import datetime as dt,json,sys
from pathlib import Path
root=Path(__file__).resolve().parents[2]
source=root/'source.json'
if not source.exists():
    print('SOURCE_MISSING: preserve the last good artifact',file=sys.stderr);sys.exit(2)
d=json.loads(source.read_text(encoding='utf-8'))
if not d.get('records'):
    print('SOURCE_INCOMPLETE: preserve the last good artifact',file=sys.stderr);sys.exit(3)
result={'generatedAt':dt.datetime.now(dt.timezone.utc).isoformat(),'sourceWindowEnd':d['sourceWindowEnd'],'count':len(d['records']),'records':d['records'],'delivery':'local artifact only'}
out=root/'last-good.json';tmp=root/'candidate.json'
tmp.write_text(json.dumps(result,indent=2),encoding='utf-8');tmp.replace(out)
print(json.dumps(result))