#!/usr/bin/env bash
# fix-artist-separators.sh
# Splits artist tags on "/" into ";" — with hardcoded exceptions for artist
# names that legitimately contain "/" (Au/Ra, HUNTR/X).
#
# Requires: ffprobe, ffmpeg, python3
#
# Usage:
#   bash fix-artist-separators.sh [music_dir]           -- dry run (no changes)
#   bash fix-artist-separators.sh [music_dir] --apply   -- actually modify files

MUSIC_DIR="${1:-/opt/navidrome/music}"
APPLY=false
[[ "${2:-}" == "--apply" ]] && APPLY=true

if [[ ! -d "$MUSIC_DIR" ]]; then
  echo "Error: directory not found: $MUSIC_DIR"
  exit 1
fi

if $APPLY; then
  echo "🔧  APPLY mode — files will be modified"
else
  echo "🔍  DRY RUN — no files will be changed (add --apply to apply)"
fi
echo "📂  Scanning: $MUSIC_DIR"
echo "🚫  Exceptions: Au/Ra, HUNTR/X"
echo ""

count_found=0
count_ok=0
count_fail=0

# Splits artist string on "/" while preserving exception names.
# Example: "HUNTR/X/EJAE/AUDREY NUNA" -> "HUNTR/X;EJAE;AUDREY NUNA"
#          "-Prey/zecki"               -> "-Prey;zecki"
#          "Au/Ra"                     -> "Au/Ra"  (exception, unchanged)
SPLIT_PY='
import sys

EXCEPTIONS = ["Au/Ra", "HUNTR/X"]
exc_lookup = [(exc, exc.lower(), exc.split("/")) for exc in EXCEPTIONS]

def smart_split(artist):
    parts = artist.split("/")
    result = []
    i = 0
    while i < len(parts):
        matched = False
        for exc, exc_lower, exc_parts in exc_lookup:
            n = len(exc_parts)
            candidate = parts[i:i+n]
            if len(candidate) == n and "/".join(candidate).lower() == exc_lower:
                result.append(exc)
                i += n
                matched = True
                break
        if not matched:
            p = parts[i].strip()
            if p:
                result.append(p)
            i += 1
    return ";".join(result)

artist = sys.stdin.read().strip()
if "/" not in artist:
    print(artist)
else:
    print(smart_split(artist))
'

get_artist() {
  ffprobe -v quiet -print_format json -show_format "$1" 2>/dev/null \
    | python3 -c "
import sys, json
data = json.load(sys.stdin)
tags = data.get('format', {}).get('tags', {})
print(next((v for k, v in tags.items() if k.lower() == 'artist'), ''))
" 2>/dev/null
}

while IFS= read -r -d '' file; do
  artist=$(get_artist "$file") || continue
  [[ "$artist" != *"/"* ]] && continue

  new_artist=$(echo "$artist" | python3 -c "$SPLIT_PY" 2>/dev/null) || continue
  [[ "$artist" == "$new_artist" ]] && continue

  count_found=$((count_found + 1))
  echo "📄  $file"
  echo "    Before : $artist"
  echo "    After  : $new_artist"

  if $APPLY; then
    ext="${file##*.}"
    tmp="${file%.*}.artist_fix_tmp.$ext"
    if ffmpeg -i "$file" -map_metadata 0 -metadata "artist=$new_artist" \
              -c copy "$tmp" -y -loglevel quiet 2>/dev/null; then
      mv "$tmp" "$file"
      echo "    ✅ Updated"
      count_ok=$((count_ok + 1))
    else
      rm -f "$tmp"
      echo "    ❌ Failed"
      count_fail=$((count_fail + 1))
    fi
  fi
  echo ""
done < <(find "$MUSIC_DIR" -type f \( \
  -name "*.mp3" -o -name "*.flac" -o \
  -name "*.m4a" -o -name "*.ogg"  -o \
  -name "*.opus" \) -print0)

echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "Files to change: $count_found"
if $APPLY; then
  echo "Updated: $count_ok  |  Failed: $count_fail"
  [[ $count_ok -gt 0 ]] && echo "" && echo "💡 Trigger a Navidrome rescan to pick up the changes."
else
  echo ""
  echo "Run with --apply to fix them:"
  echo "  bash fix-artist-separators.sh \"$MUSIC_DIR\" --apply"
fi