# -*- 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.controllers.login

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

Login controller for Kallithea

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 22, 2010

:author: marcink

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

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

"""

import logging

import re

import formencode

from formencode import htmlfill

from tg.i18n import ugettext as _

from tg import request, session, tmpl_context as c

from webob.exc import HTTPFound, HTTPBadRequest

import kallithea.lib.helpers as h

from kallithea.config.routing import url

from kallithea.lib.auth import AuthUser, HasPermissionAnyDecorator

from kallithea.lib.base import BaseController, log_in_user, render

from kallithea.lib.exceptions import UserCreationError

from kallithea.lib.utils2 import safe_str

from kallithea.model.db import User, Setting

from kallithea.model.forms import \

    LoginForm, RegisterForm, PasswordResetRequestForm, PasswordResetConfirmationForm

from kallithea.model.user import UserModel

from kallithea.model.meta import Session

log = logging.getLogger(__name__)

class LoginController(BaseController):

    def _validate_came_from(self, came_from,

            _re=re.compile(r"/(?!/)[-!#$%&'()*+,./:;=?@_~0-9A-Za-z]*$")):

        """Return True if came_from is valid and can and should be used.

        Determines if a URI reference is valid and relative to the origin;

        or in RFC 3986 terms, whether it matches this production:

          origin-relative-ref = path-absolute [ "?" query ] [ "#" fragment ]

        with the exception that '%' escapes are not validated and '#' is

        allowed inside the fragment part.

        """

        return _re.match(came_from) is not None

    def index(self):

        c.came_from = safe_str(request.GET.get('came_from', ''))

        if c.came_from:

            if not self._validate_came_from(c.came_from):

                log.error('Invalid came_from (not server-relative): %r', c.came_from)

                raise HTTPBadRequest()

        else:

            c.came_from = url('home')

        if request.POST:

            # import Login Form validator class

            login_form = LoginForm()()

            try:

                c.form_result = login_form.to_python(dict(request.POST))

                # form checks for username/password, now we're authenticated

                username = c.form_result['username']

                user = User.get_by_username_or_email(username, case_insensitive=True)

            except formencode.Invalid as errors:

                defaults = errors.value

                # remove password from filling in form again

                defaults.pop('password', None)

                return htmlfill.render(

                    render('/login.html'),

                    defaults=errors.value,

                    errors=errors.error_dict or {},

                    prefix_error=False,

                    encoding="UTF-8",

                    force_defaults=False)

            except UserCreationError as e:

                # container auth or other auth functions that create users on

                # the fly can throw this exception signaling that there's issue

                # with user creation, explanation should be provided in

                # Exception itself

                h.flash(e, 'error')

            else:

                log_in_user(user, c.form_result['remember'],

                    is_external_auth=False)

                raise HTTPFound(location=c.came_from)

        else:

            # redirect if already logged in

                raise HTTPFound(location=c.came_from)

        return render('/login.html')

    @HasPermissionAnyDecorator('hg.admin', 'hg.register.auto_activate',

                               'hg.register.manual_activate')

    def register(self):

        def_user_perms = AuthUser(dbuser=User.get_default_user()).permissions['global']

        c.auto_active = 'hg.register.auto_activate' in def_user_perms

        settings = Setting.get_app_settings()

        captcha_private_key = settings.get('captcha_private_key')

        c.captcha_active = bool(captcha_private_key)

        c.captcha_public_key = settings.get('captcha_public_key')

        if request.POST:

            register_form = RegisterForm()()

            try:

                form_result = register_form.to_python(dict(request.POST))

                form_result['active'] = c.auto_active

                if c.captcha_active:

                    from kallithea.lib.recaptcha import submit

                    response = submit(request.POST.get('g-recaptcha-response'),

                                      private_key=captcha_private_key,

                                      remoteip=request.ip_addr)

                    if not response.is_valid:

                        _value = form_result

                        _msg = _('Bad captcha')

                        error_dict = {'recaptcha_field': _msg}

                        raise formencode.Invalid(_msg, _value, None,

                                                 error_dict=error_dict)

                UserModel().create_registration(form_result)

                h.flash(_('You have successfully registered with %s') % (c.site_name or 'Kallithea'),

                        category='success')

                Session().commit()

                raise HTTPFound(location=url('login_home'))

            except formencode.Invalid as errors:

                return htmlfill.render(

                    render('/register.html'),

                    defaults=errors.value,

                    errors=errors.error_dict or {},

                    prefix_error=False,

                    encoding="UTF-8",

                    force_defaults=False)

            except UserCreationError as e:

                # container auth or other auth functions that create users on

                # the fly can throw this exception signaling that there's issue

                # with user creation, explanation should be provided in

                # Exception itself

                h.flash(e, 'error')

        return render('/register.html')

    def password_reset(self):

        settings = Setting.get_app_settings()

        captcha_private_key = settings.get('captcha_private_key')

        c.captcha_active = bool(captcha_private_key)

        c.captcha_public_key = settings.get('captcha_public_key')

        if request.POST:

            password_reset_form = PasswordResetRequestForm()()

            try:

                form_result = password_reset_form.to_python(dict(request.POST))

                if c.captcha_active:

                    from kallithea.lib.recaptcha import submit

                    response = submit(request.POST.get('g-recaptcha-response'),

                                      private_key=captcha_private_key,

                                      remoteip=request.ip_addr)

                    if not response.is_valid:

                        _value = form_result

                        _msg = _('Bad captcha')

                        error_dict = {'recaptcha_field': _msg}

                        raise formencode.Invalid(_msg, _value, None,

                                                 error_dict=error_dict)

                redirect_link = UserModel().send_reset_password_email(form_result)

                h.flash(_('A password reset confirmation code has been sent'),

                            category='success')

                raise HTTPFound(location=redirect_link)

            except formencode.Invalid as errors:

                return htmlfill.render(

                    render('/password_reset.html'),

                    defaults=errors.value,

                    errors=errors.error_dict or {},

                    prefix_error=False,

                    encoding="UTF-8",

                    force_defaults=False)

        return render('/password_reset.html')

    def password_reset_confirmation(self):

        # This controller handles both GET and POST requests, though we

        # only ever perform the actual password change on POST (since

        # GET requests are not allowed to have side effects, and do not

        # receive automatic CSRF protection).

        # The template needs the email address outside of the form.

        c.email = request.params.get('email')

        if not request.POST:

            return htmlfill.render(

                render('/password_reset_confirmation.html'),

                defaults=dict(request.params),

                encoding='UTF-8')

        form = PasswordResetConfirmationForm()()

        try:

            form_result = form.to_python(dict(request.POST))

        except formencode.Invalid as errors:

            return htmlfill.render(

                render('/password_reset_confirmation.html'),

                defaults=errors.value,

                errors=errors.error_dict or {},

                prefix_error=False,

                encoding='UTF-8')

        if not UserModel().verify_reset_password_token(

            form_result['email'],

            form_result['timestamp'],

            form_result['token'],

        ):

            return htmlfill.render(

                render('/password_reset_confirmation.html'),

                defaults=form_result,

                errors={'token': _('Invalid password reset token')},

                prefix_error=False,

                encoding='UTF-8')

        UserModel().reset_password(form_result['email'], form_result['password'])

        h.flash(_('Successfully updated password'), category='success')

        raise HTTPFound(location=url('login_home'))

    def logout(self):

        session.delete()

        log.info('Logging out and deleting session for user')

        raise HTTPFound(location=url('home'))

    def authentication_token(self):

        """Return the CSRF protection token for the session - just like it

        could have been screen scraped from a page with a form.

        Only intended for testing but might also be useful for other kinds

        of automation.

        """

        return h.authentication_token()

        :param user: `AuthUser` instance

        """

        user_id = user.user_id

        user_is_admin = user.is_admin

        log.debug('Getting PERMISSION tree')

        compute = conditional_cache('short_term', 'cache_desc',

                                    condition=cache, func=_cached_perms_data)

        return compute(user_id, user_is_admin)

    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'].iteritems()

                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'].iteritems()

                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'].iteritems()

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

    @staticmethod

    def check_ip_allowed(user, ip_addr):

        """

        Check if the given IP address (a `str`) is allowed for the given

        user (an `AuthUser` or `db.User`).

        """

        allowed_ips = AuthUser.get_allowed_ips(user.user_id, cache=True)

        if check_ip_access(source_ip=ip_addr, allowed_ips=allowed_ips):

            log.debug('IP:%s is in range of %s', ip_addr, allowed_ips)

            return True

        else:

            log.info('Access for IP:%s forbidden, '

                     'not in %s' % (ip_addr, allowed_ips))

            return False

    def __repr__(self):

        return "<AuthUser('id:%s[%s] auth:%s')>" \

            % (self.user_id, self.username, (self.is_authenticated or self.is_default_user))

    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):

        """

        Deserializes an `AuthUser` from a cookie `dict`.

        """

        au = AuthUser(

            user_id=cookie.get('user_id'),

            is_external_auth=cookie.get('is_external_auth', False),

        )

        au.is_authenticated = True

        return au

    @classmethod

    def get_allowed_ips(cls, user_id, cache=False):

        _set = set()

        default_ips = UserIpMap.query().filter(UserIpMap.user_id ==

                                        User.get_default_user(cache=True).user_id)

        if cache:

            default_ips = default_ips.options(FromCache("sql_cache_short",

                                              "get_user_ips_default"))

        for ip in default_ips:

            try:

                _set.add(ip.ip_addr)

            except ObjectDeletedError:

                # since we use heavy caching sometimes it happens that we get

                # deleted objects here, we just skip them

                pass

        user_ips = UserIpMap.query().filter(UserIpMap.user_id == user_id)

        if cache:

            user_ips = user_ips.options(FromCache("sql_cache_short",

                                                  "get_user_ips_%s" % user_id))

        for ip in user_ips:

            try:

                _set.add(ip.ip_addr)

            except ObjectDeletedError:

                # since we use heavy caching sometimes it happens that we get

                # deleted objects here, we just skip them

                pass

        return _set or set(['0.0.0.0/0', '::/0'])

def set_available_permissions(config):

    """

    This function will propagate globals with all available defined

    permission given in db. We don't want to check each time from db for new

    permissions since adding a new permission also requires application restart

    ie. to decorate new views with the newly created permission

    :param config: current config instance

    """

    log.info('getting information about all available permissions')

    try:

        all_perms = Session().query(Permission).all()

        config['available_permissions'] = [x.permission_name for x in all_perms]

    finally:

        Session.remove()

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

# CHECK DECORATORS

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

def _redirect_to_login(message=None):

    """Return an exception that must be raised. It will redirect to the login

    page which will redirect back to the current URL after authentication.

    The optional message will be shown in a flash message."""

    from kallithea.lib import helpers as h

    if message:

        h.flash(message, category='warning')

    p = request.path_qs

    log.debug('Redirecting to login page, origin: %s', p)

    return HTTPFound(location=url('login_home', came_from=p))

# Use as decorator

class LoginRequired(object):

    """Client must be logged in as a valid User, or we'll redirect to the login

    page.

    If the "default" user is enabled and allow_default_user is true, that is

    considered valid too.

    Also checks that IP address is allowed.

    """

    def __init__(self, allow_default_user=False):

        self.allow_default_user = allow_default_user

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        controller = fargs[0]

        user = request.authuser

        loc = "%s:%s" % (controller.__class__.__name__, func.__name__)

        log.debug('Checking access for user %s @ %s', user, loc)

        # Check if we used an API key to authenticate.

        if user.authenticating_api_key is not None:

            log.info('user %s authenticated with API key ****%s @ %s',

                     user, user.authenticating_api_key[-4:], loc)

            return func(*fargs, **fkwargs)

        # CSRF protection: Whenever a request has ambient authority (whether

        # through a session cookie or its origin IP address), it must include

        # the correct token, unless the HTTP method is GET or HEAD (and thus

        # guaranteed to be side effect free. In practice, the only situation

        # where we allow side effects without ambient authority is when the

        # authority comes from an API key; and that is handled above.

        if request.method not in ['GET', 'HEAD']:

            token = request.POST.get(secure_form.token_key)

            if not token or token != secure_form.authentication_token():

                log.error('CSRF check failed')

                raise HTTPForbidden()

        # regular user authentication

            if self.allow_default_user:

                log.info('default user @ %s', loc)

                return func(*fargs, **fkwargs)

            log.info('default user is not accepted here @ %s', loc)

        raise _redirect_to_login()

# Use as decorator

class NotAnonymous(object):

    """Ensures that client is not logged in as the "default" user, and

    redirects to the login page otherwise. Must be used together with

    LoginRequired."""

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        cls = fargs[0]

        user = request.authuser

        log.debug('Checking that user %s is not anonymous @%s', user.username, cls)

        if user.is_default_user:

            raise _redirect_to_login(_('You need to be a registered user to '

                                       'perform this action'))

        else:

            return func(*fargs, **fkwargs)

class _PermsDecorator(object):

    """Base class for controller decorators with multiple permissions"""

    def __init__(self, *required_perms):

        self.required_perms = required_perms # usually very short - a list is thus fine

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        cls = fargs[0]

        user = request.authuser

        log.debug('checking %s permissions %s for %s %s',

          self.__class__.__name__, self.required_perms, cls, user)

        if self.check_permissions(user):

            log.debug('Permission granted for %s %s', cls, user)

            return func(*fargs, **fkwargs)

        else:

            log.info('Permission denied for %s %s', cls, user)

            if user.is_default_user:

                raise _redirect_to_login(_('You need to be signed in to view this page'))

            else:

                raise HTTPForbidden()

    def check_permissions(self, user):

        raise NotImplementedError()

class HasPermissionAnyDecorator(_PermsDecorator):

    """

    Checks the user has any of the given global permissions.

    """

    def check_permissions(self, user):

        global_permissions = user.permissions['global'] # usually very short

        return any(p in global_permissions for p in self.required_perms)

class _PermDecorator(_PermsDecorator):

    """Base class for controller decorators with a single permission"""

    def __init__(self, required_perm):

        _PermsDecorator.__init__(self, [required_perm])

        self.required_perm = required_perm

class HasRepoPermissionLevelDecorator(_PermDecorator):

    """

    Checks the user has at least the specified permission level for the requested repository.

    """

    def check_permissions(self, user):

        repo_name = get_repo_slug(request)

        return user.has_repository_permission_level(repo_name, self.required_perm)

class HasRepoGroupPermissionLevelDecorator(_PermDecorator):

    """

    Checks the user has any of given permissions for the requested repository group.

    """

    def check_permissions(self, user):

        repo_group_name = get_repo_group_slug(request)

        return user.has_repository_group_permission_level(repo_group_name, self.required_perm)

class HasUserGroupPermissionLevelDecorator(_PermDecorator):

    """

    Checks for access permission for any of given predicates for specific

    user group. In order to fulfill the request any of predicates must be meet

    """

    def check_permissions(self, user):

        user_group_name = get_user_group_slug(request)

        return user.has_user_group_permission_level(user_group_name, self.required_perm)

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

# CHECK FUNCTIONS

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

class _PermsFunction(object):

    """Base function for other check functions with multiple permissions"""

    def __init__(self, *required_perms):

        self.required_perms = required_perms # usually very short - a list is thus fine

    def __nonzero__(self):

        """ Defend against accidentally forgetting to call the object

            and instead evaluating it directly in a boolean context,

            which could have security implications.

        """

        raise AssertionError(self.__class__.__name__ + ' is not a bool and must be called!')

    def __call__(self, *a, **b):

        raise NotImplementedError()

class HasPermissionAny(_PermsFunction):

    def __call__(self, purpose=None):

        global_permissions = request.authuser.permissions['global'] # usually very short

        ok = any(p in global_permissions for p in self.required_perms)

        log.debug('Check %s for global %s (%s): %s',

            request.authuser.username, self.required_perms, purpose, ok)

        return ok

class _PermFunction(_PermsFunction):

    """Base function for other check functions with a single permission"""

    def __init__(self, required_perm):

        _PermsFunction.__init__(self, [required_perm])

        self.required_perm = required_perm

class HasRepoPermissionLevel(_PermFunction):

    def __call__(self, repo_name, purpose=None):

        return request.authuser.has_repository_permission_level(repo_name, self.required_perm, purpose)

class HasRepoGroupPermissionLevel(_PermFunction):

    def __call__(self, group_name, purpose=None):

        return request.authuser.has_repository_group_permission_level(group_name, self.required_perm, purpose)

class HasUserGroupPermissionLevel(_PermFunction):

    def __call__(self, user_group_name, purpose=None):

        return request.authuser.has_user_group_permission_level(user_group_name, self.required_perm, purpose)

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

# SPECIAL VERSION TO HANDLE MIDDLEWARE AUTH

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

class HasPermissionAnyMiddleware(object):

    def __init__(self, *perms):

        self.required_perms = set(perms)

    def __call__(self, user, repo_name, purpose=None):

        # repo_name MUST be unicode, since we handle keys in ok

        # dict by unicode

        repo_name = safe_unicode(repo_name)

        user = AuthUser(user.user_id)

        try:

            ok = user.permissions['repositories'][repo_name] in self.required_perms

        except KeyError:

            ok = False

        log.debug('Middleware check %s for %s for repo %s (%s): %s', user.username, self.required_perms, repo_name, purpose, ok)

        return ok

def check_ip_access(source_ip, allowed_ips=None):

    """

    Checks if source_ip is a subnet of any of allowed_ips.

    :param source_ip:

    :param allowed_ips: list of allowed ips together with mask

    """