/*
* Copyright (C) 2003-2013 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 "RssPlaylistPlugin.hxx"
#include "PlaylistPlugin.hxx"
#include "MemorySongEnumerator.hxx"
#include "InputStream.hxx"
#include "Song.hxx"
#include "tag/Tag.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"
#include "Log.hxx"
#include <glib.h>
#include <assert.h>
#include <string.h>
static constexpr Domain rss_domain("rss");
/**
* This is the state object for the GLib XML parser.
*/
struct RssParser {
/**
* The list of songs (in reverse order because that's faster
* while adding).
*/
std::forward_list<SongPointer> songs;
/**
* The current position in the XML file.
*/
enum {
ROOT, ITEM,
} state;
/**
* The current tag within the "entry" element. This is only
* valid if state==ITEM. TAG_NUM_OF_ITEM_TYPES means there
* is no (known) tag.
*/
TagType tag;
/**
* The current song. It is allocated after the "location"
* element.
*/
Song *song;
RssParser()
:state(ROOT) {}
};
static const gchar *
get_attribute(const gchar **attribute_names, const gchar **attribute_values,
const gchar *name)
{
for (unsigned i = 0; attribute_names[i] != NULL; ++i)
if (g_ascii_strcasecmp(attribute_names[i], name) == 0)
return attribute_values[i];
return NULL;
}
static void
rss_start_element(gcc_unused GMarkupParseContext *context,
const gchar *element_name,
const gchar **attribute_names,
const gchar **attribute_values,
gpointer user_data, gcc_unused GError **error)
{
RssParser *parser = (RssParser *)user_data;
switch (parser->state) {
case RssParser::ROOT:
if (g_ascii_strcasecmp(element_name, "item") == 0) {
parser->state = RssParser::ITEM;
parser->song = Song::NewRemote("rss:");
parser->tag = TAG_NUM_OF_ITEM_TYPES;
}
break;
case RssParser::ITEM:
if (g_ascii_strcasecmp(element_name, "enclosure") == 0) {
const gchar *href = get_attribute(attribute_names,
attribute_values,
"url");
if (href != NULL) {
/* create new song object, and copy
the existing tag over; we cannot
replace the existing song's URI,
because that attribute is
immutable */
Song *song = Song::NewRemote(href);
if (parser->song != NULL) {
song->tag = parser->song->tag;
parser->song->tag = NULL;
parser->song->Free();
}
parser->song = song;
}
} else if (g_ascii_strcasecmp(element_name, "title") == 0)
parser->tag = TAG_TITLE;
else if (g_ascii_strcasecmp(element_name, "itunes:author") == 0)
parser->tag = TAG_ARTIST;
break;
}
}
static void
rss_end_element(gcc_unused GMarkupParseContext *context,
const gchar *element_name,
gpointer user_data, gcc_unused GError **error)
{
RssParser *parser = (RssParser *)user_data;
switch (parser->state) {
case RssParser::ROOT:
break;
case RssParser::ITEM:
if (g_ascii_strcasecmp(element_name, "item") == 0) {
if (strcmp(parser->song->uri, "rss:") != 0)
parser->songs.emplace_front(parser->song);
else
parser->song->Free();
parser->state = RssParser::ROOT;
} else
parser->tag = TAG_NUM_OF_ITEM_TYPES;
break;
}
}
static void
rss_text(gcc_unused GMarkupParseContext *context,
const gchar *text, gsize text_len,
gpointer user_data, gcc_unused GError **error)
{
RssParser *parser = (RssParser *)user_data;
switch (parser->state) {
case RssParser::ROOT:
break;
case RssParser::ITEM:
if (parser->tag != TAG_NUM_OF_ITEM_TYPES) {
if (parser->song->tag == NULL)
parser->song->tag = new Tag();
parser->song->tag->AddItem(parser->tag,
text, text_len);
}
break;
}
}
static const GMarkupParser rss_parser = {
rss_start_element,
rss_end_element,
rss_text,
nullptr,
nullptr,
};
static void
rss_parser_destroy(gpointer data)
{
RssParser *parser = (RssParser *)data;
if (parser->state >= RssParser::ITEM)
parser->song->Free();
}
/*
* The playlist object
*
*/
static SongEnumerator *
rss_open_stream(struct input_stream *is)
{
RssParser parser;
GMarkupParseContext *context;
char buffer[1024];
size_t nbytes;
bool success;
Error error2;
GError *error = NULL;
/* parse the RSS XML file */
context = g_markup_parse_context_new(&rss_parser,
G_MARKUP_TREAT_CDATA_AS_TEXT,
&parser, rss_parser_destroy);
while (true) {
nbytes = is->LockRead(buffer, sizeof(buffer), error2);
if (nbytes == 0) {
if (error2.IsDefined()) {
g_markup_parse_context_free(context);
LogError(error2);
return NULL;
}
break;
}
success = g_markup_parse_context_parse(context, buffer, nbytes,
&error);
if (!success) {
FormatError(rss_domain,
"XML parser failed: %s", error->message);
g_error_free(error);
g_markup_parse_context_free(context);
return NULL;
}
}
success = g_markup_parse_context_end_parse(context, &error);
if (!success) {
FormatError(rss_domain,
"XML parser failed: %s", error->message);
g_error_free(error);
g_markup_parse_context_free(context);
return NULL;
}
parser.songs.reverse();
MemorySongEnumerator *playlist =
new MemorySongEnumerator(std::move(parser.songs));
g_markup_parse_context_free(context);
return playlist;
}
static const char *const rss_suffixes[] = {
"rss",
NULL
};
static const char *const rss_mime_types[] = {
"application/rss+xml",
"text/xml",
NULL
};
const struct playlist_plugin rss_playlist_plugin = {
"rss",
nullptr,
nullptr,
nullptr,
rss_open_stream,
nullptr,
rss_suffixes,
rss_mime_types,
};