Files
gonic/server/lastfm/lastfm.go
2019-06-05 17:34:01 +01:00

97 lines
2.3 KiB
Go

package lastfm
import (
"crypto/md5"
"encoding/hex"
"encoding/xml"
"fmt"
"net/http"
"net/url"
"sort"
"strconv"
"time"
"github.com/pkg/errors"
"github.com/sentriz/gonic/model"
)
var (
baseURL = "https://ws.audioscrobbler.com/2.0/"
client = &http.Client{
Timeout: 10 * time.Second,
}
)
func GetSession(apiKey, secret, token string) (string, error) {
params := url.Values{}
params.Add("method", "auth.getSession")
params.Add("api_key", apiKey)
params.Add("token", token)
params.Add("api_sig", getParamSignature(params, secret))
resp, err := makeRequest("GET", params)
if err != nil {
return "", errors.Wrap(err, "making session GET")
}
return resp.Session.Key, nil
}
func Scrobble(apiKey, secret, session string, track *model.Track,
stampMili int, submission bool) error {
params := url.Values{}
if submission {
params.Add("method", "track.Scrobble")
// last.fm wants the timestamp in seconds
params.Add("timestamp", strconv.Itoa(stampMili/1e3))
} else {
params.Add("method", "track.updateNowPlaying")
}
params.Add("api_key", apiKey)
params.Add("sk", session)
params.Add("artist", track.TagTrackArtist)
params.Add("track", track.TagTitle)
params.Add("album", track.Album.TagTitle)
params.Add("albumArtist", track.Artist.Name)
params.Add("trackNumber", strconv.Itoa(track.TagTrackNumber))
params.Add("api_sig", getParamSignature(params, secret))
_, err := makeRequest("POST", params)
return err
}
func getParamSignature(params url.Values, secret string) string {
// the parameters must be in order before hashing
paramKeys := make([]string, 0)
for k := range params {
paramKeys = append(paramKeys, k)
}
sort.Strings(paramKeys)
toHash := ""
for _, k := range paramKeys {
toHash += k
toHash += params[k][0]
}
toHash += secret
hash := md5.Sum([]byte(toHash))
return hex.EncodeToString(hash[:])
}
func makeRequest(method string, params url.Values) (*LastFM, error) {
req, _ := http.NewRequest(method, baseURL, nil)
req.URL.RawQuery = params.Encode()
resp, err := client.Do(req)
if err != nil {
return nil, errors.Wrap(err, "get")
}
defer resp.Body.Close()
decoder := xml.NewDecoder(resp.Body)
lastfm := &LastFM{}
err = decoder.Decode(lastfm)
if err != nil {
return nil, errors.Wrap(err, "decoding")
}
if lastfm.Error != nil {
return nil, fmt.Errorf("parsing: %v", lastfm.Error.Value)
}
return lastfm, nil
}