import json

import math

import os

import shutil

from django.conf import settings

from django.core.management.base import BaseCommand, CommandError

from django.db import transaction

from PIL import Image as ImagePIL

from sorl.thumbnail import get_thumbnail

from iconolab.models import Image, ImageStats, Item, ItemMetadata

class BaseImportImagesCommand(BaseCommand):

    def handle(self, *args, **options):

        raise NotImplementedError

    def get_image_dir(self, natural_key, collection):

    ##

    def create_item_and_metadata(

            self,

            natural_key,

            collection,

            metadata_dict,

            image_files,

            options

    ):

        target_dir = os.path.join(settings.MEDIA_ROOT, Image.media.field.upload_to)

        if not os.path.isdir(target_dir):

            raise CommandError("Image target dir does not exists : %s" % target_dir)

        # TODO: Make it fully transactional. if there is a problem on the image creation, some data

        # files can persists.

        with transaction.atomic():

            print('#### Creating item '+natural_key+' (natural key) in database')

            item_object = Item.objects.create(

                collection=collection

            )

            ItemMetadata.objects.create(

                item=item_object,

                metadata=json.dumps(metadata_dict),

                natural_key=natural_key

            )

            print('#### preparing image folder for item ' + natural_key)

            item_image_dir = self.get_image_dir(natural_key, collection)

            target_item_image_dir = os.path.join(target_dir, item_image_dir)

            os.makedirs(target_item_image_dir, exist_ok=True)

            print('-->' + target_item_image_dir, "directory created")

            print('#### Computing item image(s)')

            image_file_name_fill = int(math.log10(len(image_files)))+1

            for i, image in enumerate(image_files):

                (_, ext) = os.path.splitext(image)

                dest_image_name = "{0}_{1:0{2}d}.jpg".format(natural_key, i+1, image_file_name_fill)

                image_path = os.path.join(target_item_image_dir, dest_image_name)

                if options.get('no-jpg-conversion') or ext in settings.NO_IMG_CONVERSION_EXTS:

                    print('##### Copying file %s to %s without converting'%(str(image), image_path))

                    shutil.copy(image, image_path)

                else:

                    if os.path.isfile(image_path):

                        print('##### A jpeg file already exists in target dir for %s' % image)

                    else:

                        im = ImagePIL.open(image)

                        print('##### Generating or copying jpeg for %s to %s' % (image, image_path))

                        im.thumbnail(im.size)

                        im.save(image_path, 'JPEG', quality=options.get(

                            'jpeg_quality', settings.IMG_JPG_DEFAULT_QUALITY))

                new_image = Image.objects.create(

                    item=item_object,

                    media=os.path.join(Image.media.field.upload_to, item_image_dir, dest_image_name),

                    name=os.path.join(item_image_dir, dest_image_name)

                )

                ImageStats.objects.create(

                    image=new_image

                )

            print('### Generating thumbnails for item '+natural_key)

            for image in item_object.images.all():

                for size in settings.PREGENERATE_THUMBNAILS_SIZES:

                    print('#### Thumbnail for size '+size)

                    get_thumbnail(image.media, size, crop=False)