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')

        # redirect if already logged in

            raise HTTPFound(location=c.came_from)

        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)

        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:

        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(h.literal(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, and if using API key instead

    of regular cookie authentication, checks that API key access is allowed

    (based on `api_access` parameter and the API view whitelist).

    """

    def __init__(self, api_access=False, allow_default_user=False):

        self.api_access = api_access

        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.

        api_key = user.authenticating_api_key

        if api_key is not None:

            # Check that controller is enabled for API key usage.

            if not self.api_access and not allowed_api_access(loc, api_key=api_key):

                # controller does not allow API access

                log.warning('API access to %s is not allowed', loc)

                raise HTTPForbidden()

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

                     user, 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 user.is_authenticated:

            log.info('user %s authenticated with regular auth @ %s', user, loc)

            return func(*fargs, **fkwargs)

        elif user.is_default_user:

            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)

        else:

            log.warning('user %s NOT authenticated with regular auth @ %s', user, 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 _basic_security_checks():

        """Perform basic security/sanity checks before processing the request."""

        # Only allow the following HTTP request methods.

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

            raise webob.exc.HTTPMethodNotAllowed()

        # Also verify the _method override - no longer allowed.

        if request.params.get('_method') is None:

            pass # no override, no problem

        else:

            raise webob.exc.HTTPMethodNotAllowed()

        # Make sure CSRF token never appears in the URL. If so, invalidate it.

        if secure_form.token_key in request.GET:

            log.error('CSRF key leak detected')

            session.pop(secure_form.token_key, None)

            session.save()

            from kallithea.lib import helpers as h

            h.flash(_('CSRF token leak has been detected - all form tokens have been expired'),

                    category='error')

        # WebOb already ignores request payload parameters for anything other

        # than POST/PUT, but double-check since other Kallithea code relies on

        # this assumption.

        if request.method not in ['POST', 'PUT'] and request.POST:

            log.error('%r request with payload parameters; WebOb should have stopped this', request.method)

            raise webob.exc.HTTPBadRequest()

    def __call__(self, environ, context):

        try:

            request.ip_addr = _get_ip_addr(environ)

            # make sure that we update permissions each time we call controller

            self._basic_security_checks()

            # set globals for auth user

            bearer_token = None

            try:

                # Request.authorization may raise ValueError on invalid input

                type, params = request.authorization

            except (ValueError, TypeError):

                pass

            else:

                if type.lower() == 'bearer':

                    bearer_token = params

                request.GET.get('api_key'),

                bearer_token,

                session.get('authuser'),

            )

            log.info('IP: %s User: %s accessed %s',

                request.ip_addr, request.authuser,

                safe_unicode(_get_access_path(environ)),

            )

            return super(BaseController, self).__call__(environ, context)

        except webob.exc.HTTPException as e:

            return e

class BaseRepoController(BaseController):

    """

    Base class for controllers responsible for loading all needed data for

    repository loaded items are

    c.db_repo_scm_instance: instance of scm repository

    c.db_repo: instance of db

    c.repository_followers: number of followers

    c.repository_forks: number of forks

    c.repository_following: weather the current user is following the current repo

    """

    def _before(self, *args, **kwargs):

        super(BaseRepoController, self)._before(*args, **kwargs)

        if c.repo_name:  # extracted from routes

            _dbr = Repository.get_by_repo_name(c.repo_name)

            if not _dbr:

                return

            log.debug('Found repository in database %s with state `%s`',

                      safe_unicode(_dbr), safe_unicode(_dbr.repo_state))

            route = getattr(request.environ.get('routes.route'), 'name', '')

            # allow to delete repos that are somehow damages in filesystem

            if route in ['delete_repo']:

                return

            if _dbr.repo_state in [Repository.STATE_PENDING]:

                if route in ['repo_creating_home']:

                    return

                check_url = url('repo_creating_home', repo_name=c.repo_name)

                raise webob.exc.HTTPFound(location=check_url)

            dbr = c.db_repo = _dbr

            c.db_repo_scm_instance = c.db_repo.scm_instance

            if c.db_repo_scm_instance is None:

                log.error('%s this repository is present in database but it '

                          'cannot be created as an scm instance', c.repo_name)

                from kallithea.lib import helpers as h