# RhodeCode VCSServer provides access to different vcs backends via network.
# Copyright (C) 2014-2020 RhodeCode GmbH
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA

import os
import tempfile

from svn import client
from svn import core
from svn import ra

from mercurial import error

from vcsserver.str_utils import safe_bytes

core.svn_config_ensure(None)
svn_config = core.svn_config_get_config(None)


class RaCallbacks(ra.Callbacks):
    @staticmethod
    def open_tmp_file(pool):  # pragma: no cover
        (fd, fn) = tempfile.mkstemp()
        os.close(fd)
        return fn

    @staticmethod
    def get_client_string(pool):
        return b'RhodeCode-subversion-url-checker'


class SubversionException(Exception):
    pass


class SubversionConnectionException(SubversionException):
    """Exception raised when a generic error occurs when connecting to a repository."""


def normalize_url(url):
    if not url:
        return url
    if url.startswith(b'svn+http://') or url.startswith(b'svn+https://'):
        url = url[4:]
    url = url.rstrip(b'/')
    return url


def _create_auth_baton(pool):
    """Create a Subversion authentication baton. """
    # Give the client context baton a suite of authentication
    # providers.h
    platform_specific = [
        'svn_auth_get_gnome_keyring_simple_provider',
        'svn_auth_get_gnome_keyring_ssl_client_cert_pw_provider',
        'svn_auth_get_keychain_simple_provider',
        'svn_auth_get_keychain_ssl_client_cert_pw_provider',
        'svn_auth_get_kwallet_simple_provider',
        'svn_auth_get_kwallet_ssl_client_cert_pw_provider',
        'svn_auth_get_ssl_client_cert_file_provider',
        'svn_auth_get_windows_simple_provider',
        'svn_auth_get_windows_ssl_server_trust_provider',
    ]

    providers = []

    for p in platform_specific:
        if getattr(core, p, None) is not None:
            try:
                providers.append(getattr(core, p)())
            except RuntimeError:
                pass

    providers += [
        client.get_simple_provider(),
        client.get_username_provider(),
        client.get_ssl_client_cert_file_provider(),
        client.get_ssl_client_cert_pw_file_provider(),
        client.get_ssl_server_trust_file_provider(),
    ]

    return core.svn_auth_open(providers, pool)


class SubversionRepo(object):
    """Wrapper for a Subversion repository.

    It uses the SWIG Python bindings, see above for requirements.
    """
    def __init__(self, svn_url: bytes = b'', username: bytes = b'', password: bytes = b''):

        self.username = username
        self.password = password
        self.svn_url = core.svn_path_canonicalize(svn_url)

        self.auth_baton_pool = core.Pool()
        self.auth_baton = _create_auth_baton(self.auth_baton_pool)
        # self.init_ra_and_client() assumes that a pool already exists
        self.pool = core.Pool()

        self.ra = self.init_ra_and_client()
        self.uuid = ra.get_uuid(self.ra, self.pool)

    def init_ra_and_client(self):
        """Initializes the RA and client layers, because sometimes getting
        unified diffs runs the remote server out of open files.
        """

        if self.username:
            core.svn_auth_set_parameter(self.auth_baton,
                                        core.SVN_AUTH_PARAM_DEFAULT_USERNAME,
                                        self.username)
        if self.password:
            core.svn_auth_set_parameter(self.auth_baton,
                                        core.SVN_AUTH_PARAM_DEFAULT_PASSWORD,
                                        self.password)

        callbacks = RaCallbacks()
        callbacks.auth_baton = self.auth_baton

        try:
            return ra.open2(self.svn_url, callbacks, svn_config, self.pool)
        except SubversionException as e:
            # e.child contains a detailed error messages
            msglist = []
            svn_exc = e
            while svn_exc:
                if svn_exc.args[0]:
                    msglist.append(svn_exc.args[0])
                svn_exc = svn_exc.child
            msg = '\n'.join(msglist)
            raise SubversionConnectionException(msg)


class svnremoterepo(object):
    """ the dumb wrapper for actual Subversion repositories """

    def __init__(self, username: bytes = b'', password: bytes = b'', svn_url: bytes = b''):
        self.username = username or b''
        self.password = password or b''
        self.path = normalize_url(svn_url)

    def svn(self):
        try:
            return SubversionRepo(self.path, self.username, self.password)
        except SubversionConnectionException as e:
            raise error.Abort(safe_bytes(e))