import type { ExtensionContext } from "@selesai/code";

/** Pi exposes replaced extension contexts as ordinary Errors without a stable code. */
export function isStaleExtensionContextError(error: unknown): boolean {
	return error instanceof Error
		&& /extension ctx is stale|extension context no longer active|stale after session replacement or reload/i.test(error.message);
}

/** Run a synchronous operation against a cached UI context without leaking replacement errors. */
export function withCachedUiContext<T>(
	ctx: ExtensionContext | null | undefined,
	onStale: () => void,
	run: (ctx: ExtensionContext) => T,
): T | undefined {
	if (!ctx) return undefined;
	try {
		if (!ctx.hasUI) return undefined;
		return run(ctx);
	} catch (error) {
		if (!isStaleExtensionContextError(error)) throw error;
		onStale();
		return undefined;
	}
}