# -*- coding: utf-8 -*-
"""Generate protocol/git_user_fw_ver.h from current git HEAD + branch.

用户固件版本 (01 0C) 线格式: {branch}_{short6}[optional '*']
  例: develop_0aedb4   /  feature-ui_57448b*

- short6 = git rev-parse --short=6 HEAD（小写 hex）
- branch 清洗为 [A-Za-z0-9.-]，整串（不含 dirty '*') ≤ 24
- dirty working tree 时末尾追加 '*'

用法（IAR Pre-build）:
  python \"$PROJ_DIR$\\..\\..\\tools\\gen_git_user_fw_ver.py\"
"""
from __future__ import annotations

import os
import re
import subprocess

ROOT = os.path.normpath(os.path.join(os.path.dirname(os.path.abspath(__file__)), ".."))
OUT = os.path.join(ROOT, "protocol", "git_user_fw_ver.h")
BUILD_ID_MAX = 24  # without trailing dirty '*'


def _git(*args: str) -> str | None:
    try:
        return subprocess.check_output(
            ["git", *args],
            cwd=ROOT,
            stderr=subprocess.DEVNULL,
            text=True,
        ).strip()
    except (subprocess.CalledProcessError, FileNotFoundError, OSError):
        return None


def sanitize_branch(name: str) -> str:
    if not name or name == "HEAD":
        return "DETACHED"
    # feature/foo → feature-foo；去掉其它非法字符
    s = name.replace("/", "-")
    s = re.sub(r"[^A-Za-z0-9.-]+", "-", s)
    s = re.sub(r"-{2,}", "-", s).strip("-.")
    return s or "DETACHED"


def make_build_id(branch: str, short6: str) -> str:
    """Ensure '{branch}_{short6}' length ≤ BUILD_ID_MAX; keep commit suffix intact."""
    short6 = short6.lower()[:6].ljust(6, "0")
    suffix = "_" + short6
    max_br = BUILD_ID_MAX - len(suffix)
    if max_br < 1:
        return short6[:BUILD_ID_MAX]
    br = branch[:max_br]
    return br + suffix


def main() -> int:
    full = _git("rev-parse", "HEAD") or ("0" * 40)
    if len(full) < 6 or not all(c in "0123456789abcdefABCDEF" for c in full):
        full = "0" * 40
    full = full.lower()
    short6 = full[:6]

    br_raw = _git("rev-parse", "--abbrev-ref", "HEAD") or "DETACHED"
    branch = sanitize_branch(br_raw)

    dirty = False
    st = _git("status", "--porcelain")
    if st:
        dirty = True

    build_id = make_build_id(branch, short6)
    wire = build_id + ("*" if dirty else "")
    # C string escape
    wire_c = wire.replace("\\", "\\\\").replace('"', '\\"')

    text = f"""/* Auto-generated by tools/gen_git_user_fw_ver.py — do not edit.
 * git HEAD{' (dirty)' if dirty else ''}: {full}
 * branch: {br_raw} → {branch}
 * 01 0C wire: {wire}
 */
#ifndef GIT_USER_FW_VER_H
#define GIT_USER_FW_VER_H

#define GIT_COMMIT_ID_FULL   "{full}"
#define GIT_BRANCH_NAME      "{branch}"
#define GIT_COMMIT_SHORT6    "{short6}"
#define GIT_DIRTY            ({1 if dirty else 0})
#define GIT_BUILD_ID         "{wire_c}"
#define GIT_BUILD_ID_LEN     {len(wire)}u

#endif /* GIT_USER_FW_VER_H */
"""
    os.makedirs(os.path.dirname(OUT), exist_ok=True)
    old = ""
    if os.path.isfile(OUT):
        with open(OUT, "r", encoding="utf-8") as f:
            old = f.read()
    if old != text:
        with open(OUT, "w", encoding="utf-8", newline="\n") as f:
            f.write(text)
        print(f"gen_git_user_fw_ver: wrote {OUT} ({wire})")
    else:
        print(f"gen_git_user_fw_ver: up-to-date ({wire})")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())