branch: externals/emms
commit 03206d049a69669c65e657116e2e022da3954a70
Author: Fran Burstall <fran.burst...@gmail.com>
Commit: Fran Burstall <fran.burst...@gmail.com>
* emms-listenbrainz-scrobbler.el: new file
Scrobble tracks to listenbrainz.org
---
emms-listenbrainz-scrobbler.el | 262 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 262 insertions(+)
diff --git a/emms-listenbrainz-scrobbler.el b/emms-listenbrainz-scrobbler.el
new file mode 100644
index 0000000000..8cd26b6604
--- /dev/null
+++ b/emms-listenbrainz-scrobbler.el
@@ -0,0 +1,262 @@
+;;; emms-listenbrainz-scrobbler.el --- Listenbrainz Scrobbling API -*-
lexical-binding: t; -*-
+
+;; Copyright (C) 2024 Free Software Foundation, Inc.
+
+;; Author: Fran Burstall <fran.burst...@gmail.com>
+;; Keywords: emms, listenbrainz
+
+;; EMMS is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+;;
+;; EMMS is distributed in the hope that it will be useful, but WITHOUT
+;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+;; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+;; License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with EMMS; see the file COPYING. If not, write to the Free
+;; Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+;; MA 02110-1301, USA.
+
+;;; Commentary:
+
+;; To use listenbrainz you need to add a user token to
+;; ~/.authinfo.gpg or an equivalent file understood by auth-source
+;; with a line like this:
+
+;; machine api.listenbrainz.org password 0abc1de2-245-67fa-8906b-bc123d4dbdaa
+
+;; To enable scrobbling call (emms-listenbrainz-scrobbler-enable).
+
+
+;;; Code:
+
+;;* Requires
+
+(require 'emms-playing-time)
+(require 'auth-source)
+(require 'json)
+(require 'url-vars)
+
+;;* Vars
+
+(defvar emms-listenbrainz-scrobbler-host
+ "api.listenbrainz.org"
+ "Listenbrainz server we target.")
+
+(defvar emms-listenbrainz-scrobbler-token nil
+ "Listenbrainz user token.
+
+Note that the preferred way of authenticating is using authinfo.")
+
+(defvar emms-listenbrainz-scrobbler-submission-url
+ (concat "https://"; emms-listenbrainz-scrobbler-host "/1/submit-listens")
+ "URL for submissions.")
+
+(defvar emms-listenbrainz-scrobbler-track-play-start-timestamp
+ nil
+ "Time when a track started playing.")
+
+(defvar emms-listenbrainz-scrobbler-display-submissions
+ t
+ "Whether to display a user message on every submission.")
+
+(defvar emms-listenbrainz-scrobbler-running
+ nil
+ "Non-nil if emms-listenbrainz-scrobbler is active.")
+
+
+;;* User token
+
+(defun emms-listenbrainz-scrobbler--get-auth-token ()
+ "Return user token from auth-source."
+ (plist-get (car (auth-source-search :host emms-listenbrainz-scrobbler-host
+ :max 1
+ :require '(:secret)))
+ :secret))
+
+(declare-function emms-listenbrainz-scrobbler-get-token
"emms-listenbrainz-scrobbler")
+(let ((token))
+ (defun emms-listenbrainz-scrobbler-get-token ()
+ "Return user token."
+ (unless token
+ (setq token (emms-listenbrainz-scrobbler--get-auth-token)))
+ (cond ((functionp token) (funcall token))
+ ((characterp token) token)
+ (t emms-listenbrainz-scrobbler-token))))
+
+
+;;* Payload
+;; there are two types of query: listen and now-playing. The latter
+;; is ephemeral and does not want the listened_at timestamp.
+
+(defun emms-listenbrainz-scrobbler-make-query (track &optional playing-now)
+ "Collect the data from TRACK. No timestamp when PLAYING-NOW is non-nil."
+ (let ((artist (substring-no-properties (emms-track-get track 'info-artist)))
+ (title (substring-no-properties (emms-track-get track 'info-title)))
+ (album (substring-no-properties (emms-track-get track 'info-album)))
+ (track-number (emms-track-get track 'info-tracknumber))
+ ;; (musicbrainz-id "")
+ (track-length (emms-track-get track
+ 'info-playing-time))
+ payload metadata extra-data data)
+ (unless (and title artist) (error "Track title and artist must be known"))
+ ;; assemble metadata
+ (push (cons "artist_name" artist) metadata)
+ (push (cons "track_name" title) metadata)
+ (when album (push (cons "release_name" album) metadata))
+ ;; additional data
+ (when track-number (push (cons "tracknumber" (string-to-number
track-number))
+ extra-data))
+ (when track-number (push (cons "duration" track-length) extra-data))
+ (when extra-data (push (cons "additional_info" extra-data) metadata))
+ ;; payload
+ (push (cons "track_metadata" metadata) payload)
+ (unless playing-now
+ (push (cons "listened_at"
+ (or emms-listenbrainz-scrobbler-track-play-start-timestamp
+ (time-convert nil 'integer)))
+ payload))
+ ;; the whole package
+ (push (cons "payload" (vector payload)) data)
+ (push (cons "listen_type" (if playing-now "playing_now" "single")) data)
+ data))
+
+
+;;* Asynchronous submission
+
+;; In memorium: seek how much shorter, neater and comprehensible this code is.
+
+;; (defun emms-listenbrainz-scrobbler-make-async-submission-call (track
&optional playing-now)
+;; "Submit listen, or playing-now if PLAYING-NOW non-nil, of TRACK to
listenbrainz."
+;; (let ((data (emms-listenbrainz-scrobbler-make-query track playing-now))
+;; (token (emms-listenbrainz-scrobbler-get-token))
+;; (title (emms-track-get track 'info-title)))
+;; (request emms-listenbrainz-scrobbler-submission-url
+;; :type "POST"
+;; :parser 'json-read
+;; :headers `(("Content-type" . "application/json; charset=utf-8")
+;; ("Authorization" . ,(concat "Token " token)))
+;; :data (json-encode data)
+;; :success
+;; (lambda (&rest _)
+;; (when (and (not playing-now)
emms-listenbrainz-scrobbler-display-submissions)
+;; (message "Listenbrainz: submitted %s." title)))
+;; :error
+;; (cl-function (lambda (&rest args &key error-thrown &allow-other-keys)
+;; (message "Listenbrainz error: %S when submitting %s"
+;; error-thrown title))))))
+
+;; we try to use the built-in url. This was a struggle to get right
+;; with respect to handling things like kanji. The solution is to
+;; encode absolutely anything beyond literal strings (so output of
+;; concat, for example) that might end up in the request: not just
+;; data but headers!
+
+(defun emms-listenbrainz-scrobbler-make-async-submission-call (track &optional
playing-now)
+ "Submit listen, or playing-now if PLAYING-NOW non-nil, of TRACK to
listenbrainz."
+ (let* ((payload (emms-listenbrainz-scrobbler-make-query track playing-now))
+ (token (emms-listenbrainz-scrobbler-get-token))
+ (token-string (encode-coding-string (concat "Token " token) 'utf-8))
+ (url-request-method "POST")
+ (url-request-data (encode-coding-string (json-encode payload) 'utf-8))
+ (url-request-extra-headers `(("Content-type" . "application/json;
charset=utf-8")
+ ("Authorization" . ,token-string))))
+ (ignore url-request-method
+ url-request-data
+ url-request-extra-headers)
+ (url-retrieve
+ emms-listenbrainz-scrobbler-submission-url
+ #'emms-listenbrainz-scrobbler-submission-callback
+ (list (cons track playing-now)))))
+
+(defun emms-listenbrainz-scrobbler-submission-callback (status &optional
cbargs)
+ "Callback to handle response from listenbrainz server.
+
+Ignore STATUS argument and store submission data in CBARGS."
+ (ignore status)
+ (when (< (point-max) 1)
+ (error "No response from submission server"))
+ (goto-char (point-min ))
+ (let* ((response (ignore-errors
+ (re-search-forward "\n\n")
+ (json-read)))
+ (track (car cbargs))
+ (playing-now (cdr cbargs))
+ (title (emms-track-get track 'info-title)))
+ (cond ((string= "ok" (alist-get 'status response))
+ (when (and (not playing-now)
emms-listenbrainz-scrobbler-display-submissions)
+ (message "Listenbrainz: submitted %s." title))
+ ;; tidy up
+ (kill-buffer))
+ ((assoc 'error response)
+ (message "Listenbrainz error: %s while submitting %s"
+ (alist-get 'error response)
+ title))
+ (t (error "Listenbrainz: unhandled error while submitting %s"
title)))))
+
+
+;;* Hooks
+
+(defun emms-listenbrainz-scrobbler-start-hook ()
+ "Record track start time."
+ (setq emms-listenbrainz-scrobbler-track-play-start-timestamp
+ (time-convert nil 'integer))
+ (let* ((current-track (emms-playlist-current-selected-track))
+ (good-to-submit (eq (emms-track-type current-track) 'file)))
+ (when good-to-submit
+ (emms-listenbrainz-scrobbler-make-async-submission-call
+ current-track t))))
+
+(defun emms-listenbrainz-scrobbler-stop-hook ()
+ "Submit the track to listenbrainz if we have listened long enough.
+
+That is, if it has been played for 240 seconds or half the length of the
track."
+ (let ((current-track (emms-playlist-current-selected-track)))
+ (let ((track-length (emms-track-get current-track 'info-playing-time)))
+ (when (and track-length
+ ;; only submit files
+ (eq (emms-track-type current-track) 'file))
+ (when (and
+ ;; track must be longer than 30 secs
+ (> track-length 30)
+ ;; track must be played for more than 240 secs or
+ ;; half the tracks length, whichever comes first.
+ (> emms-playing-time (min 240 (/ track-length 2))))
+ (emms-listenbrainz-scrobbler-make-async-submission-call
+ current-track))))))
+
+
+;;* Entry points
+(defun emms-listenbrainz-scrobbler-enable ()
+ "Enable the scrobbler and submit played tracks."
+ (interactive)
+ ;; check we have credentials
+ (if (emms-listenbrainz-scrobbler-get-token)
+ (unless emms-listenbrainz-scrobbler-running
+ (add-hook 'emms-player-started-hook
+ 'emms-listenbrainz-scrobbler-start-hook t)
+ (add-hook 'emms-player-stopped-hook
+ 'emms-listenbrainz-scrobbler-stop-hook)
+ (add-hook 'emms-player-finished-hook
+ 'emms-listenbrainz-scrobbler-stop-hook)
+ (setq emms-listenbrainz-scrobbler-running t))
+ (error "Listenbrainz scrobbler: no user token. Please supply and try
again")))
+
+(defun emms-listenbrainz-scrobbler-disable ()
+ "Disable the scrobbler and don't submit played tracks."
+ (interactive)
+ (when emms-listenbrainz-scrobbler-running
+ (remove-hook 'emms-player-started-hook
+ 'emms-listenbrainz-scrobbler-start-hook)
+ (remove-hook 'emms-player-stopped-hook
+ 'emms-listenbrainz-scrobbler-stop-hook)
+ (remove-hook 'emms-player-finished-hook
+ 'emms-listenbrainz-scrobbler-stop-hook)
+ (setq emms-listenbrainz-scrobbler-running nil)))
+
+
+(provide 'emms-listenbrainz-scrobbler)
+;;; emms-listenbrainz-scrobbler.el ends here
