# -*- test-case-name: twisted.web.test.test_xmlrpc -*-
# Copyright (c) 2001-2009 Twisted Matrix Laboratories.
# See LICENSE for details.

"""
A generic resource for publishing objects via XML-RPC.

Maintainer: Itamar Shtull-Trauring
"""

# System Imports
import sys, xmlrpclib, urlparse

# Sibling Imports
from twisted.web import resource, server, http
from twisted.internet import defer, protocol, reactor
from twisted.python import log, reflect, failure

# These are deprecated, use the class level definitions
NOT_FOUND = 8001
FAILURE = 8002


# Useful so people don't need to import xmlrpclib directly
Fault = xmlrpclib.Fault
Binary = xmlrpclib.Binary
Boolean = xmlrpclib.Boolean
DateTime = xmlrpclib.DateTime

# On Python 2.4 and earlier, DateTime.decode returns unicode.
if sys.version_info[:2] < (2, 5):
    _decode = DateTime.decode
    DateTime.decode = lambda self, value: _decode(self, value.encode('ascii'))


class NoSuchFunction(Fault):
    """
    There is no function by the given name.
    """


class Handler:
    """
    Handle a XML-RPC request and store the state for a request in progress.

    Override the run() method and return result using self.result,
    a Deferred.

    We require this class since we're not using threads, so we can't
    encapsulate state in a running function if we're going  to have
    to wait for results.

    For example, lets say we want to authenticate against twisted.cred,
    run a LDAP query and then pass its result to a database query, all
    as a result of a single XML-RPC command. We'd use a Handler instance
    to store the state of the running command.
    """

    def __init__(self, resource, *args):
        self.resource = resource # the XML-RPC resource we are connected to
        self.result = defer.Deferred()
        self.run(*args)

    def run(self, *args):
        # event driven equivalent of 'raise UnimplementedError'
        self.result.errback(
            NotImplementedError("Implement run() in subclasses"))


class XMLRPC(resource.Resource):
    """
    A resource that implements XML-RPC.

    You probably want to connect this to '/RPC2'.

    Methods published can return XML-RPC serializable results, Faults,
    Binary, Boolean, DateTime, Deferreds, or Handler instances.

    By default methods beginning with 'xmlrpc_' are published.

    Sub-handlers for prefixed methods (e.g., system.listMethods)
    can be added with putSubHandler. By default, prefixes are
    separated with a '.'. Override self.separator to change this.
    """

    # Error codes for Twisted, if they conflict with yours then
    # modify them at runtime.
    NOT_FOUND = 8001
    FAILURE = 8002

    isLeaf = 1
    separator = '.'
    allowedMethods = ('POST',)

    def __init__(self, allowNone=False):
        resource.Resource.__init__(self)
        self.subHandlers = {}
        self.allowNone = allowNone

    def putSubHandler(self, prefix, handler):
        self.subHandlers[prefix] = handler

    def getSubHandler(self, prefix):
        return self.subHandlers.get(prefix, None)

    def getSubHandlerPrefixes(self):
        return self.subHandlers.keys()

    def render_POST(self, request):
        request.content.seek(0, 0)
        request.setHeader("content-type", "text/xml")
        try:
            args, functionPath = xmlrpclib.loads(request.content.read())
        except Exception, e:
            f = Fault(self.FAILURE, "Can't deserialize input: %s" % (e,))
            self._cbRender(f, request)
        else:
            try:
                function = self._getFunction(functionPath)
            except Fault, f:
                self._cbRender(f, request)
            else:
                d = defer.maybeDeferred(function, *args)
                d.addErrback(self._ebRender)
                d.addCallback(self._cbRender, request)
        return server.NOT_DONE_YET


    def _cbRender(self, result, request):
        if isinstance(result, Handler):
            result = result.result
        if not isinstance(result, Fault):
            result = (result,)
        try:
            try:
                content = xmlrpclib.dumps(
                    result, methodresponse=True,
                    allow_none=self.allowNone)
            except Exception, e:
                f = Fault(self.FAILURE, "Can't serialize output: %s" % (e,))
                content = xmlrpclib.dumps(f, methodresponse=True,
                                          allow_none=self.allowNone)

            request.setHeader("content-length", str(len(content)))
            request.write(content)
        except:
            log.err()
        request.finish()


    def _ebRender(self, failure):
        if isinstance(failure.value, Fault):
            return failure.value
        log.err(failure)
        return Fault(self.FAILURE, "error")

    def _getFunction(self, functionPath):
        """
        Given a string, return a function, or raise NoSuchFunction.

        This returned function will be called, and should return the result
        of the call, a Deferred, or a Fault instance.

        Override in subclasses if you want your own policy. The default
        policy is that given functionPath 'foo', return the method at
        self.xmlrpc_foo, i.e. getattr(self, "xmlrpc_" + functionPath).
        If functionPath contains self.separator, the sub-handler for
        the initial prefix is used to search for the remaining path.
        """
        if functionPath.find(self.separator) != -1:
            prefix, functionPath = functionPath.split(self.separator, 1)
            handler = self.getSubHandler(prefix)
            if handler is None:
                raise NoSuchFunction(self.NOT_FOUND,
                    "no such subHandler %s" % prefix)
            return handler._getFunction(functionPath)

        f = getattr(self, "xmlrpc_%s" % functionPath, None)
        if not f:
            raise NoSuchFunction(self.NOT_FOUND,
                "function %s not found" % functionPath)
        elif not callable(f):
            raise NoSuchFunction(self.NOT_FOUND,
                "function %s not callable" % functionPath)
        else:
            return f

    def _listFunctions(self):
        """
        Return a list of the names of all xmlrpc methods.
        """
        return reflect.prefixedMethodNames(self.__class__, 'xmlrpc_')


class XMLRPCIntrospection(XMLRPC):
    """
    Implement the XML-RPC Introspection API.

    By default, the methodHelp method returns the 'help' method attribute,
    if it exists, otherwise the __doc__ method attribute, if it exists,
    otherwise the empty string.

    To enable the methodSignature method, add a 'signature' method attribute
    containing a list of lists. See methodSignature's documentation for the
    format. Note the type strings should be XML-RPC types, not Python types.
    """

    def __init__(self, parent):
        """
        Implement Introspection support for an XMLRPC server.

        @param parent: the XMLRPC server to add Introspection support to.
        """

        XMLRPC.__init__(self)
        self._xmlrpc_parent = parent

    def xmlrpc_listMethods(self):
        """
        Return a list of the method names implemented by this server.
        """
        functions = []
        todo = [(self._xmlrpc_parent, '')]
        while todo:
            obj, prefix = todo.pop(0)
            functions.extend([prefix + name for name in obj._listFunctions()])
            todo.extend([ (obj.getSubHandler(name),
                           prefix + name + obj.separator)
                          for name in obj.getSubHandlerPrefixes() ])
        return functions

    xmlrpc_listMethods.signature = [['array']]

    def xmlrpc_methodHelp(self, method):
        """
        Return a documentation string describing the use of the given method.
        """
        method = self._xmlrpc_parent._getFunction(method)
        return (getattr(method, 'help', None)
                or getattr(method, '__doc__', None) or '')

    xmlrpc_methodHelp.signature = [['string', 'string']]

    def xmlrpc_methodSignature(self, method):
        """
        Return a list of type signatures.

        Each type signature is a list of the form [rtype, type1, type2, ...]
        where rtype is the return type and typeN is the type of the Nth
        argument. If no signature information is available, the empty
        string is returned.
        """
        method = self._xmlrpc_parent._getFunction(method)
        return getattr(method, 'signature', None) or ''

    xmlrpc_methodSignature.signature = [['array', 'string'],
                                        ['string', 'string']]


def addIntrospection(xmlrpc):
    """
    Add Introspection support to an XMLRPC server.

    @param xmlrpc: The xmlrpc server to add Introspection support to.
    """
    xmlrpc.putSubHandler('system', XMLRPCIntrospection(xmlrpc))


class QueryProtocol(http.HTTPClient):

    def connectionMade(self):
        self.sendCommand('POST', self.factory.path)
        self.sendHeader('User-Agent', 'Twisted/XMLRPClib')
        self.sendHeader('Host', self.factory.host)
        self.sendHeader('Content-type', 'text/xml')
        self.sendHeader('Content-length', str(len(self.factory.payload)))
        if self.factory.user:
            auth = '%s:%s' % (self.factory.user, self.factory.password)
            auth = auth.encode('base64').strip()
            self.sendHeader('Authorization', 'Basic %s' % (auth,))
        self.endHeaders()
        self.transport.write(self.factory.payload)

    def handleStatus(self, version, status, message):
        if status != '200':
            self.factory.badStatus(status, message)

    def handleResponse(self, contents):
        self.factory.parseResponse(contents)


payloadTemplate = """<?xml version="1.0"?>
<methodCall>
<methodName>%s</methodName>
%s
</methodCall>
"""


class _QueryFactory(protocol.ClientFactory):

    deferred = None
    protocol = QueryProtocol

    def __init__(self, path, host, method, user=None, password=None,
                 allowNone=False, args=()):
        self.path, self.host = path, host
        self.user, self.password = user, password
        self.payload = payloadTemplate % (method,
            xmlrpclib.dumps(args, allow_none=allowNone))
        self.deferred = defer.Deferred()

    def parseResponse(self, contents):
        if not self.deferred:
            return
        try:
            response = xmlrpclib.loads(contents)[0][0]
        except:
            deferred, self.deferred = self.deferred, None
            deferred.errback(failure.Failure())
        else:
            deferred, self.deferred = self.deferred, None
            deferred.callback(response)

    def clientConnectionLost(self, _, reason):
        if self.deferred is not None:
            deferred, self.deferred = self.deferred, None
            deferred.errback(reason)

    clientConnectionFailed = clientConnectionLost

    def badStatus(self, status, message):
        deferred, self.deferred = self.deferred, None
        deferred.errback(ValueError(status, message))



class Proxy:
    """
    A Proxy for making remote XML-RPC calls.

    Pass the URL of the remote XML-RPC server to the constructor.

    Use proxy.callRemote('foobar', *args) to call remote method
    'foobar' with *args.

    @ivar queryFactory: object returning a factory for XML-RPC protocol. Mainly
        useful for tests.
    """
    queryFactory = _QueryFactory

    def __init__(self, url, user=None, password=None, allowNone=False):
        """
        @type url: C{str}
        @param url: The URL to which to post method calls.  Calls will be made
        over SSL if the scheme is HTTPS.  If netloc contains username or
        password information, these will be used to authenticate, as long as
        the C{user} and C{password} arguments are not specified.

        @type user: C{str} or None
        @param user: The username with which to authenticate with the server
        when making calls.  If specified, overrides any username information
        embedded in C{url}.  If not specified, a value may be taken from C{url}
        if present.

        @type password: C{str} or None
        @param password: The password with which to authenticate with the
        server when making calls.  If specified, overrides any password
        information embedded in C{url}.  If not specified, a value may be taken
        from C{url} if present.

        @type allowNone: C{bool} or None
        @param allowNone: allow the use of None values in parameters. It's
        passed to the underlying xmlrpclib implementation. Default to False.
        """
        scheme, netloc, path, params, query, fragment = urlparse.urlparse(url)
        netlocParts = netloc.split('@')
        if len(netlocParts) == 2:
            userpass = netlocParts.pop(0).split(':')
            self.user = userpass.pop(0)
            try:
                self.password = userpass.pop(0)
            except:
                self.password = None
        else:
            self.user = self.password = None
        hostport = netlocParts[0].split(':')
        self.host = hostport.pop(0)
        try:
            self.port = int(hostport.pop(0))
        except:
            self.port = None
        self.path = path
        if self.path in ['', None]:
            self.path = '/'
        self.secure = (scheme == 'https')
        if user is not None:
            self.user = user
        if password is not None:
            self.password = password
        self.allowNone = allowNone

    def callRemote(self, method, *args):
        """
        Call remote XML-RPC C{method} with given arguments.

        @return: a L{defer.Deferred} that will fire with the method response,
            or a failure if the method failed. Generally, the failure type will
            be L{Fault}, but you can also have an C{IndexError} on some buggy
            servers giving empty responses.
        """
        factory = self.queryFactory(
            self.path, self.host, method, self.user,
            self.password, self.allowNone, args)
        if self.secure:
            from twisted.internet import ssl
            reactor.connectSSL(self.host, self.port or 443,
                               factory, ssl.ClientContextFactory())
        else:
            reactor.connectTCP(self.host, self.port or 80, factory)
        return factory.deferred


__all__ = [
    "XMLRPC", "Handler", "NoSuchFunction", "Proxy",

    "Fault", "Binary", "Boolean", "DateTime"]
