from django.core import meta, validators
from django.models import core
from django.utils.translation import gettext_lazy as _

class Permission(meta.Model):
    name = meta.CharField(_('name'), maxlength=50)
    package = meta.ForeignKey(core.Package, db_column='package')
    codename = meta.CharField(_('codename'), maxlength=100)
    class META:
        verbose_name = _('Permission')
        verbose_name_plural = _('Permissions')
        unique_together = (('package', 'codename'),)
        ordering = ('package', 'codename')

    def __repr__(self):
        return "%s | %s" % (self.package_id, self.name)

class Group(meta.Model):
    name = meta.CharField(_('name'), maxlength=80, unique=True)
    permissions = meta.ManyToManyField(Permission, blank=True, filter_interface=meta.HORIZONTAL)
    class META:
        verbose_name = _('Group')
        verbose_name_plural = _('Groups')
        ordering = ('name',)
        admin = meta.Admin(
            search_fields = ('name',),
        )

    def __repr__(self):
        return self.name

class User(meta.Model):
    username = meta.CharField(_('username'), maxlength=30, unique=True, validator_list=[validators.isAlphaNumeric])
    first_name = meta.CharField(_('first name'), maxlength=30, blank=True)
    last_name = meta.CharField(_('last name'), maxlength=30, blank=True)
    email = meta.EmailField(_('e-mail address'), blank=True)
    password_md5 = meta.CharField(_('password'), maxlength=32, help_text=_("Use an MD5 hash -- not the raw password."))
    is_staff = meta.BooleanField(_('staff status'), help_text=_("Designates whether the user can log into this admin site."))
    is_active = meta.BooleanField(_('active'), default=True)
    is_superuser = meta.BooleanField(_('superuser status'))
    last_login = meta.DateTimeField(_('last login'), default=meta.LazyDate())
    date_joined = meta.DateTimeField(_('date joined'), default=meta.LazyDate())
    groups = meta.ManyToManyField(Group, blank=True,
        help_text=_("In addition to the permissions manually assigned, this user will also get all permissions granted to each group he/she is in."))
    user_permissions = meta.ManyToManyField(Permission, blank=True, filter_interface=meta.HORIZONTAL)
    class META:
        verbose_name = _('User')
        verbose_name_plural = _('Users')
        module_constants = {
            'SESSION_KEY': '_auth_user_id',
        }
        ordering = ('username',)
        exceptions = ('SiteProfileNotAvailable',)
        admin = meta.Admin(
            fields = (
                (None, {'fields': ('username', 'password_md5')}),
                (_('Personal info'), {'fields': ('first_name', 'last_name', 'email')}),
                (_('Permissions'), {'fields': ('is_staff', 'is_active', 'is_superuser', 'user_permissions')}),
                (_('Important dates'), {'fields': ('last_login', 'date_joined')}),
                (_('Groups'), {'fields': ('groups',)}),
            ),
            list_display = ('username', 'email', 'first_name', 'last_name', 'is_staff'),
            list_filter = ('is_staff', 'is_superuser'),
            search_fields = ('username', 'first_name', 'last_name', 'email'),
        )

    def __repr__(self):
        return self.username

    def get_absolute_url(self):
        return "/users/%s/" % self.username

    def is_anonymous(self):
        return False

    def get_full_name(self):
        full_name = '%s %s' % (self.first_name, self.last_name)
        return full_name.strip()

    def set_password(self, raw_password):
        import md5
        self.password_md5 = md5.new(raw_password).hexdigest()

    def check_password(self, raw_password):
        "Returns a boolean of whether the raw_password was correct."
        import md5
        return self.password_md5 == md5.new(raw_password).hexdigest()

    def get_group_permissions(self):
        "Returns a list of permission strings that this user has through his/her groups."
        if not hasattr(self, '_group_perm_cache'):
            import sets
            cursor = db.cursor()
            cursor.execute("""
                SELECT p.package, p.codename
                FROM auth_permissions p, auth_groups_permissions gp, auth_users_groups ug
                WHERE p.id = gp.permission_id
                    AND gp.group_id = ug.group_id
                    AND ug.user_id = %s""", [self.id])
            self._group_perm_cache = sets.Set(["%s.%s" % (row[0], row[1]) for row in cursor.fetchall()])
        return self._group_perm_cache

    def get_all_permissions(self):
        if not hasattr(self, '_perm_cache'):
            import sets
            self._perm_cache = sets.Set(["%s.%s" % (p.package_id, p.codename) for p in self.get_permission_list()])
            self._perm_cache.update(self.get_group_permissions())
        return self._perm_cache

    def has_perm(self, perm):
        "Returns True if the user has the specified permission."
        if not self.is_active:
            return False
        if self.is_superuser:
            return True
        return perm in self.get_all_permissions()

    def has_perms(self, perm_list):
        "Returns True if the user has each of the specified permissions."
        for perm in perm_list:
            if not self.has_perm(perm):
                return False
        return True

    def has_module_perms(self, package_name):
        "Returns True if the user has any permissions in the given package."
        if self.is_superuser:
            return True
        return bool(len([p for p in self.get_all_permissions() if p[:p.index('.')] == package_name]))

    def get_and_delete_messages(self):
        messages = []
        for m in self.get_message_list():
            messages.append(m.message)
            m.delete()
        return messages

    def email_user(self, subject, message, from_email=None):
        "Sends an e-mail to this User."
        from django.core.mail import send_mail
        send_mail(subject, message, from_email, [self.email])

    def get_profile(self):
        """
        Returns site-specific profile for this user. Raises
        SiteProfileNotAvailable if this site does not allow profiles.
        """
        if not hasattr(self, '_profile_cache'):
            from django.conf.settings import AUTH_PROFILE_MODULE
            if not AUTH_PROFILE_MODULE:
                raise SiteProfileNotAvailable
            try:
                app, mod = AUTH_PROFILE_MODULE.split('.')
                module = __import__('ellington.%s.apps.%s' % (app, mod), [], [], [''])
                self._profile_cache = module.get_object(user_id=self.id)
            except ImportError:
                try:
                    module = __import__('django.models.%s' % AUTH_PROFILE_MODULE, [], [], [''])
                    self._profile_cache = module.get_object(user__id__exact=self.id)
                except ImportError:
                    raise SiteProfileNotAvailable
        return self._profile_cache

    def _module_create_user(username, email, password):
        "Creates and saves a User with the given username, e-mail and password."
        import md5
        password_md5 = md5.new(password).hexdigest()
        now = datetime.datetime.now()
        user = User(None, username, '', '', email.strip().lower(), password_md5, False, True, False, now, now)
        user.save()
        return user

    def _module_make_random_password(length=10, allowed_chars='abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ23456789'):
        "Generates a random password with the given length and given allowed_chars"
        # Note that default value of allowed_chars does not have "I" or letters
        # that look like it -- just to avoid confusion.
        from random import choice
        return ''.join([choice(allowed_chars) for i in range(length)])

class Message(meta.Model):
    user = meta.ForeignKey(User)
    message = meta.TextField(_('Message'))

    def __repr__(self):
        return self.message