# -*- coding: utf-8 -*-
from catalogue.models import Book
from librarian import DocProvider, IOFile
from django.http import HttpResponse


class RedakcjaDocProvider(DocProvider):
    """Used for getting books' children."""

    def __init__(self, publishable):
        self.publishable = publishable

    def by_slug(self, slug):
        return IOFile.from_string(
            Book.objects.get(dc_slug=slug).materialize(publishable=self.publishable).encode('utf-8'))


def serve_file(file_path, name, mime_type):
    def read_chunks(f, size=8192):
        chunk = f.read(size)
        while chunk:
            yield chunk
            chunk = f.read(size)

    response = HttpResponse(mimetype=mime_type)
    response['Content-Disposition'] = 'attachment; filename=%s' % name
    with open(file_path) as f:
        for chunk in read_chunks(f):
            response.write(chunk)
    return response