// Licensed under the Apache License, Version 2.0
// <LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// All files in the project carrying such notice may not be copied, modified, or distributed
// except according to those terms.

// Minimal null-terminated wide string support from wio.

use std::ffi::{OsStr, OsString};
use std::os::windows::ffi::{OsStrExt, OsStringExt};
use std::slice;

pub trait ToWideNull {
    fn to_wide_null(&self) -> Vec<u16>;
}

impl<T: AsRef<OsStr>> ToWideNull for T {
    fn to_wide_null(&self) -> Vec<u16> {
        self.as_ref().encode_wide().chain(Some(0)).collect()
    }
}

pub trait FromWidePtrNull {
    unsafe fn from_wide_ptr_null(wide: *const u16) -> Self;
}

impl FromWidePtrNull for OsString {
    unsafe fn from_wide_ptr_null(wide: *const u16) -> Self {
        assert!(!wide.is_null());

        for i in 0.. {
            if *wide.offset(i) == 0 {
                return Self::from_wide(&slice::from_raw_parts(wide, i as usize));
            }
        }
        unreachable!()
    }
}