var Utils = require("../Utils.js");


/**
 * Morse Code translation operations.
 *
 * @author tlwr [toby@toby.codes]
 * @copyright Crown Copyright 2017
 * @license Apache-2.0
 *
 * @namespace
 */
var MorseCode = module.exports = {

    /**
     * @constant
     * @default
     */
    FORMAT_OPTIONS: ["-/.", "_/.", "Dash/Dot", "DASH/DOT", "dash/dot"],
    /**
     * @constant
     * @default
     */
    LETTER_DELIM_OPTIONS: ["Space", "Line feed", "CRLF", "Forward slash", "Backslash", "Comma", "Semi-colon", "Colon"],
    /**
     * @constant
     * @default
     */
    WORD_DELIM_OPTIONS: ["Line feed", "CRLF", "Forward slash", "Backslash", "Comma", "Semi-colon", "Colon"],
    /**
     * @constant
     * @default
     */
    MORSE_TABLE: {
        "A": "<dot><dash>",
        "B": "<dash><dot><dot><dot>",
        "C": "<dash><dot><dash><dot>",
        "D": "<dash><dot><dot>",
        "E": "<dot>",
        "F": "<dot><dot><dash><dot>",
        "G": "<dash><dash><dot>",
        "H": "<dot><dot><dot><dot>",
        "I": "<dot><dot>",
        "J": "<dot><dash><dash><dash>",
        "K": "<dash><dot><dash>",
        "L": "<dot><dash><dot><dot>",
        "M": "<dash><dash>",
        "N": "<dash><dot>",
        "O": "<dash><dash><dash>",
        "P": "<dot><dash><dash><dot>",
        "Q": "<dash><dash><dot><dash>",
        "R": "<dot><dash><dot>",
        "S": "<dot><dot><dot>",
        "T": "<dash>",
        "U": "<dot><dot><dash>",
        "V": "<dot><dot><dot><dash>",
        "W": "<dot><dash><dash>",
        "X": "<dash><dot><dot><dash>",
        "Y": "<dash><dot><dash><dash>",
        "Z": "<dash><dash><dot><dot>",
        "1": "<dot><dash><dash><dash><dash>",
        "2": "<dot><dot><dash><dash><dash>",
        "3": "<dot><dot><dot><dash><dash>",
        "4": "<dot><dot><dot><dot><dash>",
        "5": "<dot><dot><dot><dot><dot>",
        "6": "<dash><dot><dot><dot><dot>",
        "7": "<dash><dash><dot><dot><dot>",
        "8": "<dash><dash><dash><dot><dot>",
        "9": "<dash><dash><dash><dash><dot>",
        "0": "<dash><dash><dash><dash><dash>",
        ".": "<dot><dash><dot><dash><dot><dash>",
        ",": "<dash><dash><dot><dot><dash><dash>",
        ":": "<dash><dash><dash><dot><dot><dot>",
        ";": "<dash><dot><dash><dot><dash><dot>",
        "!": "<dash><dot><dash><dot><dash><dash>",
        "?": "<dot><dot><dash><dash><dot><dot>",
        "'": "<dot><dash><dash><dash><dash><dot>",
        "\"": "<dot><dash><dot><dot><dash><dot>",
        "/": "<dash><dot><dot><dash><dot>",
        "-": "<dash><dot><dot><dot><dot><dash>",
        "+": "<dot><dash><dot><dash><dot>",
        "(": "<dash><dot><dash><dash><dot>",
        ")": "<dash><dot><dash><dash><dot><dash>",
        "@": "<dot><dash><dash><dot><dash><dot>",
        "=": "<dash><dot><dot><dot><dash>",
        "&": "<dot><dash><dot><dot><dot>",
        "_": "<dot><dot><dash><dash><dot><dash>",
        "$": "<dot><dot><dot><dash><dot><dot><dash>"
    },


    /**
     * To Morse Code operation.
     *
     * @param {number} input
     * @param {Object[]} args
     * @returns {string}
     */
    runTo: function(input, args) {
        var format = args[0].split("/");
        var dash = format[0];
        var dot = format[1];

        var letterDelim = Utils.charRep[args[1]];
        var wordDelim = Utils.charRep[args[2]];

        input = input.split(/\r?\n/);
        input = Array.prototype.map.call(input, function(line) {
            var words = line.split(/ +/);
            words = Array.prototype.map.call(words, function(word) {
                var letters = Array.prototype.map.call(word, function(character) {
                    var letter = character.toUpperCase();
                    if (typeof MorseCode.MORSE_TABLE[letter] == "undefined") {
                        return "";
                    }

                    return MorseCode.MORSE_TABLE[letter];
                });

                return letters.join("<ld>");
            });
            line = words.join("<wd>");
            return line;
        });
        input = input.join("\n");

        input = input.replace(
            /<dash>|<dot>|<ld>|<wd>/g,
            function(match) {
                switch (match) {
                    case "<dash>": return dash;
                    case "<dot>": return dot;
                    case "<ld>": return letterDelim;
                    case "<wd>": return wordDelim;
                }
            }
        );

        return input;
    },


    /**
     * From Morse Code operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runFrom: (function() {
        var reversedTable = null;
        var reverseTable = function() {
            reversedTable = {};

            for (var letter in MorseCode.MORSE_TABLE) {
                var signal = MorseCode.MORSE_TABLE[letter];
                reversedTable[signal] = letter;
            }
        };

        return function(input, args) {
            if (reversedTable === null) {
                reverseTable();
            }

            var letterDelim = Utils.charRep[args[0]];
            var wordDelim = Utils.charRep[args[1]];

            input = input.replace(/-|‐|−|_|–|—|dash/ig, "<dash>"); //hyphen-minus|hyphen|minus-sign|undersore|en-dash|em-dash
            input = input.replace(/\.|·|dot/ig, "<dot>");

            var words = input.split(wordDelim);
            words = Array.prototype.map.call(words, function(word) {
                var signals = word.split(letterDelim);

                var letters = signals.map(function(signal) {
                    return reversedTable[signal];
                });

                return letters.join("");
            });
            words = words.join(" ");

            return words;
        };
    })(),

};