"""Repackage official Waitress 3.0.2 metadata for the tested Python 3.8 build.

The HTTP server and security fixes are kept byte-for-byte. Only the CLI name
resolver gets a Python 3.8 fallback. The local version identifies the adaptation.
"""
import base64
import csv
import hashlib
import io
from pathlib import Path
import zipfile

UPSTREAM_SHA256 = 'c56d67fd6e87c2ee598b76abdd4e96cfad1f24cacdea5078d382b1f9d7b5ed2e'
VERSION = '3.0.2+win7.1'


def repackage(source, destination):
    source, destination = Path(source), Path(destination)
    if hashlib.sha256(source.read_bytes()).hexdigest() != UPSTREAM_SHA256:
        raise ValueError('Unexpected upstream Waitress wheel checksum')
    old_info, new_info = 'waitress-3.0.2.dist-info', 'waitress-%s.dist-info' % VERSION
    destination.mkdir(parents=True, exist_ok=True)
    target = destination / ('waitress-%s-py3-none-any.whl' % VERSION)
    records = []
    with zipfile.ZipFile(source) as src, zipfile.ZipFile(target, 'w', zipfile.ZIP_DEFLATED) as out:
        for name in src.namelist():
            if name.endswith('/RECORD'):
                continue
            content = src.read(name)
            new_name = name.replace(old_info, new_info)
            if name == 'waitress/runner.py':
                assert b'import pkgutil\n' in content and b'pkgutil.resolve_name(args[0])' in content
                content = content.replace(b'import pkgutil\n',
                    b'try:\n    from pkgutil import resolve_name\nexcept ImportError:\n    from pkgutil_resolve_name import resolve_name\n')
                content = content.replace(b'pkgutil.resolve_name(args[0])', b'resolve_name(args[0])')
            if name == old_info + '/METADATA':
                content = content.replace(b'Version: 3.0.2\n', ('Version: %s\n' % VERSION).encode())
                content = content.replace(b'Requires-Python: >=3.9.0\n',
                    b'Requires-Python: >=3.8.0\nRequires-Dist: pkgutil-resolve-name==1.3.10; python_version < "3.9"\n')
                assert b'Requires-Python: >=3.8.0\n' in content
            out.writestr(new_name, content)
            digest = base64.urlsafe_b64encode(hashlib.sha256(content).digest()).rstrip(b'=').decode()
            records.append((new_name, 'sha256=' + digest, str(len(content))))
        records.append((new_info + '/RECORD', '', ''))
        record = io.StringIO(newline='')
        csv.writer(record, lineterminator='\n').writerows(records)
        out.writestr(new_info + '/RECORD', record.getvalue())
    with zipfile.ZipFile(source) as src, zipfile.ZipFile(target) as dest:
        assert all(src.read(name) == dest.read(name) for name in src.namelist()
                   if name.startswith('waitress/') and name != 'waitress/runner.py')
    return target


if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('source', type=Path)
    parser.add_argument('destination', type=Path)
    args = parser.parse_args()
    print(repackage(args.source, args.destination))