#!/usr/bin/env python3

"""Git-specific common helpers for the git extension.

Python port of ``git-common.sh`` / ``git-common.ps1`` — contains only

git-specific branch validation and detection logic.

"""

from __future__ import annotations

import re

import shutil

import subprocess

import sys

from pathlib import Path

def has_git(repo_root: Path | None = None) -> bool:

"""Check if we have git available at the repo root."""

root = Path(repo_root) if repo_root is not None else Path.cwd()

git_marker = root / ".git"

if not (git_marker.is_dir() or git_marker.is_file()):

return False

if shutil.which("git") is None:

return False

result = subprocess.run(

["git", "-C", str(root), "rev-parse", "--is-inside-work-tree"],

capture_output=True,

text=True,

)

return result.returncode == 0

def effective_branch_name(raw: str) -> str:

"""Strip a single optional path segment (e.g. gitflow "feat/004-name" -> "004-name").

Only when the full name is exactly two slash-free segments; otherwise

returns the raw name.

"""

match = re.fullmatch(r"([^/]+)/([^/]+)", raw)

if match:

return match.group(2)

return raw

def check_feature_branch(raw: str, has_git_repo: bool) -> bool:

"""Validate that a branch name matches the expected feature branch pattern.

Accepts sequential (###-* with >=3 digits) or timestamp (YYYYMMDD-HHMMSS-*)

formats, either at the start of the branch or after path-style namespace

prefixes. Logic aligned with the bash/PowerShell twins.

"""

if not has_git_repo:

print(

"[specify] Warning: Git repository not detected; skipped branch validation",

file=sys.stderr,

)

return True

branch = effective_branch_name(raw)

feature_segment = branch.rsplit("/", 1)[-1]

# Accept sequential prefix (3+ digits) but exclude malformed timestamps:

# 7-or-8 digit date + 6-digit time with no trailing slug.

is_sequential = bool(

re.match(r"^[0-9]{3,}-", feature_segment)

and not re.match(r"^[0-9]{7}-[0-9]{6}-", feature_segment)

and not re.fullmatch(r"[0-9]{7,8}-[0-9]{6}", feature_segment)

)

is_timestamp = bool(re.match(r"^[0-9]{8}-[0-9]{6}-", feature_segment))

if not is_sequential and not is_timestamp:

print(f"ERROR: Not on a feature branch. Current branch: {raw}", file=sys.stderr)

print(

"Feature branches should be named like: 001-feature-name, "

"1234-feature-name, 20260319-143022-feature-name, or "

"<prefix>/001-feature-name",

file=sys.stderr,

)

return False

return True