from django.contrib.auth.models import User

from django.db import models

from django.utils.translation import ugettext as _

import random

random.seed()

# no 0,1,o,l,O (difficult to differentiate)

KEY_CHARS = '23456789' + \

            'abcdefghijklmnpqrstuvwxyz' + \

            'ABCDEFGHIJKLMNPQRSTUVWXYZ'  

KEY_SIZE = 11

# database column length

KEY_MAX_SIZE = 20

def generate_key(size=KEY_SIZE):

    key = ''.join([random.choice(KEY_CHARS) for i in range(size)])

    return key

class KeyModel(models.Model):        

    key      = models.CharField(max_length=KEY_MAX_SIZE, db_index=True, unique=True, blank=False)

    adminkey = models.CharField(max_length=KEY_MAX_SIZE, db_index=True, unique=True, blank=False)

    class Meta:

        abstract = True

class PermanentModel(KeyModel):

    """

    Permanent model: delete only sets a flag in database 

    """

    deleted = models.BooleanField(default=False, db_index=True)

    state = models.CharField(max_length=16, blank=False)

    class Meta:

        abstract = True

    def delete(self):

        self.deleted = True

        self.save()

    def undelete(self):

        self.deleted = False

        self.save()

    def real_delete(self):

        super(KeyModel, self).delete() 

class AuthorModel(models.Model):

    user = models.ForeignKey(User, blank=True, null=True)

    name = models.CharField(_("Name:"), max_length=100, null=True, blank=True)

    email = models.CharField(_("Email:"), max_length=100, null=True, blank=True)

    class Meta:

        abstract = True

    def get_name(self):

        if self.user:

            return self.user.username

        else:

            return self.name

    def get_email(self):

        if self.user:

            return self.user.email

        else:

            return self.email

    def set_email_or_user(self, email_or_user):

        if type(email_or_user) == User:

            self.user = email_or_user

        else:

            self.email = email_or_user

        self.save()

class KeyManager(models.Manager):

    """

    Manager for key-models

    """

    def _gen_key(self):

        # generate unique key

        key = generate_key()

        while self.filter(key=key).count():

            key = generate_key()

        return key

    def _gen_adminkey(self):

        # generate unique adminkey

        adminkey = generate_key()

        while self.filter(adminkey=adminkey).count():

            adminkey = generate_key()

        return adminkey

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

        key = self._gen_key()

        adminkey = self._gen_adminkey()

        obj = models.Manager.create(self, key=key, adminkey=adminkey, *args, **kwargs)

        return obj

    def update_keys(self, comment):

        comment.key = self._gen_key()

        comment.adminkey = self._gen_adminkey()

    def real_all(self):

        return super(KeyManager, self).get_query_set()

class Manager(KeyManager):

    """

    Manager for permanent- and key- models

    """

    def get_query_set(self):

        return super(KeyManager, self).get_query_set().filter(deleted=False)