#!/usr/bin/env python3
"""Confirm that a Git remote points at the configured release repository."""

from __future__ import annotations

import argparse
from pathlib import Path
import re
import sys
from urllib.parse import unquote, urlsplit


class RemoteValidationError(ValueError):
	pass


def repository_identity(value: str) -> tuple[str, str]:
	if not value or any(character in value for character in "\r\n\0"):
		raise RemoteValidationError("repository URL is empty or malformed")
	scp = re.fullmatch(r"(?:[^@/:]+@)?([^/:]+):(.+)", value)
	if scp is not None and "://" not in value:
		return _remote_identity(scp.group(1), scp.group(2))
	parts = urlsplit(value)
	if parts.scheme in {"https", "http", "ssh", "git"}:
		hostname = parts.hostname
		if hostname is None:
			raise RemoteValidationError("repository URL has no host")
		host = hostname.casefold()
		if parts.port is not None:
			host += f":{parts.port}"
		return _remote_identity(host, unquote(parts.path))
	if parts.scheme == "file":
		return "file", str(Path(unquote(parts.path)).expanduser().resolve())
	if parts.scheme:
		raise RemoteValidationError(f"unsupported repository URL scheme: {parts.scheme}")
	return "file", str(Path(value).expanduser().resolve())


def remote_matches(actual: str, expected: list[str]) -> bool:
	actual_identity = repository_identity(actual)
	return any(repository_identity(candidate) == actual_identity for candidate in expected)


def _remote_identity(host: str, path: str) -> tuple[str, str]:
	normalized = path.strip("/")
	if normalized.endswith(".git"):
		normalized = normalized[:-4]
	if not host or not normalized or normalized.startswith("../"):
		raise RemoteValidationError("repository URL has an invalid host or path")
	return host.casefold(), normalized


def main() -> int:
	parser = argparse.ArgumentParser(description=__doc__)
	parser.add_argument("actual")
	parser.add_argument("expected", nargs="+")
	arguments = parser.parse_args()
	try:
		if not remote_matches(arguments.actual, arguments.expected):
			raise RemoteValidationError(
				"configured Git remote does not point at the expected release repository"
			)
	except RemoteValidationError as exc:
		print(f"Release remote validation failed: {exc}", file=sys.stderr)
		return 1
	return 0


if __name__ == "__main__":
	raise SystemExit(main())