import { storagePath } from '$lib';
import { json } from '@sveltejs/kit';
import { stat, access, constants } from 'fs/promises';
import type { RequestHandler } from './$types';

type Status = 'OK' | 'ERROR';
type Result = { status: Status; checks: Checks };

type Checks = { [key: string]: CheckResult };
type CheckResult = true | string;

const fileExists = async (path: string) => !!(await stat(path).catch(() => false));
const isDirectory = async (path: string) =>
	!!(await stat(path)
		.then((s) => s.isDirectory())
		.catch(() => false));
const isWritable = async (path: string) =>
	await access(path, constants.W_OK)
		.then(() => true)
		.catch(() => false);

const checkStoragePath = async (path: string): Promise<CheckResult> => {
	if (!fileExists(path)) {
		return '`STORAGE_PATH` does not exist';
	} else if (!isDirectory(path)) {
		return '`STORAGE_PATH` is not a directory';
	} else if (!isWritable(path)) {
		return '`STORAGE_PATH` is not writable';
	}
	return true;
};

export const GET: RequestHandler = async () => {
	const storagePathResult = await checkStoragePath(storagePath);

	const checks: Checks = {
		storagePath: storagePathResult,
	};

	const healthy = Object.values(checks)
		.map((r) => (r === true ? true : false))
		.reduce((prev, next) => prev && next, true);

	const status = healthy ? 'OK' : 'ERROR';

	const result: Result = { status, checks };
	const httpStatus = healthy ? 200 : 500;

	return json(result, { status: httpStatus, headers: { healthy: healthy.toString() } });
};