win-desktop-utils 0.1.1

use std::ffi::OsStr;
use std::os::windows::ffi::OsStrExt;

use windows::core::PCWSTR;
use windows::Win32::Foundation::HWND;
use windows::Win32::UI::Shell::{IsUserAnAdmin, ShellExecuteW};
use windows::Win32::UI::WindowsAndMessaging::SW_SHOWNORMAL;

use crate::error::{Error, Result};

fn to_wide_os(value: &OsStr) -> Vec<u16> {
    value.encode_wide().chain(std::iter::once(0)).collect()
}

fn to_wide_str(value: &str) -> Vec<u16> {
    OsStr::new(value)
        .encode_wide()
        .chain(std::iter::once(0))
        .collect()
}

fn quote_arg(arg: &str) -> String {
    let escaped = arg.replace('"', "\\\"");
    format!("\"{escaped}\"")
}

/// Returns `true` if the current process is running elevated.
pub fn is_elevated() -> Result<bool> {
    let is_admin = unsafe { IsUserAnAdmin() };
    Ok(is_admin.as_bool())
}

/// Relaunches the current executable with elevation using the Windows `runas` shell verb.
pub fn restart_as_admin(args: &[String]) -> Result<()> {
    let exe = std::env::current_exe()?;
    let exe_w = to_wide_os(exe.as_os_str());

    let verb_w = to_wide_str("runas");

    let joined_args = args
        .iter()
        .map(|a| quote_arg(a))
        .collect::<Vec<_>>()
        .join(" ");
    let args_w = to_wide_str(&joined_args);

    let result = unsafe {
        ShellExecuteW(
            Some(HWND::default()),
            PCWSTR(verb_w.as_ptr()),
            PCWSTR(exe_w.as_ptr()),
            PCWSTR(args_w.as_ptr()),
            PCWSTR::null(),
            SW_SHOWNORMAL,
        )
    };

    let code = result.0 as isize;
    if code <= 32 {
        Err(Error::WindowsApi {
            context: "ShellExecuteW(runas)",
            code: code as i32,
        })
    } else {
        Ok(())
    }
}