import json
import logging
from collections import OrderedDict
from twisted.internet import defer
from twisted.web.client import Agent, HTTPConnectionPool
import treq
from treq.client import HTTPClient
from xml.etree import ElementTree
from txupnp.util import etree_to_dict, flatten_keys, return_types, _return_types, none_or_str, none
from txupnp.fault import handle_fault, UPnPError
from txupnp.constants import POST, ENVELOPE, BODY, XML_VERSION, IP_SCHEMA, SERVICE, SSDP_IP_ADDRESS, DEVICE, ROOT, service_types

log = logging.getLogger(__name__)


class StringProducer(object):
    def __init__(self, body):
        self.body = body
        self.length = len(body)

    def startProducing(self, consumer):
        consumer.write(self.body)
        return defer.succeed(None)

    def pauseProducing(self):
        pass

    def stopProducing(self):
        pass


def xml_arg(name, arg):
    return "<%s>%s</%s>" % (name, arg, name)


def get_soap_body(service_name, method, param_names, **kwargs):
    args = "".join(xml_arg(n, kwargs.get(n)) for n in param_names)
    return '\n%s\n<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"><s:Body><u:%s xmlns:u="%s">%s</u:%s></s:Body></s:Envelope>' % (XML_VERSION, method, service_name, args, method)


class _SCPDCommand(object):
    def __init__(self, gateway_address, service_port, control_url, service_id, method, param_names, returns,
                 reactor=None):
        if not reactor:
            from twisted.internet import reactor
        self._reactor = reactor
        self._pool = HTTPConnectionPool(reactor)
        self.agent = Agent(reactor, connectTimeout=1)
        self._http_client = HTTPClient(self.agent, data_to_body_producer=StringProducer)
        self.gateway_address = gateway_address
        self.service_port = service_port
        self.control_url = control_url
        self.service_id = service_id
        self.method = method
        self.param_names = param_names
        self.returns = returns

    def extract_body(self, xml_response, service_key=IP_SCHEMA):
        content_dict = etree_to_dict(ElementTree.fromstring(xml_response))
        envelope = content_dict[ENVELOPE]
        return flatten_keys(envelope[BODY], "{%s}" % service_key)

    def extract_response(self, body):
        body = handle_fault(body)  # raises UPnPError if there is a fault
        if '%sResponse' % self.method in body:
            response_key = '%sResponse' % self.method
        else:
            log.error(body.keys())
            raise UPnPError("unknown response fields")
        response = body[response_key]
        extracted_response = tuple([response[n] for n in self.returns])
        if len(extracted_response) == 1:
            return extracted_response[0]
        return extracted_response

    @defer.inlineCallbacks
    def send_upnp_soap(self, **kwargs):
        soap_body = get_soap_body(self.service_id, self.method, self.param_names, **kwargs).encode()
        headers = OrderedDict((
            ('SOAPAction', '%s#%s' % (self.service_id, self.method)),
            ('Host', ('%s:%i' % (SSDP_IP_ADDRESS, self.service_port))),
            ('Content-Type', 'text/xml'),
            ('Content-Length', len(soap_body))
        ))
        response = yield self._http_client.request(
            POST, url=self.control_url, data=soap_body, headers=headers
        )
        xml_response = yield response.content()
        response = self.extract_response(self.extract_body(xml_response))
        if not response:
            log.debug("empty response to %s\n%s", self.method, xml_response)
        defer.returnValue(response)

    @staticmethod
    def _process_result(results):
        """
        this method gets decorated automatically with a function that maps result types to the types
        defined in the @return_types decorator
        """
        return results

    @defer.inlineCallbacks
    def __call__(self, **kwargs):
        if set(kwargs.keys()) != set(self.param_names):
            raise Exception("argument mismatch")
        response = yield self.send_upnp_soap(**kwargs)
        result = self._process_result(response)
        defer.returnValue(result)


class SCPDResponse(object):
    def __init__(self, url, headers, content):
        self.url = url
        self.headers = headers
        self.content = content

    def get_element_tree(self):
        return ElementTree.fromstring(self.content)

    def get_element_dict(self, service_key):
        return flatten_keys(etree_to_dict(self.get_element_tree()), "{%s}" % service_key)

    def get_action_list(self):
        return self.get_element_dict(SERVICE)["scpd"]["actionList"]["action"]

    def get_device_info(self):
        return self.get_element_dict(DEVICE)[ROOT]


class SCPDCommandRunner(object):
    def __init__(self, gateway):
        self._gateway = gateway
        self._unsupported_actions = {}
        self._registered_commands = {}

    @defer.inlineCallbacks
    def _discover_commands(self, service):
        scpd_url = self._gateway.base_address + service.scpd_path.encode()
        response = yield treq.get(scpd_url)
        content = yield response.content()
        try:
            scpd_response = SCPDResponse(scpd_url,
                                         response.headers, content)
            for action_dict in scpd_response.get_action_list():
                self._register_command(action_dict, service.service_type)
        except Exception as err:
            log.exception("failed to parse scpd response (%s) from %s\nheaders:\n%s\ncontent\n%s",
                          err, scpd_url, response.headers, content)
        defer.returnValue(None)

    @defer.inlineCallbacks
    def discover_commands(self):
        for service_type in service_types:
            service = self._gateway.get_service(service_type)
            if not service:
                continue
            yield self._discover_commands(service)
        log.debug(self.debug_commands())

    @staticmethod
    def _soap_function_info(action_dict):
        if not action_dict.get('argumentList'):
            log.debug("don't know how to handle argument list: %s", action_dict)
            return (
                action_dict['name'],
                [],
                []
            )
        arg_dicts = action_dict['argumentList']['argument']
        if not isinstance(arg_dicts, list):  # when there is one arg, ew
            arg_dicts = [arg_dicts]
        return (
            action_dict['name'],
            [i['name'] for i in arg_dicts if i['direction'] == 'in'],
            [i['name'] for i in arg_dicts if i['direction'] == 'out']
        )

    def __register_command(self, action_info, service_type):
        func_info = self._soap_function_info(action_info)
        command = _SCPDCommand(self._gateway.base_address, self._gateway.port,
                               self._gateway.base_address + self._gateway.get_service(service_type).control_path.encode(),
                               self._gateway.get_service(service_type).service_id.encode(), *func_info)
        current = getattr(self, command.method)
        if hasattr(current, "_return_types"):
            command._process_result = _return_types(*current._return_types)(command._process_result)
        setattr(command, "__doc__", current.__doc__)
        setattr(self, command.method, command)
        self._registered_commands[command.method] = service_type
        log.debug("registered %s %s", service_type, action_info['name'])
        return True

    def _register_command(self, action_info, service_type):
        try:
            return self.__register_command(action_info, service_type)
        except Exception as err:
            s = self._unsupported_actions.get(service_type, [])
            s.append((action_info, err))
            self._unsupported_actions[service_type] = s
            log.error("failed to setup command for %s\n%s", service_type, action_info)

    def debug_commands(self):
        return json.dumps({
            'available': self._registered_commands,
            'failed': self._unsupported_actions
        }, indent=2)

    @staticmethod
    @return_types(none)
    def AddPortMapping(NewRemoteHost, NewExternalPort, NewProtocol, NewInternalPort, NewInternalClient,
                       NewEnabled, NewPortMappingDescription, NewLeaseDuration):
        """Returns None"""
        raise NotImplementedError()

    @staticmethod
    @return_types(bool, bool)
    def GetNATRSIPStatus():
        """Returns (NewRSIPAvailable, NewNATEnabled)"""
        raise NotImplementedError()

    @staticmethod
    @return_types(none_or_str, int, str, int, str, bool, str, int)
    def GetGenericPortMappingEntry(NewPortMappingIndex):
        """
        Returns (NewRemoteHost, NewExternalPort, NewProtocol, NewInternalPort, NewInternalClient, NewEnabled,
                 NewPortMappingDescription, NewLeaseDuration)
        """
        raise NotImplementedError()

    @staticmethod
    @return_types(int, str, bool, str, int)
    def GetSpecificPortMappingEntry(NewRemoteHost, NewExternalPort, NewProtocol):
        """Returns (NewInternalPort, NewInternalClient, NewEnabled, NewPortMappingDescription, NewLeaseDuration)"""
        raise NotImplementedError()

    @staticmethod
    @return_types(none)
    def SetConnectionType(NewConnectionType):
        """Returns None"""
        raise NotImplementedError()

    @staticmethod
    @return_types(str)
    def GetExternalIPAddress():
        """Returns (NewExternalIPAddress)"""
        raise NotImplementedError()

    @staticmethod
    @return_types(str, str)
    def GetConnectionTypeInfo():
        """Returns (NewConnectionType, NewPossibleConnectionTypes)"""
        raise NotImplementedError()

    @staticmethod
    @return_types(str, str, int)
    def GetStatusInfo():
        """Returns (NewConnectionStatus, NewLastConnectionError, NewUptime)"""
        raise NotImplementedError()

    @staticmethod
    @return_types(none)
    def ForceTermination():
        """Returns None"""
        raise NotImplementedError()

    @staticmethod
    @return_types(none)
    def DeletePortMapping(NewRemoteHost, NewExternalPort, NewProtocol):
        """Returns None"""
        raise NotImplementedError()

    @staticmethod
    @return_types(none)
    def RequestConnection():
        """Returns None"""
        raise NotImplementedError()

    @staticmethod
    def GetCommonLinkProperties():
        """Returns (NewWANAccessType, NewLayer1UpstreamMaxBitRate, NewLayer1DownstreamMaxBitRate, NewPhysicalLinkStatus)"""
        raise NotImplementedError()

    @staticmethod
    def GetTotalBytesSent():
        """Returns (NewTotalBytesSent)"""
        raise NotImplementedError()

    @staticmethod
    def GetTotalBytesReceived():
        """Returns (NewTotalBytesReceived)"""
        raise NotImplementedError()

    @staticmethod
    def GetTotalPacketsSent():
        """Returns (NewTotalPacketsSent)"""
        raise NotImplementedError()

    @staticmethod
    def GetTotalPacketsReceived():
        """Returns (NewTotalPacketsReceived)"""
        raise NotImplementedError()

    @staticmethod
    def X_GetICSStatistics():
        """Returns (TotalBytesSent, TotalBytesReceived, TotalPacketsSent, TotalPacketsReceived, Layer1DownstreamMaxBitRate, Uptime)"""
        raise NotImplementedError()

    @staticmethod
    def GetDefaultConnectionService():
        """Returns (NewDefaultConnectionService)"""
        raise NotImplementedError()

    @staticmethod
    def SetDefaultConnectionService(NewDefaultConnectionService):
        """Returns (None)"""
        raise NotImplementedError()