import os
import shutil
import uuid

from django.db import models
from django.dispatch import receiver

from .models import Exercice
from api.settings import MEDIA_ROOT


# These two auto-delete files from filesystem when they are unneeded:

@receiver(models.signals.post_delete, sender=Exercice)
def auto_delete_file_on_delete(sender, instance, **kwargs):
    """
    Deletes file from filesystem
    when corresponding `MediaFile` object is deleted.
    """
    print(instance, instance.exo_model.path, instance.id_code)
    if instance.exo_model:
        if os.path.isfile(instance.exo_model.path):
            os.remove(instance.exo_model.path)
        if os.path.isdir(f'{MEDIA_ROOT}/uploads/exercices/exo_{instance.id_code}'):
            shutil.rmtree(f'{MEDIA_ROOT}/uploads/exercices/exo_{instance.id_code}')
            #os.rmdir(f'{MEDIA_ROOT}/uploads/exercices/exo_{instance.id_code}')
            


@receiver(models.signals.pre_save, sender=Exercice)
def auto_delete_file_on_change(sender, instance, **kwargs):
    """
    Deletes old file from filesystem
    when corresponding `MediaFile` object is updated
    with new file.
    """
    if not instance.pk:
        return False

    try:
        old_file = Exercice.objects.get(id_code=instance.id_code).exo_model
    except Exercice.DoesNotExist:
        return False

    new_file = instance.exo_model
    if not old_file == new_file:
        if os.path.isfile(old_file.path):
            os.remove(old_file.path)