A script to add the currently playing track to a predefined playlist

spotify-star-adder.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'rspotify'
require 'open3'
require 'uri'
require 'json'

# To use script
# 1/ Create an app at: https://developer.spotify.com/dashboard/applications
# 2/ Find your playlist ID (copy from the playlist Spotify URI's end)

PREF_PATH = File.expand_path('~/Library/Preferences/spotify_starrer_persistence.json')
REDIRECT_URL = 'https://example.com/callback'

# variable constants

def client_id
  persistent('client_id') { as_prompt 'Enter your client_id' }
end
def client_secret
  persistent('client_secret') { as_prompt 'Enter your client_secret' }
end
def playlist_id
  persistent('playlist_id') { as_prompt 'Enter your playlist_id' }
end

# helpers

def persistent(k, force = false)
  data = JSON.parse(File.read(PREF_PATH)) rescue {}
  return data[k] if !force && data[k]
  data[k] = yield
  File.write(PREF_PATH, data.to_json)
  data[k]
end

def osascript(script)
  Open3.popen3('osascript', *script.split(/\n/).map { |line| ['-e', line] }.flatten) {|_, stdout, _, _|
    return stdout.read.chomp
  }
end

def pbpaste
  Open3.popen3('pbpaste') {|_, stdout, _, _| return stdout.read.chomp }
end

def as_prompt(message)
  out = osascript(%{tell app "System Events" to return text returned of (display dialog "#{message.gsub('"','\"')}" default answer "")})
  raise if out.empty?
  out
end

def as_message(message)
  osascript(%{tell app "System Events" to display dialog "#{message.gsub('"','\"')}"})
end

# spotify

def oauth_flow
  RSpotify.authenticate(client_id, client_secret)
  scopes = 'user-read-private user-read-email playlist-modify-public playlist-modify-private'
  system('open', "https://accounts.spotify.com/authorize/?client_id=#{client_id}&response_type=code&redirect_uri=#{CGI.escape(REDIRECT_URL)}&scope=#{CGI.escape(scopes)}")
  sleep(1)
  as_message("Copy the code from the URL to the clipboard")
  code = pbpaste
  request_data = {grant_type: 'authorization_code', code: code, redirect_uri: REDIRECT_URL}
  auth = JSON.parse(RestClient.post(RSpotify::TOKEN_URI, request_data, RSpotify.send(:auth_header)))
  user = JSON.parse(RestClient.get('https://api.spotify.com/v1/me', {
    'Authorization' => "Bearer #{auth['access_token']}",
  }))
  auth['token'] = auth['access_token']
  {'auth' => auth, 'user' => user}
end

def authenticated_user!(auth)
  RSpotify.authenticate(client_id, client_secret)
  user_args = auth['user'].merge('credentials' => auth['auth'])
  RSpotify::User.new(user_args).tap do |u|
    #u.class.send(:refresh_token, u.id)
  end
end

def current_track_id
  track_id = osascript(<<-END)
    tell application "Spotify" to return the id of the current track
  END
  track_id.split(':').last
end

def add_to_starred_playlist(user, track_id)
  RSpotify.authenticate(client_id, client_secret)
  pl = RSpotify::Playlist.find(user.id, playlist_id)
  t = RSpotify::Track.find(track_id)
  pl.add_tracks!([t])
end

# code

if __FILE__ == $0
  client_id
  client_secret
  playlist_id
  auth = persistent('auth') { oauth_flow }
  u = authenticated_user!(auth)
  add_to_starred_playlist(u, current_track_id)
end