"""
Models for the comments application.
"""
from django.db import models
from django.conf import settings
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes import generic
from django.contrib.auth.models import User
from django.core import urlresolvers

from core.markup import site_markup


COMMENT_MAX_LENGTH = getattr(settings, 'COMMENT_MAX_LENGTH', 3000)

class CommentManager(models.Manager):
    """Manager for the Comment model class."""

    def for_object(self, obj, filter_public=True):
        """QuerySet for all comments for a particular model instance."""
        ct = ContentType.objects.get_for_model(obj)
        qs = self.get_query_set().filter(content_type__pk=ct.id,
                object_id=obj.id)
        if filter_public:
            qs = qs.filter(is_public=True)
        return qs


class Comment(models.Model):
    """My own version of a Comment class that can attach comments to any other model."""
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = generic.GenericForeignKey('content_type', 'object_id')
    user = models.ForeignKey(User)
    comment = models.TextField(max_length=COMMENT_MAX_LENGTH)
    html = models.TextField(blank=True)
    creation_date = models.DateTimeField(auto_now_add=True)
    ip_address = models.IPAddressField('IP Address')
    is_public = models.BooleanField(default=True, 
            help_text='Uncheck this field to make the comment invisible.')
    is_removed = models.BooleanField(default=False,
            help_text='Check this field to replace the comment with a ' \
                    '"This comment has been removed" message')

    # Attach manager
    objects = CommentManager()

    class Meta:
        ordering = ('creation_date', )

    def __unicode__(self):
        return u'%s: %s...' % (self.user.username, self.comment[:50])

    def save(self, force_insert=False, force_update=False):
        self.html = site_markup(self.comment)
        super(Comment, self).save(force_insert, force_update)

    def get_absolute_url(self):
        return self.get_content_object_url() + ('#c%s' % self.id)

    def get_content_object_url(self):
        """
        Get a URL suitable for redirecting to the content object.
        """
        return urlresolvers.reverse(
            "comments-url-redirect",
            args=(self.content_type_id, self.object_id)
        )


class CommentFlag(models.Model):
    """This model represents a user flagging a comment as inappropriate."""
    user = models.ForeignKey(User)
    comment = models.ForeignKey(Comment)
    flag_date = models.DateTimeField(auto_now_add=True)

    def __unicode__(self):
        return u'Comment ID %s flagged by %s' % (self.comment.id, self.user.username)

    class Meta:
        ordering = ('flag_date', )

    def get_comment_url(self):
        return '<a href="/admin/comments/comment/%s">Comment</a>' % self.comment.id
    get_comment_url.allow_tags = True