bookwyrm/bookwyrm/templatetags/utilities.py

""" template filters for really common utilities """
import os
from uuid import uuid4
from django import template
from django.utils.translation import gettext_lazy as _
from django.templatetags.static import static


register = template.Library()


@register.filter(name="uuid")
def get_uuid(identifier):
    """for avoiding clashing ids when there are many forms"""
    return f"{identifier}{uuid4()}"


@register.filter(name="username")
def get_user_identifier(user):
    """use localname for local users, username for remote"""
    return user.localname if user.localname else user.username


@register.filter(name="book_title")
def get_title(book, too_short=5):
    """display the subtitle if the title is short"""
    if not book:
        return ""
    title = book.title
    if len(title) <= too_short and book.subtitle:
        title = _("%(title)s: %(subtitle)s") % {
            "title": title,
            "subtitle": book.subtitle,
        }
    return title


@register.simple_tag(takes_context=False)
def comparison_bool(str1, str2, reverse=False):
    """idk why I need to write a tag for this, it returns a bool"""
    if reverse:
        return str1 != str2
    return str1 == str2


@register.filter(is_safe=True)
def truncatepath(value, arg):
    """Truncate a path by removing all directories except the first and truncating ."""
    path = os.path.normpath(value.name)
    path_list = path.split(os.sep)
    try:
        length = int(arg)
    except ValueError:  # invalid literal for int()
        return path_list[-1]  # Fail silently.
    return f"{path_list[0]}/…{path_list[-1][-length:]}"


@register.simple_tag(takes_context=False)
def get_book_cover_thumbnail(book, size="medium", ext="jpg"):
    """Returns a book thumbnail at the specified size and extension,
    with fallback if needed"""
    if size == "":
        size = "medium"
    try:
        cover_thumbnail = getattr(book, f"cover_bw_book_{size}_{ext}")
        return cover_thumbnail.url
    except OSError:
        return static("images/no_cover.jpg")


@register.filter(name="get_isni_bio")
def get_isni_bio(existing, author):
    """Returns the isni bio string if an existing author has an isni listed"""
    if len(existing) == 0:
        return ""
    for value in existing:
        if "bio" in value and author.isni == value["isni"]:
            return value["bio"]

    return ""