#!/bin/bash
TIMEOUT=10

function renameSong() {
  fullSongPath=$1
  songFileBaseName=$(basename "${fullSongPath}")
  songFileExtension="${songFileBaseName##*.}"

  if [ "${songFileExtension}" == "mp3" ]; then
    if [ -f "${fullSongPath}" ]; then
      echo "Trying to recognize song: ${fullSongPath}"
      songRecOutput=$(timeout ${TIMEOUT} songrec recognize "${fullSongPath}" --csv)
      if [ $? -eq 0 ]; then
        songRecOutput=$(echo -e "${songRecOutput}" | tail -1)
        parsedMetaData=$(parseMetaData "${songRecOutput}")
        readarray -d "|" -t parsedMetaDataParts <<< "${parsedMetaData}" newSongPath="$(dirname "${fullSongPath}")/${parsedMetaDataParts[0]}/${parsedMetaDataParts[1]}"
        mkdir -p "${newSongPath}"
        songName=$(echo "${parsedMetaDataParts[2]}" | tr -d '\n')
        mv -f "${fullSongPath}" "${newSongPath}/${songName}.${songFileExtension}"
      else
        echo "Failed to recognize song within ${TIMEOUT} seconds.  Skipping."
      fi
    else
      echo "Failed to find song: ${fullSongPath}"
    fi

    echo "-------------------------------------------------------"

    else
      echo "The following extension is not supported: ${songFileExtension}.  Skipping."
  fi
}

function trim() {
  var="$*"
  var="${var#"${var%%[![:space:]]*}"}"
  var="${var%"${var##*[![:space:]]}"}"
  printf '%s' "${var}"
}

function fetchCsvPart() {
  text=$1
  csvPartNr=$2
  csvPart=$(echo "${text}" | awk -v idx="${csvPartNr}" 'BEGIN {FPAT = "([^,]*)|(\"[^\"]+\")"}{printf("%s", $idx)}')
  echo "${csvPart//\"/}"
}

function parseMetaData() {
  metaData=$1
  albumName=$(fetchCsvPart "${metaData}" "2")
  artistAndSongName=$(fetchCsvPart "${metaData}" "1")
  readarray -d "-" -t artistAndSongNameParts <<< "${artistAndSongName}"
  artistName=$(trim "${artistAndSongNameParts[0]}")
  songName=$(trim "${artistAndSongNameParts[1]}")
  songName="${songName//[\/]/ _ }"

  if [ "${artistName}" == "" ]; then
    artistName="Unknown"
  fi

  if [ "${albumName}" == "" ]; then
    albumName="Unknown"
  fi

  echo "${artistName}|${albumName}|${songName}"
}

# Main

IFS=$(echo -en "\n\b")

if [ $# -gt 0 ]; then
  fsArg=$(realpath "$1")
  if [ -f "${fsArg}" ]; then
    renameSong "${fsArg}"
  elif [ -d "${fsArg}" ]; then
    songFilePaths=$(find "${fsArg}" -maxdepth 1 -mindepth 1 -type f -exec readlink -f {} \;)
    for songFilePath in ${songFilePaths}; do
      renameSong "${songFilePath}"
    done
  else
    echo "The provided argument does not seem to be a valid file or directory: ${fsArg}"
  fi
else
  echo "Please provide either a song file name or a directory containing one or more song files."
fi