boards/models/image.py

import hashlib
import os
from random import random
import time

from django.db import models
from django.template.defaultfilters import filesizeformat

from boards import thumbs, utils
import boards
from boards.models.base import Viewable
from boards.utils import get_upload_filename

__author__ = 'neko259'


IMAGE_THUMB_SIZE = (200, 150)
HASH_LENGTH = 36

CSS_CLASS_IMAGE = 'image'
CSS_CLASS_THUMB = 'thumb'


class PostImageManager(models.Manager):
    def create_with_hash(self, image):
        image_hash = utils.get_file_hash(image)
        existing = self.filter(hash=image_hash)
        if len(existing) > 0:
            post_image = existing[0]
        else:
            post_image = PostImage.objects.create(image=image)

        return post_image

    def get_random_images(self, count, include_archived=False, tags=None):
        images = self.filter(post_images__thread__archived=include_archived)
        if tags is not None:
            images = images.filter(post_images__threads__tags__in=tags)
        return images.order_by('?')[:count]


class PostImage(models.Model, Viewable):
    objects = PostImageManager()

    class Meta:
        app_label = 'boards'
        ordering = ('id',)

    width = models.IntegerField(default=0)
    height = models.IntegerField(default=0)

    pre_width = models.IntegerField(default=0)
    pre_height = models.IntegerField(default=0)

    image = thumbs.ImageWithThumbsField(upload_to=get_upload_filename,
                                        blank=True, sizes=(IMAGE_THUMB_SIZE,),
                                        width_field='width',
                                        height_field='height',
                                        preview_width_field='pre_width',
                                        preview_height_field='pre_height')
    hash = models.CharField(max_length=HASH_LENGTH)

    def save(self, *args, **kwargs):
        """
        Saves the model and computes the image hash for deduplication purposes.
        """

        if not self.pk and self.image:
            self.hash = utils.get_file_hash(self.image)
        super(PostImage, self).save(*args, **kwargs)

    def __str__(self):
        return self.image.url

    def get_view(self):
        metadata = '{}, {}'.format(self.image.name.split('.')[-1],
                                   filesizeformat(self.image.size))
        return '<div class="{}">' \
               '<a class="{}" href="{full}">' \
               '<img class="post-image-preview"' \
               ' src="{}"' \
               ' alt="{}"' \
               ' width="{}"' \
               ' height="{}"' \
               ' data-width="{}"' \
               ' data-height="{}" />' \
               '</a>' \
               '<div class="image-metadata">'\
               '<a href="{full}" download>{image_meta}</a>'\
               '</div>' \
               '</div>'\
            .format(CSS_CLASS_IMAGE, CSS_CLASS_THUMB,
                    self.image.url_200x150,
                    str(self.hash), str(self.pre_width),
                    str(self.pre_height), str(self.width), str(self.height),
                    full=self.image.url, image_meta=metadata)

    def get_random_associated_post(self):
        posts = boards.models.Post.objects.filter(images__in=[self])
        return posts.order_by('?').first()