#  Copyright 2008-2015 Nokia Networks
#  Copyright 2016-     Robot Framework Foundation
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

from __future__ import absolute_import

from contextlib import contextmanager

try:
    import httplib
    import xmlrpclib
except ImportError:  # Py3
    import http.client as httplib
    import xmlrpc.client as xmlrpclib
import re
import socket
import sys
import time

try:
    from xml.parsers.expat import ExpatError
except ImportError:   # No expat in IronPython 2.7
    class ExpatError(Exception):
        pass

from robot.errors import RemoteError
from robot.utils import (is_bytes, is_dict_like, is_list_like, is_number,
                         is_string, timestr_to_secs, unic, DotDict,
                         IRONPYTHON, JYTHON, PY2)


class Remote(object):
    ROBOT_LIBRARY_SCOPE = 'TEST SUITE'

    def __init__(self, uri='http://127.0.0.1:8270', timeout=None):
        """Connects to a remote server at ``uri``.

        Optional ``timeout`` can be used to specify a timeout to wait when
        initially connecting to the server and if a connection accidentally
        closes. Timeout can be given as seconds (e.g. ``60``) or using
        Robot Framework time format (e.g. ``60s``, ``2 minutes 10 seconds``).

        The default timeout is typically several minutes, but it depends on
        the operating system and its configuration. Notice that setting
        a timeout that is shorter than keyword execution time will interrupt
        the keyword.

        Timeouts do not work with IronPython.
        """
        if '://' not in uri:
            uri = 'http://' + uri
        if timeout:
            timeout = timestr_to_secs(timeout)
        self._uri = uri
        self._client = XmlRpcRemoteClient(uri, timeout)

    def get_keyword_names(self, attempts=2):
        for i in range(attempts):
            time.sleep(i)
            try:
                return self._client.get_keyword_names()
            except TypeError as err:
                error = err
        raise RuntimeError('Connecting remote server at %s failed: %s'
                           % (self._uri, error))

    def get_keyword_arguments(self, name):
        try:
            return self._client.get_keyword_arguments(name)
        except TypeError:
            return ['*args']

    def get_keyword_types(self, name):
        try:
            return self._client.get_keyword_types(name)
        except TypeError:
            return None

    def get_keyword_tags(self, name):
        try:
            return self._client.get_keyword_tags(name)
        except TypeError:
            return None

    def get_keyword_documentation(self, name):
        try:
            return self._client.get_keyword_documentation(name)
        except TypeError:
            return None

    def run_keyword(self, name, args, kwargs):
        coercer = ArgumentCoercer()
        args = coercer.coerce(args)
        kwargs = coercer.coerce(kwargs)
        result = RemoteResult(self._client.run_keyword(name, args, kwargs))
        sys.stdout.write(result.output)
        if result.status != 'PASS':
            raise RemoteError(result.error, result.traceback, result.fatal,
                              result.continuable)
        return result.return_


class ArgumentCoercer(object):
    binary = re.compile('[\x00-\x08\x0B\x0C\x0E-\x1F]')
    non_ascii = re.compile('[\x80-\xff]')

    def coerce(self, argument):
        for handles, handler in [(is_string, self._handle_string),
                                 (is_bytes, self._handle_bytes),
                                 (is_number, self._pass_through),
                                 (is_dict_like, self._coerce_dict),
                                 (is_list_like, self._coerce_list),
                                 (lambda arg: True, self._to_string)]:
            if handles(argument):
                return handler(argument)

    def _handle_string(self, arg):
        if self._string_contains_binary(arg):
            return self._handle_binary_in_string(arg)
        return arg

    def _string_contains_binary(self, arg):
        return (self.binary.search(arg) or
                is_bytes(arg) and self.non_ascii.search(arg))

    def _handle_binary_in_string(self, arg):
        try:
            if not is_bytes(arg):
                arg = arg.encode('ASCII')
        except UnicodeError:
            raise ValueError('Cannot represent %r as binary.' % arg)
        return xmlrpclib.Binary(arg)

    def _handle_bytes(self, arg):
        # http://bugs.jython.org/issue2429
        if IRONPYTHON or JYTHON:
            arg = str(arg)
        return xmlrpclib.Binary(arg)

    def _pass_through(self, arg):
        return arg

    def _coerce_list(self, arg):
        return [self.coerce(item) for item in arg]

    def _coerce_dict(self, arg):
        return dict((self._to_key(key), self.coerce(arg[key])) for key in arg)

    def _to_key(self, item):
        item = self._to_string(item)
        self._validate_key(item)
        return item

    def _to_string(self, item):
        item = unic(item) if item is not None else ''
        return self._handle_string(item)

    def _validate_key(self, key):
        if isinstance(key, xmlrpclib.Binary):
            raise ValueError('Dictionary keys cannot be binary. Got %s%r.'
                             % ('b' if PY2 else '', key.data))
        if IRONPYTHON:
            try:
                key.encode('ASCII')
            except UnicodeError:
                raise ValueError('Dictionary keys cannot contain non-ASCII '
                                 'characters on IronPython. Got %r.' % key)


class RemoteResult(object):

    def __init__(self, result):
        if not (is_dict_like(result) and 'status' in result):
            raise RuntimeError('Invalid remote result dictionary: %s' % result)
        self.status = result['status']
        self.output = unic(self._get(result, 'output'))
        self.return_ = self._get(result, 'return')
        self.error = unic(self._get(result, 'error'))
        self.traceback = unic(self._get(result, 'traceback'))
        self.fatal = bool(self._get(result, 'fatal', False))
        self.continuable = bool(self._get(result, 'continuable', False))

    def _get(self, result, key, default=''):
        value = result.get(key, default)
        return self._convert(value)

    def _convert(self, value):
        if isinstance(value, xmlrpclib.Binary):
            return bytes(value.data)
        if is_dict_like(value):
            return DotDict((k, self._convert(v)) for k, v in value.items())
        if is_list_like(value):
            return [self._convert(v) for v in value]
        return value


class XmlRpcRemoteClient(object):

    def __init__(self, uri, timeout=None):
        self.uri = uri
        self.timeout = timeout

    @property
    @contextmanager
    def _server(self):
        if self.uri.startswith('https://'):
            transport = TimeoutHTTPSTransport(timeout=self.timeout)
        else:
            transport = TimeoutHTTPTransport(timeout=self.timeout)
        server = xmlrpclib.ServerProxy(self.uri, encoding='UTF-8',
                                       transport=transport)
        try:
            yield server
        except (socket.error, xmlrpclib.Error) as err:
            raise TypeError(err)
        finally:
            server('close')()

    def get_keyword_names(self):
        with self._server as server:
            return server.get_keyword_names()
            
    def get_keyword_arguments(self, name):
        with self._server as server:
            return server.get_keyword_arguments(name)

    def get_keyword_types(self, name):
        with self._server as server:
            return server.get_keyword_types(name)

    def get_keyword_tags(self, name):
        with self._server as server:
            return server.get_keyword_tags(name)

    def get_keyword_documentation(self, name):
        with self._server as server:
            return server.get_keyword_documentation(name)

    def run_keyword(self, name, args, kwargs):
        with self._server as server:
            run_keyword_args = [name, args, kwargs] if kwargs else [name, args]
            try:
                return server.run_keyword(*run_keyword_args)
            except xmlrpclib.Fault as err:
                message = err.faultString
            except socket.error as err:
                message = 'Connection to remote server broken: %s' % err
            except ExpatError as err:
                message = ('Processing XML-RPC return value failed. '
                        'Most often this happens when the return value '
                        'contains characters that are not valid in XML. '
                        'Original error was: ExpatError: %s' % err)
            raise RuntimeError(message)


# Custom XML-RPC timeouts based on
# http://stackoverflow.com/questions/2425799/timeout-for-xmlrpclib-client-requests

class TimeoutHTTPTransport(xmlrpclib.Transport):
    _connection_class = httplib.HTTPConnection

    def __init__(self, use_datetime=0, timeout=None):
        xmlrpclib.Transport.__init__(self, use_datetime)
        if not timeout:
            timeout = socket._GLOBAL_DEFAULT_TIMEOUT
        self.timeout = timeout

    def make_connection(self, host):
        if self._connection and host == self._connection[0]:
            return self._connection[1]
        chost, self._extra_headers, x509 = self.get_host_info(host)
        self._connection = host, self._connection_class(chost, timeout=self.timeout)
        return self._connection[1]


if IRONPYTHON:

    class TimeoutHTTPTransport(xmlrpclib.Transport):

        def __init__(self, use_datetime=0, timeout=None):
            xmlrpclib.Transport.__init__(self, use_datetime)
            if timeout:
                raise RuntimeError('Timeouts are not supported on IronPython.')


class TimeoutHTTPSTransport(TimeoutHTTPTransport):
    _connection_class = httplib.HTTPSConnection