import random
import uuid
from functools import cached_property, reduce

import readtime
from django.contrib.auth.models import AbstractUser
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.template.defaultfilters import slugify
from django.urls import reverse
from django.utils import timezone

from articles.utils import (
    build_full_absolute_url,
    format_article_content,
    get_html_to_text_converter,
    truncate_words_after_char_count,
)


class User(AbstractUser):
    pass


class Article(models.Model):
    DRAFT = "draft"
    PUBLISHED = "published"
    STATUS_CHOICES = [
        (DRAFT, "Draft"),
        (PUBLISHED, "Published"),
    ]
    title = models.CharField(max_length=255)
    content = models.TextField()
    status = models.CharField(max_length=15, choices=STATUS_CHOICES, default=DRAFT)
    published_at = models.DateTimeField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    author = models.ForeignKey(User, on_delete=models.PROTECT, default=1)
    views_count = models.IntegerField(default=0)
    slug = models.SlugField(unique=True, max_length=255)
    keywords = models.CharField(max_length=255, blank=True)
    has_code = models.BooleanField(default=False, blank=True)
    is_home = models.BooleanField(default=False, blank=True)
    custom_css = models.TextField(blank=True)
    draft_key = models.UUIDField(default=uuid.uuid4)

    class Meta:
        ordering = ["-published_at"]

    def __str__(self):
        return f"{self.title}"

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

    def get_abstract(self):
        html = self.get_formatted_content
        return html.split("<!--more-->")[0]

    @cached_property
    def get_description(self):
        html = self.get_formatted_content
        converter = get_html_to_text_converter()
        text = converter.handle(html)
        return truncate_words_after_char_count(text, 160)

    @cached_property
    def get_formatted_content(self):
        return format_article_content(self.content)

    def publish(self):
        if not self.published_at:
            self.published_at = timezone.now()
        self.status = self.PUBLISHED
        self.save()
        return self

    def unpublish(self):
        self.published_at = None
        self.status = self.DRAFT
        self.save()
        return self

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.title)
        return super().save(*args, **kwargs)

    @property
    def draft_public_url(self):
        url = self.get_absolute_url() + f"?draft_key={self.draft_key}"
        return build_full_absolute_url(request=None, url=url)

    def refresh_draft_key(self):
        self.draft_key = uuid.uuid4()
        self.save()

    def get_read_time(self):
        content = self.get_formatted_content
        if content:
            return readtime.of_html(content).minutes
        return 0

    @cached_property
    def get_related_articles(self):
        related_articles = set()
        for keyword in self.get_formatted_keywords:
            potential_articles = Article.objects.filter(
                keywords__icontains=keyword,
                status=Article.PUBLISHED,
            ).exclude(pk=self.pk)
            for article in potential_articles:
                if keyword in article.get_formatted_keywords:
                    related_articles.add(article)
        sample_size = min([len(related_articles), 3])
        return random.sample(related_articles, sample_size)

    @cached_property
    def get_formatted_keywords(self):
        return list(
            filter(None, map(lambda k: k.strip().lower(), self.keywords.split(",")))
        )

    @cached_property
    def get_minified_custom_css(self):
        def reducer(res, next_char):
            if len(res) == 0:
                return next_char
            if res[-1] == next_char == " ":
                return res
            return res + next_char

        css = self.custom_css.replace("\n", " ")
        return reduce(reducer, css, "")

    def get_admin_url(self):
        content_type = ContentType.objects.get_for_model(self.__class__)
        return reverse(
            "admin:%s_%s_change" % (content_type.app_label, content_type.model),
            args=(self.id,),
        )