'use strict'

var downloader = require('./downloader.js');
var IO = require('./io.js');
var NOAA = require('./noaa.js');

module.exports = {
    //=========================
    //     Read-only vars
    //=========================
    dirs: {
        txt: 'data/meteo/txt/',
        json: 'data/meteo/json/'
    },

    months: [null, 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],

    //==========================
    //        Downloads
    //==========================
    /**
     *
     */
    getYear: function(station, year) {
        var path = module.exports.dirs.txt + station + '/';
        var filename = station + 'h' + year + '.txt';

        var url = 'http://www.ndbc.noaa.gov/view_text_file.php?'+
            'filename=' + filename + '.gz&dir=data/historical/stdmet/';

        downloader.mkdir(path);
        return downloader.download(url, path + filename);
    },

    /**
     *
     */
    getMonth: function(station, month, year) {
        var path = module.exports.dirs.txt + station + '/';
        var filename = station + month.toString(16) + year + '.txt';

        var url = 'http://www.ndbc.noaa.gov/view_text_file.php?' +
            'filename=' + filename + '.gz&dir=data/stdmet/' + module.exports.months[month] + '/';

        downloader.mkdir(path);
        return downloader.download(url, path + filename);
    },

    /**
     *
     */
    getNewest: function(station, month, year) {
        var path = module.exports.dirs.txt + station + '/';
        var filename = station + month.toString(16) + year + '-newest.txt';

        var url = 'http://www.ndbc.noaa.gov/data/stdmet/' + module.exports.months[month] + '/' + station + '.txt';

        downloader.mkdir(path);
        return downloader.download(url, path + filename);
    },

    /**
     *
     */
    getCurrent: function(station) {
        var filename = station + '.txt';

        var url = 'http://www.ndbc.noaa.gov/data/realtime2/' + filename;

        return downloader.download(url, dir + filename);
    },

    //==========================
    //     Transformations
    //==========================

    /**
     *
     */
    parseAllMonths: function(station, year) {
        var arr = [];
        var txtPath = module.exports.dirs.txt + station + '/';
        var jsonPath = module.exports.dirs.json + '/';

        for (var month = 1; month <= 12; month++) {
            arr.push(IO.read(txtPath + station + month.toString(16) + year + '-newest.txt').then(NOAA.parseTxt));
            arr.push(IO.read(txtPath + station + month.toString(16) + year + '.txt').then(NOAA.parseTxt));
        }

        return Promise.all(arr)
            .then(NOAA.aggregate)
            .then(NOAA.convert)
            .then(function(str) {
                return IO.write(jsonPath + station + '-' + year + '.json', str);
            });
    },

    /**
     *
     */
    parseYear: function(station, year) {
        var txtPath = module.exports.dirs.txt + station + '/';
        var jsonPath = module.exports.dirs.json + '/';

        return IO.read(txtPath + station + 'h' + year + '.txt')
            .then(NOAA.parseTxt)
            .then(NOAA.convert)
            .then(function(str) {
                return IO.write(jsonPath + station + '-' + year + '.json', str);
            });
    },

    //========================================
    //   Promise Collections used in loops
    //========================================

    /**
     *
     */
    getAllYears: function(station, startYear, endYear) {
        var arr = [];
        for (var year = startYear; year <= endYear; year++) {
            arr.push(module.exports.getYear(station, year));
        }

        return Promise.all(arr);
    },

    /**
     *
     */
    getAllMonths: function(station, year) {
        var arr = [];
        for (var month = 1; month <= 12; month++) {
            arr.push(module.exports.getMonth(station, month, year));
        }

        return Promise.all(arr);
    },

    /**
     *
     */
    getAllNewest: function(station, year) {
        var arr = [];
        for (var month = 1; month <= 12; month++) {
            arr.push(module.exports.getNewest(station, month, year));
        }

        return Promise.all(arr);
    },

    /**
     *
     */
    parseAllYears: function(station, startYear, endYear) {
        var arr = [];

        for (var year = startYear; year <= endYear; year++) {
            arr.push(module.exports.parseYear(station, year));
        }

        return Promise.all(arr);
    }
};