spotify.go

package main

// credit to https://github.com/lacymorrow/album-art
// thanks for the token too :)

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"net/http"
	"net/url"
	// "sort"
	"strings"

	"github.com/godbus/dbus/v5"
)

const (
	art_endpoint = "https://api.spotify.com/v1"
	auth_endpoint = "https://accounts.spotify.com/api/token"
	art_api_id = "3f974573800a4ff5b325de9795b8e603"
	art_api_secret = "ff188d2860ff44baa57acc79c121a3b9"
	art_api_auth = art_api_id + ":" + art_api_secret
)

type spotifyFetcher struct{}

type spotifyAccess struct{
	AccessToken string `json:"access_token"`
}

type spotifySeach struct{
	Tracks spotifyTrack `json:"tracks"`
	Albums struct{
		Items []spotifyAlbum `json:"items"`
	} `json:"albums"`
}

type spotifyTrack struct{
	Items []spotifyTrackObject `json:"items"`
}

type spotifyTrackObject struct{
	Album spotifyAlbum `json:"album"`
}

type spotifyAlbum struct{
	Images []spotifyArt
	Name string
}

type spotifyArt struct {
	Width int
	Height int
	URL string
}

func handleSpotErr(err error) string {
	fmt.Fprintln(os.Stderr, err)
	return "music"
}

func (spotifyFetcher) getAlbumArt(artist, album, title string, mdata map[string]dbus.Variant) string {
	spotSearchQuery := url.PathEscape(url.QueryEscape(fmt.Sprintf("track:%s artist:%s album:%s", title, artist, album)))
	if album == "" {
		spotSearchQuery = url.PathEscape(url.QueryEscape(fmt.Sprintf("track:%s artist:%s", title, artist)))
	}
	artUrl, _ := url.Parse(fmt.Sprintf("%s/search?q=%s&type=track,album&limit=1", art_endpoint, spotSearchQuery))
	authUrl, _ := url.Parse(auth_endpoint)

	req, err := http.NewRequest("POST", authUrl.String(), strings.NewReader("grant_type=client_credentials"))
	if err != nil {
		return handleSpotErr(err)
	}
	req.Header.Add("Authorization", "Basic " + base64.StdEncoding.EncodeToString([]byte(art_api_auth)))
	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return handleSpotErr(err)
	}

	body, err := io.ReadAll(resp.Body)
	spot := &spotifyAccess{}
	if err := json.Unmarshal(body, &spot); err != nil {
		return handleSpotErr(err)
	}

	req, err = http.NewRequest("GET", artUrl.String(), strings.NewReader(""))
	req.Header.Add("Authorization", "Bearer " + spot.AccessToken)
	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	resp, err = http.DefaultClient.Do(req)
	if err != nil {
		return handleSpotErr(err)
	}

	body, err = io.ReadAll(resp.Body)
	logger.Debug(string(body))

	spotifyData := &spotifySeach{}
	if err := json.Unmarshal(body, &spotifyData); err != nil {
		return handleSpotErr(err)
	}

	// may or may not be needed (will see)
	/*
	sort.Slice(images, func(i, j int) bool {
		return images[i].Width > images[j].Width
	})
	*/

	if len(spotifyData.Tracks.Items) != 0 {
		return spotifyData.Tracks.Items[0].Album.Images[0].URL
	}

	if len(spotifyData.Albums.Items) == 0 {
		// nothing found
		fmt.Fprintln(os.Stderr, "Nothing found on spotify for", album)
		return "music"
	}

	return spotifyData.Albums.Items[0].Images[0].URL
}