# Copyright (c) 2025 SandAI. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import annotations

import subprocess
from pathlib import Path


def get_git_version(short: bool = True, length: int = 7) -> str:
    """
    获取当前仓库的 Git 提交 ID。默认返回短 SHA。
    当无法通过 git 命令获取时，回退读取 .git/HEAD/packed-refs。
    """
    # 以本文件为锚点推断仓库根目录：.../magi_compiler/magi_compiler/utils/version.py → .../magi_compiler
    repo_root = Path(__file__).resolve().parents[2]
    git_dir = repo_root / ".git"

    # 优先通过 git 命令获取
    try:
        sha = subprocess.check_output(
            ["git", "-C", str(repo_root), "rev-parse", "HEAD"], text=True, stderr=subprocess.DEVNULL
        ).strip()
        return sha[:length] if short else sha
    except Exception:
        pass

    # 回退：解析 .git/HEAD
    try:
        head = (git_dir / "HEAD").read_text().strip()
        if head.startswith("ref:"):
            ref_path = head.split(" ", 1)[1].strip()
            ref_file = git_dir / ref_path
            if ref_file.exists():
                sha = ref_file.read_text().strip()
            else:
                # 可能被打包到 packed-refs
                packed = git_dir / "packed-refs"
                sha = ""
                if packed.exists():
                    with packed.open() as f:
                        for line in f:
                            line = line.strip()
                            if not line or line.startswith("#") or line.startswith("^"):
                                continue
                            parts = line.split(" ")
                            if len(parts) == 2 and parts[1] == ref_path:
                                sha = parts[0]
                                break
                if not sha:
                    return "unknown"
        else:
            # detached HEAD，HEAD 文件直接保存 SHA
            sha = head
        return sha[:length] if short else sha
    except Exception:
        return "unknown"