import os

from django.db import models
from django.core.exceptions import ValidationError
from django.urls import reverse

from users.models import School


class Category(models.Model):
    """Une catégorie de contenu."""
    name = models.CharField(
        max_length=255,
        verbose_name="Nom de la catégorie"
    )
    description_short = models.TextField(
        verbose_name="Description courte",
        null=True,
    )
    description = models.TextField(
        verbose_name="Description de la catégorie",
        default=""
    )
    image = models.ImageField(
        verbose_name="Illustration de la catégorie",
        null=True,
    )

    def get_absolute_url(self):
        return reverse('content:category', kwargs={'pk': self.pk})

    def __str__(self):
        return self.name


def get_upload_to(instance, filename):
    extension = filename.split('.')[-1]
    return "static/media/"+instance.school.name+"/"+instance.category.name+'.'+extension


def validate_file_extension(value):
    ext = os.path.splitext(value.name)[1]  # [0] returns path+filename
    valid_extensions = ['mp4', 'avi', 'mov']
    if not ext.lower() in valid_extensions:
        raise ValidationError(u'Unsupported file extension.')


class Content(models.Model):
    """Un contenu du site (vidéo)."""
    name = models.CharField(
        max_length=255,
        verbose_name="Nom du contenu"
    )
    school_owner = models.ForeignKey(
        School,
        on_delete=models.CASCADE,
    )
    category = models.ForeignKey(
        Category,
        on_delete=models.SET_NULL,
        verbose_name="Catégorie",
        null=True
    )
    file = models.FileField(
        verbose_name="Fichier",
        validators=[validate_file_extension],
        upload_to=get_upload_to
    )

    def __str__(self):
        return self.name