# Download video from URL in background. When no [LINK] specified, it tries to update previously downloaded link.
# Usage: vdl [LINK]
vdl()
{
  # Check that ffmpeg and ffprobe are available.
  if [[ "$(ffmpeg -version)" = "" ]] || [[ "$(ffprobe -version)" = "" ]]; then
    echo -e "${color_red}ffmpeg and ffprobe are required.${color_default}"
    return 1
  fi

  local target="${@}" # What to download/update.

  # If no [LINK] provided, try to read from `src.txt`.
  [[ "${target}" = "" ]] && target="$(cat src.txt)" 

  # If could not get [LINK] eventually, show an error and exit.
  if [[ "${target}" = "" ]]; then
    echo -e "${color_red}Could not determine [LINK] to download.${color_default}"
    echo "Usage: vdl [LINK]"
    return 2
  fi

  # Save [LINK] for later use.
  [[ -f "src.txt" ]] || echo "${target}" > src.txt

  # Download [LINK] content.
  yt-dlp -f 'bestvideo[height<=?1081]+bestaudio/best' --download-archive index.txt --embed-thumbnail --embed-subs --write-auto-subs --embed-metadata --merge-output-format mkv -cio '%(playlist_index)000006d_%(id)s.%(ext)s' "${target}" # || _vdl_retry
}

# Temporary fix for crashes.
_vdl_retry() {
  for file in *.part; do
    local number="${file%%_*}"
    rm ${number}*
  done
  vdl
}

# download all videos from file.
alias vdl_file="vdl -a"