#!/usr/bin/env bash
set -euo pipefail

# Accepts path as $1 or $INPUT_FILE_PATH
TARGET="${1:-${INPUT_FILE_PATH:-}}"

if [[ -z "$TARGET" ]]; then
  echo "Error: No file or directory path provided" >&2
  exit 1
fi

if [[ ! -e "$TARGET" ]]; then
  echo "Error: Path does not exist: $TARGET" >&2
  exit 1
fi

convert_file() {
  local input="$1"
  local ext="${input##*.}"
  local dir
  dir="$(dirname "$input")"
  local base
  base="$(basename "$input" ".$ext")"
  local output="$dir/$base.mp3"

  if [[ "${ext,,}" == "mp3" ]]; then
    echo "Skipping (already MP3): $input"
    return 0
  fi

  if [[ -f "$output" ]]; then
    echo "Skipping (output exists): $output"
    return 0
  fi

  echo "Converting: $input → $output"
  ffmpeg -i "$input" -codec:a libmp3lame -b:a 320k -map_metadata 0 -id3v2_version 3 -y "$output" 2>/dev/null

  if [[ $? -eq 0 ]]; then
    echo "  ✓ Done"
  else
    echo "  ✗ Failed" >&2
    return 1
  fi
}

AUDIO_EXTS="flac|wav|ogg|wma|aac|m4a|opus|aiff|aif|ape|wv|alac|dsf|dff"
converted=0
failed=0

if [[ -f "$TARGET" ]]; then
  if convert_file "$TARGET"; then
    converted=$((converted + 1))
  else
    failed=$((failed + 1))
  fi
elif [[ -d "$TARGET" ]]; then
  while IFS= read -r -d '' file; do
    if convert_file "$file"; then
      converted=$((converted + 1))
    else
      failed=$((failed + 1))
    fi
  done < <(find "$TARGET" -type f -regextype posix-extended -iregex ".*\.($AUDIO_EXTS)" -print0 | sort -z)

  if [[ $converted -eq 0 && $failed -eq 0 ]]; then
    echo "No audio files found in: $TARGET"
    exit 0
  fi
else
  echo "Error: Not a file or directory: $TARGET" >&2
  exit 1
fi

echo ""
echo "Summary: $converted converted, $failed failed"