/**

* Shared Linux input-tool resolution — display server and input tool.

*

* The display decision comes from the resolved provider's bound host, never an ambient read, and

* the chosen tool is memoized on that provider instance — no module state, so two runtimes with

* different hosts resolve and keep their own selection (#3794). A refusal is never cached.

*/

import { AppError } from '@agent-device/kernel/errors';

import { resolveLinuxToolProvider, type LinuxToolProvider } from './tool-provider.ts';

import type { DisplayServer } from './display.ts';

import type { LinuxInputSelection } from './input-tool.ts';

export async function ensureInputTool(

provider: LinuxToolProvider = resolveLinuxToolProvider(),

): Promise<LinuxInputSelection> {

const display: DisplayServer = provider.display.detectDisplayServer();

if (provider.inputSelection?.display === display) return provider.inputSelection;

if (display === 'wayland') {

if (await provider.whichCommand('ydotool')) {

provider.inputSelection = { tool: 'ydotool', display };

return provider.inputSelection;

}

throw new AppError(

'TOOL_MISSING',

'ydotool is required for input synthesis on Wayland (xdotool does not work on Wayland). Install it via your package manager.',

);

}

if (await provider.whichCommand('xdotool')) {

provider.inputSelection = { tool: 'xdotool', display };

return provider.inputSelection;

}

throw new AppError(

'TOOL_MISSING',

'xdotool is required for input synthesis on X11. Install it via your package manager.',

);

}