use anyhow::Result;
use windows::Win32::UI::{
    Input::KeyboardAndMouse::GetKeyboardLayoutNameW, WindowsAndMessaging::KL_NAMELENGTH,
};
use windows_core::HSTRING;

use crate::PlatformKeyboardLayout;

pub(crate) struct WindowsKeyboardLayout {
    id: String,
    name: String,
}

impl PlatformKeyboardLayout for WindowsKeyboardLayout {
    fn id(&self) -> &str {
        &self.id
    }

    fn name(&self) -> &str {
        &self.name
    }
}

impl WindowsKeyboardLayout {
    pub(crate) fn new() -> Result<Self> {
        let mut buffer = [0u16; KL_NAMELENGTH as usize];
        unsafe { GetKeyboardLayoutNameW(&mut buffer)? };
        let id = HSTRING::from_wide(&buffer).to_string();
        let entry = windows_registry::LOCAL_MACHINE.open(format!(
            "System\\CurrentControlSet\\Control\\Keyboard Layouts\\{}",
            id
        ))?;
        let name = entry.get_hstring("Layout Text")?.to_string();
        Ok(Self { id, name })
    }

    pub(crate) fn unknown() -> Self {
        Self {
            id: "unknown".to_string(),
            name: "unknown".to_string(),
        }
    }
}