LilSchool/apps/course/models.py

import arrow
from random import shuffle
from uuid import uuid4
from django.db import models
from django.core.exceptions import ValidationError
from django.utils import timezone
from django.utils.timezone import now
from django.contrib.auth import get_user_model
from django.urls import reverse_lazy
from django.conf import settings
from polymorphic_tree.models import PolymorphicMPTTModel, PolymorphicTreeForeignKey

from apps.school.models import LiveLesson
from project.mixins import BaseModel, DeactivatedMixin

from apps.content.models import ImageObject, Gallery, Video, ContestWork

User = get_user_model()


class Like(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    ip = models.GenericIPAddressField(blank=True, null=True)

    created_at = models.DateTimeField(auto_now_add=True)
    update_at = models.DateTimeField(auto_now=True)


def default_slug():
    return str(uuid4())


def deferred_start_at_validator(value):
    if value < now():
        raise ValidationError(
            'Дата и время начала курса не может быть меньше текущих.',
        )


class Course(BaseModel, DeactivatedMixin):
    DRAFT = 0
    PENDING = 1
    PUBLISHED = 2
    ARCHIVED = 3
    DENIED = 4
    STATUS_CHOICES = (
        (DRAFT, 'Draft'),
        (PENDING, 'Pending'),
        (PUBLISHED, 'Published'),
        (ARCHIVED, 'Archived'),
        (DENIED, 'Denied')
    )
    AGE_LT5 = 1
    AGE_57 = 2
    AGE_79 = 3
    AGE_912 = 4
    AGE_1215 = 5
    AGE_1518 = 6
    AGE_GT18 = 7
    AGE_CHOICES = (
        (0, 'Любой возраст'),
        (AGE_LT5, 'до 5'),
        (AGE_57, '5-7'),
        (AGE_79, '7-9'),
        (AGE_912, '9-12'),
        (AGE_1215, '12-15'),
        (AGE_1518, '15-18'),
        (AGE_GT18, 'от 18'),
    )
    slug = models.SlugField(
        allow_unicode=True, null=True, blank=True,
        max_length=100, unique=True, db_index=True,
    )
    author = models.ForeignKey(
        User, on_delete=models.SET_NULL, null=True, blank=True
    )
    title = models.CharField('Название курса', default='', max_length=100, db_index=True)
    short_description = models.TextField(
        'Краткое описание курса', default='', db_index=True
    )
    from_author = models.TextField(
        'От автора', default='', null=True, blank=True
    )
    cover = models.ForeignKey(
        ImageObject, related_name='course_covers',
        verbose_name='Обложка курса', on_delete=models.SET_NULL,
        null=True, blank=True,
    )
    price = models.DecimalField(
        'Цена курса', help_text='Если цена не выставлена, то курс бесплатный',
        max_digits=10, decimal_places=2, null=True, blank=True
    )
    age = models.SmallIntegerField(choices=AGE_CHOICES, default=0)
    is_infinite = models.BooleanField(default=False)
    deferred_start_at = models.DateTimeField(
        'Отложенный запуск курса', help_text='Заполнить если курс отложенный',
        null=True, blank=True, validators=[deferred_start_at_validator],
    )
    category = models.ForeignKey('Category', null=True, blank=True, on_delete=models.PROTECT, related_name='courses')
    duration = models.IntegerField('Продолжительность курса', default=0)
    is_featured = models.BooleanField(default=False)
    status = models.PositiveSmallIntegerField(
        'Статус', default=DRAFT, choices=STATUS_CHOICES
    )
    likes = models.ManyToManyField(Like, blank=True)
    materials = models.ManyToManyField('Material', blank=True)
    gallery = models.ForeignKey(
        Gallery, verbose_name='Галерея работ',
        on_delete=models.CASCADE, null=True, blank=True,
        related_name='results_gallery',
    )

    created_at = models.DateTimeField(auto_now_add=True)
    update_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name = 'Курс'
        verbose_name_plural = 'Курсы'
        ordering = ['-is_featured', ]

    def __str__(self):
        return str(self.id) + ' ' + self.title

    # def save(self, *args, **kwargs):
    #     if not self.slug:
    #         self.slug = slugify(
    #             self.title[:90],
    #             allow_unicode=True
    #         )

    #     if Course.objects.filter(slug=self.slug).exclude(id=self.id).exists():
    #         self.slug += '_' + str(uuid4())[:6]

    #     return super().save()

    @property
    def url(self):
        return self.get_absolute_url()

    def get_absolute_url(self):
        return reverse_lazy('course', args=[self.id])

    @property
    def is_free(self):
        if self.price:
            return False
        return True

    @property
    def deferred_start_at_humanize(self):
        return arrow.get(self.deferred_start_at, settings.TIME_ZONE).humanize(locale='ru')

    @property
    def created_at_humanize(self):
        return arrow.get(self.created_at, settings.TIME_ZONE).humanize(locale='ru')

    @property
    def is_deferred_start(self):
        if not self.deferred_start_at:
            return False

        if timezone.now() < self.deferred_start_at:
            return True
        return False

    @property
    def count_videos_in_lessons(self):
        return Video.objects.filter(lesson__in=self.lessons.all()).count()

    @classmethod
    def shuffle(cls, qs, order_is_featured = True):
        if order_is_featured:
            featured = []
            other = []
            for c in list(qs):
                if c.is_featured:
                    featured.append(c)
                else:
                    other.append(c)
            shuffle(featured)
            shuffle(other)
            return featured + other
        else:
            all = list(qs)
            shuffle(all)
            return all


class Category(models.Model):
    title = models.CharField('Название категории', max_length=100)

    def __str__(self):
        return self.title

    class Meta:
        verbose_name = 'Категория'
        verbose_name_plural = 'Категории'
        ordering = ['title']


class Lesson(BaseModel, DeactivatedMixin):
    title = models.CharField('Название урока', max_length=100)
    short_description = models.TextField('Краткое описание урока')
    author = models.ForeignKey(
        User, on_delete=models.SET_NULL, null=True, blank=True
    )
    course = models.ForeignKey(
        Course, on_delete=models.CASCADE, related_name='lessons'
    )
    cover = models.ForeignKey(
        ImageObject, related_name='lesson_covers',
        verbose_name='Обложка урока', on_delete=models.SET_NULL,
        null=True, blank=True,
    )
    created_at = models.DateTimeField(auto_now_add=True)
    update_at = models.DateTimeField(auto_now=True)
    position = models.PositiveSmallIntegerField(
        'Положение на странице',
        default=1,
    )

    def __str__(self):
        return self.title

    def set_last_position(self):
        if self.course:
            self.position = self.course.lessons.count()

    def save(self, *args, **kwargs):
        if not self.author and self.course and self.course.author:
            self.author = self.course.author
        super().save(*args, **kwargs)

    class Meta:
        verbose_name = 'Урок'
        verbose_name_plural = 'Уроки'
        ordering = ('title',)


class Material(models.Model):
    title = models.CharField('Название материала', max_length=100)
    cover = models.ForeignKey(
        ImageObject, related_name='material_covers',
        verbose_name='Обложка материала', on_delete=models.SET_NULL,
        null=True, blank=True,
    )
    short_description = models.TextField('Краткое описание материала')

    created_at = models.DateTimeField(auto_now_add=True)
    update_at = models.DateTimeField(auto_now=True)

    def __str__(self):
        return self.title

    class Meta:
        verbose_name = 'Материал'
        verbose_name_plural = 'Материалы'
        ordering = ('title',)


class Comment(PolymorphicMPTTModel, DeactivatedMixin):
    OBJ_TYPE_COURSE = 'course'
    OBJ_TYPE_LESSON = 'lesson'
    OBJ_TYPE_LIVE_LESSON = 'live-lesson'
    content = models.TextField('Текст комментария', default='')
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    parent = PolymorphicTreeForeignKey(
        'self', null=True, blank=True, related_name='children',
        db_index=True, on_delete=models.PROTECT
    )

    created_at = models.DateTimeField(auto_now_add=True)
    update_at = models.DateTimeField(auto_now=True)

    @property
    def created_at_humanize(self):
        return arrow.get(self.created_at, settings.TIME_ZONE).humanize(locale='ru')

    def __str__(self):
        return self.content

    class Meta:
        ordering = ('-created_at',)

    class MPTTMeta:
        order_insertion_by = ['-created_at']


class CourseComment(Comment):
    course = models.ForeignKey(
        Course, on_delete=models.CASCADE, related_name='comments'
    )

    class Meta(Comment.Meta):
        verbose_name = 'Комментарий курса'
        verbose_name_plural = 'Комментарии курсов'


class LessonComment(Comment):
    lesson = models.ForeignKey(
        Lesson, on_delete=models.CASCADE, related_name='comments'
    )

    class Meta(Comment.Meta):
        verbose_name = 'Комментарий урока'
        verbose_name_plural = 'Комментарии уроков'


class LiveLessonComment(Comment):
    live_lesson = models.ForeignKey(
        LiveLesson, on_delete=models.CASCADE, related_name='comments'
    )

    class Meta(Comment.Meta):
        verbose_name = 'Комментарий урока школы'
        verbose_name_plural = 'Комментарии уроков школы'


class ContestWorkComment(Comment):
    contest_work = models.ForeignKey(ContestWork, on_delete=models.CASCADE, related_name='comments')