# # -*- coding: utf-8 -*-
# from __future__ import unicode_literals
# # Erik Stein <code@classlibrary.net>, 2016

import os
import uuid
from django.conf import settings
from django.db import models
# TODO Use improved slugify
from django.utils.text import slugify


class UUIDMixin(models.Model):
    uuid_hex = models.CharField(max_length=32, null=False, editable=False)

    class Meta:
        abstract = True

    # TODO Make auto-initializing UUID-field
    def get_uuid(self):
        if not self.uuid_hex:
            self.uuid_hex = uuid.uuid4().hex
        return str(uuid.UUID(self.uuid_hex))


def get_upload_path(instance, filename, storage):
    """
    Returns /<uuid_hex>/original/<slugified name>.<extension>
    where
        - uuid and name are fields from instance,
        - filename is slugified and shortened to a max length including the extension.
        - extension is preserved from original filename
    """
    name, ext = os.path.splitext(filename)
    name = slugify(name)
    name = name[:(storage.FILENAME_MAX_LENGTH - len(ext))]
    filename = "%s%s" % (name, ext)
    return os.path.join(
        instance.get_uuid(),
        instance.storage.ORIGINAL_FILE_PREFIX,
        filename
    )