Update Slack status with Spotify track

update_slack_status_with_spotify_track.rb

#!/bin/ruby

require "pathname"
module UpdateSlackStatusWithSpotifyTrack
  module_function

  DBFILE = Pathname.new("/tmp/current_track")

  class Spotify
    SpotifyData = Struct.new(
      :player_position, 
      :player_state, 
      :track_artist, 
      :track_name, 
      :track_duration
    )

    attr_accessor :data

    def initialize
      hydrate_from_osascript
    end

    def hydrate_from_osascript
      output = %x[
        osascript \
          -e 'tell application "Spotify" to set playerPosition to player position' \
          -e 'tell application "Spotify" to set playerState to player state' \
          -e 'tell application "Spotify" to set trackArtist to artist of current track' \
          -e 'tell application "Spotify" to set trackName to name of current track' \
          -e 'tell application "Spotify" to set trackDuration to duration of current track' \
          -e 'set d to "|"' \
          -e '{playerPosition, d, playerState, d, trackArtist, d, trackName, d, trackDuration}'
      ].chomp

      self.data = SpotifyData.new(*output.split(", |, "))
    end

    def player_position
      data.player_position.to_f
    end

    def playing?
      data.player_state == "playing"
    end

    def track_title
      return "" unless playing?
      [data.track_artist, data.track_name].join(" - ")
    end

    def track_duration
      data.track_duration.to_i / 1000
    end

    def track_duration_remaining
      track_duration - player_position
    end
  end

  require "net/http"
  require "uri"
  require "json"
  module Slack
    module_function

    API_KEY = ARGV[0]

    def update_status(text:, emoji:, expiration: 0)
      payload = {
        profile: {
          status_emoji: emoji,
          status_expiration: expiration,
          status_text: text
        }
      }

      uri = URI("https://slack.com/api/users.profile.set")
      http = Net::HTTP.new(uri.host, uri.port)
      http.use_ssl = true

      request = Net::HTTP::Post.new(uri.request_uri)
      request.add_field("Content-Type", "application/json; charset=utf-8")
      request.add_field("Authorization", "Bearer #{API_KEY}")
      request.body = JSON.dump(payload)

      http.request(request)
    end
  end

  def call
    current = spotify.track_title
    previous = read_track_title

    return if current == previous

    current == "" ? reset : update(current)
  rescue SignalException
    reset
  end

  def spotify
    @spotify ||= Spotify.new
  end

  def reset
    store_track_title ""

    Slack.update_status(
      emoji: "",
      text: ""
    )
  end

  def update(track_title)
    store_track_title track_title

    Slack.update_status(
      emoji: ":headphones:",
      expiration: (Time.new + spotify.track_duration_remaining + 60).to_i,
      text: track_title
    )
  end

  def store_track_title(song)
    File.write(DBFILE, song)
  end

  def read_track_title
    File.exist?(DBFILE) ? File.read(DBFILE) : ""
  end
end

UpdateSlackStatusWithSpotifyTrack.call