error pages

app.py

@@ -53,6 +53,15 @@ def create_app():
             db.session.commit()
         return dict(config=app.config, site_settings=site_settings)
 
+    @app.context_processor
+    def inject_unread_notifications():
+        from flask_login import current_user
+        from utils import get_unread_count
+        if current_user.is_authenticated:
+            unread_count = get_unread_count(current_user.id)
+            return {'unread_notifications': unread_count}
+        return {'unread_notifications': 0}
+
     @app.template_filter('asset_version')
     def asset_version_filter(filename):
         """Template filter to get version hash for static assets"""
@@ -134,6 +143,34 @@ def create_app():
 
 app = create_app()
 
+@app.errorhandler(404)
+def page_not_found(e):
+    from flask import render_template
+    return render_template('common/404.html'), 404
+
+@app.errorhandler(403)
+def forbidden(e):
+    from flask import render_template
+    return render_template('common/403.html'), 403
+
+@app.errorhandler(401)
+def unauthorized(e):
+    from flask import render_template
+    return render_template('common/401.html'), 401
+
+@app.errorhandler(400)
+def bad_request(e):
+    from flask import render_template
+    return render_template('common/400.html'), 400
+
+@app.errorhandler(500)
+def internal_server_error(e):
+    from flask import render_template
+    import traceback
+    error_details = f"{str(e)}\n\n{traceback.format_exc()}"
+    app.logger.error(f"500 error: {error_details}")
+    return render_template('common/500.html', error=error_details), 500
+
 @app.route('/uploads/profile_pics/<filename>')
 def profile_pic(filename):
     return send_from_directory('/app/uploads/profile_pics', filename)