bgneal@696: """images.py
bgneal@696: 
bgneal@696: This module contains image processing routines for the user_photos application.
bgneal@696: 
bgneal@696: """
bgneal@696: import datetime
bgneal@696: import logging
bgneal@696: from io import BytesIO
bgneal@696: import os.path
bgneal@696: import uuid
bgneal@696: 
bgneal@696: from django.conf import settings
bgneal@696: from PIL import Image
bgneal@696: 
bgneal@696: 
bgneal@696: logger = logging.getLogger(__name__)
bgneal@696: 
bgneal@696: 
bgneal@697: def process_file(f, user, bucket):
bgneal@696:     """Perform processing on the given uploaded image file:
bgneal@696: 
bgneal@696:     * The image is resized if necessary
bgneal@696:     * A thumbnail version is created
bgneal@696:     * The image and thumbnail are uploaded to an S3 bucket
bgneal@696:     * The image and thumbnail URLs are returned as a tuple
bgneal@696: 
bgneal@696:     """
bgneal@696:     logger.info('Processing image file for {}: {}'.format(user.username, f.name))
bgneal@696: 
bgneal@696:     unique_key = uuid.uuid4().hex
bgneal@696:     ext = os.path.splitext(f.name)[1]
bgneal@696:     filename = '/tmp/' + unique_key + ext
bgneal@696:     with open(filename, 'wb') as fp:
bgneal@696:         for chunk in f.chunks():
bgneal@696:             fp.write(chunk)
bgneal@696: 
bgneal@696:     # Resize image if necessary
bgneal@696:     image = Image.open(filename)
bgneal@696:     if image.size > settings.USER_PHOTOS_MAX_SIZE:
bgneal@696:         logger.debug('Resizing from {} to {}'.format(image.size, settings.USER_PHOTOS_MAX_SIZE))
bgneal@696:         image.thumbnail(settings.USER_PHOTOS_MAX_SIZE, Image.ANTIALIAS)
bgneal@696:         image.save(filename)
bgneal@696: 
bgneal@696:     # Create thumbnail
bgneal@696:     logger.debug('Creating thumbnail')
bgneal@696:     image = Image.open(filename)
bgneal@696:     image.thumbnail(settings.USER_PHOTOS_THUMB_SIZE, Image.ANTIALIAS)
bgneal@696:     thumb = BytesIO()
bgneal@696:     image.save(thumb, format=image.format)
bgneal@696: 
bgneal@696:     # Upload both images to S3
bgneal@697:     logging.debug('Uploading image')
bgneal@696:     now = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')
bgneal@697:     metadata = {'user': user.username, 'date': now}
bgneal@697:     file_key = unique_key + ext
bgneal@697:     bucket.upload_from_filename(file_key, filename, metadata)
bgneal@696: 
bgneal@696:     logging.debug('Uploading thumbnail')
bgneal@697:     thumb_key = '{}t{}'.format(unique_key, ext)
bgneal@697:     bucket.upload_from_string(thumb_key, thumb.getvalue())
bgneal@696: 
bgneal@696:     os.remove(filename)
bgneal@696: 
bgneal@696:     logger.info('Completed processing image file for {}: {}'.format(user.username, f.name))
bgneal@696: 
bgneal@696:     url_base = '{}/{}/'.format(settings.USER_PHOTOS_BASE_URL,
bgneal@696:                                settings.USER_PHOTOS_BUCKET)
bgneal@696: 
bgneal@697:     return (url_base + file_key, url_base + thumb_key)