import arrow
from datetime import datetime, timedelta, date

from django.conf import settings
from django.db import models
from django.urls import reverse_lazy
from django.utils.functional import cached_property
from django.utils.timezone import now

from project.mixins import BaseModel, DeactivatedMixin

from apps.content.models import ImageObject
from apps.payment import models as payment_models


class SchoolSchedule(models.Model):
    WEEKDAY_SHORT_NAMES = ('пн', 'вт', 'ср', 'чт', 'пт', 'сб', 'вс')
    WEEKDAY_CHOICES = (
        (1, 'понедельник'),
        (2, 'вторник'),
        (3, 'среда'),
        (4, 'четверг'),
        (5, 'пятница'),
        (6, 'суббота'),
        (7, 'воскресенье'),
    )
    weekday = models.PositiveSmallIntegerField(
        'День недели', choices=WEEKDAY_CHOICES,
    )
    title = models.CharField('Заголовок', default='', max_length=100, db_index=True)
    short_description = models.CharField(
        'Короткое описание', default='', max_length=100, db_index=True
    )
    description = models.TextField('Описание')
    materials = models.TextField('Материалы')
    age = models.PositiveSmallIntegerField('Возраст', default=0)
    month_price = models.DecimalField('Цена', max_digits=8, decimal_places=2, default=0)
    day_discount = models.DecimalField(
        'Скидка, в валюте', max_digits=8, decimal_places=2, default=0
    )
    start_at = models.TimeField('Начало урока', null=True)
    cover = models.ForeignKey(
        ImageObject,
        related_name='schoolschedule_cover',
        verbose_name='Обложка дня',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
    )
    trial_lesson = models.URLField(default='', blank=True)
    is_camp = models.BooleanField(default=False)

    class Meta:
        ordering = ('weekday',)
        verbose_name = 'Расписание'
        verbose_name_plural = 'Расписания'
        unique_together = (('weekday', 'is_camp'),)

    def __str__(self):
        return dict(self.WEEKDAY_CHOICES).get(self.weekday, '')

    def is_online(self):
        end_at = datetime.combine(now().today(), self.start_at) + timedelta(hours=1)
        return self.start_at <= now().time() and end_at.time() >= now().time() and self.weekday == now().isoweekday()

    @cached_property
    def current_live_lesson(self):
        september2018 = date(2018, 9, 1)
        date_start = max(september2018, now().date())
        live_lesson = LiveLesson.objects.filter(
            date__week_day=self.weekday % 7 + 1,
            date__range=[date_start, date_start + timedelta(days=6)],
            deactivated_at__isnull=True,
            is_camp=False,
        ).first()
        return live_lesson

    @cached_property
    def previous_live_lesson(self):
        now_time = now()
        live_lesson = LiveLesson.objects.filter(
            date__week_day=self.weekday % 7 + 1,
            date__range=[(now_time - timedelta(days=8)).date(), (now_time - timedelta(days=1)).date()],
            deactivated_at__isnull=True,
            is_camp=False,
        ).first()
        return live_lesson

    @cached_property
    def current_camp_lesson(self):
        date_start = now().date()
        live_lesson = LiveLesson.objects.filter(
            date__week_day=self.weekday % 7 + 1,
            date__range=[date_start, date_start + timedelta(days=6)],
            deactivated_at__isnull=True,
            is_camp=True,
        ).first()
        return live_lesson

    @cached_property
    def previous_camp_lesson(self):
        now_time = now()
        live_lesson = LiveLesson.objects.filter(
            date__week_day=self.weekday % 7 + 1,
            date__range=[(now_time - timedelta(days=8)).date(), (now_time - timedelta(days=1)).date()],
            deactivated_at__isnull=True,
            is_camp=True,
        ).first()
        return live_lesson

    @property
    def start_at_humanize(self):
        return arrow.get(datetime.combine(datetime.today(), self.start_at), settings.TIME_ZONE).humanize(locale='ru') if self.start_at else None


class SchoolScheduleImage(models.Model):
    schoolschedule = models.ForeignKey(
        SchoolSchedule,
        on_delete=models.CASCADE,
        verbose_name='День занятия',
        related_name='schoolschedule_images',
    )
    img = models.ForeignKey(
        ImageObject,
        related_name='schoolschedule_images',
        verbose_name='Объект изображения',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
    )

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

    class Meta:
        verbose_name = 'Изображение работ'
        verbose_name_plural = 'Изображения работ'
        ordering = ('-created_at',)


class LiveLesson(BaseModel, DeactivatedMixin):
    title = models.CharField('Название урока', max_length=100, default='', blank=True)
    short_description = models.TextField('Краткое описание урока', default='', blank=True)
    stream = models.URLField('Ссылка на VIMEO', default='', blank=True)
    date = models.DateField(default=now, unique=True)
    materials = models.TextField('Материалы', blank=True, default='')
    cover = models.ForeignKey(
        ImageObject,
        related_name='livelesson_covers',
        verbose_name='Обложка урока школы',
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
    )
    is_camp = models.BooleanField(default=False)

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

    class Meta:
        verbose_name = 'Урок онлайн школы'
        verbose_name_plural = 'Уроки онлайн школы'
        ordering = ('-date', 'title',)

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        if not self.id and LiveLesson.objects.filter(date=self.date).exists():
            self.date = (datetime.combine(self.date, now().time()) + timedelta(days=1)).date()
        super().save(*args, **kwargs)

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

    def get_absolute_url(self):
        return (reverse_lazy('school:camp-lesson-detail', kwargs={'lesson_date': self.date.strftime('%d-%m-%y')})
            if self.is_camp
            else reverse_lazy('school:lesson-detail', kwargs={'lesson_date': self.date.strftime('%d-%m-%y')}))

    def stream_index(self):
        return self.stream.split('/')[-1]

    @cached_property
    def school_schedule(self):
        try:
            return SchoolSchedule.objects.get(weekday=self.date.isoweekday(), is_camp=self.is_camp)
        except SchoolSchedule.DoesNotExist:
            return None

    @property
    def is_online(self):
        # если урок открыт, он сегодняшний и прошло не больше часа с момента старта - значит онлайн
        if self.is_opened and self.school_schedule:
            today = now().date()
            end_at = datetime.combine(today, self.school_schedule.start_at) + timedelta(hours=1)
            return self.date == today and end_at.time() >= now().time()
        return False

    @property
    def is_opened(self):
        # если есть заголовок и дата меньше сегодняшней (прошлый урок) или сегодняшняя и время показа урока уже пришло
        # тогда урок считается открытым к просмотру
        today = now().date()
        return self.title and (self.date < today or (self.date == today and self.school_schedule
                                                     and self.school_schedule.start_at <= now().time()))