import type { RpcClient } from "@neoinkjs/rpc";

/**
 * Subscribes to notifications named `method` on `client`, narrowing each
 * notification's first parameter with `isValue` before handing it to
 * `handler`; anything with a different method name, or whose first param
 * fails the guard, is silently ignored. Both `subscribeInput` (`input.ts`)
 * and `subscribeResize` (`resize.ts`) are this exact shape — one method
 * name, one narrowed scalar param — so it lives here once rather than being
 * copy-pasted per notification kind.
 */
export function subscribeNotification<T>(
  client: RpcClient,
  method: string,
  isValue: (value: unknown) => value is T,
  handler: (value: T) => void,
): () => void {
  return client.onNotification((receivedMethod, params) => {
    if (receivedMethod !== method) return;
    const value = params[0];
    if (isValue(value)) handler(value);
  });
}