from django.db import models


class DBFile(models.Model):
    """ Model to store and access uploaded files """

    # This is kept as `name` and not something like `md5` because the file
    # operations pass around `name` as the identifier, so it's kept the same
    # to make sense.
    name = models.CharField(max_length=100)
    filehash = models.CharField(max_length=32, primary_key=True)

    # file data
    content_type = models.CharField(max_length=100)
    b64 = models.TextField()
    mtime = models.DateTimeField(auto_now=True)

    def __unicode__(self):
        return u"{filehash} <{content_type}>".format(
            filehash=self.filehash, content_type=self.content_type)

    def save(self, **kwargs):
        if self.content_type is None:
            # If content type guessing fails,
            # use octet stream as a major fallback
            self.content_type = "application/octet-stream"
        super(DBFile, self).save(**kwargs)