build.py

#!/usr/bin/env python3.8
import hashlib
import io
import json
import pathlib
import tarfile

def make_tarinfo(path, data):
    fob = io.BytesIO(data.encode())
    info = tarfile.TarInfo(name=path)
    info.size = fob.getbuffer().nbytes
    return info, fob

def make_tar(dist, ident, datamap):
    dist.mkdir(parents=True, exist_ok=True)
    file_out = io.BytesIO()
    with tarfile.open(mode='w:gz', fileobj=file_out) as tar:
        for path, data in datamap.items():
            tar.addfile(*make_tarinfo(f"{ident}/{path}", data))
    file_out.seek(0)
    (dist / f'{ident}.tar.gz').write_bytes(file_out.getvalue())

def apply_vars(text, data=None):
    data = {} if data is None else dict(data)
    for key, value in data.items():
        text = text.replace(key, json.dumps(value))
    return text

def bump_version(filename):
    filepath = pathlib.Path(filename).resolve()
    version = filepath.read_text()
    s = version.split('.')
    s[-1] = str(int(s[-1]) + 1)
    version = '.'.join(s)
    filepath.write_text(version)
    return version

def main():
    path = pathlib.Path(__file__).resolve().parent
    templates = path / 'templates'
    dist = path / 'dist'

    css_b = (path / 'reactor.css').read_bytes()
    css = css_b.decode()
    bundle = (templates / 'custom_css_bundle.js').read_text()
    plugin = (templates / 'plugin.json').read_text()
    version = bump_version(path / 'version')

    ident = f"custom-css-{''.join(version.split('.'))}"

    bundle = apply_vars(bundle, {"$id$": ident, "$CSS$": css})
    bundle_name = f"custom_css_{hashlib.sha1(css_b).hexdigest()}.js"
    plugin = apply_vars(plugin, {"$id$": ident, "$VERSION$": version, "$BUNDLE_PATH$": bundle_name})

    make_tar(dist, ident, {bundle_name: bundle, 'plugin.json': plugin,})

if __name__ == '__main__':
    main()