Add restart functionality for cancelled jobs

- Add restart button in job history for cancelled jobs
- Add /job/<id>/restart route in web interface
- Add restart_job method in QueueManager to reset cancelled jobs to queued

templates/history.html

@@ -161,6 +161,28 @@
             cancelForm.appendChild(cancelBtn);
             actionsElement.appendChild(cancelForm);
         } else if (status === 'cancelled') {
+            const restartForm = document.createElement('form');
+            restartForm.method = 'post';
+            restartForm.action = `/job/${jobId}/restart`;
+            restartForm.style.display = 'inline';
+            restartForm.style.marginRight = '0.5rem';
+            restartForm.onsubmit = () => confirm('Are you sure you want to restart this cancelled job?');
+
+            const restartBtn = document.createElement('button');
+            restartBtn.type = 'submit';
+            restartBtn.className = 'restart-btn';
+            restartBtn.style.background = '#10b981';
+            restartBtn.style.color = 'white';
+            restartBtn.style.border = 'none';
+            restartBtn.style.padding = '0.25rem 0.5rem';
+            restartBtn.style.borderRadius = '4px';
+            restartBtn.style.fontSize = '0.8rem';
+            restartBtn.style.cursor = 'pointer';
+            restartBtn.textContent = 'Restart';
+
+            restartForm.appendChild(restartBtn);
+            actionsElement.appendChild(restartForm);
+
             const deleteForm = document.createElement('form');
             deleteForm.method = 'post';
             deleteForm.action = `/job/${jobId}/delete`;
@@ -281,6 +303,9 @@
                     <div class="job-progress">{{ job.result.get('status', 'Processing...') }}</div>
                     {% endif %}
                     {% elif job.status == 'cancelled' %}
+                    <form method="post" action="/job/{{ job.id }}/restart" style="display: inline; margin-right: 0.5rem;" onsubmit="return confirm('Are you sure you want to restart this cancelled job?')">
+                        <button type="submit" class="restart-btn" style="background: #10b981; color: white; border: none; padding: 0.25rem 0.5rem; border-radius: 4px; font-size: 0.8rem; cursor: pointer;">Restart</button>
+                    </form>
                     <form method="post" action="/job/{{ job.id }}/delete" style="display: inline;" onsubmit="return confirm('Are you sure you want to delete this cancelled job?')">
                         <button type="submit" class="delete-btn" style="background: #dc2626; color: white; border: none; padding: 0.25rem 0.5rem; border-radius: 4px; font-size: 0.8rem; cursor: pointer;">Delete</button>
                     </form>

vidai/queue.py

@@ -90,6 +90,26 @@ class QueueManager:
 
         return True
 
+    def restart_job(self, queue_id: int, user_id: int = None) -> bool:
+        """Restart a cancelled job."""
+        # Get job status first
+        job = get_queue_status(queue_id)
+        if not job:
+            return False
+
+        # Check ownership if user_id provided
+        if user_id and job['user_id'] != user_id:
+            return False
+
+        # Only allow restart of cancelled jobs
+        if job['status'] != 'cancelled':
+            return False
+
+        # Reset retry_count and update status to queued
+        update_queue_status(queue_id, 'queued', retry_count=0)
+
+        return True
+
     def _can_start_job(self, job: Dict[str, Any]) -> bool:
         """Check if a job can be started (worker available)."""
         from .config import get_analysis_backend, get_training_backend

vidai/web.py

@@ -359,6 +359,21 @@ def cancel_job(job_id):
     return redirect(url_for('history'))
 
 
+@app.route('/job/<int:job_id>/restart', methods=['POST'])
+@login_required
+def restart_job(job_id):
+    """Restart a cancelled job."""
+    user = get_current_user_session()
+    from .queue import queue_manager
+
+    if queue_manager.restart_job(job_id, user['id']):
+        flash('Job restarted successfully!', 'success')
+    else:
+        flash('Failed to restart job or access denied.', 'error')
+
+    return redirect(url_for('history'))
+
+
 @app.route('/job_result/<int:job_id>')
 @login_required
 def job_result(job_id):