"""Immutable content-addressed Web releases with offline gzip compression."""
from pathlib import Path
import hashlib, gzip, json, shutil, os
root=Path(__file__).resolve().parents[1]
source=root/'build/web'
output=root/'build/web-deploy'
files=sorted(p for p in source.iterdir() if p.is_file() and not p.name.endswith(('.gz','.br')))
identity=hashlib.sha256()
for p in files:
    identity.update(p.name.encode()+b'\0'+p.read_bytes())
version=identity.hexdigest()[:16]
if output.exists(): shutil.rmtree(output)
release=output/'releases'/version
release.mkdir(parents=True)
report=[]
for p in files:
    destination=release/p.name
    shutil.copyfile(p,destination)
    raw=p.read_bytes()
    if p.suffix in ['.wasm','.pck','.js','.html']:
        compressed=gzip.compress(raw,compresslevel=9,mtime=0)
        assert gzip.decompress(compressed)==raw
        z=destination.with_name(destination.name+'.gz')
        z.write_bytes(compressed)
        os.utime(z,(destination.stat().st_mtime,destination.stat().st_mtime))
        report.append({'file':p.name,'original':len(raw),'gzip':len(compressed),'sha256':hashlib.sha256(raw).hexdigest()})
html=(source/'index.html').read_text()
html=html.replace('<head>','<head>\n\t\t<base href="/pub/zombie-fps/releases/'+version+'/">',1)
(output/'index.html').write_text(html)
(root/'build/web-compression-report.json').write_text(json.dumps({'version':version,'files':report},indent=2)+'\n')
print('Release:',version)
for r in report: print(r['file'],r['original'],'->',r['gzip'])
print('Total:',sum(r['original'] for r in report),'->',sum(r['gzip'] for r in report))