import os
import shutil
from urllib.parse import urlparse
from django.db import models
from django.conf import settings
from django.urls import reverse
from django.utils.dates import MONTHS
from django.db.models.functions import Lower
from django.core.exceptions import ValidationError
from django_countries.fields import CountryField

from ram.utils import DeduplicatedStorage
from ram.models import BaseModel, Image, PropertyInstance
from metadata.models import Scale, Manufacturer, Shop, Tag


class Publisher(models.Model):
    name = models.CharField(max_length=200)
    country = CountryField(blank=True)
    website = models.URLField(blank=True)

    class Meta:
        ordering = ["name"]

    def __str__(self):
        return self.name


class Author(models.Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)

    class Meta:
        ordering = ["last_name", "first_name"]

    def __str__(self):
        return f"{self.last_name}, {self.first_name}"

    @property
    def short_name(self):
        return f"{self.last_name} {self.first_name[0]}."


class BaseBook(BaseModel):
    ISBN = models.CharField(max_length=17, blank=True)  # 13 + dashes
    language = models.CharField(
        max_length=7,
        choices=sorted(settings.LANGUAGES, key=lambda s: s[1]),
        default="en",
    )
    number_of_pages = models.SmallIntegerField(null=True, blank=True)
    publication_year = models.SmallIntegerField(null=True, blank=True)
    shop = models.ForeignKey(
        Shop, on_delete=models.CASCADE, null=True, blank=True
    )
    price = models.DecimalField(
        max_digits=10,
        decimal_places=2,
        null=True,
        blank=True,
    )
    purchase_date = models.DateField(null=True, blank=True)
    tags = models.ManyToManyField(Tag, related_name="bookshelf", blank=True)

    def delete(self, *args, **kwargs):
        shutil.rmtree(
            os.path.join(
                settings.MEDIA_ROOT, "images", "books", str(self.uuid)
            ),
            ignore_errors=True,
        )
        super(BaseBook, self).delete(*args, **kwargs)


def book_image_upload(instance, filename):
    return os.path.join("images", "books", str(instance.book.uuid), filename)


def magazine_image_upload(instance, filename):
    return os.path.join("images", "magazines", str(instance.uuid), filename)


class BaseBookImage(Image):
    book = models.ForeignKey(
        BaseBook, on_delete=models.CASCADE, related_name="image"
    )
    image = models.ImageField(
        upload_to=book_image_upload,
        storage=DeduplicatedStorage,
    )


class BaseBookProperty(PropertyInstance):
    book = models.ForeignKey(
        BaseBook,
        on_delete=models.CASCADE,
        null=False,
        blank=False,
        related_name="property",
    )


class Book(BaseBook):
    title = models.CharField(max_length=200)
    authors = models.ManyToManyField(Author, blank=True)
    publisher = models.ForeignKey(Publisher, on_delete=models.CASCADE)

    class Meta:
        ordering = ["title"]

    def __str__(self):
        return self.title

    @property
    def publisher_name(self):
        return self.publisher.name

    @property
    def authors_list(self):
        return ", ".join(a.short_name for a in self.authors.all())

    def get_absolute_url(self):
        return reverse(
            "bookshelf_item", kwargs={"selector": "book", "uuid": self.uuid}
        )


class Catalog(BaseBook):
    manufacturer = models.ForeignKey(
        Manufacturer,
        on_delete=models.CASCADE,
    )
    years = models.CharField(max_length=12)
    scales = models.ManyToManyField(Scale)

    class Meta:
        ordering = ["manufacturer", "publication_year"]

    def __str__(self):
        # if the object is new, return an empty string to avoid
        # calling self.scales.all() which would raise a infinite recursion
        if self.pk is None:
            return str()  # empty string
        scales = self.get_scales()
        return "%s %s %s" % (self.manufacturer.name, self.years, scales)

    def get_absolute_url(self):
        return reverse(
            "bookshelf_item", kwargs={"selector": "catalog", "uuid": self.uuid}
        )

    def get_scales(self):
        return "/".join([s.scale for s in self.scales.all()])

    get_scales.short_description = "Scales"


class Magazine(BaseModel):
    name = models.CharField(max_length=200)
    publisher = models.ForeignKey(Publisher, on_delete=models.CASCADE)
    website = models.URLField(blank=True)
    ISBN = models.CharField(max_length=17, blank=True)  # 13 + dashes
    image = models.ImageField(
        blank=True,
        upload_to=magazine_image_upload,
        storage=DeduplicatedStorage,
    )
    language = models.CharField(
        max_length=7,
        choices=sorted(settings.LANGUAGES, key=lambda s: s[1]),
        default="en",
    )
    tags = models.ManyToManyField(Tag, related_name="magazine", blank=True)

    def delete(self, *args, **kwargs):
        shutil.rmtree(
            os.path.join(
                settings.MEDIA_ROOT, "images", "magazines", str(self.uuid)
            ),
            ignore_errors=True,
        )
        super(Magazine, self).delete(*args, **kwargs)

    class Meta:
        ordering = [Lower("name")]

    def __str__(self):
        return self.name

    def get_absolute_url(self):
        return reverse("magazine", kwargs={"uuid": self.uuid})

    def website_short(self):
        if self.website:
            return urlparse(self.website).netloc.replace("www.", "")


class MagazineIssue(BaseBook):
    magazine = models.ForeignKey(
        Magazine, on_delete=models.CASCADE, related_name="issue"
    )
    issue_number = models.CharField(max_length=100)
    publication_month = models.SmallIntegerField(
        null=True, blank=True, choices=MONTHS.items()
    )

    class Meta:
        unique_together = ("magazine", "issue_number")
        ordering = [
            "magazine",
            "publication_year",
            "publication_month",
            "issue_number",
        ]

    def __str__(self):
        return f"{self.magazine.name} - {self.issue_number}"

    def clean(self):
        if self.magazine.published is False and self.published is True:
            raise ValidationError(
                "Cannot set an issue as published if the magazine is not "
                "published."
            )

    def preview(self):
        return self.image.first().image_thumbnail(100)

    @property
    def publisher(self):
        return self.magazine.publisher

    def get_absolute_url(self):
        return reverse(
            "issue", kwargs={"uuid": self.uuid, "magazine": self.magazine.uuid}
        )