"""Git utilities."""

# Used also from setup.py, so don't pull in anything additional here (like mypy or typing):

from __future__ import annotations

import os

import subprocess

def is_git_repo(dir: str) -> bool:

"""Is the given directory version-controlled with git?"""

return os.path.exists(os.path.join(dir, ".git"))

def have_git() -> bool:

"""Can we run the git executable?"""

try:

subprocess.check_output(["git", "--help"])

return True

except subprocess.CalledProcessError:

return False

except OSError:

return False

def git_revision(dir: str) -> bytes:

"""Get the SHA-1 of the HEAD of a git repository."""

return subprocess.check_output(["git", "rev-parse", "HEAD"], cwd=dir).strip()

def git_revision_no_subprocess(dir: str) -> bytes | None:

"""Get the SHA-1 of HEAD by reading git files directly, without a subprocess.

Returns None if the revision cannot be determined this way (e.g. unusual

git state), in which case the caller should fall back to git_revision().

"""

try:

head_path = os.path.join(dir, ".git", "HEAD")

with open(head_path, "rb") as f:

head = f.read().strip()

if head.startswith(b"ref: "):

ref = head[5:] # e.g. b"refs/heads/main"

ref_path = os.path.join(dir, ".git", os.fsdecode(ref))

if os.path.exists(ref_path):

with open(ref_path, "rb") as f:

return f.read().strip()

# The ref may be in packed-refs instead of a loose file.

packed_refs_path = os.path.join(dir, ".git", "packed-refs")

if os.path.exists(packed_refs_path):

with open(packed_refs_path, "rb") as f:

for line in f:

if line.startswith(b"#"):

continue

parts = line.strip().split()

if len(parts) >= 2 and parts[1] == ref:

return parts[0]

return None

# Detached HEAD: content is the SHA itself.

if len(head) == 40 and all(chr(c) in "0123456789abcdef" for c in head):

return head

return None

except OSError:

return None

def is_dirty(dir: str) -> bool:

"""Check whether a git repository has uncommitted changes."""

output = subprocess.check_output(["git", "status", "-uno", "--porcelain"], cwd=dir)

return output.strip() != b""