Source code for ciowarehouse.handlers.handler_directory_cover

"""A file *handler* for directories with a cover."""

from os.path import join, basename, exists, getmtime
from shutil import rmtree
from warnings import catch_warnings, simplefilter

from PIL import Image

from ciowarehouse.lib.utils import THUMBNAIL_LARGE, thumbnail_create
from ..lib.utils import IGNORED_PREFIX, IGNORED_SUFFIX
from ..lib.i18n import _
from .handler_directory import HandlerDirectory


IMAGES_DIR = 'Images'


# =============================================================================
def includeme(configurator):
    """Function to include a CioWarehouse handler.

    :type  configurator: pyramid.config.Configurator
    :param configurator:
        Object used to do configuration declaration within the application.
    """
    HandlerDirectory.register(configurator, HandlerDirectoryCover)


# =============================================================================
class HandlerDirectoryCover(HandlerDirectory):
    """Class to manage a Cover directory."""

    uid = 'directory_cover'
    label = _('Cover directory handling')

    # -------------------------------------------------------------------------
    @classmethod
    def thumbnails_obsolete(cls, abs_file, thumb_dir):
        """Check if thumbnails are obsolete.

        See: :meth:`ciowarehouse.handlers.Handler.thumbnails_obsolete`
        """
        cover = cls._cover(abs_file)
        has_cover = cover is not None
        has_thumbnails = exists(thumb_dir)
        return (has_cover and not has_thumbnails) \
            or (not has_cover and has_thumbnails) \
            or (has_cover and has_thumbnails and
                getmtime(cover) > getmtime(thumb_dir))

    # -------------------------------------------------------------------------
    def thumbnails(
            self, warehouse, abs_file, thumb_dir, request=None, registry=None):
        """Create the small and large thumbnails representing the file.

        See: :meth:`ciowarehouse.handlers.Handler.thumbnails`
        """
        # pylint: disable = unused-argument
        if not warehouse.lock(abs_file):
            return  # pragma: nocover

        # Find cover
        cover = self._cover(abs_file)
        if cover is None:
            if exists(thumb_dir):
                rmtree(thumb_dir)
            warehouse.unlock(abs_file)
            return

        # Load cover
        try:
            with catch_warnings():
                simplefilter('ignore')
                image = Image.open(cover)
        except (IOError, Image.DecompressionBombError):  # pragma: nocover
            warehouse.unlock(abs_file)
            return

        # Wartermark
        watermark = Image.open(
            self.abspath_from_home('handler_directory_cover.png'))
        watermark.thumbnail((
            warehouse.thumbnail_sizes[0][0] / 4,
            warehouse.thumbnail_sizes[0][1] / 4))

        # Create thumbnails
        abs_thumb = join(thumb_dir, '{0}.jpg'.format(THUMBNAIL_LARGE))
        thumbnail_create(
            image, warehouse.thumbnail_sizes, abs_thumb, watermark)
        warehouse.unlock(abs_file)

    # -------------------------------------------------------------------------
    @classmethod
    def _cover(cls, abs_dir):
        """Look for the cover image.

        :param str abs_dir:
            Absolute path to the current directory.
        :rtype: str
        """
        name = basename(abs_dir).lower()
        cover = join(abs_dir, IMAGES_DIR, f'{name}.jpg')
        if exists(cover):
            return cover

        cover = join(abs_dir, f'{name}.jpg')
        if exists(cover):
            return cover

        if name[0] != IGNORED_PREFIX or name[-1:] != IGNORED_SUFFIX:
            return None
        name = name[1:-1]

        cover = join(abs_dir, IMAGES_DIR, f'{name}.jpg')
        if exists(cover):
            return cover

        cover = join(abs_dir, f'{name}.jpg')
        return cover if exists(cover) else None