"""Download pinned public model weights and official gRefCOCO annotations.
No model execution, private tokens, or changes to other projects.
"""
from pathlib import Path
import urllib.request,urllib.parse,json,hashlib,time,concurrent.futures
ROOT=Path(__file__).resolve().parents[1]
ASSETS=ROOT/'assets';ASSETS.mkdir(parents=True,exist_ok=True)
def get_json(url):
 with urllib.request.urlopen(url,timeout=45) as r:return json.load(r)
def download(url,path):
 path=Path(path);path.parent.mkdir(parents=True,exist_ok=True)
 if path.exists() and path.stat().st_size>0:return str(path)
 for attempt in range(3):
  try:
   with urllib.request.urlopen(url,timeout=90) as r,open(str(path)+'.part','wb') as f:
    while True:
     b=r.read(1024*1024)
     if not b:break
     f.write(b)
   Path(str(path)+'.part').replace(path);print('downloaded',str(path),path.stat().st_size,flush=True);return str(path)
  except Exception:
   if attempt==2:raise
   time.sleep(2)
def main():
 # Reproduction uses the executed lock, never the current upstream HEAD.
 lock=ROOT/'protocol/asset_manifest.json';manifest=json.loads(lock.read_text())
 jobs=[]
 for rel,expected in manifest['file_sha256'].items():
  p=Path(rel);assert p.parts[0]=='assets' and '..' not in p.parts
  if p.parts[1]=='models':
   meta=manifest['models'][p.parts[2]];prefix='https://huggingface.co/'+meta['repo'];name='/'.join(p.parts[3:])
  else:
   assert p.parts[1]=='grefcoco';meta=manifest['dataset'];prefix='https://huggingface.co/datasets/'+meta['repo'];name='/'.join(p.parts[2:])
  jobs.append((prefix+'/resolve/'+meta['revision']+'/'+urllib.parse.quote(name),ROOT/p))
 with concurrent.futures.ThreadPoolExecutor(max_workers=4) as ex:
  for result in ex.map(lambda args:download(*args),jobs):pass
 for _,path in jobs:
  h=hashlib.sha256()
  with path.open('rb') as f:
   for b in iter(lambda:f.read(1024*1024),b''):h.update(b)
  assert h.hexdigest()==manifest['file_sha256'][str(path.relative_to(ROOT))],'Asset checksum mismatch: '+str(path)
 (ASSETS/'asset_manifest.json').write_text(lock.read_text())
 print(json.dumps({'status':'ASSETS_VERIFIED','files':len(jobs),'lock':str(lock)}),flush=True)
if __name__=='__main__':main()