from django.db import models
from django.conf import settings
from django.utils.crypto import get_random_string


def generate_coureur_id():
	"""Generate a unique 10-character id for Coureur."""
	# allowed chars: letters + digits
	# loop until we find an unused id (call happens at instance creation time)
	while True:
		s = get_random_string(10, allowed_chars='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
		if not Coureur.objects.filter(id=s).exists():
			return s


class Course(models.Model):
	nom = models.CharField(max_length=100)
	date = models.DateField()
	depart = models.DateTimeField(null=True, blank=True)
	fin = models.DateTimeField(null=True, blank=True)

	TYPE_UNIQUE = 'unique'
	TYPE_MULTI = 'multi'
	TYPE_CHOICES = [
		(TYPE_UNIQUE, 'Unique'),
		(TYPE_MULTI, 'Multi'),
	]
	type = models.CharField(max_length=6, choices=TYPE_CHOICES, default=TYPE_UNIQUE)

	owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='courses')

	class Meta:
		unique_together = ('nom', 'date')
		ordering = ['-date', 'nom']

	def __str__(self):
		return f"{self.nom} ({self.date})"


class Arrivee(models.Model):
	course = models.ForeignKey(Course, on_delete=models.CASCADE, related_name='arrivees')
	coureur = models.ForeignKey('Coureur', on_delete=models.CASCADE)
	temps = models.DurationField()
	rang = models.PositiveIntegerField()
	date_arrivee = models.DateTimeField(auto_now_add=True)

	class Meta:
		unique_together = ('course', 'coureur')
		ordering = ['rang']

	def __str__(self):
		return f"{self.coureur.nom} - {self.course.nom} ({self.temps})"


class Coureur(models.Model):
	# 10-char primary key
	id = models.CharField(primary_key=True, max_length=10, editable=False, default=generate_coureur_id)
	nom = models.CharField(max_length=100)
	prenom = models.CharField(max_length=100, blank=True)
	classe = models.CharField(max_length=50)

	class Meta:
		unique_together = ('nom', 'prenom', 'classe')
		ordering = ['nom', 'prenom', 'classe']

	def __str__(self):
		return f"{self.nom} {self.prenom} ({self.classe})"