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

# ── Task: Convert Audio ──

EXTENSIONS="mp3|flac|wav|ogg|wma|aac|m4a|opus|aiff|aif|ape|wv|alac|dsf|dff"
TARGET_FORMAT="${INPUT_TARGET_FORMAT:-mp3}"
DELETE_SOURCE="${INPUT_DELETE_SOURCE:-false}"

ffmpeg_args_for_format() {
  case "$1" in
    mp3)  echo "-codec:a libmp3lame -b:a 320k -id3v2_version 3" ;;
    flac) echo "-codec:a flac" ;;
    wav)  echo "-codec:a pcm_s16le" ;;
    ogg)  echo "-codec:a libvorbis -q:a 6" ;;
    aac)  echo "-codec:a aac -b:a 256k" ;;
    opus) echo "-codec:a libopus -b:a 192k" ;;
    *)    echo "Unsupported format: $1" >&2; return 1 ;;
  esac
}

FFMPEG_ARGS=$(ffmpeg_args_for_format "$TARGET_FORMAT") || exit 1

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

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

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

  echo "Converting: $input → $output"
  # shellcheck disable=SC2086
  if ffmpeg -nostdin -i "$input" $FFMPEG_ARGS -map_metadata 0 -y "$output" 2>/dev/null; then
    echo "  Done"
    if [[ "$DELETE_SOURCE" == "true" ]]; then
      rm "$input"
      echo "  Deleted source"
    fi
  else
    echo "  Failed" >&2
    return 1
  fi
}

# ── Template: File Processor ──

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

converted=0
failed=0

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

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

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