# -*- coding: utf-8 -*-

############################ Copyrights and license ############################
#                                                                              #
# Copyright 2013 AKFish <akfish@gmail.com>                                     #
# Copyright 2013 Ed Jackson <ed.jackson@gmail.com>                             #
# Copyright 2013 Jonathan J Hunt <hunt@braincorporation.com>                   #
# Copyright 2013 Peter Golm <golm.peter@gmail.com>                             #
# Copyright 2013 Steve Brown <steve@evolvedlight.co.uk>                        #
# Copyright 2013 Vincent Jacques <vincent@vincent-jacques.net>                 #
# Copyright 2014 C. R. Oldham <cro@ncbt.org>                                   #
# Copyright 2014 Thialfihar <thi@thialfihar.org>                               #
# Copyright 2014 Tyler Treat <ttreat31@gmail.com>                              #
# Copyright 2014 Vincent Jacques <vincent@vincent-jacques.net>                 #
# Copyright 2015 Daniel Pocock <daniel@pocock.pro>                             #
# Copyright 2015 Joseph Rawson <joseph.rawson.works@littledebian.org>          #
# Copyright 2015 Uriel Corfa <uriel@corfa.fr>                                  #
# Copyright 2015 edhollandAL <eholland@alertlogic.com>                         #
# Copyright 2016 Jannis Gebauer <ja.geb@me.com>                                #
# Copyright 2016 Peter Buckley <dx-pbuckley@users.noreply.github.com>          #
# Copyright 2017 Colin Hoglund <colinhoglund@users.noreply.github.com>         #
# Copyright 2017 Jannis Gebauer <ja.geb@me.com>                                #
# Copyright 2018 Agor Maxime <maxime.agor23@gmail.com>                         #
# Copyright 2018 Wan Liuyang <tsfdye@gmail.com>                                #
# Copyright 2018 sfdye <tsfdye@gmail.com>                                      #
#                                                                              #
# This file is part of PyGithub.                                               #
# http://pygithub.readthedocs.io/                                              #
#                                                                              #
# PyGithub is free software: you can redistribute it and/or modify it under    #
# the terms of the GNU Lesser General Public License as published by the Free  #
# Software Foundation, either version 3 of the License, or (at your option)    #
# any later version.                                                           #
#                                                                              #
# PyGithub is distributed in the hope that it will be useful, but WITHOUT ANY  #
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS    #
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more #
# details.                                                                     #
#                                                                              #
# You should have received a copy of the GNU Lesser General Public License     #
# along with PyGithub. If not, see <http://www.gnu.org/licenses/>.             #
#                                                                              #
################################################################################

import urllib.request, urllib.parse, urllib.error
import pickle
import time
import sys
from http.client import HTTPSConnection
import jwt

from .Requester import Requester, json
from . import AuthenticatedUser
from . import NamedUser
from . import Organization
from . import Gist
import github.PaginatedList
from . import Repository
from . import Installation
from . import Legacy
from . import License
import github.GithubObject
from . import HookDescription
from . import GitignoreTemplate
from . import Status
from . import StatusMessage
from . import RateLimit
from . import InstallationAuthorization
from . import GithubException
from . import Invitation

atLeastPython3 = sys.hexversion >= 0x03000000

DEFAULT_BASE_URL = "https://api.github.com"
DEFAULT_STATUS_URL = "https://status.github.com"
# As of 2018-05-17, Github imposes a 10s limit for completion of API requests.
# Thus, the timeout should be slightly > 10s to account for network/front-end
# latency.
DEFAULT_TIMEOUT = 15
DEFAULT_PER_PAGE = 30


class Github(object):
    """
    This is the main class you instantiate to access the Github API v3. Optional parameters allow different authentication methods.
    """

    def __init__(self, login_or_token=None, password=None, base_url=DEFAULT_BASE_URL, timeout=DEFAULT_TIMEOUT, client_id=None, client_secret=None, user_agent='PyGithub/Python', per_page=DEFAULT_PER_PAGE, api_preview=False, verify=True):
        """
        :param login_or_token: string
        :param password: string
        :param base_url: string
        :param timeout: integer
        :param client_id: string
        :param client_secret: string
        :param user_agent: string
        :param per_page: int
        :param verify: boolean or string
        """

        assert login_or_token is None or isinstance(login_or_token, str), login_or_token
        assert password is None or isinstance(password, str), password
        assert isinstance(base_url, str), base_url
        assert isinstance(timeout, int), timeout
        assert client_id is None or isinstance(client_id, str), client_id
        assert client_secret is None or isinstance(client_secret, str), client_secret
        assert user_agent is None or isinstance(user_agent, str), user_agent
        assert isinstance(api_preview, (bool))
        self.__requester = Requester(login_or_token, password, base_url, timeout, client_id, client_secret, user_agent, per_page, api_preview, verify)

    def __get_FIX_REPO_GET_GIT_REF(self):
        """
        :type: bool
        """
        return self.__requester.FIX_REPO_GET_GIT_REF

    def __set_FIX_REPO_GET_GIT_REF(self, value):
        self.__requester.FIX_REPO_GET_GIT_REF = value

    FIX_REPO_GET_GIT_REF = property(__get_FIX_REPO_GET_GIT_REF, __set_FIX_REPO_GET_GIT_REF)

    def __get_per_page(self):
        """
        :type: int
        """
        return self.__requester.per_page

    def __set_per_page(self, value):
        self.__requester.per_page = value

    # v2: Remove this property? Why should it be necessary to read/modify it after construction
    per_page = property(__get_per_page, __set_per_page)

    # v2: Provide a unified way to access values of headers of last response
    # v2: (and add/keep ad hoc properties for specific useful headers like rate limiting, oauth scopes, etc.)
    # v2: Return an instance of a class: using a tuple did not allow to add a field "resettime"
    @property
    def rate_limiting(self):
        """
        First value is requests remaining, second value is request limit.
        :type: (int, int)
        """
        remaining, limit = self.__requester.rate_limiting
        if limit < 0:
            self.get_rate_limit()
        return self.__requester.rate_limiting

    @property
    def rate_limiting_resettime(self):
        """
        Unix timestamp indicating when rate limiting will reset.
        :type: int
        """
        if self.__requester.rate_limiting_resettime == 0:
            self.get_rate_limit()
        return self.__requester.rate_limiting_resettime

    def get_rate_limit(self):
        """
        Don't forget you can access the rate limit returned in headers of last Github API v3 response, by :attr:`github.MainClass.Github.rate_limiting` and :attr:`github.MainClass.Github.rate_limiting_resettime`.

        :calls: `GET /rate_limit <http://developer.github.com/v3/rate_limit>`_
        :rtype: :class:`github.RateLimit.RateLimit`
        """
        headers, attributes = self.__requester.requestJsonAndCheck(
            'GET',
            '/rate_limit'
        )
        return RateLimit.RateLimit(self.__requester, headers, attributes, True)

    @property
    def oauth_scopes(self):
        """
        :type: list of string
        """
        return self.__requester.oauth_scopes

    def get_license(self, key=github.GithubObject.NotSet):
        """
        :calls: `GET /license/:license <https://developer.github.com/v3/licenses/#get-an-individual-license>`_
        :param key: string
        :rtype: :class:`github.License.License`
        """

        assert isinstance(key, str), key
        headers, data = self.__requester.requestJsonAndCheck(
            "GET",
            "/licenses/" + key
        )
        return github.License.License(self.__requester, headers, data, completed=True)

    def get_licenses(self):
        """
        :calls: `GET /licenses <https://developer.github.com/v3/licenses/#list-all-licenses>`_
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.License.License`
        """

        url_parameters = dict()

        return github.PaginatedList.PaginatedList(
            github.License.License,
            self.__requester,
            "/licenses",
            url_parameters
        )

    def get_user(self, login=github.GithubObject.NotSet):
        """
        :calls: `GET /users/:user <http://developer.github.com/v3/users>`_ or `GET /user <http://developer.github.com/v3/users>`_
        :param login: string
        :rtype: :class:`github.NamedUser.NamedUser`
        """
        assert login is github.GithubObject.NotSet or isinstance(login, str), login
        if login is github.GithubObject.NotSet:
            return AuthenticatedUser.AuthenticatedUser(self.__requester, {}, {"url": "/user"}, completed=False)
        else:
            headers, data = self.__requester.requestJsonAndCheck(
                "GET",
                "/users/" + login
            )
            return github.NamedUser.NamedUser(self.__requester, headers, data, completed=True)

    def get_users(self, since=github.GithubObject.NotSet):
        """
        :calls: `GET /users <http://developer.github.com/v3/users>`_
        :param since: integer
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
        """
        assert since is github.GithubObject.NotSet or isinstance(since, int), since
        url_parameters = dict()
        if since is not github.GithubObject.NotSet:
            url_parameters["since"] = since
        return github.PaginatedList.PaginatedList(
            github.NamedUser.NamedUser,
            self.__requester,
            "/users",
            url_parameters
        )

    def get_organization(self, login):
        """
        :calls: `GET /orgs/:org <http://developer.github.com/v3/orgs>`_
        :param login: string
        :rtype: :class:`github.Organization.Organization`
        """
        assert isinstance(login, str), login
        headers, data = self.__requester.requestJsonAndCheck(
            "GET",
            "/orgs/" + login
        )
        return github.Organization.Organization(self.__requester, headers, data, completed=True)

    def get_organizations(self, since=github.GithubObject.NotSet):
        """
        :calls: `GET /organizations <http://developer.github.com/v3/orgs#list-all-organizations>`_
        :param since: integer
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Organization.Organization`
        """
        assert since is github.GithubObject.NotSet or isinstance(since, int), since
        url_parameters = dict()
        if since is not github.GithubObject.NotSet:
            url_parameters["since"] = since
        return github.PaginatedList.PaginatedList(
            github.NamedUser.NamedUser,
            self.__requester,
            "/organizations",
            url_parameters
        )

    def get_repo(self, full_name_or_id, lazy=True):
        """
        :calls: `GET /repos/:owner/:repo <http://developer.github.com/v3/repos>`_ or `GET /repositories/:id <http://developer.github.com/v3/repos>`_
        :rtype: :class:`github.Repository.Repository`
        """
        assert isinstance(full_name_or_id, (str, int)), full_name_or_id
        url_base = "/repositories/" if isinstance(full_name_or_id, int) or isinstance(full_name_or_id, int) else "/repos/"
        url = "%s%s" % (url_base, full_name_or_id)
        if lazy:
            return Repository.Repository(self.__requester, {}, {"url": url}, completed=False)
        headers, data = self.__requester.requestJsonAndCheck(
            "GET",
            "%s%s" % (url_base, full_name_or_id)
        )
        return Repository.Repository(self.__requester, headers, data, completed=True)

    def get_repos(self, since=github.GithubObject.NotSet):
        """
        :calls: `GET /repositories <http://developer.github.com/v3/repos/#list-all-public-repositories>`_
        :param since: integer
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
        """
        assert since is github.GithubObject.NotSet or isinstance(since, int), since
        url_parameters = dict()
        if since is not github.GithubObject.NotSet:
            url_parameters["since"] = since
        return github.PaginatedList.PaginatedList(
            github.Repository.Repository,
            self.__requester,
            "/repositories",
            url_parameters
        )

    def get_gist(self, id):
        """
        :calls: `GET /gists/:id <http://developer.github.com/v3/gists>`_
        :param id: string
        :rtype: :class:`github.Gist.Gist`
        """
        assert isinstance(id, str), id
        headers, data = self.__requester.requestJsonAndCheck(
            "GET",
            "/gists/" + id
        )
        return github.Gist.Gist(self.__requester, headers, data, completed=True)

    def get_gists(self):
        """
        :calls: `GET /gists/public <http://developer.github.com/v3/gists>`_
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Gist.Gist`
        """
        return github.PaginatedList.PaginatedList(
            github.Gist.Gist,
            self.__requester,
            "/gists/public",
            None
        )

    def search_repositories(self, query, sort=github.GithubObject.NotSet, order=github.GithubObject.NotSet, **qualifiers):
        """
        :calls: `GET /search/repositories <http://developer.github.com/v3/search>`_
        :param query: string
        :param sort: string ('stars', 'forks', 'updated')
        :param order: string ('asc', 'desc')
        :param qualifiers: keyword dict query qualifiers
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
        """
        assert isinstance(query, str), query
        url_parameters = dict()
        if sort is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
            assert sort in ('stars', 'forks', 'updated'), sort
            url_parameters["sort"] = sort
        if order is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
            assert order in ('asc', 'desc'), order
            url_parameters["order"] = order

        query_chunks = []
        if query:  # pragma no branch (Should be covered)
            query_chunks.append(query)

        for qualifier, value in list(qualifiers.items()):
            query_chunks.append("%s:%s" % (qualifier, value))

        url_parameters["q"] = ' '.join(query_chunks)
        assert url_parameters["q"], "need at least one qualifier"

        return github.PaginatedList.PaginatedList(
            github.Repository.Repository,
            self.__requester,
            "/search/repositories",
            url_parameters
        )

    def search_users(self, query, sort=github.GithubObject.NotSet, order=github.GithubObject.NotSet, **qualifiers):
        """
        :calls: `GET /search/users <http://developer.github.com/v3/search>`_
        :param query: string
        :param sort: string ('followers', 'repositories', 'joined')
        :param order: string ('asc', 'desc')
        :param qualifiers: keyword dict query qualifiers
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
        """
        assert isinstance(query, str), query
        url_parameters = dict()
        if sort is not github.GithubObject.NotSet:
            assert sort in ('followers', 'repositories', 'joined'), sort
            url_parameters["sort"] = sort
        if order is not github.GithubObject.NotSet:
            assert order in ('asc', 'desc'), order
            url_parameters["order"] = order

        query_chunks = []
        if query:
            query_chunks.append(query)

        for qualifier, value in list(qualifiers.items()):
            query_chunks.append("%s:%s" % (qualifier, value))

        url_parameters["q"] = ' '.join(query_chunks)
        assert url_parameters["q"], "need at least one qualifier"

        return github.PaginatedList.PaginatedList(
            github.NamedUser.NamedUser,
            self.__requester,
            "/search/users",
            url_parameters
        )

    def search_issues(self, query, sort=github.GithubObject.NotSet, order=github.GithubObject.NotSet, **qualifiers):
        """
        :calls: `GET /search/issues <http://developer.github.com/v3/search>`_
        :param query: string
        :param sort: string ('comments', 'created', 'updated')
        :param order: string ('asc', 'desc')
        :param qualifiers: keyword dict query qualifiers
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Issue.Issue`
        """
        assert isinstance(query, str), query
        url_parameters = dict()
        if sort is not github.GithubObject.NotSet:
            assert sort in ('comments', 'created', 'updated'), sort
            url_parameters["sort"] = sort
        if order is not github.GithubObject.NotSet:
            assert order in ('asc', 'desc'), order
            url_parameters["order"] = order

        query_chunks = []
        if query:  # pragma no branch (Should be covered)
            query_chunks.append(query)

        for qualifier, value in list(qualifiers.items()):
            query_chunks.append("%s:%s" % (qualifier, value))

        url_parameters["q"] = ' '.join(query_chunks)
        assert url_parameters["q"], "need at least one qualifier"

        return github.PaginatedList.PaginatedList(
            github.Issue.Issue,
            self.__requester,
            "/search/issues",
            url_parameters
        )

    def search_code(self, query, sort=github.GithubObject.NotSet, order=github.GithubObject.NotSet, **qualifiers):
        """
        :calls: `GET /search/code <http://developer.github.com/v3/search>`_
        :param query: string
        :param sort: string ('indexed')
        :param order: string ('asc', 'desc')
        :param qualifiers: keyword dict query qualifiers
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.ContentFile.ContentFile`
        """
        assert isinstance(query, str), query
        url_parameters = dict()
        if sort is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
            assert sort in ('indexed',), sort
            url_parameters["sort"] = sort
        if order is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
            assert order in ('asc', 'desc'), order
            url_parameters["order"] = order

        query_chunks = []
        if query:  # pragma no branch (Should be covered)
            query_chunks.append(query)

        for qualifier, value in list(qualifiers.items()):
            query_chunks.append("%s:%s" % (qualifier, value))

        url_parameters["q"] = ' '.join(query_chunks)
        assert url_parameters["q"], "need at least one qualifier"

        return github.PaginatedList.PaginatedList(
            github.ContentFile.ContentFile,
            self.__requester,
            "/search/code",
            url_parameters
        )


    def search_commits(self, query, sort=github.GithubObject.NotSet, order=github.GithubObject.NotSet, **qualifiers):
        """
        :calls: `GET /search/commits <http://developer.github.com/v3/search>`_
        :param query: string
        :param sort: string ('author-date', 'committer-date')
        :param order: string ('asc', 'desc')
        :param qualifiers: keyword dict query qualifiers
        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Commit.Commit`
        """
        assert isinstance(query, str), query
        url_parameters = dict()
        if sort is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
            assert sort in ('author-date', 'committer-date'), sort
            url_parameters["sort"] = sort
        if order is not github.GithubObject.NotSet:  # pragma no branch (Should be covered)
            assert order in ('asc', 'desc'), order
            url_parameters["order"] = order

        query_chunks = []
        if query:  # pragma no branch (Should be covered)
            query_chunks.append(query)

        for qualifier, value in list(qualifiers.items()):
            query_chunks.append("%s:%s" % (qualifier, value))

        url_parameters["q"] = ' '.join(query_chunks)
        assert url_parameters["q"], "need at least one qualifier"

        return github.PaginatedList.PaginatedList(
            github.Commit.Commit,
            self.__requester,
            "/search/commits",
            url_parameters,
            headers={
                "Accept": "application/vnd.github.cloak-preview"
            }
        )

    def render_markdown(self, text, context=github.GithubObject.NotSet):
        """
        :calls: `POST /markdown <http://developer.github.com/v3/markdown>`_
        :param text: string
        :param context: :class:`github.Repository.Repository`
        :rtype: string
        """
        assert isinstance(text, str), text
        assert context is github.GithubObject.NotSet or isinstance(context, github.Repository.Repository), context
        post_parameters = {
            "text": text
        }
        if context is not github.GithubObject.NotSet:
            post_parameters["mode"] = "gfm"
            post_parameters["context"] = context._identity
        status, headers, data = self.__requester.requestJson(
            "POST",
            "/markdown",
            input=post_parameters
        )
        return data

    def get_hook(self, name):
        """
        :calls: `GET /hooks/:name <http://developer.github.com/v3/repos/hooks/>`_
        :param name: string
        :rtype: :class:`github.HookDescription.HookDescription`
        """
        assert isinstance(name, str), name
        headers, attributes = self.__requester.requestJsonAndCheck(
            "GET",
            "/hooks/" + name
        )
        return HookDescription.HookDescription(self.__requester, headers, attributes, completed=True)

    def get_hooks(self):
        """
        :calls: `GET /hooks <http://developer.github.com/v3/repos/hooks/>`_
        :rtype: list of :class:`github.HookDescription.HookDescription`
        """
        headers, data = self.__requester.requestJsonAndCheck(
            "GET",
            "/hooks"
        )
        return [HookDescription.HookDescription(self.__requester, headers, attributes, completed=True) for attributes in data]

    def get_gitignore_templates(self):
        """
        :calls: `GET /gitignore/templates <http://developer.github.com/v3/gitignore>`_
        :rtype: list of string
        """
        headers, data = self.__requester.requestJsonAndCheck(
            "GET",
            "/gitignore/templates"
        )
        return data

    def get_gitignore_template(self, name):
        """
        :calls: `GET /gitignore/templates/:name <http://developer.github.com/v3/gitignore>`_
        :rtype: :class:`github.GitignoreTemplate.GitignoreTemplate`
        """
        assert isinstance(name, str), name
        headers, attributes = self.__requester.requestJsonAndCheck(
            "GET",
            "/gitignore/templates/" + name
        )
        return GitignoreTemplate.GitignoreTemplate(self.__requester, headers, attributes, completed=True)

    def get_emojis(self):
        """
        :calls: `GET /emojis <http://developer.github.com/v3/emojis/>`_
        :rtype: dictionary of type => url for emoji`
        """
        headers, attributes = self.__requester.requestJsonAndCheck(
            "GET",
            "/emojis"
        )
        return attributes

    def create_from_raw_data(self, klass, raw_data, headers={}):
        """
        Creates an object from raw_data previously obtained by :attr:`github.GithubObject.GithubObject.raw_data`,
        and optionaly headers previously obtained by :attr:`github.GithubObject.GithubObject.raw_headers`.

        :param klass: the class of the object to create
        :param raw_data: dict
        :param headers: dict
        :rtype: instance of class ``klass``
        """
        return klass(self.__requester, headers, raw_data, completed=True)

    def dump(self, obj, file, protocol=0):
        """
        Dumps (pickles) a PyGithub object to a file-like object.
        Some effort is made to not pickle sensitive informations like the Github credentials used in the :class:`Github` instance.
        But NO EFFORT is made to remove sensitive information from the object's attributes.

        :param obj: the object to pickle
        :param file: the file-like object to pickle to
        :param protocol: the `pickling protocol <http://docs.python.org/2.7/library/pickle.html#data-stream-format>`_
        """
        pickle.dump((obj.__class__, obj.raw_data, obj.raw_headers), file, protocol)

    def load(self, f):
        """
        Loads (unpickles) a PyGithub object from a file-like object.

        :param f: the file-like object to unpickle from
        :return: the unpickled object
        """
        return self.create_from_raw_data(*pickle.load(f))

    def get_api_status(self):
        """
        This doesn't work with a Github Enterprise installation, because it always targets https://status.github.com.

        :calls: `GET /api/status.json <https://status.github.com/api>`_
        :rtype: :class:`github.Status.Status`
        """
        headers, attributes = self.__requester.requestJsonAndCheck(
            "GET",
            DEFAULT_STATUS_URL + "/api/status.json"
        )
        return Status.Status(self.__requester, headers, attributes, completed=True)

    def get_last_api_status_message(self):
        """
        This doesn't work with a Github Enterprise installation, because it always targets https://status.github.com.

        :calls: `GET /api/last-message.json <https://status.github.com/api>`_
        :rtype: :class:`github.StatusMessage.StatusMessage`
        """
        headers, attributes = self.__requester.requestJsonAndCheck(
            "GET",
            DEFAULT_STATUS_URL + "/api/last-message.json"
        )
        return StatusMessage.StatusMessage(self.__requester, headers, attributes, completed=True)

    def get_api_status_messages(self):
        """
        This doesn't work with a Github Enterprise installation, because it always targets https://status.github.com.

        :calls: `GET /api/messages.json <https://status.github.com/api>`_
        :rtype: list of :class:`github.StatusMessage.StatusMessage`
        """
        headers, data = self.__requester.requestJsonAndCheck(
            "GET",
            DEFAULT_STATUS_URL + "/api/messages.json"
        )
        return [StatusMessage.StatusMessage(self.__requester, headers, attributes, completed=True) for attributes in data]

    def get_installation(self, id):
        """

        :param id:
        :return:
        """
        return Installation.Installation(self.__requester, headers={}, attributes={"id": id}, completed=True)


class GithubIntegration(object):
    """
    Main class to obtain tokens for a GitHub integration.
    """

    def __init__(self, integration_id, private_key):
        """
        :param integration_id: int
        :param private_key: string
        """
        self.integration_id = integration_id
        self.private_key = private_key

    def create_jwt(self):
        """
        Creates a signed JWT, valid for 60 seconds.
        :return:
        """
        now = int(time.time())
        payload = {
            "iat": now,
            "exp": now + 60,
            "iss": self.integration_id
        }
        encrypted = jwt.encode(
            payload,
            key=self.private_key,
            algorithm="RS256"
        )

        if atLeastPython3:
            encrypted = encrypted.decode('utf-8')

        return encrypted

    def get_access_token(self, installation_id, user_id=None):
        """
        Get an access token for the given installation id.
        POSTs https://api.github.com/installations/<installation_id>/access_tokens
        :param user_id: int
        :param installation_id: int
        :return: :class:`github.InstallationAuthorization.InstallationAuthorization`
        """
        body = None
        if user_id:
            body = json.dumps({"user_id": user_id})
        conn = HTTPSConnection("api.github.com")
        conn.request(
            method="POST",
            url="/installations/{}/access_tokens".format(installation_id),
            headers={
                "Authorization": "Bearer {}".format(self.create_jwt()),
                "Accept": "application/vnd.github.machine-man-preview+json",
                "User-Agent": "PyGithub/Python"
            },
            body=body
        )
        response = conn.getresponse()
        response_text = response.read()

        if atLeastPython3:
            response_text = response_text.decode('utf-8')

        conn.close()
        if response.status == 201:
            data = json.loads(response_text)
            return InstallationAuthorization.InstallationAuthorization(
                requester=None,  # not required, this is a NonCompletableGithubObject
                headers={},  # not required, this is a NonCompletableGithubObject
                attributes=data,
                completed=True
            )
        elif response.status == 403:
            raise GithubException.BadCredentialsException(
                status=response.status,
                data=response_text
            )
        elif response.status == 404:
            raise GithubException.UnknownObjectException(
                status=response.status,
                data=response_text
            )
        raise GithubException.GithubException(
            status=response.status,
            data=response_text
        )
