import uuid
from django.db import models
from django.conf import settings


class Coaster(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    creator = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name='coasters',
    )
    challenge = models.ForeignKey(
        'challenges.Challenge',
        on_delete=models.CASCADE,
        related_name='coasters',
    )
    name = models.CharField(max_length=255, blank=True, default='')
    # Each anchor: {id, lon, lat, terrainAlt, heightOffset}
    anchors = models.JSONField(default=list)
    # Each strip:  {id, startFrac, endFrac, accel_ms2}
    acceleration_strips = models.JSONField(default=list)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        unique_together = [('creator', 'challenge')]
        ordering = ['-updated_at']

    def __str__(self):
        return f'{self.creator.username} / {self.challenge_id}'