import { VoiceHelperClient } from "./helper.ts";
import type { VoiceDevice } from "./helper-protocol.ts";

/** Device enumeration never starts capture or playback. */
export async function listNativeAudioDevices(
	signal: AbortSignal,
	customRustBinariesDir?: string,
): Promise<{ inputs: VoiceDevice[]; outputs: VoiceDevice[] }> {
	const helper = new VoiceHelperClient();
	const result = Promise.withResolvers<{ inputs: VoiceDevice[]; outputs: VoiceDevice[] }>();
	const removeEvent = helper.onEvent((event) => {
		if (event.type === "devices") result.resolve(event);
		else if (event.type === "error") result.reject(new Error(event.message));
	});
	const removeExit = helper.onExit((error) => result.reject(error));
	const abort = () => {
		result.reject(new Error("Device discovery cancelled"));
		void helper.close();
	};
	const timeout = setTimeout(() => result.reject(new Error("Audio device discovery timed out")), 5_000);
	signal.addEventListener("abort", abort, { once: true });
	// Observe discovery failures while helper startup is still pending.
	void result.promise.catch(() => {});
	let started = false;
	try {
		signal.throwIfAborted();
		await helper.start(customRustBinariesDir);
		started = true;
		signal.throwIfAborted();
		helper.send({ type: "list_devices" });
		return await result.promise;
	} catch (error) {
		const message = error instanceof Error ? error.message : "";
		if (signal.aborted) throw error;
		if (message === "Audio device discovery timed out") throw error;
		if (message.startsWith("pi-codex-voice cannot run on this system.")) throw error;
		if (!started) {
			const reason = message.startsWith("Codex voice helper is not bundled")
				? `Native audio is unavailable for ${process.platform}-${process.arch}`
				: "Native audio could not start on this system";
			throw new Error(`${reason}. Install a compatible voice helper, or build locally and set tools.customRustBinariesDir, then /reload`);
		}
		throw new Error("Audio device discovery failed. Check system audio devices and permissions, then reopen to retry");
	} finally {
		clearTimeout(timeout);
		signal.removeEventListener("abort", abort);
		removeEvent();
		removeExit();
		await helper.close();
	}
}