import { NextResponse } from "next/server";
import { getDb } from "@/lib/db";
import fs from "fs/promises";

/**
 * GET /api/health
 *
 * Health check endpoint:
 * - Verifies database connectivity.
 * - Verifies readability of NAS_ROOT_PATH.
 */
export async function GET() {
	const result = {
		db: null,
		nas: null,
	};

	// --- Database health -------------------------------------------------------
	try {
		const db = await getDb();
		await db.command({ ping: 1 });
		result.db = "ok";
	} catch (error) {
		// We don't throw here – we report the error in the JSON result
		result.db = `error: ${error.message}`;
	}

	// --- NAS health ------------------------------------------------------------
	const nasPath = process.env.NAS_ROOT_PATH || "/mnt/niederlassungen";

	try {
		const entries = await fs.readdir(nasPath);
		result.nas = {
			path: nasPath,
			entriesSample: entries.slice(0, 5),
		};
	} catch (error) {
		// It's okay if NAS is not available in some environments (like local dev),
		// we just propagate the error message in the health object.
		result.nas = `error: ${error.message}`;
	}

	return NextResponse.json(result);
}