add unread count to thread title in topic view and thread view

app/models.py

@@ -178,7 +178,7 @@ class Topics(Model):
 
         q = """
             SELECT
-                threads.title, threads.slug, threads.created_at, threads.is_locked, threads.is_stickied,
+                threads.id, threads.title, threads.slug, threads.created_at, threads.is_locked, threads.is_stickied,
                 users.username AS started_by,
             u.username AS latest_post_username,
                 ph.content AS latest_post_content,
@@ -251,6 +251,13 @@ class Avatars(Model):
 class Subscriptions(Model):
     table = "subscriptions"
 
+    def get_unread_count(self):
+        q = """SELECT COUNT(*) AS unread_count
+            FROM posts
+            LEFT JOIN subscriptions ON subscriptions.thread_id = posts.thread_id
+            WHERE subscriptions.user_id = ? AND posts.created_at > subscriptions.last_seen"""
+        return db.fetch_one(q, self.user_id)['unread_count']
+
 class APIRateLimits(Model):
     table = 'api_rate_limits'