brain/utils/git.py

"""Git-based repository identity detection."""

import subprocess
from pathlib import Path


def detect_project_identity(cwd: Path | None = None) -> str:
    """Detect project identity. Priority: git remote URL -> git folder name -> cwd name."""
    cwd = cwd or Path.cwd()

    # 1. Try git remote URL
    remote = _get_git_remote(cwd)
    if remote:
        return _normalize_remote(remote)

    # 2. Try git root folder name
    git_root = _get_git_root(cwd)
    if git_root:
        return git_root.name

    # 3. Fall back to current directory name
    return cwd.resolve().name


def _get_git_remote(cwd: Path) -> str | None:
    """Get the origin remote URL, or None."""
    try:
        result = subprocess.run(
            ["git", "remote", "get-url", "origin"],
            cwd=str(cwd),
            capture_output=True,
            text=True,
            timeout=5,
        )
        if result.returncode == 0:
            return result.stdout.strip()
    except (FileNotFoundError, subprocess.TimeoutExpired):
        pass
    return None


def _get_git_root(cwd: Path) -> Path | None:
    """Get the git repository root directory, or None."""
    try:
        result = subprocess.run(
            ["git", "rev-parse", "--show-toplevel"],
            cwd=str(cwd),
            capture_output=True,
            text=True,
            timeout=5,
        )
        if result.returncode == 0:
            return Path(result.stdout.strip())
    except (FileNotFoundError, subprocess.TimeoutExpired):
        pass
    return None


def _normalize_remote(url: str) -> str:
    """Extract project name from a git remote URL.

    Handles:
        git@github.com:user/project.git -> project
        https://github.com/user/project.git -> project
        https://github.com/user/project -> project
    """
    # Strip trailing .git
    url = url.rstrip("/")
    if url.endswith(".git"):
        url = url[:-4]

    # Get the last path segment as the project name
    return url.split("/")[-1].split(":")[-1]