from django.contrib.auth.models import Permission
from django.contrib.contenttypes.models import ContentType
from django.utils.translation import ugettext_lazy as _
from django.db import models


class RoleManager(models.Manager):
    use_in_migrations = True

    TEACHER_KEY = 'teacher'
    STUDENT_KEY = 'student'
    PARENT_KEY = 'parent'

    DEFAULT_ROLES = {
        TEACHER_KEY: _(u'Lehrperson'),
        STUDENT_KEY: _(u'Schüler'),
        # PARENT_KEY: _(u'Aufsichtsperson'),
        # SCHOOL_ADMIN_KEY: _(u'Schuladministrator')
    }

    READONLY_ROLES = []

    DEFAULT_ROLE_KEYS = DEFAULT_ROLES.keys()

    def is_key_in_defaults(self, key):
        return key in self.DEFAULT_ROLE_KEYS

    def is_key_readonly(self, key):
        return key in self.READONLY_ROLES

    def get_roles_for_user(self, user):
        return self.model.objects.filter(user_roles__user=user)

    def create_default_roles(self):
        for key, value in self.DEFAULT_ROLES.items():
            role, created = self.get_or_create(name=value, key=key)

            can_manage_school_class_content, = self._create_default_permissions()

            if key == "teacher":
                role.role_permission.add(can_manage_school_class_content.id)

    def get_default_teacher_role(self):
        return self._get_default_role(self.TEACHER_KEY)

    def get_default_student_role(self):
        return self._get_default_role(self.STUDENT_KEY)

    def _get_default_role(self, key):
        try:
            return self.get(name=self.DEFAULT_ROLES[key])
        except self.model.DoesNotExist:
            return None

    def _create_default_permissions(self):
        content_type = ContentType.objects.get_for_model(self.model)
        # edit_events = Permission.objects.get(content_type=content_type, codename="can_edit_events")
        # edit_own_comments = Permission.objects.get(content_type=content_type, codename="can_edit_own_comments")
        # delete_comments = Permission.objects.get(content_type=content_type, codename="can_delete_comments")
        # admin_school = Permission.objects.get(content_type=content_type, codename="can_admin_school")
        can_manage_school_class_content = Permission.objects.get(content_type=content_type,
                                                                 codename='can_manage_school_class_content')

        return can_manage_school_class_content,


class UserRoleManager(models.Manager):
    def create_role_for_user(self, user, role_key):
        from users.models import Role
        try:
            role = Role.objects.get(key=role_key)
        except Role.DoesNotExist:
            return None

        return self._create_user_role(user, role)

    def _create_user_role(self, user, role):
        user_role = self.model(user=user, role=role)
        user_role.save()
        return user_role