#!/usr/bin/env bash
# fix-artist-separators.sh
# Replaces " / " (space-slash-space) in audio file artist tags with ";"
#
# Safe: only matches " / " with surrounding spaces, so Au/Ra and HUNTR/X
# (no spaces around the slash) are left completely untouched.
#
# 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
#
# Example:
#   bash fix-artist-separators.sh /opt/navidrome/music --apply

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 changes)"
fi
echo "📂  Scanning: $MUSIC_DIR"
echo ""

count_found=0
count_ok=0
count_fail=0

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="${artist// \/ /;}"
  count_found=$((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 with \" / \" in artist tag: $count_found"
if $APPLY; then
  echo "Updated: $count_ok  |  Failed: $count_fail"
  if [[ $count_ok -gt 0 ]]; then
    echo ""
    echo "💡 Trigger a Navidrome rescan to pick up the changes."
  fi
else
  echo ""
  echo "Run with --apply to fix them:"
  echo "  bash fix-artist-separators.sh \"$MUSIC_DIR\" --apply"
fi