import datetime

from django.db import models

from django.contrib.contenttypes.models import ContentType

from django.contrib.sites.models import Site

from django.contrib.auth.models import User

from django.utils.translation import ugettext_lazy as _

from django.conf import settings

MIN_PHOTO_DIMENSION = 5

MAX_PHOTO_DIMENSION = 1000

# Option codes for comment-form hidden fields.

PHOTOS_REQUIRED = 'pr'

PHOTOS_OPTIONAL = 'pa'

RATINGS_REQUIRED = 'rr'

RATINGS_OPTIONAL = 'ra'

IS_PUBLIC = 'ip'

# What users get if they don't have any karma.

DEFAULT_KARMA = 5

KARMA_NEEDED_BEFORE_DISPLAYED = 3

class CommentManager(models.Manager):

    def get_security_hash(self, options, photo_options, rating_options, target):

        """

        Returns the MD5 hash of the given options (a comma-separated string such as

        'pa,ra') and target (something like 'lcom.eventtimes:5157'). Used to

        validate that submitted form options have not been tampered-with.

        """

        import md5

        return md5.new(options + photo_options + rating_options + target + settings.SECRET_KEY).hexdigest()

    def get_rating_options(self, rating_string):

        """

        Given a rating_string, this returns a tuple of (rating_range, options).

        >>> s = "scale:1-10|First_category|Second_category"

        >>> Comment.objects.get_rating_options(s)

        ([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], ['First category', 'Second category'])

        """

        rating_range, options = rating_string.split('|', 1)

        rating_range = range(int(rating_range[6:].split('-')[0]), int(rating_range[6:].split('-')[1])+1)

        choices = [c.replace('_', ' ') for c in options.split('|')]

        return rating_range, choices

    def get_list_with_karma(self, **kwargs):

        """

        Returns a list of Comment objects matching the given lookup terms, with

        _karma_total_good and _karma_total_bad filled.

        """

        extra_kwargs = {}

        extra_kwargs.setdefault('select', {})

        extra_kwargs['select']['_karma_total_good'] = 'SELECT COUNT(*) FROM comments_karmascore, comments_comment WHERE comments_karmascore.comment_id=comments_comment.id AND score=1'

        extra_kwargs['select']['_karma_total_bad'] = 'SELECT COUNT(*) FROM comments_karmascore, comments_comment WHERE comments_karmascore.comment_id=comments_comment.id AND score=-1'

        return self.filter(**kwargs).extra(**extra_kwargs)

    def user_is_moderator(self, user):

        if user.is_superuser:

            return True

        for g in user.groups.all():

            if g.id == settings.COMMENTS_MODERATORS_GROUP:

                return True

        return False

class Comment(models.Model):

    """A comment by a registered user."""

    user = models.ForeignKey(User, raw_id_admin=True)

    content_type = models.ForeignKey(ContentType)

    object_id = models.IntegerField(_('object ID'))

    headline = models.CharField(_('headline'), max_length=255, blank=True)

    comment = models.TextField(_('comment'), max_length=3000)

    rating1 = models.PositiveSmallIntegerField(_('rating #1'), blank=True, null=True)

    rating2 = models.PositiveSmallIntegerField(_('rating #2'), blank=True, null=True)

    rating3 = models.PositiveSmallIntegerField(_('rating #3'), blank=True, null=True)

    rating4 = models.PositiveSmallIntegerField(_('rating #4'), blank=True, null=True)

    rating5 = models.PositiveSmallIntegerField(_('rating #5'), blank=True, null=True)

    rating6 = models.PositiveSmallIntegerField(_('rating #6'), blank=True, null=True)

    rating7 = models.PositiveSmallIntegerField(_('rating #7'), blank=True, null=True)

    rating8 = models.PositiveSmallIntegerField(_('rating #8'), blank=True, null=True)

    # This field designates whether to use this row's ratings in aggregate

    # functions (summaries). We need this because people are allowed to post

    # multiple reviews on the same thing, but the system will only use the

    # latest one (with valid_rating=True) in tallying the reviews.

    valid_rating = models.BooleanField(_('is valid rating'))

    submit_date = models.DateTimeField(_('date/time submitted'), auto_now_add=True)

    is_public = models.BooleanField(_('is public'))

    ip_address = models.IPAddressField(_('IP address'), blank=True, null=True)

    is_removed = models.BooleanField(_('is removed'), help_text=_('Check this box if the comment is inappropriate. A "This comment has been removed" message will be displayed instead.'))

    site = models.ForeignKey(Site)

    objects = CommentManager()

    class Meta:

        verbose_name = _('comment')

        verbose_name_plural = _('comments')

        ordering = ('-submit_date',)

    class Admin:

        fields = (

            (None, {'fields': ('content_type', 'object_id', 'site')}),

            ('Content', {'fields': ('user', 'headline', 'comment')}),

            ('Ratings', {'fields': ('rating1', 'rating2', 'rating3', 'rating4', 'rating5', 'rating6', 'rating7', 'rating8', 'valid_rating')}),

            ('Meta', {'fields': ('is_public', 'is_removed', 'ip_address')}),

        )

        list_display = ('user', 'submit_date', 'content_type', 'get_content_object')

        list_filter = ('submit_date',)

        date_hierarchy = 'submit_date'

        search_fields = ('comment', 'user__username')

    def __unicode__(self):

        return "%s: %s..." % (self.user.username, self.comment[:100])

    def get_absolute_url(self):

        try:

            return self.get_content_object().get_absolute_url() + "#c" + str(self.id)

        except AttributeError:

            return ""

    def get_crossdomain_url(self):

        return "/r/%d/%d/" % (self.content_type_id, self.object_id)

    def get_flag_url(self):

        return "/comments/flag/%s/" % self.id

    def get_deletion_url(self):

        return "/comments/delete/%s/" % self.id

    def get_content_object(self):

        """

        Returns the object that this comment is a comment on. Returns None if

        the object no longer exists.

        """

        from django.core.exceptions import ObjectDoesNotExist

        try:

            return self.content_type.get_object_for_this_type(pk=self.object_id)

        except ObjectDoesNotExist:

            return None

    get_content_object.short_description = _('Content object')

    def _fill_karma_cache(self):

        """Helper function that populates good/bad karma caches."""

        good, bad = 0, 0

        for k in self.karmascore_set:

            if k.score == -1:

                bad +=1

            elif k.score == 1:

                good +=1

        self._karma_total_good, self._karma_total_bad = good, bad

    def get_good_karma_total(self):

        if not hasattr(self, "_karma_total_good"):

            self._fill_karma_cache()

        return self._karma_total_good

    def get_bad_karma_total(self):

        if not hasattr(self, "_karma_total_bad"):

            self._fill_karma_cache()

        return self._karma_total_bad

    def get_karma_total(self):

        if not hasattr(self, "_karma_total_good") or not hasattr(self, "_karma_total_bad"):

            self._fill_karma_cache()

        return self._karma_total_good + self._karma_total_bad

    def get_as_text(self):

        return _('Posted by %(user)s at %(date)s\n\n%(comment)s\n\nhttp://%(domain)s%(url)s') % \

            {'user': self.user.username, 'date': self.submit_date,

            'comment': self.comment, 'domain': self.site.domain, 'url': self.get_absolute_url()}

class FreeComment(models.Model):

    """A comment by a non-registered user."""

    content_type = models.ForeignKey(ContentType)

    object_id = models.IntegerField(_('object ID'))

    comment = models.TextField(_('comment'), max_length=3000)

    person_name = models.CharField(_("person's name"), max_length=50)

    submit_date = models.DateTimeField(_('date/time submitted'), auto_now_add=True)

    is_public = models.BooleanField(_('is public'))

    ip_address = models.IPAddressField(_('ip address'))

    # TODO: Change this to is_removed, like Comment

    approved = models.BooleanField(_('approved by staff'))

    site = models.ForeignKey(Site)

    class Meta:

        verbose_name = _('free comment')

        verbose_name_plural = _('free comments')

        ordering = ('-submit_date',)

    class Admin:

        fields = (

            (None, {'fields': ('content_type', 'object_id', 'site')}),

            ('Content', {'fields': ('person_name', 'comment')}),

            ('Meta', {'fields': ('submit_date', 'is_public', 'ip_address', 'approved')}),

        )

        list_display = ('person_name', 'submit_date', 'content_type', 'get_content_object')

        list_filter = ('submit_date',)

        date_hierarchy = 'submit_date'

        search_fields = ('comment', 'person_name')

    def __unicode__(self):

        return "%s: %s..." % (self.person_name, self.comment[:100])

    def get_absolute_url(self):

        try:

            return self.get_content_object().get_absolute_url() + "#c" + str(self.id)

        except AttributeError:

            return ""

    def get_content_object(self):

        """

        Returns the object that this comment is a comment on. Returns None if

        the object no longer exists.

        """

        from django.core.exceptions import ObjectDoesNotExist

        try:

            return self.content_type.get_object_for_this_type(pk=self.object_id)

        except ObjectDoesNotExist:

            return None

    get_content_object.short_description = _('Content object')

class KarmaScoreManager(models.Manager):

    def vote(self, user_id, comment_id, score):

        try:

            karma = self.get(comment__pk=comment_id, user__pk=user_id)

        except self.model.DoesNotExist:

            karma = self.model(None, user_id=user_id, comment_id=comment_id, score=score, scored_date=datetime.datetime.now())

            karma.save()

        else:

            karma.score = score

            karma.scored_date = datetime.datetime.now()

            karma.save()

    def get_pretty_score(self, score):

        """

        Given a score between -1 and 1 (inclusive), returns the same score on a

        scale between 1 and 10 (inclusive), as an integer.

        """

        if score is None:

            return DEFAULT_KARMA

        return int(round((4.5 * score) + 5.5))

class KarmaScore(models.Model):

    user = models.ForeignKey(User)

    comment = models.ForeignKey(Comment)

    score = models.SmallIntegerField(_('score'), db_index=True)

    scored_date = models.DateTimeField(_('score date'), auto_now=True)

    objects = KarmaScoreManager()

    class Meta:

        verbose_name = _('karma score')

        verbose_name_plural = _('karma scores')

        unique_together = (('user', 'comment'),)

    def __unicode__(self):

        return _("%(score)d rating by %(user)s") % {'score': self.score, 'user': self.user}

class UserFlagManager(models.Manager):

    def flag(self, comment, user):

        """

        Flags the given comment by the given user. If the comment has already

        been flagged by the user, or it was a comment posted by the user,

        nothing happens.

        """

        if int(comment.user_id) == int(user.id):

            return # A user can't flag his own comment. Fail silently.

        try:

            f = self.get(user__pk=user.id, comment__pk=comment.id)

        except self.model.DoesNotExist:

            from django.core.mail import mail_managers

            f = self.model(None, user.id, comment.id, None)

            message = _('This comment was flagged by %(user)s:\n\n%(text)s') % {'user': user.username, 'text': comment.get_as_text()}

            mail_managers('Comment flagged', message, fail_silently=True)

            f.save()

class UserFlag(models.Model):

    user = models.ForeignKey(User)

    comment = models.ForeignKey(Comment)

    flag_date = models.DateTimeField(_('flag date'), auto_now_add=True)

    objects = UserFlagManager()

    class Meta:

        verbose_name = _('user flag')

        verbose_name_plural = _('user flags')

        unique_together = (('user', 'comment'),)

    def __unicode__(self):

        return _("Flag by %r") % self.user

class ModeratorDeletion(models.Model):

    user = models.ForeignKey(User, verbose_name='moderator')

    comment = models.ForeignKey(Comment)

    deletion_date = models.DateTimeField(_('deletion date'), auto_now_add=True)

    class Meta:

        verbose_name = _('moderator deletion')

        verbose_name_plural = _('moderator deletions')

        unique_together = (('user', 'comment'),)

    def __unicode__(self):

        return _("Moderator deletion by %r") % self.user