"""
Validation: pathname, ref format, refname, project, action; repo discovery via pygit2.
Ported from gitweb/gitweb.perl (is_valid_pathname, is_valid_ref_format, is_valid_refname,
is_valid_project, is_valid_action). Repo check uses pygit2.discover_repository..
"""

from __future__ import annotations

import os
import re
from collections.abc import Callable

import pygit2


def is_valid_pathname(input_path: str | None) -> bool:
	"""No '.', '..' as path elements, no null, no doubled slashes. Port of is_valid_pathname."""
	if input_path is None:
		return False
	if "\0" in input_path:
		return False
	parts = input_path.strip("/").split("/")
	return all(p not in ("", ".", "..") for p in parts)


def is_valid_ref_format(input_ref: str | None) -> bool:
	"""Git-check-ref-format rules: no /., no .., no control/space/special at start/end. Port of is_valid_ref_format."""
	if input_ref is None:
		return False
	if "/." in input_ref or input_ref.startswith(".") or ".." in input_ref:
		return False
	if input_ref.endswith("/") or input_ref.endswith(".lock"):
		return False
	# No ASCII control, space, ~^:?*[
	return not re.search(r"[\x00-\x20\x7f ~^:?*\[\]]", input_ref)


def check_export_ok(
	git_dir: str,
	export_ok: str = "",
	export_auth_hook: Callable[[str], bool] | None = None,
	across_fs: bool = False,
) -> bool:
	"""True if path is a git repo (via pygit2.discover_repository) and optional export_ok file / auth hook pass."""
	if not os.path.isdir(git_dir):
		return False
	try:
		discovered = pygit2.discover_repository(git_dir, across_fs)
		if not discovered:
			return False
	except (KeyError, pygit2.GitError, OSError):
		return False
	if export_ok and not os.path.isfile(os.path.join(git_dir, export_ok)):
		return False
	return not export_auth_hook or export_auth_hook(git_dir)


def is_valid_project(
	project: str | None,
	projectroot: str,
	export_ok: str,
	strict_export: bool,
	project_in_list: Callable[[str], bool],
) -> bool:
	"""Pathname valid, dir exists, export_ok, and (if strict) in project list. Port of is_valid_project."""
	if project is None:
		return False
	if not is_valid_pathname(project):
		return False
	full = os.path.join(projectroot, project)
	if not os.path.isdir(full):
		return False
	if not check_export_ok(full, export_ok):
		return False
	return not strict_export or project_in_list(project)