import os from "node:os";
import { MIN_DARWIN_MAJOR } from "./constants.ts";

export type PlatformSupport =
	| { ok: true }
	| { ok: false; reason: string };

export type PlatformInfo = {
	platform: NodeJS.Platform;
	/** Darwin kernel release string, e.g. `25.5.0`. */
	release: string;
};

/**
 * Caps Lock LED control is supported on macOS 26+ only (Darwin major >= 25).
 */
export function checkPlatformSupport(
	info: PlatformInfo = {
		platform: process.platform,
		release: os.release(),
	},
): PlatformSupport {
	if (info.platform !== "darwin") {
		return {
			ok: false,
			reason: `pi-caps-blink is macOS-only (got ${info.platform})`,
		};
	}

	const major = Number.parseInt(info.release.split(".")[0] ?? "", 10);
	if (!Number.isFinite(major) || major < MIN_DARWIN_MAJOR) {
		return {
			ok: false,
			reason: `pi-caps-blink requires macOS 26+ (Darwin ${MIN_DARWIN_MAJOR}+; got ${info.release})`,
		};
	}

	return { ok: true };
}