#!/usr/bin/env python3
"""Remove only this source version's installed files; never recurse directories."""
import argparse
from pathlib import Path
import stat


def owned_files(source):
    files = ['lib/libxtc.a', 'lib/pkgconfig/xtc.pc', 'bin/xtc-check', 'bin/xtc',
             'share/applications/xtc.desktop', 'share/licenses/xtc/LICENSE',
             'share/doc/xtc/README.md']
    files += ['include/xtc/' + p.name for p in sorted((source / 'include/xtc').glob('*.h'))]
    files += ['share/doc/xtc/' + p.name for p in sorted((source / 'docs').glob('*.md'))]
    files += ['share/doc/xtc/decisions/' + p.name for p in sorted((source / 'docs/decisions').glob('*.md'))]
    return files


def uninstall(root, source):
    if not root.is_absolute() or root == Path('/'):
        raise ValueError('Installation root must be absolute and not /')
    files = [root / name for name in owned_files(source)]
    # Preflight before changing anything; never unlink a directory at a file path.
    for path in files:
        try:
            mode = path.lstat().st_mode
        except FileNotFoundError:
            continue
        if not (stat.S_ISREG(mode) or stat.S_ISLNK(mode)):
            raise ValueError(f'Refusing non-file: {path}')
    for path in files:
        path.unlink(missing_ok=True)
    parents = {parent for path in files for parent in path.parents if parent == root or root in parent.parents}
    for parent in sorted(parents, key=lambda p: len(p.parts), reverse=True):
        try:
            parent.rmdir()
        except (FileNotFoundError, OSError):
            pass  # Shared/nonempty directories remain untouched.


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--root', type=Path, required=True)
    args = parser.parse_args()
    uninstall(args.root, Path(__file__).resolve().parent.parent)