//! This module provides utilities to query information about the version of
//! Microsoft Windows.

use windows_kernel_sys::{base::RTL_OSVERSIONINFOW, ntoskrnl::RtlGetVersion};

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

/// Represents version information for Microsoft Windows.
pub struct VersionInfo {
  version_info: RTL_OSVERSIONINFOW,
}

impl VersionInfo {
  /// Uses [`RtlGetVersion`] to query the version info for Microsoft Windows.
  pub fn query() -> Result<Self, Error> {
    let mut version_info: RTL_OSVERSIONINFOW = unsafe { core::mem::zeroed() };

    version_info.dwOSVersionInfoSize = core::mem::size_of::<RTL_OSVERSIONINFOW>() as u32;

    unsafe { RtlGetVersion(&mut version_info) }.into_result()?;

    Ok(Self {
      version_info,
    })
  }

  /// Retrieves the major version of Microsoft Windows.
  pub fn major(&self) -> u32 { self.version_info.dwMajorVersion }

  /// Retrieves the minor version of Microsoft Windows.
  pub fn minor(&self) -> u32 { self.version_info.dwMinorVersion }

  /// Retrieves the build number of Microsoft Windows.
  pub fn build_number(&self) -> u32 { self.version_info.dwBuildNumber }
}