// PostLastFM allows access to the Last.fm API, enabling wavepipe to set a user's currently-playing
// track, as well as to enable scrobbling.
func PostLastFM(w http.ResponseWriter, r *http.Request) {
// Retrieve render
ren := context.Get(r, CtxRender).(*render.Render)
// Attempt to retrieve user from context
user := new(data.User)
if tempUser := context.Get(r, CtxUser); tempUser != nil {
user = tempUser.(*data.User)
} else {
// No user stored in context
log.Println("api: no user stored in request context!")
ren.JSON(w, 500, serverErr)
return
}
// Output struct for Last.fm response
out := LastFMResponse{}
// Check API version
if version, ok := mux.Vars(r)["version"]; ok {
// Check if this API call is supported in the advertised version
if !apiVersionSet.Has(version) {
ren.JSON(w, 400, errRes(400, "unsupported API version: "+version))
return
}
}
// Do not allow guests and below to use Last.fm functionality
if user.RoleID < data.RoleUser {
ren.JSON(w, 403, permissionErr)
return
}
// Check API action
action, ok := mux.Vars(r)["action"]
if !ok {
ren.JSON(w, 400, errRes(400, "no string action provided"))
return
}
// Check for valid action
if !set.New(lfmLogin, lfmNowPlaying, lfmScrobble).Has(action) {
ren.JSON(w, 400, errRes(400, "invalid string action provided"))
return
}
// Instantiate Last.fm package
lfm := lastfm.New(lfmAPIKey, lfmAPISecret)
// Authenticate to the Last.fm API
if action == lfmLogin {
// Retrieve username from POST body
username := r.PostFormValue("username")
if username == "" {
ren.JSON(w, 400, errRes(400, lfmLogin+": no username provided"))
return
}
// Retrieve password from POST body
password := r.PostFormValue("password")
if password == "" {
ren.JSON(w, 400, errRes(400, lfmLogin+": no password provided"))
return
}
// Send a login request to Last.fm
if err := lfm.Login(username, password); err != nil {
ren.JSON(w, 401, errRes(401, lfmLogin+": last.fm authentication failed"))
return
}
// Retrieve the API token for this user with wavepipe
token, err := lfm.GetToken()
if err != nil {
log.Println(err)
ren.JSON(w, 500, serverErr)
return
}
// Store the user's Last.fm token in the database
user.LastFMToken = token
if err := user.Update(); err != nil {
log.Println(err)
ren.JSON(w, 500, serverErr)
return
}
// Return the token authorization URL for the user
out.URL = lfm.GetAuthTokenUrl(token)
log.Println(lfmLogin, ": generated new token for user:"******"" {
ren.JSON(w, 401, errRes(401, action+": user must authenticate to last.fm"))
return
}
// Send a login request to Last.fm using token
if err := lfm.LoginWithToken(user.LastFMToken); err != nil {
// Check if token has not been authorized
if strings.HasPrefix(err.Error(), "LastfmError[14]") {
// Generate error output, but add the token authorization URL
out.URL = lfm.GetAuthTokenUrl(user.LastFMToken)
ren.JSON(w, 401, errRes(401, action+": last.fm token not yet authorized"))
return
}
// All other failures
ren.JSON(w, 401, errRes(401, action+": last.fm authentication failed"))
return
}
// Check for an ID parameter
pID, ok := mux.Vars(r)["id"]
if !ok {
ren.JSON(w, 400, errRes(400, action+": no integer song ID provided"))
return
}
// Verify valid integer ID
id, err := strconv.Atoi(pID)
if err != nil {
ren.JSON(w, 400, errRes(400, action+": invalid integer song ID"))
return
}
// Load the song by ID
song := &data.Song{ID: id}
if err := song.Load(); err != nil {
// Check for invalid ID
if err == sql.ErrNoRows {
ren.JSON(w, 404, errRes(404, action+": song ID not found"))
return
}
// All other errors
log.Println(err)
ren.JSON(w, 500, serverErr)
return
}
// Log the current action
log.Printf("%s : %s : [#%05d] %s - %s", action, user.Username, song.ID, song.Artist, song.Title)
// Create the track entity required by Last.fm from the song
track := lastfm.P{
"artist": song.Artist,
"album": song.Album,
"track": song.Title,
"timestamp": time.Now().Unix(),
}
// Check for optional timestamp parameter, which could be useful for sending scrobbles at
// past times, etc
if pTS := r.URL.Query().Get("timestamp"); pTS != "" {
// Verify valid integer timestamp
ts, err := strconv.Atoi(pTS)
if err != nil || ts < 0 {
ren.JSON(w, 400, errRes(400, action+": invalid integer timestamp"))
return
}
// Override previously set timestamp with this one
track["timestamp"] = ts
}
// Send a now playing request to the Last.fm API
if action == lfmNowPlaying {
// Perform the action
if _, err := lfm.Track.UpdateNowPlaying(track); err != nil {
log.Println(err)
ren.JSON(w, 500, serverErr)
return
}
// HTTP 200 OK with JSON
out.Error = nil
ren.JSON(w, 200, out)
return
}
// Send a scrobble request to the Last.fm API
if action == lfmScrobble {
// Perform the action
if _, err := lfm.Track.Scrobble(track); err != nil {
log.Println(err)
ren.JSON(w, 500, serverErr)
return
}
// HTTP 200 OK with JSON
out.Error = nil
ren.JSON(w, 200, out)
return
}
// Invalid action, meaning programmer error, HTTP 500
panic("no such Last.fm action: " + action)
}
