import base64
import hashlib
import json
import os
import time
from pathlib import Path

relative='cameras/24/2026-11-01/AI_134820.277+0900_FIGHT_7da55541-7109-4bd8-a577-419dad502542'
root=Path(os.environ.get('CONTEXTRA_ARTIFACT_ROOT','/data/contextra/artifacts')).resolve()
folder=(root/relative).resolve();folder.relative_to(root)
items=[]
for name in ('thumbnail.jpg','clip.mp4'):
    p=folder/name
    assert p.is_file() and not p.is_symlink() and p.stat().st_size<=12*1024**2
    blob=p.read_bytes()
    items.append({'name':name,'bytes':len(blob),'sha256':hashlib.sha256(blob).hexdigest(),
                  'base64':base64.b64encode(blob).decode()})
print(json.dumps({'at_ms':time.time_ns()//1000000,'event_id':'7da55541-7109-4bd8-a577-419dad502542','items':items}))