'use strict'

var downloader = require('./downloader');
var IO = require('./io');
var xml2js = require ('xml2js');
// var dir = 'data/stations/';

module.exports = {
    dirs: {
        xml: 'data/stations/xml/',
        json: 'data/stations/json/'
    },

    /**
     * Add station IDs here, A-Z 0-9
     */
    ids: [
        // 'ANVC1',
        // 'BDXC1',
        // 'CECC1',
        // 'CPXC1',
        // 'HBYC1',
        // 'ICAC1',
        // 'NTBC1',
        // 'PRYC1',
        // 'PTGC1',
        '46011',
        '46012',
        '46013',
        '46014',
        '46022',
        '46025',
        '46026',
        '46027',
        '46028',
        '46042',
        '46053',
        '46054',
        '46092',
        '46213',
        '46214',
        '46215',
        '46216',
        '46217',
        '46221',
        '46223',
        '46225',
        '46232',
        '46234',
        '46237',
        '46239',
        '46240',
        '46242',
        '46244',
        '46253',
        '46254',
        '46256',
        '46257'
    ],

    /**
     * Downloads each station's data XML.
     */
    getMetadata: function(station) {
        var url = 'http://www.ndbc.noaa.gov/get_observation_as_xml.php?station=' + station;
        return downloader.download(url, module.exports.dirs.xml + station + '.xml');
    },

    /**
     *
     */
    parse: function(xml) {
        return new Promise(function(resolve) {
            xml2js.parseString(xml, function(err, json) {
                var str = null;

                // Do not stringify if null.
                if (json) {
                    str = JSON.stringify(json.observation.$)
                }

                resolve(str);
            });
        });
    },

    /**
     *
     */
    parseStation: function(station) {
        return IO.read(module.exports.dirs.xml + station + '.xml')
                .then(module.exports.parse)
                .then(function(str) {
                    IO.write(module.exports.dirs.json + station + '.json', str)
                })
    },
};