weather.js

var httpreq = require('httpreq');
var fs = require('fs');
var Mustache = require('mustache');

///CONFIG
var APPID = "fdc3690e6f9a7572128fe4012b4a2500"
var CITYID = "2945024"

/// STATICS
var directions = {NNE:11.25,NE:33.75,ENE:56.25,E:78.75,ESE:101.25,SE:123.75,SSE:146.25,S:168.75,SSW:191.25,SW:213.75,WSW:236.25,W:258.75,WNW:281.25,NW:303.75,NNW:326.25,N:348.75}
var iconBaseURL = 'http://openweathermap.org/img/w/';
var TEMPLATE = '';
fs.readFile('modules/weather/template.mustache', 'utf-8', function (err, data) {
    TEMPLATE = data;
});

function pad(n, width, z) {
    z = z || '0';
    n = n + '';
    return n.length >= width ? n : new Array(width - n.length + 1).join(z) + n;
}

function fetchCurrent (cityid, cb) {
    var url = "http://api.openweathermap.org/data/2.5/weather?units=metric&id="+cityid+"&appid="+APPID;
    httpreq.get(url, function (err, res) {
        var dat = JSON.parse(res.body);
        cb({
            temp: dat.main.temp,
            wind: {speed: dat.wind.speed, dir: degToDirection(dat.wind.deg)},
            pressure: dat.main.pressure,
            humidity: dat.main.humidity,
            main: dat.weather[0].main,
            desc: dat.weather[0].description,
            icon: iconBaseURL+dat.weather[0].icon+'.png'
        });
    });
}

function fetchForecast (cityid, count, cb) {
    var url = "http://api.openweathermap.org/data/2.5/forecast?units=metric&id="+cityid+"&appid="+APPID;
    httpreq.get(url, function (err, res) {
        var dat = JSON.parse(res.body).list.slice(0,count);
        cb(dat.map(function (d) {
            var date = new Date(d.dt*1000);
            return {
                time: pad(date.getHours(),2)+':'+pad(date.getMinutes(),2),
                temp: d.main.temp,
                wind: {speed: d.wind.speed, dir: degToDirection(d.wind.deg)},
                main: d.weather[0].main,
                desc: d.weather[0].description,
                icon: iconBaseURL+d.weather[0].icon+'.png'
            }
        }));
    });
}

function degToDirection(deg) {
    var dir = 'N';
    for (i in directions) {
        if (deg > directions[i]) {
            dir = i;
        }
    }
    return dir;
}

module.exports = function (io) {
    var context = {};
    var update = function (firstUpdateCb) {
        var then = function () {
            if (context.current && context.forecast) {
                firstUpdateCb();
                then = function () {}
            }
        };
        fetchCurrent(CITYID, function (current) {
            context.current = current;
            then();
        });
        fetchForecast(CITYID, 6, function (forecast) {
            context.forecast = forecast;
            then();
        });
    };
    update(function () {
        var pushToClients = function (sock) {
            sock.emit('weather', Mustache.render(TEMPLATE, context));
        };
        io.on('connect', pushToClients);
        pushToClients(io);
    });
    setInterval(update, 10*60*1000);
}