"""
    SoftLayer.transports
    ~~~~~~~~~~~~~~~~~~~~
    XML-RPC transport layer that uses the requests library.

    :license: MIT, see LICENSE for more details.
"""
import importlib
import json
import logging
import time

import requests

from SoftLayer import consts
from SoftLayer import exceptions
from SoftLayer import utils

LOGGER = logging.getLogger(__name__)
# transports.Request does have a lot of instance attributes. :(
# pylint: disable=too-many-instance-attributes

__all__ = [
    'Request',
    'XmlRpcTransport',
    'RestTransport',
    'TimingTransport',
    'FixtureTransport',
    'SoftLayerListResult',
]

REST_SPECIAL_METHODS = {
    'deleteObject': 'DELETE',
    'createObject': 'POST',
    'createObjects': 'POST',
    'editObject': 'PUT',
    'editObjects': 'PUT',
}


class Request(object):
    """Transport request object."""

    def __init__(self):
        #: API service name. E.G. SoftLayer_Account
        self.service = None

        #: API method name. E.G. getObject
        self.method = None

        #: API Parameters.
        self.args = tuple()

        #: API headers, used for authentication, masks, limits, offsets, etc.
        self.headers = {}

        #: Transport user.
        self.transport_user = None

        #: Transport password.
        self.transport_password = None

        #: Transport headers.
        self.transport_headers = {}

        #: Boolean specifying if the server certificate should be verified.
        self.verify = None

        #: Client certificate file path.
        self.cert = None

        #: InitParameter/identifier of an object.
        self.identifier = None

        #: SoftLayer mask (dict or string).
        self.mask = None

        #: SoftLayer Filter (dict).
        self.filter = None

        #: Integer result limit.
        self.limit = None

        #: Integer result offset.
        self.offset = None


class SoftLayerListResult(list):
    """A SoftLayer API list result."""

    def __init__(self, items, total_count):

        #: total count of items that exist on the server. This is useful when
        #: paginating through a large list of objects.
        self.total_count = total_count

        super(SoftLayerListResult, self).__init__(items)


class XmlRpcTransport(object):
    """XML-RPC transport."""
    def __init__(self,
                 endpoint_url=None,
                 timeout=None,
                 proxy=None,
                 user_agent=None,
                 verify=True):

        self.endpoint_url = (endpoint_url or
                             consts.API_PUBLIC_ENDPOINT).rstrip('/')
        self.timeout = timeout or None
        self.proxy = proxy
        self.user_agent = user_agent or consts.USER_AGENT
        self.verify = verify

    def __call__(self, request):
        """Makes a SoftLayer API call against the XML-RPC endpoint.

        :param request request: Request object
        """
        largs = list(request.args)

        headers = request.headers

        if request.identifier is not None:
            header_name = request.service + 'InitParameters'
            headers[header_name] = {'id': request.identifier}

        if request.mask is not None:
            headers.update(_format_object_mask_xmlrpc(request.mask,
                                                      request.service))

        if request.filter is not None:
            headers['%sObjectFilter' % request.service] = request.filter

        if request.limit:
            headers['resultLimit'] = {
                'limit': request.limit,
                'offset': request.offset or 0,
            }

        largs.insert(0, {'headers': headers})
        request.transport_headers.setdefault('Content-Type', 'application/xml')
        request.transport_headers.setdefault('User-Agent', self.user_agent)

        url = '/'.join([self.endpoint_url, request.service])
        payload = utils.xmlrpc_client.dumps(tuple(largs),
                                            methodname=request.method,
                                            allow_none=True)

        # Prefer the request setting, if it's not None
        verify = request.verify
        if verify is None:
            verify = self.verify

        LOGGER.debug("=== REQUEST ===")
        LOGGER.info('POST %s', url)
        LOGGER.debug(request.transport_headers)
        LOGGER.debug(payload)

        try:
            resp = requests.request('POST', url,
                                    data=payload,
                                    headers=request.transport_headers,
                                    timeout=self.timeout,
                                    verify=verify,
                                    cert=request.cert,
                                    proxies=_proxies_dict(self.proxy))
            LOGGER.debug("=== RESPONSE ===")
            LOGGER.debug(resp.headers)
            LOGGER.debug(resp.content)
            resp.raise_for_status()
            result = utils.xmlrpc_client.loads(resp.content)[0][0]
            if isinstance(result, list):
                return SoftLayerListResult(
                    result, int(resp.headers.get('softlayer-total-items', 0)))
            else:
                return result
        except utils.xmlrpc_client.Fault as ex:
            # These exceptions are formed from the XML-RPC spec
            # http://xmlrpc-epi.sourceforge.net/specs/rfc.fault_codes.php
            error_mapping = {
                '-32700': exceptions.NotWellFormed,
                '-32701': exceptions.UnsupportedEncoding,
                '-32702': exceptions.InvalidCharacter,
                '-32600': exceptions.SpecViolation,
                '-32601': exceptions.MethodNotFound,
                '-32602': exceptions.InvalidMethodParameters,
                '-32603': exceptions.InternalError,
                '-32500': exceptions.ApplicationError,
                '-32400': exceptions.RemoteSystemError,
                '-32300': exceptions.TransportError,
            }
            _ex = error_mapping.get(ex.faultCode, exceptions.SoftLayerAPIError)
            raise _ex(ex.faultCode, ex.faultString)
        except requests.HTTPError as ex:
            raise exceptions.TransportError(ex.response.status_code, str(ex))
        except requests.RequestException as ex:
            raise exceptions.TransportError(0, str(ex))


class RestTransport(object):
    """REST transport.

    Currently only supports GET requests (no POST, PUT, DELETE) and lacks
    support for masks, filters, limits and offsets.
    """

    def __init__(self,
                 endpoint_url=None,
                 timeout=None,
                 proxy=None,
                 user_agent=None,
                 verify=True):

        self.endpoint_url = (endpoint_url or
                             consts.API_PUBLIC_ENDPOINT_REST).rstrip('/')
        self.timeout = timeout or None
        self.proxy = proxy
        self.user_agent = user_agent or consts.USER_AGENT
        self.verify = verify

    def __call__(self, request):
        """Makes a SoftLayer API call against the REST endpoint.

        This currently only works with GET requests

        :param request request: Request object
        """
        request.transport_headers.setdefault('Content-Type',
                                             'application/json')
        request.transport_headers.setdefault('User-Agent', self.user_agent)

        params = request.headers.copy()
        if request.mask:
            params['objectMask'] = _format_object_mask(request.mask)

        if request.limit:
            params['limit'] = request.limit

        if request.offset:
            params['offset'] = request.offset

        if request.filter:
            params['objectFilter'] = json.dumps(request.filter)

        auth = None
        if request.transport_user:
            auth = requests.auth.HTTPBasicAuth(
                request.transport_user,
                request.transport_password,
            )

        method = REST_SPECIAL_METHODS.get(request.method)
        is_special_method = True
        if method is None:
            is_special_method = False
            method = 'GET'

        body = {}
        if request.args:
            # NOTE(kmcdonald): force POST when there are arguments because
            # the request body is ignored otherwise.
            method = 'POST'
            body['parameters'] = request.args

        raw_body = None
        if body:
            raw_body = json.dumps(body)

        url_parts = [self.endpoint_url, request.service]
        if request.identifier is not None:
            url_parts.append(str(request.identifier))

        # Special methods (createObject, editObject, etc) use the HTTP verb
        # to determine the action on the resource
        if request.method is not None and not is_special_method:
            url_parts.append(request.method)

        url = '%s.%s' % ('/'.join(url_parts), 'json')

        # Prefer the request setting, if it's not None
        verify = request.verify
        if verify is None:
            verify = self.verify

        LOGGER.debug("=== REQUEST ===")
        LOGGER.info(url)
        LOGGER.debug(request.transport_headers)
        LOGGER.debug(raw_body)
        try:
            resp = requests.request(method, url,
                                    auth=auth,
                                    headers=request.transport_headers,
                                    params=params,
                                    data=raw_body,
                                    timeout=self.timeout,
                                    verify=verify,
                                    cert=request.cert,
                                    proxies=_proxies_dict(self.proxy))
            LOGGER.debug("=== RESPONSE ===")
            LOGGER.debug(resp.headers)
            LOGGER.debug(resp.text)
            resp.raise_for_status()
            result = json.loads(resp.text)

            if isinstance(result, list):
                return SoftLayerListResult(
                    result, int(resp.headers.get('softlayer-total-items', 0)))
            else:
                return result
        except requests.HTTPError as ex:
            message = json.loads(ex.response.text)['error']
            raise exceptions.SoftLayerAPIError(ex.response.status_code,
                                               message)
        except requests.RequestException as ex:
            raise exceptions.TransportError(0, str(ex))


class TimingTransport(object):
    """Transport that records API call timings."""

    def __init__(self, transport):
        self.transport = transport
        self.last_calls = []

    def __call__(self, call):
        """See Client.call for documentation."""
        start_time = time.time()

        result = self.transport(call)

        end_time = time.time()
        self.last_calls.append((call, start_time, end_time - start_time))
        return result

    def get_last_calls(self):
        """Retrieves the last_calls property.

        This property will contain a list of tuples in the form
        (Request, initiated_utc_timestamp, execution_time)
        """
        last_calls = self.last_calls
        self.last_calls = []
        return last_calls


class FixtureTransport(object):
    """Implements a transport which returns fixtures."""
    def __call__(self, call):
        """Load fixture from the default fixture path."""
        try:
            module_path = 'SoftLayer.fixtures.%s' % call.service
            module = importlib.import_module(module_path)
        except ImportError:
            raise NotImplementedError('%s fixture is not implemented'
                                      % call.service)
        try:
            return getattr(module, call.method)
        except AttributeError:
            raise NotImplementedError('%s::%s fixture is not implemented'
                                      % (call.service, call.method))


def _proxies_dict(proxy):
    """Makes a proxy dict appropriate to pass to requests."""
    if not proxy:
        return None
    return {'http': proxy, 'https': proxy}


def _format_object_mask_xmlrpc(objectmask, service):
    """Format new and old style object masks into proper headers.

    :param objectmask: a string- or dict-based object mask
    :param service: a SoftLayer API service name

    """
    if isinstance(objectmask, dict):
        mheader = '%sObjectMask' % service
    else:
        mheader = 'SoftLayer_ObjectMask'
        objectmask = _format_object_mask(objectmask)

    return {mheader: {'mask': objectmask}}


def _format_object_mask(objectmask):
    """Format the new style object mask.

    This wraps the user mask with mask[USER_MASK] if it does not already
    have one. This makes it slightly easier for users.

    :param objectmask: a string-based object mask

    """
    objectmask = objectmask.strip()
    if (not objectmask.startswith('mask') and
            not objectmask.startswith('[')):
        objectmask = "mask[%s]" % objectmask
    return objectmask