Feb 02 2026: implement issue following function

app/models/issue.py

@@ -19,6 +19,29 @@ class IssueComment(db.Model):
         return f'<IssueComment {self.id} issue={self.issue_id}>'
 
 
+# ── Issue Follower ─────────────────────────────────────────────────────────────
+# Association table linking users who opt in to receive notifications
+# for any updates on a specific issue.
+
+class IssueFollower(db.Model):
+    __tablename__ = 'issue_followers'
+
+    id         = db.Column(db.Integer, primary_key=True)
+    issue_id   = db.Column(db.Integer, db.ForeignKey('issues.id', ondelete='CASCADE'), nullable=False)
+    user_id    = db.Column(db.Integer, db.ForeignKey('users.id',  ondelete='CASCADE'), nullable=False)
+    created_at = db.Column(db.DateTime, default=now_eastern, nullable=False)
+
+    __table_args__ = (
+        db.UniqueConstraint('issue_id', 'user_id', name='uq_issue_follower'),
+    )
+
+    user  = db.relationship('User',  foreign_keys=[user_id])
+    issue = db.relationship('Issue', foreign_keys=[issue_id], back_populates='followers')
+
+    def __repr__(self):
+        return f'<IssueFollower issue={self.issue_id} user={self.user_id}>'
+
+
 class Issue(db.Model):
     __tablename__ = 'issues'
 
@@ -40,6 +63,12 @@ class Issue(db.Model):
     comments      = db.relationship('IssueComment', backref='issue', lazy='dynamic',
                                     order_by='IssueComment.created_at',
                                     cascade='all, delete-orphan')
+    followers     = db.relationship('IssueFollower', back_populates='issue',
+                                    cascade='all, delete-orphan', lazy='dynamic')
+
+    def is_followed_by(self, user):
+        """Return True if the given user is currently following this issue."""
+        return self.followers.filter_by(user_id=user.id).first() is not None
 
     def __repr__(self):
         return f'<Issue {self.id} - {self.severity}>'

app/routes/issues.py

@@ -1,9 +1,9 @@
 from app.utils.time_utils import now_eastern
 from flask import (Blueprint, render_template, redirect, url_for,
-                   flash, request, current_app)
+                   flash, request, current_app, jsonify)
 from flask_login import login_required, current_user
 from app import db
-from app.models.issue import Issue, IssueComment
+from app.models.issue import Issue, IssueComment, IssueFollower
 from app.models.facility import Facility, Area
 from app.models.user import User
 from app.utils.forms import IssueForm, IssueUpdateForm
@@ -13,6 +13,33 @@ from app.utils.notifications import notify
 bp = Blueprint('issues', __name__, url_prefix='/issues')
 
 
+# ── Shared helper ─────────────────────────────────────────────────────────────
+
+def _notify_followers(issue, title, body, exclude_user_ids=None):
+    """Dispatch a notification to every follower of the given issue.
+
+    Parameters
+    ----------
+    issue            : Issue ORM instance
+    title            : Notification headline
+    body             : Notification body
+    exclude_user_ids : Set/list of user IDs to skip (e.g. the actor themselves)
+    """
+    exclude = set(exclude_user_ids or [])
+    issue_link = url_for('issues.view', issue_id=issue.id)
+    for follower in issue.followers.all():
+        if follower.user_id in exclude:
+            continue
+        notify(
+            recipient  = follower.user,
+            title      = title,
+            body       = body,
+            link       = issue_link,
+            issue_id   = issue.id,
+            send_email = True,
+        )
+
+
 # ── List ──────────────────────────────────────────────────────────────────────
 
 @bp.route('/')
@@ -108,11 +135,13 @@ def view(issue_id):
         # ── Notifications ────────────────────────────────────────────────
         issue_link       = url_for('issues.view', issue_id=issue.id)
         new_assigned_to  = issue.assigned_to
+        # Always exclude the actor from receiving their own notifications
+        actor_id         = current_user.id
 
         # 1. Notify the assignee when status changes
         if old_status != issue.status and new_assigned_to:
             assignee = User.query.get(new_assigned_to)
-            if assignee and assignee.id != current_user.id:
+            if assignee and assignee.id != actor_id:
                 notify(
                     recipient  = assignee,
                     title      = f'Issue #{issue.id} Status Updated',
@@ -130,7 +159,7 @@ def view(issue_id):
         # 2. Notify newly assigned user when the assignee changes
         if (old_assigned_to != new_assigned_to) and new_assigned_to:
             new_assignee = User.query.get(new_assigned_to)
-            if new_assignee and new_assignee.id != current_user.id:
+            if new_assignee and new_assignee.id != actor_id:
                 notify(
                     recipient  = new_assignee,
                     title      = f'Issue #{issue.id} Assigned to You',
@@ -147,7 +176,7 @@ def view(issue_id):
         # 3. Notify the previously assigned user when unassigned
         if old_assigned_to and old_assigned_to != new_assigned_to:
             old_assignee = User.query.get(old_assigned_to)
-            if old_assignee and old_assignee.id != current_user.id:
+            if old_assignee and old_assignee.id != actor_id:
                 notify(
                     recipient  = old_assignee,
                     title      = f'Issue #{issue.id} Unassigned',
@@ -163,7 +192,7 @@ def view(issue_id):
         # 4. Notify the assignee when a comment is added (if not the commenter)
         if comment_body and new_assigned_to:
             commentee = User.query.get(new_assigned_to)
-            if commentee and commentee.id != current_user.id:
+            if commentee and commentee.id != actor_id:
                 notify(
                     recipient  = commentee,
                     title      = f'New Comment on Issue #{issue.id}',
@@ -176,12 +205,93 @@ def view(issue_id):
                     send_email = True,
                 )
 
-        db.session.commit()  # Commit notifications
+        # 5. Notify all followers of any update (status change, comment, or reassignment)
+        #    Exclude the actor and the assignee (already notified above).
+        exclude_ids = {actor_id}
+        if new_assigned_to:
+            exclude_ids.add(new_assigned_to)
+        if old_assigned_to:
+            exclude_ids.add(old_assigned_to)
+
+        changes = []
+        if old_status != issue.status:
+            changes.append(
+                f'status changed from "{old_status.replace("_"," ").title()}" '
+                f'to "{issue.status.replace("_"," ").title()}"'
+            )
+        if old_assigned_to != new_assigned_to:
+            new_name = User.query.get(new_assigned_to).username if new_assigned_to else 'Unassigned'
+            changes.append(f'reassigned to {new_name}')
+        if comment_body:
+            changes.append(f'new comment added by {current_user.username}')
+
+        if changes:
+            follower_body = (
+                f'Issue #{issue.id} in {issue.area.name} was updated by '
+                f'{current_user.username}: {"; ".join(changes)}.'
+            )
+            _notify_followers(
+                issue       = issue,
+                title       = f'Issue #{issue.id} Updated',
+                body        = follower_body,
+                exclude_user_ids = exclude_ids,
+            )
+
+        db.session.commit()  # Commit all notifications
         flash('Issue updated.', 'success')
         return redirect(url_for('issues.view', issue_id=issue_id))
 
+    is_following = issue.is_followed_by(current_user)
     comments = issue.comments.order_by(IssueComment.created_at.asc()).all()
-    return render_template('issues/view.html', issue=issue, form=form, comments=comments)
+    return render_template('issues/view.html',
+                           issue=issue,
+                           form=form,
+                           comments=comments,
+                           is_following=is_following)
+
+
+# ── Follow ────────────────────────────────────────────────────────────────────
+
+@bp.route('/<int:issue_id>/follow', methods=['POST'])
+@login_required
+def follow(issue_id):
+    issue = Issue.query.get_or_404(issue_id)
+
+    if not issue.is_followed_by(current_user):
+        follower = IssueFollower(issue_id=issue.id, user_id=current_user.id)
+        db.session.add(follower)
+        db.session.commit()
+        current_app.logger.info(
+            'ISSUE FOLLOW | issue_id=%s | user=%s',
+            issue.id, current_user.username,
+        )
+        flash('You are now following this issue and will receive notifications for any updates.', 'success')
+    else:
+        flash('You are already following this issue.', 'info')
+
+    return redirect(url_for('issues.view', issue_id=issue_id))
+
+
+# ── Unfollow ──────────────────────────────────────────────────────────────────
+
+@bp.route('/<int:issue_id>/unfollow', methods=['POST'])
+@login_required
+def unfollow(issue_id):
+    issue = Issue.query.get_or_404(issue_id)
+
+    follower = issue.followers.filter_by(user_id=current_user.id).first()
+    if follower:
+        db.session.delete(follower)
+        db.session.commit()
+        current_app.logger.info(
+            'ISSUE UNFOLLOW | issue_id=%s | user=%s',
+            issue.id, current_user.username,
+        )
+        flash('You have unfollowed this issue.', 'info')
+    else:
+        flash('You are not following this issue.', 'info')
+
+    return redirect(url_for('issues.view', issue_id=issue_id))
 
 
 # ── Standalone create (not from an inspection) ────────────────────────────────
@@ -216,7 +326,7 @@ def create():
             issue.id, issue.severity, issue.area_id, issue.assigned_to, current_user.username
         )
 
-        # ── Notify the assignee of the new issue ────────────────────────
+        # Notify the assignee of the new issue
         if issue.assigned_to:
             assignee = User.query.get(issue.assigned_to)
             if assignee and assignee.id != current_user.id:
@@ -233,7 +343,7 @@ def create():
                     issue_id   = issue.id,
                     send_email = True,
                 )
-                db.session.commit()  # Commit notification
+                db.session.commit()
 
         flash('Issue created.', 'success')
         return redirect(url_for('issues.index'))

app/templates/issues/view.html

@@ -100,6 +100,38 @@
   </div>
 
   <div class="col-lg-4">
+
+    {# ── Follow / Unfollow ──────────────────────────────────────────────── #}
+    <div class="card shadow-sm mb-3">
+      <div class="card-body d-flex align-items-center justify-content-between py-2">
+        <div>
+          <i class="bi bi-bell{{ '-fill text-primary' if is_following else ' text-muted' }} me-1"></i>
+          <span class="fw-semibold" style="font-size:.9rem;">
+            {% if is_following %}Following{% else %}Not following{% endif %}
+          </span>
+          <span class="text-muted ms-2" style="font-size:.8rem;">
+            {{ issue.followers.count() }} follower{{ 's' if issue.followers.count() != 1 else '' }}
+          </span>
+        </div>
+        {% if is_following %}
+        <form method="post" action="{{ url_for('issues.unfollow', issue_id=issue.id) }}" class="mb-0">
+          <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
+          <button type="submit" class="btn btn-outline-secondary btn-sm">
+            <i class="bi bi-bell-slash"></i> Unfollow
+          </button>
+        </form>
+        {% else %}
+        <form method="post" action="{{ url_for('issues.follow', issue_id=issue.id) }}" class="mb-0">
+          <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
+          <button type="submit" class="btn btn-outline-primary btn-sm">
+            <i class="bi bi-bell"></i> Follow
+          </button>
+        </form>
+        {% endif %}
+      </div>
+    </div>
+
+    {# ── Update Form ────────────────────────────────────────────────────── #}
     {% set can_edit = current_user.role in ['admin','supervisor'] or issue.assigned_to == current_user.id %}
     {% if can_edit %}
     <div class="card shadow-sm">