* lisp/emms-librefm-scrobbler.el: Complete working libre.fm scrobbler.

1 files changed, 145 insertions, 1 deletions

diff --git a/lisp/emms-librefm-scrobbler.el b/lisp/emms-librefm-scrobbler.el
index 0afd39e..d2b7d55 100644
--- a/lisp/emms-librefm-scrobbler.el
+++ b/lisp/emms-librefm-scrobbler.el
@@ -1,4 +1,4 @@
-;;; emms-librefm-scrobbler.el --- Last.FM Music API
+;;; emms-librefm-scrobbler.el --- Libre.FM Scrobbing API
 
 ;; Copyright (C) 2014  Free Software Foundation, Inc.
 
@@ -56,6 +56,18 @@
   ""
   "URL for submissions.")
 
+(defvar emms-librefm-scrobbler-track-play-start-timestamp
+  nil
+  "Time when a track started playing.")
+
+(defvar emms-librefm-scrobbler-display-submissions
+  nil
+  "Whether to display each submission as a message.")
+
+
+;;; ------------------------------------------------------------------
+;;; handshake
+;;; ------------------------------------------------------------------
 
 (defun emms-librefm-scrobbler-handshake-string (url username password)
   "Return the client handshake string."
@@ -135,6 +147,138 @@
     emms-librefm-scrobbler-password)))
 
 
+;;; ------------------------------------------------------------------
+;;; submission
+;;; ------------------------------------------------------------------
+
+(defun emms-librefm-scrobbler-make-query (track rating)
+  "Format the url parameters for scrobbling."
+  (setq rating
+	(cond ((equal 'love rating) "L")
+	      ((equal 'ban rating)  "B")
+	      ((equal 'skip rating) "S")
+	      (t "")))
+  (let ((artist (emms-track-get track 'info-artist))
+	(title  (emms-track-get track 'info-title))
+	(album  (or (emms-track-get track 'info-album) ""))
+	(track-number (emms-track-get track 'info-tracknumber))
+	(musicbrainz-id "")
+	(track-length (number-to-string
+		       (or (emms-track-get track
+					   'info-playing-time)
+			   0))))
+    (if (and artist title)
+	(concat
+	 "s=" emms-librefm-scrobbler-session-id
+	 "&a[0]=" (url-encode-url artist)
+	 "&t[0]=" (url-encode-url title)
+	 "&i[0]=" (url-encode-url
+		   (or emms-librefm-scrobbler-track-play-start-timestamp
+		       (format-time-string "%s")))
+	 "&o[0]=" "P"
+	 "&r[0]=" (url-encode-url rating)
+	 "&l[0]=" track-length
+	 "&b[0]=" (url-encode-url album)
+	 "&n[0]=" track-number
+	 "&m[0]=" musicbrainz-id)
+      (error "Track title and artist must be known."))))
+
+
+;;; ------------------------------------------------------------------
+;;; asynchronous submission
+;;; ------------------------------------------------------------------
+
+(defun emms-librefm-scrobbler-get-response-status ()
+  "Check the HTTP header and return the body."
+  (let ((ok200 "HTTP/1.1 200 OK"))
+    (if (< (point-max) 1)
+	(error "No response from submission server"))
+    (if (not (string= ok200 (buffer-substring-no-properties (point-min) 16)))
+	(error "submission server not responding correctly"))
+    (goto-char (point-min))
+    (re-search-forward "\n\n")
+    (buffer-substring-no-properties
+     (point-at-bol) (point-at-eol))))
+
+(defun emms-librefm-scrobbler-make-async-submission-call (track rating)
+  "Make asynchronous submission call."
+  (let ((flarb (emms-librefm-scrobbler-make-query track rating)))
+    (let* ((url-request-method "POST")
+	   (url-request-data flarb)
+	   (url-request-extra-headers
+	    `(("Content-type" . "application/x-www-form-urlencoded"))))
+      (url-retrieve emms-librefm-scrobbler-submission-url
+		    #'emms-librefm-scrobbler-async-submission-callback
+		    (list (cons track rating))))))
+
+(defun emms-librefm-scrobbler-async-submission-callback (status &optional cbargs)
+  "Pass response of asynchronous submission call to handler."
+  (let ((response (emms-librefm-scrobbler-get-response-status)))
+    ;; From the API docs: This indicates that the
+    ;; submission request was accepted for processing. It
+    ;; does not mean that the submission was valid, but
+    ;; only that the authentication and the form of the
+    ;; submission was validated.
+    (let ((track (car cbargs)))
+      (cond ((string= response "OK")
+	     (when emms-librefm-scrobbler-display-submissions
+	       (message "Libre.fm: Submitted %s"
+			(emms-track-get track 'info-title))))
+	    ((string= response "BADSESSION")
+	     (emms-librefm-scrobbler-handshake)
+	     (emms-librefm-scrobbler-make-async-submission-call (car cbargs) (cdr cbargs)))
+	    (t
+	     (error "unhandled submission failure"))))))
+
+
+;;; ------------------------------------------------------------------
+;;; hooks
+;;; ------------------------------------------------------------------
+
+(defun emms-librefm-scrobbler-start-hook ()
+  (setq emms-librefm-scrobbler-track-play-start-timestamp
+	(format-time-string "%s")))
+
+(defun emms-librefm-scrobbler-stop-hook ()
+  "Submit the track to libre.fm 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-librefm-scrobbler-make-async-submission-call
+	   current-track nil))))))
+
+(defun emms-librefm-scrobbler-enable ()
+  "Enable the scrobbler and submit played tracks."
+  (interactive)
+  (if (not emms-librefm-scrobbler-session-id)
+      (emms-librefm-scrobbler-handshake))
+  (add-hook 'emms-player-started-hook
+	    'emms-librefm-scrobbler-start-hook t)
+  (add-hook 'emms-player-stopped-hook
+	    'emms-librefm-scrobbler-stop-hook)
+  (add-hook 'emms-player-finished-hook
+	    'emms-librefm-scrobbler-stop-hook))
+
+(defun emms-librefm-scrobbler-disable ()
+  "Disable the scrobbler and don't submit played tracks."
+  (interactive)
+  (remove-hook 'emms-player-started-hook
+	       'emms-librefm-scrobbler-start-hook)
+  (remove-hook 'emms-player-stopped-hook
+	       'emms-librefm-scrobbler-stop-hook)
+  (remove-hook 'emms-player-finished-hook
+	       'emms-librefm-scrobbler-stop-hook))
+
+
 (provide 'emms-librefm-scrobbler)