import os
from PIL import Image
from django.db import models
from django.db.models.signals import post_save
from django.contrib.sitemaps import Sitemap
from django.dispatch import receiver
from django.urls import reverse
from django.apps import apps
from django.utils.html import format_html
from django.conf import settings
from django.template.defaultfilters import slugify

from photos.utils import resize_image
from utils.util import markdown_to_html


def get_upload_path(self, filename):
    return "images/book-covers/%s" % (filename)


class Book(models.Model):
    title = models.CharField(max_length=200)
    author_name = models.CharField(max_length=200)
    slug = models.CharField(max_length=50)
    read_date = models.DateTimeField()
    isbn = models.CharField(max_length=100, blank=True, null=True)
    body_markdown = models.TextField(blank=True)
    body_html = models.TextField(null=True, blank=True)
    read_in = models.TextField(null=True, blank=True)
    url = models.CharField(max_length=200, blank=True, null=True)
    pages = models.CharField(max_length=5, blank=True, null=True)
    publish_date = models.CharField(max_length=40, blank=True, null=True)
    publish_place = models.CharField(max_length=100, blank=True, null=True)
    openlib_url = models.CharField(max_length=400, blank=True, null=True)
    afflink = models.CharField(max_length=400, blank=True, null=True)
    RATINGS = (
        ('1', "1 Star"),
        ('2', "2 Stars"),
        ('3', "3 Stars"),
        ('4', "4 Stars"),
        ('5', "5 Stars"),
    )
    rating = models.CharField(max_length=1, choices=RATINGS, null=True, blank=True)
    enable_comments = models.BooleanField(default=False)
    is_public = models.BooleanField(default=True)
    image = models.FileField(upload_to=get_upload_path, null=True, blank=True)

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

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse("books:detail", kwargs={"slug": self.slug})

    def get_image_url(self):
        return '%sbook-covers/%s' % (settings.IMAGES_URL, self.image.name.split('/')[-1])

    def get_small_image_url(self):
        filename, file_extension = os.path.splitext(self.image.path)
        return "%s/book-covers/%s_small%s" % (settings.IMAGES_URL, filename.split('/')[-1], file_extension)

    def get_rating(self):
        return int(self.rating)

    @property
    def ratings_range(cls):
        return range(1, 6)

    @property
    def get_previous_admin_url(self):
        n = self.get_previous_by_read_date()
        return reverse('admin:%s_%s_change' % (self._meta.app_label,  self._meta.model_name),  args=[n.id])

    @property
    def get_next_admin_url(self):
        model = apps.get_model(app_label=self._meta.app_label, model_name=self._meta.model_name)
        try:
            return reverse('admin:%s_%s_change' % (self._meta.app_label,  self._meta.model_name),  args=[self.get_next_by_read_date().pk])
        except model.DoesNotExist:
            return ''

    def admin_thumbnail(self):
        return format_html('<img src="%s" width="100" style="width:100px" />' % (self.get_image_url()))
    admin_thumbnail.short_description = 'Thumbnail'

    def save(self, *args, **kwargs):
        if self.body_markdown:
            self.body_html = markdown_to_html(self.body_markdown)
        self.slug = slugify(self.title[:50])
        super(Book, self).save()


@receiver(post_save, sender=Book)
def post_save_events(sender, update_fields, created, instance, **kwargs):
    base_path = "%s/%s/" % (settings.MEDIA_ROOT, "/".join(str(i) for i in instance.image.name.split('/')[:-1]))
    filename, file_extension = os.path.splitext(instance.image.path)
    img = Image.open(instance.image.path)
    resize_image(img, None, 160, 78, base_path, "%s_tn%s" % (filename.split('/')[-1], file_extension))
    resize_image(img, None, 650, 78, base_path, "%s_small%s" % (filename.split('/')[-1], file_extension))


class BookHighlight(models.Model):
    book = models.ForeignKey(Book, on_delete=models.CASCADE)
    page = models.PositiveSmallIntegerField(null=True)
    location = models.CharField(max_length=200, blank=True, null=True)
    date_added = models.DateTimeField()
    body_markdown = models.TextField()

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

    def __str__(self):
        return "%s%s" % (self.book.title, self.id)

    def body_html(self):
        return markdown_to_html(self.body_markdown)


class BookSitemap(Sitemap):
    changefreq = "never"
    priority = 0.7
    protocol = "https"

    def items(self):
        return Book.objects.filter(is_public=True).exclude(body_markdown='')

    def lastmod(self, obj):
        return obj.read_date