display isni bio with existing author name

If an existing author has an isni on record and it matches an author from the isni api call,
display the isni short description to aid with identifying the appropriate author.

bookwyrm/templates/book/edit/edit_book.html

@@ -1,6 +1,7 @@
 {% extends 'layout.html' %}
 {% load i18n %}
 {% load humanize %}
+{% load utilities %}
 
 {% block title %}{% if book %}{% blocktrans with book_title=book.title %}Edit "{{ book_title }}"{% endblocktrans %}{% else %}{% trans "Add Book" %}{% endif %}{% endblock %}
 
@@ -75,6 +76,9 @@
                         <p class="help ml-5 mb-2">
                             <a href="{{ match.local_path }}" target="_blank">{% blocktrans with book_title=match.book_set.first.title %}Author of <em>{{ book_title }}</em>{% endblocktrans %}</a>
                         </p>
+                        <p class="help ml-5">
+                            {{ author.existing_isnis|get_isni_bio:match }}
+                        </p>
                         {% endfor %}
                         <label class="label mt-2">
                             <input type="radio" name="author_match-{{ counter }}" value="{{ author.name }}" required> {% trans "This is a new author" %}

bookwyrm/templatetags/utilities.py

@@ -1,5 +1,6 @@
 """ template filters for really common utilities """
 import os
+from functools import reduce
 from uuid import uuid4
 from django import template
 from django.utils.translation import gettext_lazy as _
@@ -66,3 +67,14 @@ def get_book_cover_thumbnail(book, size="medium", ext="jpg"):
         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 ""
+    match = reduce(
+        (lambda a: a if a.hasattr("bio") and author.isni == a.isni else ""), existing
+    )
+    return match["bio"]

bookwyrm/views/books/edit_book.py

@@ -75,11 +75,14 @@ class EditBook(View):
                     for a in author_matches
                     if i["isni"] == a.isni
                 ]
+
                 isni_matches = list(filter(lambda x: x not in exists, isni_authors))
+
                 data["author_matches"].append(
                     {
                         "name": author.strip(),
                         "matches": author_matches,
+                        "existing_isnis": exists,
                         "isni_matches": isni_matches,
                     }
                 )