from django.db import models
from django.contrib.auth.models import User
from django.db.models.signals import post_save
from django.dispatch import receiver


def _bg_upload_path(instance, filename):
    ext = filename.rsplit('.', 1)[-1].lower()
    return f'backgrounds/bg_{instance.user_id}.{ext}'


class UserProfile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='profile')
    lastfm_session_key = models.CharField(max_length=100, blank=True)
    lastfm_username = models.CharField(max_length=100, blank=True)
    lastfm_scrobble = models.BooleanField(default=True)
    background_image = models.FileField(upload_to=_bg_upload_path, null=True, blank=True)

    def has_lastfm(self) -> bool:
        return bool(self.lastfm_session_key)

    def __str__(self):
        return f"Profile of {self.user.username}"


@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    if created:
        UserProfile.objects.create(user=instance)


@receiver(post_save, sender=User)
def save_user_profile(sender, instance, **kwargs):
    if hasattr(instance, 'profile'):
        instance.profile.save()