#!/usr/bin/env ucode

'use strict';

import { readfile, writefile, open, mkdir, rename } from 'fs';
import { connect } from 'ubus';

const HISTORY_DIR = '/var/lib/wifihistory';
const HISTORY_FILE = HISTORY_DIR + '/history.json';
const LOCK_FILE = '/var/lock/wifihistory.lock';

function load_history() {
	let content = readfile(HISTORY_FILE);
	if (content == null)
		return {};

	try {
		return json(content) || {};
	}
	catch (e) {
		return {};
	}
}

function save_history(data) {
	let tmp = HISTORY_FILE + '.tmp';

	writefile(tmp, sprintf('%J', data));
	rename(tmp, HISTORY_FILE);
}

function poll_stations() {
	let ubus = connect();
	if (!ubus) {
		warn('Failed to connect to ubus\n');
		return;
	}

	let now = time();
	let history = load_history();
	let seen_macs = {};

	let wifi_status = ubus.call('network.wireless', 'status');
	if (!wifi_status)
		return;

	let hints = ubus.call('luci-rpc', 'getHostHints') || {};

	for (let radio in wifi_status) {
		let ifaces = wifi_status[radio]?.interfaces;
		if (!ifaces)
			continue;

		for (let iface in ifaces) {
			let ifname = iface?.ifname;
			if (!ifname)
				continue;

			let info = ubus.call('iwinfo', 'info', { device: ifname });
			let ssid = info?.ssid || '';

			let assoc = ubus.call('iwinfo', 'assoclist', { device: ifname });
			if (!assoc?.results)
				continue;

			for (let bss in assoc.results) {
				let mac = bss?.mac;
				if (!mac)
					continue;

				mac = uc(mac);
				seen_macs[mac] = true;

				let hostname = hints?.[mac]?.name || '';
				let ipv4 = hints?.[mac]?.ipaddrs?.[0] || '';
				let ipv6 = hints?.[mac]?.ip6addrs?.[0] || '';

				let existing = history[mac];
				let first_seen = existing?.first_seen || now;

				history[mac] = {
					mac: mac,
					hostname: hostname,
					ipv4: ipv4,
					ipv6: ipv6,
					network: ssid,
					ifname: ifname,
					connected: true,
					signal: bss?.signal || 0,
					noise: bss?.noise || 0,
					first_seen: first_seen,
					last_seen: now
				};
			}
		}
	}

	for (let mac in history)
		if (!seen_macs[mac])
			history[mac].connected = false;

	ubus.disconnect();

	save_history(history);
}

mkdir(HISTORY_DIR);

let lock_fd = open(LOCK_FILE, 'w');
if (!lock_fd) {
	warn('Failed to open lock file\n');
	exit(1);
}

if (!lock_fd.lock('xn')) {
	warn('Another instance is already running\n');
	lock_fd.close();
	exit(1);
}

poll_stations();

lock_fd.lock('u');
lock_fd.close();