var os = require('os');
var ps = require('portscanner');
var nl = require('./numberlogger.js');
var config = require('./config.js');
var express = require('express');
var compression = require('compression');

var PORT = 3369;

var serverstat = {
    "uptime": os.uptime(),
    "load": [0, 0, 0],
    "services": {},
    "stats" : {}
};

var serverinfo = {
    "hostname": os.hostname(),
    "release": os.release(),
    "cpuname": os.cpus()[0].model,
    "cpunum": os.cpus().length,
    "totmem": Math.round(os.totalmem()/1024/1024),
    "desc" : config.description,
    "stats": {}
};

var statResponse = {};

function checkp(key) {
    ps.checkPortStatus(config.services[key], 'localhost', function (error, status) {
        serverstat.services[key] = (status == 'open');
    })
}

var logger = function (name, length) {
    this.name = name;
    this.sec = new nl(name + ":sec", length);
    this.min = new nl(name + ":min", length);
    this.hrs = new nl(name + ":hrs", length);
    this.day = new nl(name + ":day", length);
    this.time = new Date();
};

logger.prototype.add = function (time, x) {
    function average(l, n) {
        var sum = 0;
        for (var i = 0; i < n; ++i)
            sum += l.ns[l.len - 1 - i];
        return sum / n;
    }

    if (time.getDay() != this.time.getDay())
        this.day.add(average(this.hrs, 24));
    if (time.getHours() != this.time.getHours())
        this.hrs.add(average(this.min, 60));
    if (time.getMinutes() != this.time.getMinutes())
        this.min.add(average(this.sec, 60));
    this.sec.add(x);
    this.time = time;
};

logger.prototype.setupResponse = function(res){
    var host = this;
    var stat = [];
    function setupSingleStat(id){
        stat.push(host[id].name);
        res[host[id].name] = function (stat) {
            stat.stats[host.name] = host[id].stringify();
        };
    }
    console.log("Setting up response for "+this.name);
    setupSingleStat("sec");
    setupSingleStat("min");
    setupSingleStat("hrs");
    setupSingleStat("day");
    serverinfo.stats[this.name] = stat;
};

logger.prototype.stringify = function () {
    return [this.sec.stringify(), this.min.stringify(), this.hrs.stringify(), this.day.stringify()];
};

var cpustat = new logger("cpu", 100);
var memstat = new logger("mem", 100);
cpustat.setupResponse(statResponse);
memstat.setupResponse(statResponse);

function refreshStat() {
    for (var key in config.services) {
        if (config.services.hasOwnProperty(key)) {
            checkp(key);
        }
    }
    serverstat.uptime = os.uptime();
    serverstat.load = os.loadavg();
}

refreshStat();

setInterval(refreshStat, 1000);

function getCPUInfo() {
    var cpus = os.cpus();

    var user = 0;
    var nice = 0;
    var sys = 0;
    var idle = 0;
    var irq = 0;

    for (var cpu in cpus) 
        if (cpus.hasOwnProperty(cpu)) {

            user += cpus[cpu].times.user;
            nice += cpus[cpu].times.nice;
            sys += cpus[cpu].times.sys;
            irq += cpus[cpu].times.irq;
            idle += cpus[cpu].times.idle;
        }

    var total = user + nice + sys + idle + irq;

    return {
        'idle': idle,
        'total': total
    };
}

function getUsage() {

    var stats = getCPUInfo();

    setInterval(function () {
        var nstats = getCPUInfo();

        var idle = nstats.idle - stats.idle;
        var total = nstats.total - stats.total;
        var perc = 1 - idle / total;

        stats = nstats;

        var time = new Date();

        cpustat.add(time, perc);
        memstat.add(time, memPercentage());
    }, 1000);
}

function memPercentage() {
    return 1 - os.freemem() / os.totalmem();
}

getUsage();

var app = express();
app.use(compression());
app.get('/', function (req, res) {
    res.append('Content-Type', 'application/json');
    res.append('Access-Control-Allow-Origin', '*');
    res.send(JSON.stringify(serverinfo));
});

app.get('/stat', function (req, res) {
    res.append('Content-Type', 'application/json');
    res.append('Access-Control-Allow-Origin', '*');
    var stat = JSON.parse(JSON.stringify(serverstat));
    for (var query in req.query)
    if (req.query.hasOwnProperty(query))
        statResponse[req.query[query]](stat);
    res.send(JSON.stringify(stat));
});
app.listen(PORT);
console.log("Server listening on: %s", PORT);