# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from django.db import migrations


def create_attachments(apps, schema_editor):
    Album = apps.get_model("music", "Album")
    Attachment = apps.get_model("common", "Attachment")

    album_attachment_mapping = {}
    def get_mimetype(path):
        if path.lower().endswith('.png'):
            return "image/png"
        return "image/jpeg"

    for album in Album.objects.filter(attachment_cover=None).exclude(cover="").exclude(cover=None):
        try:
            album_attachment_mapping[album] = Attachment(
                file=album.cover,
                size=album.cover.size,
                mimetype=get_mimetype(album.cover.path),
            )
        except FileNotFoundError:
            print('Skipping missing cover file {}'.format(album.cover.path))

    Attachment.objects.bulk_create(album_attachment_mapping.values(), batch_size=2000)
    # map each attachment to the corresponding album
    # and bulk save
    for album, attachment in album_attachment_mapping.items():
        album.attachment_cover = attachment

    Album.objects.bulk_update(album_attachment_mapping.keys(), fields=['attachment_cover'], batch_size=2000)


def rewind(apps, schema_editor):
    pass


class Migration(migrations.Migration):

    dependencies = [("music", "0042_album_attachment_cover")]

    operations = [migrations.RunPython(create_attachments, rewind)]