#!/usr/bin/python3
"""Prepare a private Openbox runtime using local APT metadata and installed dependencies."""
import hashlib
import json
from pathlib import Path
import shutil
import subprocess
import apt

ROOT=Path(__file__).resolve().parents[2]
destination=ROOT/'build_blender_native'/'desktop-runtime'
archives=destination/'archives';archives.mkdir(parents=True,exist_ok=True)
cache=apt.Cache();pending=[cache['openbox'].candidate];selected={}
while pending:
    version=pending.pop()
    if version is None:raise RuntimeError('OPENBOX_PACKAGE_UNAVAILABLE')
    name=version.package.name
    if name in selected:continue
    selected[name]=version
    for dependency in version.get_dependencies('Depends','PreDepends'):
        if dependency.installed_target_versions:continue
        candidates=dependency.target_versions
        if not candidates:raise RuntimeError('DEPENDENCY_UNAVAILABLE: '+dependency.rawstr)
        candidate=next((item for item in candidates if item==item.package.candidate),candidates[0])
        pending.append(candidate)
report={'schemaVersion':1,'status':'PREPARED_UNVERIFIED','validation':'NOT_RUN','packages':[]}
for name,version in selected.items():
    archive_name=Path(version.filename).name
    cached=Path('/var/cache/apt/archives')/archive_name
    if cached.is_file() and not (archives/archive_name).exists():shutil.copyfile(cached,archives/archive_name)
    file=Path(version.fetch_binary(str(archives),allow_unauthenticated=False))
    subprocess.run(['dpkg-deb','--extract',str(file),str(destination)],check=True)
    report['packages'].append({'name':name,'version':version.version,'sha256':hashlib.sha256(file.read_bytes()).hexdigest(),'bytes':file.stat().st_size})
(destination/'manifest.json').write_text(json.dumps(report,indent=2)+'\n')
print(json.dumps({'directory':str(destination),**report}),flush=True)