Can't get script working :-(

[mirikbb]

I have liquidsoap 2.3 installed and playing basic playlist is working well via icecast 2.4.4. As I have a big playlist and NOT streaming 24/7, I want to implement following logic:

1. songs are played randomly
2. send to icecast not only track and artist, but also album name
3. every song already played is moved from playlist to backup list => when stream is stopped and restarted (next hour/day/week) it will not play already played songs. So despite several restarts of stream, each song will be played at the end only once
4. when playlist will become empty, it is replaced by backup

As I am not programmer and it is hard for me to understand the scripting language, I am seeking for help.
Using the script below (generated by chatgpt and copilot), I am getting a lot of errors like parse error, value has no method, undefined variable ....
Of course the path variables and output icecast variables I am using are different then pasted here.

Thanks a lot for any help.

# File paths
playlist_file = "/path/to/playlist.m3u"
backup_file = "/path/to/backup.m3u"

# Function to extract and send metadata, including album
def set_metadata(s)
  # Extract artist, title, and album from the track's metadata
  metadata = source.metadata.s
  title = metadata["title"]
  artist = metadata["artist"]
  album = metadata["album"]

  # Create custom metadata string for Icecast
  if (album != "")
    custom_metadata = "#{artist} - #{title} (Album: #{album})"
  else
    custom_metadata = "#{artist} - #{title}"
  end

  # Update the Icecast metadata
  [("title", custom_metadata)]
end

# Load the playlist in random mode
main_playlist = playlist(playlist_file, random=true)

# Add metadata hook to attach album
main_playlist_with_metadata = map_metadata(set_metadata, main_playlist)

# Custom function to handle played songs
def track_done_hook(s)
  played_song = source.name(s)

  # Append the played song to the backup file
  system("echo '#{played_song}' >> #{backup_file}")

  # Remove the played song from the playlist file
  system("sed -i '/#{played_song}/d' #{playlist_file}")

  # Check if the playlist is empty, and replace it with the backup if needed
  system("
    if [ ! -s #{playlist_file} ]; then
      cp #{backup_file} #{playlist_file}
      > #{backup_file}  # Clear the backup after restoring the playlist
    fi
  ")

  ()
end

# Attach track_done_hook
main_playlist_with_hooks = on_track(track_done_hook, main_playlist_with_metadata)

# Output the stream to Icecast
output.icecast(
  %mp3,
  host="localhost",
  port=8000,
  password="hackme",
  mount="/stream",
  name="My Random Radio Stream",
  description="Streaming Songs Randomly",
  genre="Various",
  main_playlist_with_hooks
)

[mirikbb]

Finally I made it! I have spend a lot of hours reading the manual, discussions and asking google, but finally I made the script from scratch by myself.