Show unread count in post sidebar link

amanuensis/backend/post.py

@@ -4,8 +4,7 @@ Post query interface
 
 from typing import Optional, Sequence, Tuple
 
-from sqlalchemy import select, update, func
+from sqlalchemy import select, update, func, or_, DateTime
-from sqlalchemy.sql.sqltypes import DateTime
 
 from amanuensis.db import DbContext, Post
 from amanuensis.db.models import Lexicon, Membership
@@ -87,3 +86,13 @@ def get_posts_for_membership(
     ).scalars()
 
     return new_posts, old_posts
+
+
+def get_unread_count(db: DbContext, membership_id: int) -> int:
+    """Get the number of posts that the member has not seen"""
+    return db(
+        select(func.count(Post.id))
+        .join(Membership, Membership.lexicon_id == Post.lexicon_id)
+        .where(or_(Membership.last_post_seen.is_(None), Post.created > Membership.last_post_seen))
+        .where(Membership.id == membership_id)
+    ).scalar()

amanuensis/db/models.py

@@ -656,7 +656,7 @@ class Post(ModelBase):
     ################
 
     # The timestamp the post was created
-    created = Column(DateTime, nullable=False, server_default=func.utcnow())
+    created = Column(DateTime, nullable=False, server_default=func.now())
 
     # The body of the post
     body = Column(Text, nullable=False)

amanuensis/server/__init__.py

@@ -76,6 +76,7 @@ def get_app(
             "memq": memq,
             "charq": charq,
             "indq": indq,
+            "postq": postq,
             "current_lexicon": current_lexicon,
             "current_membership": current_membership
         }

amanuensis/server/lexicon.jinja

@@ -18,7 +18,7 @@
 {% block sb_posts %}<a 
     {% if current_page == "posts" %}class="current-page"
     {% else %}href="{{ url_for('lexicon.posts.list', lexicon_name=g.lexicon.name) }}"
-    {% endif %}>Posts</a>{% endblock %}
+    {% endif %}>Posts{% set unread_count = postq.get_unread_count(g.db, current_membership.id) if current_membership else None %}{% if unread_count %} ({{ unread_count }}){% endif %}</a>{% endblock %}
 {% block sb_rules %}<a 
     {% if current_page == "rules" %}class="current-page"
     {% else %}href="{{ url_for('lexicon.rules', lexicon_name=g.lexicon.name) }}"