/* Copyright (C) 2016 J.F.Dockes
* 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.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef _CDPLUGIN_H_INCLUDED_
#define _CDPLUGIN_H_INCLUDED_
#include <string>
#include "upmpdutils.hxx"
#include "libupnpp/device/vdir.hxx"
class CDPluginServices;
/// Interface to media server modules
///
/// The main operations, Browse and Search, return content as UpSong
/// structures. At the very minimum, id, parentid, iscontainer and
/// title should be properly set for each entry. Id is very important for
/// directories (containers), because this is the main parameter to
/// the browse call. title is what gets displayed in lists by the
/// control point.
///
/// The rest of the UpSong fields are only meaningful for items
/// (tracks), and only one is mandatory: uri.
///
/// The item uri will be used by the renderer for fetching the data to
/// be played. Three types can be used:
/// - A direct URL, usable by the renderer for fetching the data from
/// wherever it is (for example a radio stream HTTP URL).
/// - A vdir URL: this should have a host/port part matching the media
/// server host/port (which can be obtained through the environment
/// interface). Data will be fetched by libupnp using the vdir
/// interface. This is simple but limited: the libupnp HTTP server
/// does not emit "accept-range" headers, meaning that most CPs will
/// not try range requests, and that seeking will not work. No
/// redirects are possible. The URL path part should begin with the
/// pathprefix, which is how the request will be routed to the
/// appropriate plugin.
/// - A libmicrohttpd URL. A plugin may start a microhttpd instance,
/// and receive the connections directly. The host/port will be
/// obtained from the configuration. The advantage is that redirects
/// and range requests are possible, but it is a bit more
/// complicated as some libmicrohttpd knowledge is required.
class CDPlugin {
public:
CDPlugin(const std::string& name, CDPluginServices *services)
: m_name(name), m_services(services) {
}
virtual ~CDPlugin() {
}
/// List children or return metadata for target object. You can
/// probably get by without implementing BFMeta in most cases.
enum BrowseFlag {BFChildren, BFMeta};
/// Browse object at objid, which should be a container, and
/// return its content.
///
/// This reflects an UPnP Browse action. Refer to UPnP documentation.
///
/// @param objid the object to browse. The top directory for a plugin will
// be '0$plugin_name$', e.g. '0$qobuz$'
/// @param stidx first entry to return.
/// @param cnt number of entries.
/// @param[output] entries output content.
/// @param sortcrits csv list of sort criteria.
/// @param flg browse flag
/// @return total number of matched entries in container
virtual int browse(
const std::string& objid, int stidx, int cnt,
std::vector<UpSong>& entries,
const std::vector<std::string>& sortcrits = std::vector<std::string>(),
BrowseFlag flg = BFChildren) = 0;
/// Search under object at objid.
///
/// This reflects an UPnP Search action, refer to UPnP
/// documentation. Most plugins won't be able to actually perform
/// the search under container operation. Plain search should be
/// good enough.
///
/// @param objid the object to search
/// @param stidx first entry to return.
/// @param cnt number of entries.
/// @param[output] entries output content.
/// @param sortcrits csv list of sort criteria.
/// @return total number of matched entries in container
virtual int search(
const std::string& ctid, int stidx, int cnt,
const std::string& searchstr,
std::vector<UpSong>& entries,
const std::vector<std::string>& sortcrits = std::vector<std::string>())
= 0;
const std::string& getname() {
return m_name;
}
virtual bool startInit() = 0;
std::string m_name;
CDPluginServices *m_services;
};
/// Service/Environment interface for media server modules
class CDPluginServices {
public:
/// Returns the plugin to which belongs the parameter path, based
/// on the path prefix above.
virtual CDPlugin *getpluginforpath(const std::string& path) = 0;
/// Retrieve the "friendly name" for the media server, for display purposes
virtual std::string getfname() = 0;
/// IP address and port used by the libupnp HTTP server.
///
/// This is the host address / network interface and port used by
/// libupnp, which can only support one. URLs intended to be
/// served this way (by adding a vdir) should should use this
/// address as this is the only one guaranteed to be accessible
/// from clients (in case this server has several interfaces).
/// The getupnpport() call is unused at present because no module
/// uses the internal server (all use the microhttpd started by
/// plgwithslave).
/// The getupnpaddr() call is used to determine the host for the
/// microhttp server (so it works on the same i/f as the upnp one,
/// always).
///
/// The microhttpd instance uses port 49149 by default. The value
/// can be changed with the "plgmicrohttpport" configuration
/// variable. The local mediaserver (uprcl) uses neither the
/// libupnp HTTP server nor microhttpd, but an internal Python
/// server instance, on port 9090 by default (can be changed with
/// the "uprclhostport" configuration variable).
virtual std::string getupnpaddr(CDPlugin *) = 0;
virtual int getupnpport(CDPlugin *) = 0;
/// Add a virtual directory and set file operation interface. path
/// must be equal or begin with the pathprefix. Not used at all at present.
virtual bool setfileops(CDPlugin *, const std::string& path,
UPnPProvider::VirtualDir::FileOps ops)= 0;
/// Main configuration file access.
static bool config_get(const std::string& nm, std::string& val);
/// Port to start the microhttp server on
static int microhttpport();
/// For modules which use the common microhttpd server
/// (tidal/qobuz/gmusic). Returns something like "/tidal" (no end
/// slash), which must be inserted at the top of the track URLs
/// paths so that an HTTP request can be processed-for /
/// dispatched-to the right plugin.
static std::string getpathprefix(CDPlugin *plg) {
return getpathprefix(plg->getname());
}
static std::string getpathprefix(const std::string& name) {
return std::string("/") + name;
}
};
#endif /* _CDPLUGIN_H_INCLUDED_ */