pymeds/ContentDirectory.py

# Licensed under the MIT license
# http://opensource.org/licenses/mit-license.php
# Copyright 2005, Tim Potter <tpot@samba.org>
# Copyright 2006 John-Mark Gurney <gurney_j@resnet.uoregon.edu>

#
# This module implements the Content Directory Service (CDS) service
# type as documented in the ContentDirectory:1 Service Template
# Version 1.01
#

#
# TODO: Figure out a nicer pattern for debugging soap server calls as
# twisted swallows the tracebacks.  At the moment I'm going:
#
# try:
#     ....
# except:
#     traceback.print_exc(file = log.logfile)
#

from twisted.python import log
from twisted.web import resource, static

from elementtree.ElementTree import Element, SubElement, tostring
from upnp import UPnPPublisher
from DIDLLite import DIDLElement, Container, Movie, Resource, MusicTrack

import traceback
from urllib import quote

class ContentDirectoryControl(UPnPPublisher, dict):
    """This class implements the CDS actions over SOAP."""

    def getnextID(self):
        ret = str(self.nextID)
        self.nextID += 1
        return ret

    def addContainer(self, parent, title, klass = Container, **kwargs):
        ret = self.addItem(parent, klass, title, **kwargs)
        self.children[ret] = []
        return ret

    def addItem(self, parent, klass, *args, **kwargs):
        assert isinstance(self[parent], Container)
        nid = self.getnextID()
        i = klass(nid, parent, *args, **kwargs)
        self.children[parent].append(i)
        self[i.id] = i
        return i.id

    def getchildren(self, item):
        assert isinstance(self[item], Container)
        return self.children[item][:]

    def __init__(self, title, *args):
        super(ContentDirectoryControl, self).__init__(*args)
        fakeparent = '-1'
        self.nextID = 0
        self.children = { fakeparent: []}
        self.needupdate = False
        self.updateId = 0
        self[fakeparent] = Container(None, '-1', 'fake')
        root = self.addContainer(fakeparent, title)
        assert root == '0'
        del self[fakeparent]
        del self.children[fakeparent]

    def doupdate(self):
        if self.needupdate:
            self.needupdate += 1
            self.needupdate = False

    # Required actions

    def soap_GetSearchCapabilities(self, *args, **kwargs):
        """Required: Return the searching capabilities supported by the device."""

        log.msg('GetSearchCapabilities()')
        return { 'SearchCapabilitiesResponse': { 'SearchCaps': '' }}

    def soap_GetSortCapabilities(self, *args, **kwargs):
        """Required: Return the CSV list of meta-data tags that can be used in
        sortCriteria."""

        log.msg('GetSortCapabilities()')
        return { 'SortCapabilitiesResponse': { 'SortCaps': '' }}
        
    def soap_GetSystemUpdateID(self, *args, **kwargs):
        """Required: Return the current value of state variable SystemUpdateID."""

        log.msg('GetSystemUpdateID()')
        self.needupdate = True
        return { 'SystemUpdateIdResponse': { 'Id': self.updateId }}

    BrowseFlags = ('BrowseMetaData', 'BrowseDirectChildren')

    def soap_Browse(self, *args):
        """Required: Incrementally browse the native heirachy of the Content
        Directory objects exposed by the Content Directory Service."""

        (ObjectID, BrowseFlag, Filter, StartingIndex, RequestedCount,
         SortCriteria) = args
        StartingIndex = int(StartingIndex)
        RequestedCount = int(RequestedCount)

        log.msg('Browse(ObjectID=%s, BrowseFlags=%s, Filter=%s, '
                'StartingIndex=%s RequestedCount=%s SortCriteria=%s)' %
                (`ObjectID`, `BrowseFlag`, `Filter`, `StartingIndex`,
                 `RequestedCount`, `SortCriteria`))

        didl = DIDLElement()
        result = {}

        try:
            if BrowseFlag == 'BrowseDirectChildren':
                ch = self.getchildren(ObjectID)[StartingIndex: StartingIndex + RequestedCount]
                filter(lambda x, s = self, d = didl: d.addItem(s[x.id]) and None, ch)
            else:
                didl.addItem(self[ObjectID])

            result = {'BrowseResponse': {'Result': didl.toString() ,
                                         'NumberReturned': didl.numItems(),
                                         'TotalMatches': didl.numItems(),
                                         'UpdateID': 0}}

        except:
            traceback.print_exc(file=log.logfile)

        log.msg('Returning: %s' % result)

        return result

    # Optional actions

    def soap_Search(self, *args, **kwargs):
        """Search for objects that match some search criteria."""

        (ContainerID, SearchCriteria, Filter, StartingIndex,
         RequestedCount, SortCriteria) = args

        log.msg('Search(ContainerID=%s, SearchCriteria=%s, Filter=%s, ' \
                'StartingIndex=%s, RequestedCount=%s, SortCriteria=%s)' %
                (`ContainerID`, `SearchCriteria`, `Filter`,
                 `StartingIndex`, `RequestedCount`, `SortCriteria`))
        
    def soap_CreateObject(self, *args, **kwargs):
        """Create a new object."""

        (ContainerID, Elements) = args

        log.msg('CreateObject(ContainerID=%s, Elements=%s)' %
                (`ContainerID`, `Elements`))

    def soap_DestroyObject(self, *args, **kwargs):
        """Destroy the specified object."""

        (ObjectID) = args

        log.msg('DestroyObject(ObjectID=%s)' % `ObjectID`)

    def soap_UpdateObject(self, *args, **kwargs):
        """Modify, delete or insert object metadata."""

        (ObjectID, CurrentTagValue, NewTagValue) = args

        log.msg('UpdateObject(ObjectID=%s, CurrentTagValue=%s, ' \
                'NewTagValue=%s)' % (`ObjectID`, `CurrentTagValue`,
                                     `NewTagValue`))

    def soap_ImportResource(self, *args, **kwargs):
        """Transfer a file from a remote source to a local
        destination in the Content Directory Service."""

        (SourceURI, DestinationURI) = args

        log.msg('ImportResource(SourceURI=%s, DestinationURI=%s)' %
                (`SourceURI`, `DestinationURI`))

    def soap_ExportResource(self, *args, **kwargs):
        """Transfer a file from a local source to a remote
        destination.""" 

        (SourceURI, DestinationURI) = args

        log.msg('ExportResource(SourceURI=%s, DestinationURI=%s)' %
                (`SourceURI`, `DestinationURI`))        

    def soap_StopTransferResource(self, *args, **kwargs):
        """Stop a file transfer initiated by ImportResource or
        ExportResource.""" 

        (TransferID) = args

        log.msg('StopTransferResource(TransferID=%s)' % TransferID)

    def soap_GetTransferProgress(self, *args, **kwargs):
        """Query the progress of a file transfer initiated by
        an ImportResource or ExportResource action."""

        (TransferID, TransferStatus, TransferLength, TransferTotal) = args

        log.msg('GetTransferProgress(TransferID=%s, TransferStatus=%s, ' \
                'TransferLength=%s, TransferTotal=%s)' %
                (`TransferId`, `TransferStatus`, `TransferLength`,
                 `TransferTotal`))
                                                          
    def soap_DeleteResource(self, *args, **kwargs):
        """Delete a specified resource."""

        (ResourceURI) = args

        log.msg('DeleteResource(ResourceURI=%s)' % `ResourceURI`)

    def soap_CreateReference(self, *args, **kwargs):
        """Create a reference to an existing object."""

        (ContainerID, ObjectID) = args

        log.msg('CreateReference(ContainerID=%s, ObjectID=%s)' %
                (`ContainerID`, `ObjectID`))

class ContentDirectoryServer(resource.Resource):
    def __init__(self, title):
        resource.Resource.__init__(self)
        self.putChild('scpd.xml', static.File('content-directory-scpd.xml'))
        self.control = ContentDirectoryControl(title)
        self.putChild('control', self.control)