import random
import string
from django.utils.text import slugify
from django.core.mail import send_mail
from django.template.loader import render_to_string
from django.utils.html import strip_tags
from django.conf import settings
from django.utils.text import slugify


def send_email(user, subject, msg):
    send_mail(
        subject,
        msg,
        settings.EMAIL_FROM_ADDRESS,
        [user.email],
        fail_silently=False,
    )


def send_html_email(subject, recipient_list, template, context):
    """A function responsible for sending HTML email"""
    # Render the HTML template
    html_message = render_to_string(template, context)

    # Generate plain text version of the email (optional)
    plain_message = strip_tags(html_message)

    # Send the email
    send_mail(
        subject,
        plain_message,
        settings.EMAIL_FROM_ADDRESS,
        recipient_list,
        html_message=html_message,
    )


def random_string_generator(size=10, chars=string.ascii_lowercase + string.digits):
    return "".join(random.choice(chars) for _ in range(size))


def unique_slug_generator(instance, new_slug=None):
    """
    Assumes the instance has a model with a slug field and a title
    character (char) field.
    """
    if new_slug is not None:
        slug = new_slug
    else:
        slug = slugify(instance.title)

    Klass = instance.__class__
    qs_exists = Klass.objects.filter(slug=slug).exists()
    if qs_exists:
        new_slug = "{slug}-{randstr}".format(
            slug=slug, randstr=random_string_generator(size=4)
        )
        return unique_slug_generator(instance, new_slug=new_slug)
    return slug