downloads track(s) (plural) from spotify (premium) with librespot LO LOLOLOLOLLO OLOLOLLOLLOLOOLLOLOOLOLOLOOLOLOLOLOLO

librespot-download.go

package main

// AS OF this being posted, librespot-golang has some deadlocking and you will need to use this fork: https://github.com/benpye/librespot-golang

import (
	"Spotify"
	"librespot"
	"librespot/core"
	"librespot/utils"

	"github.com/mitchellh/ioprogress"

	"encoding/json"
	"strings"

	"io/ioutil"
	"io"
	"os"

	"log"
	"fmt"
)

const (
  username = "change this change this"
	password = "change this change this"
	deviceName = "librespot"
)

func main() {
	if len(os.Args) < 2 {
		fmt.Println(`usage:", os.Args[0], "(json of [ [id, filename], [id, filename] ])
like [ ["7sNoYrWSysPqaTT5LCMEmn", "/dev/shm/oedo-controller.ogg"] ] and multiple assets etc`)
		os.Exit(0)
	}

	var tracksToDownload [][]string
	err := json.Unmarshal([]byte(os.Args[1]), &tracksToDownload)
	if err != nil {
		log.Fatal("your json argument is invalid:", err)
	}

	var session *core.Session

	log.Println("logging in... checking if blob exists (spotify-auth-blob.bin)")
	blobBytes, err := ioutil.ReadFile("spotify-auth-blob.bin")
	if err != nil && !os.IsNotExist(err) {
		log.Fatal("err loading blob:", err)
	}
	if blobBytes != nil {
		log.Println("blob exists, logging in with it...")
		session, err = librespot.LoginSaved(username, blobBytes, deviceName)
	} else {
		log.Println("blob doesn't exist, logging in with username & password... (will create blob)")
		session, err = librespot.Login(username, password, deviceName)
	}
	if err != nil {
		log.Fatal("err logging in:", err)
	}
	if blobBytes == nil {
		log.Println("creating blob... (spotify-auth-blob.bin)")
		blobFile, err := os.Create("spotify-auth-blob.bin")
		if err != nil {
			log.Fatal("err creating blob file:", err)
		}
		blobFile.Write(session.ReusableAuthBlob())
		blobFile.Close()
		log.Println("wrote blob.")
	}
	// phew
	log.Println("iterating through argument...")
	for _, trackToDownload := range tracksToDownload {
		if strings.HasPrefix(trackToDownload[0], "spotify:track:") {
			trackToDownload[0] = strings.TrimPrefix(trackToDownload[0], "spotify:track:")
		}
		log.Println("loading track " + trackToDownload[0])
		track, err := session.Mercury().GetTrack(utils.Base62ToHex(trackToDownload[0]))
		if err != nil {
			log.Println("err loading track:", err)
			continue
		}
		trackName := track.GetName()
		if trackName == "" {
			log.Println("track doesn't exist, skipping...")
			continue
		}
		var selectedFile *Spotify.AudioFile
		for _, file := range track.GetFile() {
			if file.GetFormat() == Spotify.AudioFile_OGG_VORBIS_320 {
				selectedFile = file
				break
			}
		}

		if len(trackToDownload) < 2 || trackToDownload[1] == "" {
			trackToDownload = []string{
				trackToDownload[0],
				strings.Replace(strings.Replace(strings.ToLower(trackName), " ", "-", -1), "/", "", -1) + ".ogg",
			}
		}

		downloadFile, err := os.Create(trackToDownload[1])
		if err != nil {
			log.Println("err creating file " + trackToDownload[1] + ":", err)
			log.Println("skipping track " + trackName)
			continue
		}
		log.Println("downloading track " + trackName + "...")

		audioFile, err := session.Player().LoadTrack(selectedFile, track.GetGid())
		if err != nil {
			log.Println("err downloading track:", err)
			log.Println("skipping track " + trackName)
			continue
		}

		// copy
		progressReader := &ioprogress.Reader{
			Reader: audioFile,
		}

		io.Copy(downloadFile, progressReader)
		downloadFile.Close()
		log.Println("track " + trackName + " finished")
	}
	log.Println("finished")
}