Media type refractors, pep8, lint

[mediagoblin.git] / mediagoblin / media_types / image / processing.py

# GNU MediaGoblin -- federated, autonomous media hosting
# Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import Image
import os
import logging

from mediagoblin import mg_globals as mgg
from mediagoblin.processing import BadMediaFail, \
    create_pub_filepath
from mediagoblin.tools.exif import exif_fix_image_orientation, \
    extract_exif, clean_exif, get_gps_data, get_useful

_log = logging.getLogger(__name__)

SUPPORTED_FILETYPES = ['png', 'gif', 'jpg', 'jpeg']


def sniff_handler(media_file, **kw):
    if kw.get('media') is not None:  # That's a double negative!
        name, ext = os.path.splitext(kw['media'].filename)
        clean_ext = ext[1:].lower()  # Strip the . from ext and make lowercase

        _log.debug('name: {0}\next: {1}\nlower_ext: {2}'.format(
                name,
                ext,
                clean_ext))

        if clean_ext in SUPPORTED_FILETYPES:
            _log.info('Found file extension in supported filetypes')
            return True
        else:
            _log.debug('Media present, extension not found in {0}'.format(
                    SUPPORTED_FILETYPES))
    else:
        _log.warning('Need additional information (keyword argument \'media\')'
                     ' to be able to handle sniffing')

    return False


def process_image(entry):
    """
    Code to process an image
    """
    workbench = mgg.workbench_manager.create_workbench()
    # Conversions subdirectory to avoid collisions
    conversions_subdir = os.path.join(
        workbench.dir, 'conversions')
    os.mkdir(conversions_subdir)

    queued_filepath = entry.queued_media_file
    queued_filename = workbench.localized_file(
        mgg.queue_store, queued_filepath,
        'source')

    filename_bits = os.path.splitext(queued_filename)
    basename = os.path.split(filename_bits[0])[1]
    extension = filename_bits[1].lower()

    # EXIF extraction
    exif_tags = extract_exif(queued_filename)
    gps_data = get_gps_data(exif_tags)

    try:
        thumb = Image.open(queued_filename)
    except IOError:
        raise BadMediaFail()

    thumb = exif_fix_image_orientation(thumb, exif_tags)

    thumb.thumbnail(
        (mgg.global_config['media:thumb']['max_width'],
         mgg.global_config['media:thumb']['max_height']),
        Image.ANTIALIAS)

    # Copy the thumb to the conversion subdir, then remotely.
    thumb_filename = 'thumbnail' + extension
    thumb_filepath = create_pub_filepath(entry, thumb_filename)

    tmp_thumb_filename = os.path.join(
        conversions_subdir, thumb_filename)

    with file(tmp_thumb_filename, 'w') as thumb_file:
        thumb.save(thumb_file)

    mgg.public_store.copy_local_to_storage(
        tmp_thumb_filename, thumb_filepath)

    # If the size of the original file exceeds the specified size of a `medium`
    # file, a `medium.jpg` files is created and later associated with the media
    # entry.
    medium = Image.open(queued_filename)

    # Fix orientation
    medium = exif_fix_image_orientation(medium, exif_tags)

    if medium.size[0] > mgg.global_config['media:medium']['max_width'] \
        or medium.size[1] > mgg.global_config['media:medium']['max_height']:
        medium.thumbnail(
            (mgg.global_config['media:medium']['max_width'],
             mgg.global_config['media:medium']['max_height']),
            Image.ANTIALIAS)

    medium_filename = 'medium' + extension
    medium_filepath = create_pub_filepath(entry, medium_filename)

    tmp_medium_filename = os.path.join(
        conversions_subdir, medium_filename)

    with file(tmp_medium_filename, 'w') as medium_file:
        medium.save(medium_file)

    mgg.public_store.copy_local_to_storage(
        tmp_medium_filename, medium_filepath)

    # we have to re-read because unlike PIL, not everything reads
    # things in string representation :)
    queued_file = file(queued_filename, 'rb')

    with queued_file:
        #create_pub_filepath(entry, queued_filepath[-1])
        original_filepath = create_pub_filepath(entry, basename + extension)

        with mgg.public_store.get_file(original_filepath, 'wb') \
            as original_file:
            original_file.write(queued_file.read())

    # Remove queued media file from storage and database
    mgg.queue_store.delete_file(queued_filepath)
    entry.queued_media_file = []

    # Insert media file information into database
    media_files_dict = entry.setdefault('media_files', {})
    media_files_dict['thumb'] = thumb_filepath
    media_files_dict['original'] = original_filepath
    media_files_dict['medium'] = medium_filepath

    # Insert exif data into database
    media_data = entry.setdefault('media_data', {})
    media_data['exif'] = {
        'clean': clean_exif(exif_tags)}
    media_data['exif']['useful'] = get_useful(
        media_data['exif']['clean'])
    media_data['gps'] = gps_data

    # clean up workbench
    workbench.destroy_self()

if __name__ == '__main__':
    import sys
    import pprint

    pp = pprint.PrettyPrinter()

    result = extract_exif(sys.argv[1])
    gps = get_gps_data(result)
    clean = clean_exif(result)
    useful = get_useful(clean)

    print pp.pprint(
        clean)