playlist: Add despotify playlist plugin

For spotify playlists or tracks. Uses a spt uri, so with mpc you can
add playlists with

  mpc load spt://spotify:user:simon.kagstrom:playlist:3SUwkOe5VbVHysZcidEZtH

src/playlist/despotify_playlist_plugin.c

@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2011 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include "config.h"
+#include "playlist/despotify_playlist_plugin.h"
+#include "playlist_plugin.h"
+#include "playlist_list.h"
+#include "conf.h"
+#include "uri.h"
+#include "tag.h"
+#include "song.h"
+#include "input_stream.h"
+#include "glib_compat.h"
+#include "despotify_utils.h"
+
+#include <glib.h>
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <despotify.h>
+
+struct despotify_playlist {
+	struct playlist_provider base;
+
+	struct despotify_session *session;
+	GSList *list;
+};
+
+static void
+add_song(struct despotify_playlist *ctx, struct ds_track *track)
+{
+	const char *dsp_scheme = despotify_playlist_plugin.schemes[0];
+	struct song *song;
+	char uri[128];
+	char *ds_uri;
+
+	/* Create a spt://... URI for MPD */
+	g_snprintf(uri, sizeof(uri), "%s://", dsp_scheme);
+	ds_uri = uri + strlen(dsp_scheme) + 3;
+
+	if (despotify_track_to_uri(track, ds_uri) != ds_uri) {
+		/* Should never really fail, but let's be sure */
+		g_debug("Can't add track %s\n", track->title);
+		return;
+	}
+
+	song = song_remote_new(uri);
+	song->tag = mpd_despotify_tag_from_track(track);
+
+	ctx->list = g_slist_prepend(ctx->list, song);
+}
+
+static bool
+parse_track(struct despotify_playlist *ctx,
+		struct ds_link *link)
+{
+	struct ds_track *track;
+
+	track = despotify_link_get_track(ctx->session, link);
+	if (!track)
+		return false;
+	add_song(ctx, track);
+
+	return true;
+}
+
+static bool
+parse_playlist(struct despotify_playlist *ctx,
+		struct ds_link *link)
+{
+	struct ds_playlist *playlist;
+	struct ds_track *track;
+
+	playlist = despotify_link_get_playlist(ctx->session, link);
+	if (!playlist)
+		return false;
+
+	for (track = playlist->tracks; track; track = track->next)
+		add_song(ctx, track);
+
+	return true;
+}
+
+static bool
+despotify_playlist_init(G_GNUC_UNUSED const struct config_param *param)
+{
+	return mpd_despotify_get_session() != NULL;
+}
+
+static void
+despotify_playlist_finish(void)
+{
+}
+
+
+static struct playlist_provider *
+despotify_playlist_open_uri(const char *url)
+{
+	struct despotify_playlist *ctx;
+	struct despotify_session *session;
+	struct ds_link *link;
+	bool parse_result;
+
+	session = mpd_despotify_get_session();
+	if (!session)
+		goto clean_none;
+
+	/* Get link without spt:// */
+	link = despotify_link_from_uri(url + strlen(despotify_playlist_plugin.schemes[0]) + 3);
+	if (!link) {
+		g_debug("Can't find %s\n", url);
+		goto clean_none;
+	}
+
+	ctx = g_new(struct despotify_playlist, 1);
+
+	ctx->list = NULL;
+	ctx->session = session;
+	playlist_provider_init(&ctx->base, &despotify_playlist_plugin);
+
+	switch (link->type)
+	{
+	case LINK_TYPE_TRACK:
+		parse_result = parse_track(ctx, link);
+		break;
+	case LINK_TYPE_PLAYLIST:
+		parse_result = parse_playlist(ctx, link);
+		break;
+	default:
+		parse_result = false;
+		break;
+	}
+	despotify_free_link(link);
+	if (!parse_result)
+		goto clean_playlist;
+
+	ctx->list = g_slist_reverse(ctx->list);
+
+	return &ctx->base;
+
+clean_playlist:
+	g_slist_free(ctx->list);
+clean_none:
+
+	return NULL;
+}
+
+static void
+track_free_callback(gpointer data, G_GNUC_UNUSED gpointer user_data)
+{
+	struct song *song = (struct song *)data;
+
+	song_free(song);
+}
+
+static void
+despotify_playlist_close(struct playlist_provider *_playlist)
+{
+	struct despotify_playlist *ctx = (struct despotify_playlist *)_playlist;
+
+	g_slist_foreach(ctx->list, track_free_callback, NULL);
+	g_slist_free(ctx->list);
+
+	g_free(ctx);
+}
+
+
+static struct song *
+despotify_playlist_read(struct playlist_provider *_playlist)
+{
+	struct despotify_playlist *ctx = (struct despotify_playlist *)_playlist;
+	struct song *out;
+
+	if (!ctx->list)
+		return NULL;
+
+	/* Remove the current track */
+	out = ctx->list->data;
+	ctx->list = g_slist_remove(ctx->list, out);
+
+	return out;
+}
+
+
+static const char *const despotify_schemes[] = {
+		"spt",
+		NULL
+};
+
+const struct playlist_plugin despotify_playlist_plugin = {
+		.name = "despotify",
+
+		.init = despotify_playlist_init,
+		.finish = despotify_playlist_finish,
+		.open_uri = despotify_playlist_open_uri,
+		.read = despotify_playlist_read,
+		.close = despotify_playlist_close,
+
+		.schemes = despotify_schemes,
+};

src/playlist/despotify_playlist_plugin.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2011 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_PLAYLIST_DESPOTIFY_PLAYLIST_PLUGIN_H
+#define MPD_PLAYLIST_DESPOTIFY_PLAYLIST_PLUGIN_H
+
+extern const struct playlist_plugin despotify_playlist_plugin;
+
+#endif

src/playlist_list.c

@@ -24,6 +24,7 @@
 #include "playlist/m3u_playlist_plugin.h"
 #include "playlist/xspf_playlist_plugin.h"
 #include "playlist/lastfm_playlist_plugin.h"
+#include "playlist/despotify_playlist_plugin.h"
 #include "playlist/pls_playlist_plugin.h"
 #include "playlist/asx_playlist_plugin.h"
 #include "playlist/rss_playlist_plugin.h"
@@ -47,6 +48,9 @@ static const struct playlist_plugin *const playlist_plugins[] = {
 	&pls_playlist_plugin,
 	&asx_playlist_plugin,
 	&rss_playlist_plugin,
+#ifdef ENABLE_DESPOTIFY
+	&despotify_playlist_plugin,
+#endif
 #ifdef ENABLE_LASTFM
 	&lastfm_playlist_plugin,
 #endif