"use strict";

import path from 'path';
import fs from 'fs';

import sysinfo from 'systeminformation';

import log from '../../lib/io/NamespacedLog.mjs'; const l = log("infobroker");

// HACK: Make sure __dirname is defined when using es6 modules. I forget where I found this - a PR with a source URL would be great :D
const __dirname = import.meta.url.slice(7, import.meta.url.lastIndexOf("/"));


class InfoBroker {
	constructor() {
		this.allowed_tables = {
			// name → sysinfo name
			cpu: "cpu",
			cpu_live: async () => {
				return {
					frequency: await sysinfo.cpuCurrentSpeed(),
					temperature: await sysinfo.cpuTemperature()
				};
			},
			meta: async () => await this.make_table_meta()
		};
	}
	
	is_valid_table(name) {
		return Object.keys(this.allowed_tables).includes(name);
	}
	
	async make_table_meta() {
		return {
			version: JSON.parse(fs.promises.readFile(path.resolve(__dirname, "../../../package.json"), "utf-8")).version,
			versions_env: process.versions,
			pid: process.pid,
			uptime: process.uptime(),
			memory: process.memoryUsage(),
		};
	}
	
	async fetch_table(name) {
		if(!(typeof name === "string"))
			throw new Exception(`Error: Expected name to be of type string, but received value of type ${typeof name} instead.`);
		
		if(!this.is_valid_table(name)) {
			l.warn(`Unrecognised table '${name}' requested, returning null`);
			return null;
		}
		
		let name_translated = this.allowed_tables[name];
		
		if(typeof name_translated === "function")
			return await name_translated();
		
		return await sysinfo[name_translated]();
	}
}

export default InfoBroker;