feat(v1): add basic backend and frontend

backend/processing/tasks.py

@@ -0,0 +1,56 @@
+from pathlib import Path
+
+from celery import shared_task
+from django.utils import timezone
+
+from .algorithms import ProcessingError, average_images, histogram, subtract_images
+from .models import ImageSession, ProcessingJob
+from .storage import delete_relative_file, load_image_array, save_image_array
+
+
+@shared_task(bind=True)
+def run_batch_job(self, job_id, operation, session_ids):
+    job = ProcessingJob.objects.get(id=job_id)
+    job.status = ProcessingJob.STATUS_RUNNING
+    job.progress = 10
+    job.save(update_fields=["status", "progress", "updated_at"])
+    try:
+        sessions = list(ImageSession.objects.filter(id__in=session_ids))
+        if len(sessions) != len(session_ids):
+            raise ProcessingError("One or more sessions do not exist.")
+        images = [load_image_array(session.processed_image or session.original_image) for session in sessions]
+        job.progress = 45
+        job.save(update_fields=["progress", "updated_at"])
+        if operation == "average":
+            result = average_images(images)
+        elif operation == "subtract":
+            result = subtract_images(images[0], images[1])
+        else:
+            raise ProcessingError(f"Unsupported batch operation '{operation}'.")
+        relative_path = save_image_array(result, f"batch-{operation}")
+        job.status = ProcessingJob.STATUS_COMPLETE
+        job.progress = 100
+        job.result_image = relative_path
+        job.result_histogram = histogram(result)
+        job.error = ""
+        job.save(update_fields=["status", "progress", "result_image", "result_histogram", "error", "updated_at"])
+    except Exception as exc:
+        job.status = ProcessingJob.STATUS_FAILED
+        job.error = str(exc)
+        job.progress = 100
+        job.save(update_fields=["status", "error", "progress", "updated_at"])
+        raise
+
+
+@shared_task
+def cleanup_expired_sessions():
+    expired = ImageSession.objects.filter(expires_at__lt=timezone.now())
+    for session in expired:
+        delete_relative_file(session.original_image)
+        delete_relative_file(session.processed_image)
+    expired.delete()
+
+    old_jobs = ProcessingJob.objects.filter(created_at__lt=timezone.now() - timezone.timedelta(hours=24))
+    for job in old_jobs:
+        delete_relative_file(job.result_image)
+    old_jobs.delete()