import arrow
from django.db import models
from django.utils import timezone
from django.contrib.auth import get_user_model

from mptt.models import MPTTModel, TreeForeignKey

from .manager import CategoryQuerySet

User = get_user_model()


class Like(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE)

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


class Course(models.Model):
    PENDING = 0
    PUBLISHED = 1
    ARCHIVED = 2
    STATUS_CHOICES = (
        (PENDING, 'Pending'),
        (PUBLISHED, 'Published'),
        (ARCHIVED, 'Archived'),
    )
    author = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True)
    title = models.CharField('Название курса', max_length=100, db_index=True)
    short_description = models.TextField('Краткое описание курса', db_index=True)
    from_author = models.TextField('От автора', default='', null=True, blank=True)
    cover = models.ImageField('Фон курса', upload_to='courses')
    price = models.DecimalField('Цена курса', help_text='Если цены нету, то курс бесплатный', max_digits=10, decimal_places=2, null=True, blank=True)
    is_infinite = models.BooleanField(default=False)
    deferred_start_at = models.DateTimeField('Отложенный запуск курса', help_text='Заполнить если курс отложенный', null=True, blank=True)
    category = models.ForeignKey('Category', on_delete=models.PROTECT)
    duration = models.IntegerField('Продолжительность курса', default=0)
    is_featured = models.BooleanField(default=False)
    url = models.URLField('Ссылка', default='')
    status = models.PositiveSmallIntegerField('Статус', default=0, choices=STATUS_CHOICES)
    likes = models.ManyToManyField(Like, blank=True)
    materials = models.ManyToManyField('Material', blank=True)

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

    @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).humanize(locale='ru')

    @property
    def created_at_humanize(self):
        return arrow.get(self.created_at).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

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

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


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'


class Lesson(models.Model):
    title = models.CharField('Название урока', max_length=100)
    short_description = models.TextField('Краткое описание урока')
    course = models.ForeignKey(Course, on_delete=models.CASCADE, related_name='lessons')
    cover = models.ImageField('Фон урока', upload_to='lessons')

    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 = 'Урок'
        verbose_name_plural = 'Уроки'
        ordering = ('title',)


class Material(models.Model):
    title = models.CharField('Название материала', max_length=100)
    cover = models.ImageField('Фон материала', upload_to='materials')
    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(MPTTModel):
    author = models.ForeignKey(User, on_delete=models.PROTECT)
    content = models.TextField('Текст комментария', default='')

    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).humanize(locale='ru')

    def __str__(self):
        return self.content

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

    class MPTTMeta:
        order_insertion_by = ['-created_at']
        abstract = True


class CourseComment(Comment):
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True, on_delete=models.PROTECT)
    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):
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True, on_delete=models.PROTECT)
    lesson = models.ForeignKey(Lesson, on_delete=models.CASCADE, related_name='comments')

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