cryptoquote.js

#!/usr/bin/env node
'use strict';

var prompt = require('prompt');
var argv   = require('minimist')(process.argv.slice(2), {
	alias: {
		h: 'help',
		v: 'version',
		s: 'string',
	}
});

if(argv.help) {
	console.log('Usage: snatch [options] [tags]\n');
	console.log('Options:');
	console.log('  ');
	console.log('  -s, --string      ');
	console.log('  -h, --help        print this help');
	console.log('  -v, --version     print version number');
	process.exit(0);
}

if(argv.version) {
	console.log('0.1');
	process.exit(0);
}

var globals = {};

globals.main = function(userprompt) {
	prompt.message = '';
	prompt.delimiter = '';
	prompt.override = argv;
	prompt.start();
	prompt.get([{
		name: 'string',
		type: 'string',
		description: 'Enter the encrypted string:',
	}], function(err, userprompt) {
		globals.cryptedstring = userprompt.string.toLowerCase().split('');
		globals.promptreplace();
	});
};

globals.promptreplace = function() {
	globals.freqcount = Cipher.getCharFreq(globals.cryptedstring);
	if(globals.freqcount === false) {
		console.log('done!');
		return true;
	}
	console.log(globals.freqcount);
	prompt.start();
	prompt.get([{
		name: 'replace',
		type: 'string',
		pattern: /[a-zA-Z]=[a-zA-Z]?$/,
		description: 'Try a replacement:',
		message: 'must be x=y format'
	}], function(err, userprompt) {
		var sp = userprompt.replace.split('=');
		Cipher.addMap(sp[0], sp[1]);
		console.log(Cipher.rotate(globals.cryptedstring, Cipher.keymap));
		globals.promptreplace();
	});
};


var Cipher = {
	keymap: {}
};

Cipher.addMap = function(x, y) {
	if(! y) {
		delete Cipher.keymap[x];
	}
	else {
		for(var prop in Cipher.keymap) {
			if(Cipher.keymap.hasOwnProperty(prop) && Cipher.keymap[prop] === y ) {
				delete Cipher.keymap[prop];
				break;
			}
		}
		Cipher.keymap[x] = y;
	}
	console.log(Cipher.keymap);
};

Cipher.rotate = function(str, map) {
	return str.map(function(e) {
		if(map.hasOwnProperty(e)) {
			return map[e.toLowerCase()].toUpperCase();
		}
		else return e;
	})
	.join('');
};

Cipher.getCharFreq = function(input) {
	var freq = {};
	if(typeof input === 'string') {
		input = input.split('');
	}
	if(! Array.isArray(input)) {
		return false;
	}
	input.forEach(function(e) {
		if(e.match(/^\w$/)){
			if(freq[e] === undefined) {
				freq[e] = 0;
			}
			freq[e]++;
		}
	});
	var str = Object.keys(freq).filter(function(e) {
		return Cipher.keymap[e] ? false : true;
	});
	if(str.length === 0) {
		return true;
	}
	return str.sort(function(a, b) {
		return freq[a] > freq[b] ? -1 : freq[a] < freq[b] ? 1 : 0;
	})
	.map(function(k) {
		return String(k).toLowerCase() + ':' + String(freq[k]);
	})
	.join(', ');
};

globals.main();