from django.db import models
from django.utils.text import slugify
from django.urls import reverse

from django.contrib.auth import get_user_model
User = get_user_model()

from offers.models import Offer
from locations.models import Location, SubLocation

class Course(models.Model):
    user = models.ForeignKey(User, on_delete=models.PROTECT)
    offer = models.ForeignKey(Offer, on_delete=models.PROTECT)
    location = models.ForeignKey(Location, on_delete=models.PROTECT)
    sublocation = models.ForeignKey(SubLocation, on_delete=models.PROTECT)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    start_at = models.DateTimeField(null=True, blank=True)
    max_attendees = models.IntegerField(blank=False)
    price = models.DecimalField(max_digits=6, decimal_places=2)

    def __str__(self):
        return self.offer.name

    def get_absolute_url(self):
        return reverse('courses:show', kwargs={'id': self.id})

    class Meta():
        ordering = ['start_at']


class CourseUnit(models.Model):
    course = models.ForeignKey(Course, models.CASCADE, null=True, blank=True)
    start_at = models.DateTimeField(null=True, blank=False)
    end_at = models.DateTimeField(null=True, blank=False)

    def save(self, *args, **kwargs):
        if (self.course.start_at == None) or (self.start_at < self.course.start_at):
            self.course.start_at = self.start_at
            self.course.save()
        super().save(*args, **kwargs)

    class Meta():
        ordering = ['start_at']