#!/usr/bin/env ucode
/*
Luci statistics - collectd configuration generator
(c) 2008-2022 Jo-Philipp Wich <jo@mein.io>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

		http://www.apache.org/licenses/LICENSE-2.0

*/

'use strict';

import { lsdir, open } from 'fs';
import { cursor } from 'uci';

const uci = cursor();
const sections = uci.get_all('luci_statistics');

const plugins = {
	collectd: [
		[ 'BaseDir', 'Include', 'PIDFile', 'PluginDir', 'TypesDB', 'Interval', 'ReadThreads', 'Hostname' ],
		[],
		[]
	],
	logfile: [
		[ 'LogLevel', 'File' ],
		[ 'Timestamp' ],
		[]
	],
};

function parse_units(ustr) {
	let val = 0;

	// unit map
	const map = {
		y  : 60 * 60 * 24 * 366,
		m  : 60 * 60 * 24 * 31,
		w  : 60 * 60 * 24 * 7,
		d  : 60 * 60 * 24,
		h  : 60 * 60,
		min: 60
	};

	// parse input string
	for (let spec in match(lc(ustr), /([0-9.]+)([a-z]*)/g)) {
		let num = +spec[1];
		let mul = map[spec[2]] ?? map[substr(spec[2], 0, 1)] ?? 1;

		val += num * mul;
	}

	return int(val);
}

const preprocess = {
	RRATimespans: function(val) {
		return join(' ', map(split(val, /\s+/), parse_units));
	}
};


function _bool(s, n, nopad) {
	if (s == '1')
		return `${nopad ? '' : '\t'}${n} true\n`;

	if (s == '0')
		return `${nopad ? '' : '\t'}${n} false\n`;

	return '';
}

function _string(s, n, nopad) {
	if (s) {
		if (n == 'Port' || n == 'Irq' || match(s, /[^0-9]/)) {
			if (!match(s, /[^\w]/) && n != 'Port' && n != 'Irq')
				return `${nopad ? '' : '\t'}${n} ${trim(s)}\n`;
			else
				return `${nopad ? '' : '\t'}${n} "${trim(s)}"\n`;
		}
		else {
			return `${nopad ? '' : '\t'}${n} ${trim(s)}\n`;
		}
	}

	return '';
}

function _expand(s, n, nopad) {
	let str = "";

	if (type(s) == 'string') {
		for (let v in split(s, /\s+/))
			str += _string(v, n, nopad);
	}
	else if (type(s) == 'array') {
		for (let v in s)
			str += _string(v, n, nopad);
	}

	return str;
}

function _list_expand(c, l, nopad) {
	let str = '';

	for (let n in l) {
		if (c[n]) {
			if (preprocess[n])
				c[n] = preprocess[n](c[n]);

			let m = match(n, /^(\w+)ses$/);
			let k;

			if (m)
				k = `${m[1]}s`;
			else
				k = replace(n, /^(\w+)s$/, '$1');

			str += _expand(c[n], k, nopad);
		}
	}

	return str;
}


function config_generic(c, singles, bools, lists, nopad) {
	let str = '';

	if (c) {
		for (let key in singles) {
			if (preprocess[key])
				c[key] = preprocess[key](c[key]);

			str += _string(c[key], key, nopad);
		}

		for (let key in bools) {
			if (preprocess[key])
				c[key] = preprocess[key](c[key]);

			str += _bool(c[key], key, nopad);
		}

		if (lists)
			str += _list_expand(c, lists, nopad);
	}

	return str;
}

function config_exec(c) {
	let str = "";

	for (let k, s in sections) {
		for (let key, type in { Exec: 'collectd_exec_input', NotificationExec: 'collectd_exec_notify' }) {
			if (s['.type'] == type) {
				let cmd   = replace(trim(s.cmdline), /\s+/g, '" "');
				let user  = s.cmduser ?? 'nobody';
				let group = s.cmdgroup;

				if (cmd)
					str += `\t${key} "${user}${group ? `:${group}` : ''}" "${cmd}"\n`;
			}
		}
	}

	return str;
}

function config_curl(c) {
	let str = "";

	for (let k, s in sections) {
		if (s['.type'] == 'collectd_curl_page') {
			str += `\t<Page "${s.name}">\n`
			     + `\t\tURL "${s.url}"\n`
			     + `\t\tMeasureResponseTime true\n`
			     + `\t</Page>\n`;
		}
	}

	return str;
}

function config_iptables(c) {
	let str = "";

	for (let k, s in sections) {
		for (let type, verb in { collectd_iptables_match: 'Chain', collectd_iptables_match6: 'Chain6' }) {
			if (s['.type'] == type) {
				let tname = `${s.table}`;
				let chain = `${s.chain}`;

				if (match(tname, /^\S+$/) && match(chain, /^\S+$/) && match(rule, /^\S+$/) && match(name, /^\S+$/)) {
					str += `\t${verb} "${tname}" "${chain}"`;

					let rule = `${s.rule}`;

					if (match(rule, /^\S+$/)) {
						str += ` "${rule}"`;

						let name = `${s.name}`;

						if (match(name, /^\S+$/))
							str += ` "${name}"`;
					}

					str += '\n';
				}
			}
		}
	}

	return str;
}

function config_network(c) {
	let str = '';

	for (let k, s in sections) {
		for (let key, type in { Listen: 'collectd_network_listen', Server: 'collectd_network_server' }) {
			if (s['.type'] == type && s.host) {
				if (s.port)
					str += `\t${key} "${s.host}" "${s.port}"\n`;
				else
					str += `\t${key} "${s.host}"\n`;
			}
		}
	}

	return str
		+ _string(c.MaxPacketSize, 'MaxPacketSize')
		+ _string(c.TimeToLive, 'TimeToLive')
		+ _bool(c.Forward, 'Forward')
		+ _bool(c.ReportStats, 'ReportStats')
	;
}

function section(plugin) {
	let config = sections[`collectd_${plugin}`] ?? sections.collectd;

	if (config && (plugin == 'collectd' || config.enable == '1')) {
		let params;

		if (type(plugins[plugin]) == 'function')
			params = plugins[plugin](config);
		else
			params = config_generic(config, ...plugins[plugin], plugin == 'collectd');

		if (plugin != 'collectd')
			print(`LoadPlugin ${plugin}\n${length(params) ? `<Plugin ${plugin}>\n${params}</Plugin>\n` : ''}\n`);
		else
			print(`${params ?? ''}\n`);
	}
}


let plugin_dir = '/usr/share/luci/statistics/plugins';

for (let filename in lsdir(plugin_dir)) {
	let name = replace(filename, /\.json$/, '');

	switch (name) {
	case 'exec':     plugins[name] = config_exec;     break;
	case 'iptables': plugins[name] = config_iptables; break;
	case 'curl':     plugins[name] = config_curl;     break;
	case 'network':  plugins[name] = config_network;  break;
	default:
		plugins[name] = json(open(`${plugin_dir}/${filename}`))?.legend;
	}
}


section('collectd');
section('logfile');

for (let plugin in plugins)
	if (plugin != 'collectd' && plugin != 'logfile')
		section(plugin);