"""

Storing files according to a custom storage system

``FileField`` and its variations can take a ``storage`` argument to specify how

and where files should be stored.

"""

import random

import tempfile

from pathlib import Path

from django.core.files.storage import FileSystemStorage

from django.db import models

class CustomValidNameStorage(FileSystemStorage):

    def get_valid_name(self, name):

        # mark the name to show that this was called

        return name + "_valid"

temp_storage_location = tempfile.mkdtemp()

temp_storage = FileSystemStorage(location=temp_storage_location)

def callable_storage():

    return temp_storage

class CallableStorage(FileSystemStorage):

    def __call__(self):

        # no-op implementation.

        return self

class Storage(models.Model):

    def custom_upload_to(self, filename):

        return "foo"

    def random_upload_to(self, filename):

        # This returns a different result each time,

        # to make sure it only gets called once.

        return "%s/%s" % (random.randint(100, 999), filename)

    def pathlib_upload_to(self, filename):

        return Path("bar") / filename

    normal = models.FileField(storage=temp_storage, upload_to="tests")

    custom = models.FileField(storage=temp_storage, upload_to=custom_upload_to)

    pathlib_callable = models.FileField(

        storage=temp_storage, upload_to=pathlib_upload_to

    )

    pathlib_direct = models.FileField(storage=temp_storage, upload_to=Path("bar"))

    random = models.FileField(storage=temp_storage, upload_to=random_upload_to)

    custom_valid_name = models.FileField(

        storage=CustomValidNameStorage(location=temp_storage_location),

        upload_to=random_upload_to,

    )

    storage_callable = models.FileField(

        storage=callable_storage, upload_to="storage_callable"

    )

    storage_callable_class = models.FileField(

        storage=CallableStorage, upload_to="storage_callable_class"

    )

    default = models.FileField(

        storage=temp_storage, upload_to="tests", default="tests/default.txt"

    )

    empty = models.FileField(storage=temp_storage)

    limited_length = models.FileField(

        storage=temp_storage, upload_to="tests", max_length=20

    )

    extended_length = models.FileField(

        storage=temp_storage, upload_to="tests", max_length=300

    )