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

# 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, see <http://www.gnu.org/licenses/>.

"""

kallithea.lib.auth

~~~~~~~~~~~~~~~~~~

authentication and permission libraries

This file was forked by the Kallithea project in July 2014.

Original author and date, and relevant copyright and licensing information is below:

:created_on: Apr 4, 2010

:author: marcink

:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import hashlib

import itertools

import logging

import os

import string

import bcrypt

import ipaddr

from decorator import decorator

from sqlalchemy.orm import joinedload

from sqlalchemy.orm.exc import ObjectDeletedError

from tg import request

from tg.i18n import ugettext as _

from webob.exc import HTTPForbidden, HTTPFound

from kallithea.config.routing import url

from kallithea.lib.utils2 import ascii_bytes, ascii_str, safe_bytes

from kallithea.lib.vcs.utils.lazy import LazyProperty

from kallithea.model.db import (Permission, User, UserApiKeys, UserGroup, UserGroupMember, UserGroupRepoGroupToPerm, UserGroupRepoToPerm, UserGroupToPerm,

                                UserGroupUserGroupToPerm, UserIpMap, UserToPerm)

from kallithea.model.meta import Session

from kallithea.model.user import UserModel

log = logging.getLogger(__name__)

class PasswordGenerator(object):

    """

    This is a simple class for generating password from different sets of

    characters

    usage::

        passwd_gen = PasswordGenerator()

        #print 8-letter password containing only big and small letters

            of alphabet

        passwd_gen.gen_password(8, passwd_gen.ALPHABETS_BIG_SMALL)

    """

    ALPHABETS_NUM = r'''1234567890'''

    ALPHABETS_SMALL = r'''qwertyuiopasdfghjklzxcvbnm'''

    ALPHABETS_BIG = r'''QWERTYUIOPASDFGHJKLZXCVBNM'''

    ALPHABETS_SPECIAL = r'''`-=[]\;',./~!@#$%^&*()_+{}|:"<>?'''

    ALPHABETS_FULL = ALPHABETS_BIG + ALPHABETS_SMALL \

        + ALPHABETS_NUM + ALPHABETS_SPECIAL

    ALPHABETS_ALPHANUM = ALPHABETS_BIG + ALPHABETS_SMALL + ALPHABETS_NUM

    ALPHABETS_BIG_SMALL = ALPHABETS_BIG + ALPHABETS_SMALL

    ALPHABETS_ALPHANUM_BIG = ALPHABETS_BIG + ALPHABETS_NUM

    ALPHABETS_ALPHANUM_SMALL = ALPHABETS_SMALL + ALPHABETS_NUM

    def gen_password(self, length, alphabet=ALPHABETS_FULL):

        assert len(alphabet) <= 256, alphabet

        l = []

        while len(l) < length:

            i = ord(os.urandom(1))

            if i < len(alphabet):

                l.append(alphabet[i])

        return ''.join(l)

def get_crypt_password(password):

    """

    Cryptographic function used for bcrypt password hashing.

    :param password: password to hash

            return None

        if not dbuser.active:

            log.info('Db user %s not active', dbuser.username)

            return None

        allowed_ips = AuthUser.get_allowed_ips(dbuser.user_id)

        if not check_ip_access(source_ip=ip_addr, allowed_ips=allowed_ips):

            log.info('Access for %s from %s forbidden - not in %s', dbuser.username, ip_addr, allowed_ips)

            return None

        return cls(dbuser=dbuser, is_external_auth=is_external_auth)

    def __init__(self, user_id=None, dbuser=None, is_external_auth=False):

        self.is_external_auth = is_external_auth # container auth - don't show logout option

        # These attributes will be overridden below if the requested user is

        # found or anonymous access (using the default user) is enabled.

        self.user_id = None

        self.username = None

        self.api_key = None

        self.name = ''

        self.lastname = ''

        self.email = ''

        self.admin = False

        # Look up database user, if necessary.

        if user_id is not None:

            assert dbuser is None

            log.debug('Auth User lookup by USER ID %s', user_id)

            dbuser = UserModel().get(user_id)

            assert dbuser is not None

        else:

            assert dbuser is not None

            log.debug('Auth User lookup by database user %s', dbuser)

        log.debug('filling %s data', dbuser)

        self.is_anonymous = dbuser.is_default_user

        if dbuser.is_default_user and not dbuser.active:

            self.username = 'None'

            self.is_default_user = False

        else:

            # copy non-confidential database fields from a `db.User` to this `AuthUser`.

            for k, v in dbuser.get_dict().items():

                assert k not in ['api_keys', 'permissions']

                setattr(self, k, v)

            self.is_default_user = dbuser.is_default_user

        log.debug('Auth User is now %s', self)

    @LazyProperty

    def permissions(self):

    def has_repository_permission_level(self, repo_name, level, purpose=None):

        required_perms = {

            'read': ['repository.read', 'repository.write', 'repository.admin'],

            'write': ['repository.write', 'repository.admin'],

            'admin': ['repository.admin'],

        }[level]

        actual_perm = self.permissions['repositories'].get(repo_name)

        ok = actual_perm in required_perms

        log.debug('Checking if user %r can %r repo %r (%s): %s (has %r)',

            self.username, level, repo_name, purpose, ok, actual_perm)

        return ok

    def has_repository_group_permission_level(self, repo_group_name, level, purpose=None):

        required_perms = {

            'read': ['group.read', 'group.write', 'group.admin'],

            'write': ['group.write', 'group.admin'],

            'admin': ['group.admin'],

        }[level]

        actual_perm = self.permissions['repositories_groups'].get(repo_group_name)

        ok = actual_perm in required_perms

        log.debug('Checking if user %r can %r repo group %r (%s): %s (has %r)',

            self.username, level, repo_group_name, purpose, ok, actual_perm)

        return ok

    def has_user_group_permission_level(self, user_group_name, level, purpose=None):

        required_perms = {

            'read': ['usergroup.read', 'usergroup.write', 'usergroup.admin'],

            'write': ['usergroup.write', 'usergroup.admin'],

            'admin': ['usergroup.admin'],

        }[level]

        actual_perm = self.permissions['user_groups'].get(user_group_name)

        ok = actual_perm in required_perms

        log.debug('Checking if user %r can %r user group %r (%s): %s (has %r)',

            self.username, level, user_group_name, purpose, ok, actual_perm)

        return ok

    @property

    def api_keys(self):

        return self._get_api_keys()

    def _get_api_keys(self):

        api_keys = [self.api_key]

        for api_key in UserApiKeys.query() \

                .filter_by(user_id=self.user_id, is_expired=False):

            api_keys.append(api_key.api_key)

        return api_keys

    @property

    def is_admin(self):

        return self.admin

    @property

    def repositories_admin(self):

        """

        Returns list of repositories you're an admin of

        """

        return [x[0] for x in self.permissions['repositories'].items()

                if x[1] == 'repository.admin']

    @property

    def repository_groups_admin(self):

        """

        Returns list of repository groups you're an admin of

        """

        return [x[0] for x in self.permissions['repositories_groups'].items()

                if x[1] == 'group.admin']

    @property

    def user_groups_admin(self):

        """

        Returns list of user groups you're an admin of

        """

        return [x[0] for x in self.permissions['user_groups'].items()

                if x[1] == 'usergroup.admin']

    def __repr__(self):

        return "<%s %s: %r>" % (self.__class__.__name__, self.user_id, self.username)

    def to_cookie(self):

        """ Serializes this login session to a cookie `dict`. """

        return {

            'user_id': self.user_id,

            'is_external_auth': self.is_external_auth,

        }

    @staticmethod

    def from_cookie(cookie, ip_addr):

    if not settings.GIT_EXECUTABLE_PATH:

        log.warning('No git executable configured - check "git_path" in the ini file.')

        return None

    try:

        stdout, stderr = GitRepository._run_git_command(['--version'])

    except RepositoryError as e:

        # message will already have been logged as error

        log.warning('No working git executable found - check "git_path" in the ini file.')

        return None

    if stderr:

        log.warning('Error/stderr from "%s --version":\n%s', settings.GIT_EXECUTABLE_PATH, safe_str(stderr))

    if not stdout:

        log.warning('No working git executable found - check "git_path" in the ini file.')

        return None

    output = safe_str(stdout).strip()

    m = re.search(r"\d+.\d+.\d+", output)

    if m:

        ver = StrictVersion(m.group(0))

        log.debug('Git executable: "%s", version %s (parsed from: "%s")',

                  settings.GIT_EXECUTABLE_PATH, ver, output)

        if ver < git_req_ver:

            log.error('Kallithea detected %s version %s, which is too old '

                      'for the system to function properly. '

                      'Please upgrade to version %s or later. '

                      'If you strictly need Mercurial repositories, you can '

                      'clear the "git_path" setting in the ini file.',

                      settings.GIT_EXECUTABLE_PATH, ver, git_req_ver)

            log.error("Terminating ...")

            sys.exit(1)

    else:

        ver = StrictVersion('0.0.0')

        log.warning('Error finding version number in "%s --version" stdout:\n%s',

                    settings.GIT_EXECUTABLE_PATH, output)

    return ver

#===============================================================================

# CACHE RELATED METHODS

#===============================================================================

def conditional_cache(region, prefix, condition, func):

    """

    Conditional caching function use like::

            #heavy computation function

            return data

        # depending from condition the compute is wrapped in cache or not

        compute = conditional_cache('short_term', 'cache_desc', condition=True, func=func)

        return compute(arg)

    :param region: name of cache region

    :param prefix: cache region prefix

    :param condition: condition for cache to be triggered, and return data cached

    """

    wrapped = func

    if condition:

        log.debug('conditional_cache: True, wrapping call of '

                  'func: %s into %s region cache' % (region, func))

        wrapped = beaker.cache._cache_decorate((prefix,), None, None, region)(func)

    return wrapped