CLI controls for Spotify and (Apple) Music

tunes.rb

#!/usr/bin/env ruby
# encoding: utf-8
#
# CLI music controller for Spotify and Apple Music
# By default affects whichever one is running, preferring Spotify
# if both are. Change the order of KNOWN_PLAYERS to reverse that.
#
# If the first argument is either "music" or "spotify," it will
# target that app. If the app is not running, it will be launched.
# When no app is specified and neither are running, it returns nothing
# and does not launch an app.
#
# When run with no argument, it returns the current track and artist.
# It also accepts the following commands:
#
# - play
# - pause
# - next
# - prev
# - vol [0-100]
# - mute

KNOWN_PLAYERS = ["Spotify", "Music"]

class Players
  attr_accessor :apps
  attr_reader :player

  # @param apps array of (string) app names
  def initialize(apps)
    @apps = apps
    @player = active
  end

  # @param app (string) app name
  # @return boolean app is recognized
  def legit?(app)
    @apps.map {|a| a.downcase }.include?(app)
  end

  # Are any of the known apps running?
  # @return boolean
  def any?
    not %x{ps ax -o command=|grep -E "(#{@apps.join('|')})\.app/Contents/MacOS/\\1"|grep -v grep}.strip.empty?
  end

  # Return first active (running and playing) player in the array
  # @return Player or nil
  def active
    if self.any?
      active_player = nil
      @apps.each {|app|
        player = Player.new(app)
        if player.active?
          active_player = player
          break
        end
      }
      active_player
    else
      nil
    end
  end

  # Return first running player in the array
  # @return Player or nil
  def running
    if self.any?
      active_player = nil
      @apps.each {|app|
        player = Player.new(app)
        if player.running?
          active_player = player
          break
        end
      }
      active_player
    else
      nil
    end
  end
end

class Player < String
  attr_reader :app

  def initialize(app)
    @app = app.capitalize
  end

  # App is running and playing
  # @return boolean
  def active?
    self.running? && self.playing?
  end

  # Is app running?
  # @return boolean
  def running?
    not `ps ax|grep "#{@app}.app/Contents/MacOS/#{@app}"|grep -v grep`.strip.empty?
  end

  # Is player state playing?
  # @return boolean
  def playing?
    res = %x{osascript -e 'tell application "#{@app}" to return (player state is equal to playing)'}.strip
    res == 'true'
  end

  # Currently playing track
  # @return hash {:title, :artist}
  def track
    res = %x{osascript -e 'tell application "#{@app}" to return (name of current track) & "::" & (artist of current track)'}.strip.split(/::/)
    "#{res[0]} — #{res[1]} (#{@app})"
  end

  # Pause the active player
  # @return success message
  def pause
    %x{osascript -e 'tell application "#{@app}" to pause'}.strip
    "#{@app} paused"
  end

  # Play the active player
  # @return track title string
  def play
    %x{osascript -e 'tell application "#{@app}" to play'}.strip
    track
  end

  # Skip to the next track in active player
  # @return string with new track
  def next
    %x{osascript -e 'tell application "#{@app}" to next track'}.strip
    track
  end

  # Skip to the previous track in active player
  # @return string with new track
  def prev
    %x{osascript -e 'tell application "#{@app}" to previous track'}.strip
    track
  end

  # Get active player volume
  # @return string with current volume
  def volume
    res = %x{osascript -e 'tell application "#{@app}" to return sound volume'}.strip
    "#{@app} Volume: #{res}%"
  end

  # Set active player volume
  # @return string with new volume
  def set_volume(level)
    %x{osascript -e 'tell application "#{@app}" to set sound volume to #{level.to_i}'}
    volume
  end

  # Set active player volume to 0
  # @return string with new volume
  def mute
    set_volume(0)
    volume
  end
end

players = Players.new(KNOWN_PLAYERS)

if players.legit?(ARGV[0])
  player = Player.new(ARGV.shift)
else
  player = players.running
end

if player.nil?
  $stderr.puts "No music app running"
  Process.exit 1
end

case ARGV[0]
when /play/
  puts player.play
when /pause/
  puts player.pause
when /(fwd|next)/
  puts player.next
when /(back|prev)/
  puts player.prev
when /vol(ume)?/
  if ARGV[1].nil?
    puts player.volume
  else
    puts player.set_volume ARGV[1].to_i
  end
when /mute/
  puts player.mute
when /(player|which)/
  puts player.app
else
  unless player.active?
    $stderr.puts "No track playing"
  else
    puts player.track
    Process.exit 0
  end
end