#!/usr/bin/env python3
# -*- coding: utf-8 -*-
r'''把 watchdog.sh 里裸用的 $BUILT 换成 ${BUILT:-0}。

背景：
    watchdog.sh 开头有 `set -u`（未定义变量直接报错退出）。
    我给 restart_tunnel() 里加了 `write_state 0 0 "$BUILT"`，
    但这个函数定义在 `BUILT=$(read_state built 0)` **之前**，
    函数被调用时 BUILT 还不存在 -> 报 "BUILT: 未绑定的变量"。

    这么写一次就够，然后用 bash -n 和实跑验证。
'''
from pathlib import Path

WD = Path("/root/lanremote-relay/watchdog.sh")


def main() -> int:
    text = WD.read_text(encoding="utf-8")

    old = 'write_state 0 0 "$BUILT"'
    new = 'write_state 0 0 "${BUILT:-0}"'
    count = text.count(old)
    if count:
        text = text.replace(old, new)
        WD.write_text(text, encoding="utf-8", newline="\n")
    print("  替换 %d 处" % count)

    print()
    print("  现在所有 BUILT 用法:")
    for index, line in enumerate(WD.read_text(encoding="utf-8").splitlines(),
                                 1):
        if "BUILT" in line:
            mark = ""
            if "$BUILT" in line and "${BUILT:-0}" not in line:
                mark = "   <-- 检查这里"
            print("    %3d: %s%s" % (index, line.strip(), mark))
    return 0


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