''' Reads a .rhosts file '''

from django.conf import settings
from django.contrib.auth.models import Group
from .models import CasUser


def hasUser(user, allowed_domains=[]):
    ''' Check that `user` appears in the rhosts file.
    If `allowed_domains` is not empty, also checks that the user belongs to one
    of the specified domains. '''

    def clearLine(line):
        line = line.strip()
        hashPos = line.find('#')
        if hashPos >= 0:
            line = line[:hashPos]
        return line

    with open(settings.RHOSTS_PATH, 'r') as handle:
        for line in handle:
            line = clearLine(line)
            if not line:
                continue

            spl = line.split()
            if len(spl) != 2:
                continue  # Not a login line

            domain, login = spl
            if login != user:  # Not the ones we're looking for
                continue

            if domain[:2] != '+@':  # Not a valid domain
                continue
            domain = domain[2:]

            if allowed_domains != [] and domain not in allowed_domains:
                continue

            return True
    return False


def default_allowed(user):
    return hasUser(user, allowed_domains=['eleves'])


class NoBOcalException(Exception):
    def __str__():
        return "The BOcal group was not created"


def bocalGroup():
    qs = Group.objects.filter(name='BOcal')
    if qs.count() != 1:
        raise NoBOcalException
    return qs[0]


def stripCasPrivileges(user):
    user.groups.remove(bocalGroup())
    user.is_staff = False
    user.save()


def grantBOcalPrivileges(user):
    user.is_staff = True
    user.groups.add(bocalGroup())
    user.save()


def requireCasUser(fct):
    def hasCas(user):
        if user.is_anonymous:
            return False
        return CasUser.objects.filter(user=user).count() > 0

    def wrap(user, *args, **kwargs):
        if not hasCas(user):
            return
        return fct(user, *args, **kwargs)
    return wrap


@requireCasUser
def evalRhostsPrivileges(user):
    if default_allowed(user.username):
        grantBOcalPrivileges(user)
    else:
        stripCasPrivileges(user)


@requireCasUser
def logout(user):
    stripCasPrivileges()


def forceReevalRhosts(fct):
    def wrap(req, *args, **kwargs):
        evalRhostsPrivileges(req.user)
        return fct(req, *args, **kwargs)
    return wrap