Get currently playing track on Spotify desktop - MacOS and Linux

spotify.applescript

on escape_quotes(string_to_escape)
  set AppleScript's text item delimiters to the "\""
  set the item_list to every text item of string_to_escape
  set AppleScript's text item delimiters to the "\\\""
  set string_to_escape to the item_list as string
  set AppleScript's text item delimiters to ""
  return string_to_escape
end escape_quotes

tell application "Spotify"
  set ctrack to "{"
  set ctrack to ctrack & "\"artist\": \"" & my escape_quotes(current track's artist) & "\""
  set ctrack to ctrack & ",\"album\": \"" & my escape_quotes(current track's album) & "\""
  set ctrack to ctrack & ",\"disc_number\": " & current track's disc number
  set ctrack to ctrack & ",\"duration\": " & current track's duration
  set ctrack to ctrack & ",\"played_count\": " & current track's played count
  set ctrack to ctrack & ",\"track_number\": " & current track's track number
  set ctrack to ctrack & ",\"popularity\": " & current track's popularity
  set ctrack to ctrack & ",\"id\": \"" & current track's id & "\""
  set ctrack to ctrack & ",\"name\": \"" & my escape_quotes(current track's name) & "\""
  set ctrack to ctrack & ",\"album_artist\": \"" & my escape_quotes(current track's album artist) & "\""
  set ctrack to ctrack & ",\"artwork_url\": \"" & current track's artwork url & "\""
  set ctrack to ctrack & ",\"spotify_url\": \"" & current track's spotify url & "\""
  set ctrack to ctrack & "}"

  return ctrack
end tell

spotify.go

package main

import (
  "log"
  "fmt"
  "runtime"
  "os/exec"

  dbus "github.com/godbus/dbus"
)

// Track is a struct to represent what's mostly synonymous with a Song
type Track struct {
	Genre       string
	Meta        Meta
	Title       string `json:"name"`
	Artist      string `json:"artist"`
	Album       string `json:"album"`
	AlbumArtist string `json:"album_artist"`
	ArtworkUrl  string `json:"artwork_url"`
}

func main() {
  var trackIdentifier func() (*Track, error)

	if runtime.GOOS == "linux" {
		trackIdentifier = trackIdentifierLinux
	} else if runtime.GOOS == "darwin" {
		trackIdentifier = trackIdentifierDarwin
	}

  track, _ := trackIdentifier()

  fmt.Printf("Track: %v\n", track)
}

// trackIdentifierLinux is the linux variant of a function to identify tracks.
func trackIdentifierLinux() (*Track, error) {
	conn, err := dbus.SessionBus()

	if err != nil {
		log.Panicf("Could not open a session bus. Error: %s", err.Error())
	}

	spotify := conn.Object("org.mpris.MediaPlayer2.spotify", "/org/mpris/MediaPlayer2")

	metadata, _ := spotify.GetProperty("org.mpris.MediaPlayer2.Player.Metadata")
	songData := metadata.Value().(map[string]dbus.Variant)

	track := Track{
		Title:       songData["xesam:title"].Value().(string),
		Artist:      songData["xesam:artist"].Value().([]string)[0],
		Album:       songData["xesam:album"].Value().(string),
		AlbumArtist: songData["xesam:albumArtist"].Value().([]string)[0],
		ArtworkUrl:  songData["mpris:artUrl"].Value().(string),
	}

	return &track, nil
}

// trackIdentifierDarwin is the MacOS variant.
func trackIdentifierDarwin() (*Track, error) {
	cmd := exec.Command("osascript", "spotify.applescript")
	out, _ := cmd.CombinedOutput()

	track := &Track{}
	err := json.Unmarshal(out, track)

	return track, err
}