cirious_codex_term 0.2.1

use std::io;

/// Represents the dimensions of the terminal window.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct TerminalSize {
  width: u16,
  height: u16,
}

impl TerminalSize {
  /// Queries the terminal size.
  ///
  /// # Safety
  ///
  /// This function is safe to call because the underlying FFI calls
  /// (`ioctl` on Unix or `GetConsoleScreenBufferInfo` on Windows)
  /// are standard system calls that do not rely on undefined state
  /// provided by the caller.
  ///
  /// # Errors
  /// Returns an `io::Result` if the terminal size cannot be determined.
  #[inline]
  pub fn get() -> io::Result<Self> {
    #[cfg(windows)]
    {
      use windows_sys::Win32::System::Console::{
        GetConsoleScreenBufferInfo, GetStdHandle, CONSOLE_SCREEN_BUFFER_INFO, STD_OUTPUT_HANDLE,
      };
      #[allow(unsafe_code)]
      unsafe {
        let handle = GetStdHandle(STD_OUTPUT_HANDLE);
        let mut info: CONSOLE_SCREEN_BUFFER_INFO = std::mem::zeroed();
        if GetConsoleScreenBufferInfo(handle, &mut info) == 0 {
          return Err(io::Error::last_os_error());
        }
        Ok(Self {
          width: (info.srWindow.Right - info.srWindow.Left + 1) as u16,
          height: (info.srWindow.Bottom - info.srWindow.Top + 1) as u16,
        })
      }
    }

    #[cfg(unix)]
    {
      use libc::{ioctl, winsize, STDOUT_FILENO, TIOCGWINSZ};
      use std::mem::MaybeUninit;

      let mut w = MaybeUninit::<winsize>::uninit();
      #[allow(unsafe_code)]
      let res = unsafe { ioctl(STDOUT_FILENO, TIOCGWINSZ, w.as_mut_ptr()) };
      if res == 0 {
        #[allow(unsafe_code)]
        let size = unsafe { w.assume_init() };
        Ok(Self {
          width: size.ws_col,
          height: size.ws_row,
        })
      } else {
        Err(io::Error::last_os_error())
      }
    }
  }

  /// Returns the width of the terminal window.
  #[must_use]
  #[inline]
  pub const fn width(&self) -> u16 {
    self.width
  }

  /// Returns the height of the terminal window.
  #[must_use]
  #[inline]
  pub const fn height(&self) -> u16 {
    self.height
  }
}