"""Fetch information about any current git repo."""

import functools
import logging
import subprocess
from typing import List, Optional, TypeVar

from typing_extensions import TypedDict

logger = logging.getLogger(__name__)

T = TypeVar("T")


def exec_git(command: List[str]) -> Optional[str]:
    try:
        return subprocess.check_output(
            ["git"] + command, encoding="utf-8", stderr=subprocess.DEVNULL
        ).strip()
    except BaseException:
        return None


def _sanitize_remote_url(remote_url: Optional[str]) -> Optional[str]:
    if remote_url is None:
        return None
    scheme_separator = remote_url.find("://")
    if scheme_separator == -1:
        return remote_url
    scheme = remote_url[:scheme_separator].lower()
    if scheme not in ("http", "https"):
        return remote_url
    authority_start = scheme_separator + len("://")
    authority_end = len(remote_url)
    for delimiter in ("/", "?", "#"):
        delimiter_index = remote_url.find(delimiter, authority_start)
        if delimiter_index != -1:
            authority_end = min(authority_end, delimiter_index)
    userinfo_end = remote_url.rfind("@", authority_start, authority_end)
    if userinfo_end == -1:
        return remote_url
    return remote_url[:authority_start] + remote_url[userinfo_end + 1 :]


class GitInfo(TypedDict, total=False):
    repo_name: Optional[str]
    remote_url: Optional[str]
    commit: Optional[str]
    branch: Optional[str]
    author_name: Optional[str]
    author_email: Optional[str]
    commit_time: Optional[str]
    dirty: Optional[bool]
    tags: Optional[str]


@functools.lru_cache(maxsize=1)
def get_git_info(remote: str = "origin") -> GitInfo:
    """Get information about the git repository."""
    if not exec_git(["rev-parse", "--is-inside-work-tree"]):
        return GitInfo(
            remote_url=None,
            commit=None,
            branch=None,
            author_name=None,
            author_email=None,
            commit_time=None,
            dirty=None,
            tags=None,
            repo_name=None,
        )

    return {
        "remote_url": _sanitize_remote_url(exec_git(["remote", "get-url", remote])),
        "commit": exec_git(["rev-parse", "HEAD"]),
        "commit_time": exec_git(["log", "-1", "--format=%ct"]),
        "branch": exec_git(["rev-parse", "--abbrev-ref", "HEAD"]),
        "tags": exec_git(
            ["describe", "--tags", "--exact-match", "--always", "--dirty"]
        ),
        "dirty": exec_git(["status", "--porcelain"]) != "",
        "author_name": exec_git(["log", "-1", "--format=%an"]),
        "author_email": exec_git(["log", "-1", "--format=%ae"]),
        "repo_name": (exec_git(["rev-parse", "--show-toplevel"]) or "").split("/")[-1],
    }