# GNU MediaGoblin -- federated, autonomous media hosting
# Copyright (C) 2011 Free Software Foundation, Inc
#
# 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
from mediagoblin.db.util import ObjectId
from celery.task import task

from mediagoblin import mg_globals as mgg
from contextlib import contextmanager


THUMB_SIZE = 180, 180
MEDIUM_SIZE = 640, 640


def create_pub_filepath(entry, filename):
    return mgg.public_store.get_unique_filepath(
            ['media_entries',
             unicode(entry['_id']),
             filename])

@contextmanager
def closing(callback):
    try:
        yield callback
    finally:
        pass

@task
def process_media_initial(media_id):
    workbench = mgg.workbench_manager.create_workbench()

    entry = mgg.database.MediaEntry.one(
        {'_id': ObjectId(media_id)})

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

    thumb = Image.open(queued_filename)
    thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
    # ensure color mode is compatible with jpg
    if thumb.mode != "RGB":
        thumb = thumb.convert("RGB")

    thumb_filepath = create_pub_filepath(entry, 'thumbnail.jpg')

    thumb_file = mgg.public_store.get_file(thumb_filepath, 'w')
    with closing(thumb_file):
        thumb.save(thumb_file, "JPEG", quality=90)

    """
    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)
    medium_processed = False

    if medium.size[0] > MEDIUM_SIZE[0] or medium.size[1] > MEDIUM_SIZE[1]:
        medium.thumbnail(MEDIUM_SIZE, Image.ANTIALIAS)

        if medium.mode != "RGB":
            medium = medium.convert("RGB")

        medium_filepath = create_pub_filepath(entry, 'medium.jpg')

        medium_file = mgg.public_store.get_file(medium_filepath, 'w')
        with closing(medium_file):
            medium.save(medium_file, "JPEG", quality=90)
            medium_processed = True

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

    with queued_file:
        original_filepath = create_pub_filepath(entry, queued_filepath[-1])
        
        with closing(mgg.public_store.get_file(original_filepath, 'wb')) as original_file:
            original_file.write(queued_file.read())

    mgg.queue_store.delete_file(queued_filepath)
    entry['queued_media_file'] = []
    media_files_dict = entry.setdefault('media_files', {})
    media_files_dict['thumb'] = thumb_filepath
    media_files_dict['original'] = original_filepath
    if medium_processed:
        media_files_dict['medium'] = medium_filepath
    entry['state'] = u'processed'
    entry.save()

    # clean up workbench
    workbench.destroy_self()