_rel%%/*}"
  _subpath="${_rel#*/}"          # album/.../title.mp3
  if [ "$_artist_seg" != "$_canon" ]; then
    _destdir="$MUSIC/$_canon/$(dirname "$_subpath")"
    _dest="$_destdir/$(basename "$_fp")"
    if [ -e "$_dest" ]; then
      printf 'apply: skip (exists): %s\n' "$_dest" >&2
      return 0
    fi
    mkdir -p "$_destdir"
    mv "$_fp" "$_dest" || return 1
    # 빈 원본 앨범/아티스트 폴더 정리
    rmdir -p "$MUSIC/$_artist_seg/$(dirname "$_subpath")" 2>/dev/null || true
    _fp="$_dest"
  fi
  _tmp="$(dirname "$_fp")/.qndl-tag-$$.mp3"
  if ffmpeg -v error -y -i "$_fp" -map 0 -c copy -metadata album_artist="$_canon" "$_tmp" 2>/dev/null; then
    mv "$_tmp" "$_fp"
  else
    rm -f "$_tmp"
    printf 'apply: tag failed: %s\n' "$_fp" >&2
    return 1
  fi
}

_sub="${1:-}"
[ $# -gt 0 ] && shift
case "$_sub" in
normalize) cmd_normalize "$@" ;;
apply) cmd_apply "$@" ;;
*) printf 'usage: qndl-artist {normalize|apply|apply-download|merge} ...\n' >&2; exit 2 ;;
esac