random-word.js

function randomWord(chain, length) {
	// get initial prefix
	word = randomOccurance(chain, '');

	for (var i = 0; i < length - 2; i++) {
		lastTwoLetters = word.substr(-2);

		// restart if chain hits dead end
		if (chain[lastTwoLetters] == undefined) {
			return randomWord(chain, length);
		}

		word += randomOccurance(chain, lastTwoLetters);
	}

	return word;
}

/*
 * If an occurrence occurs 5 times after a prefix, and the prefix's total
 * is 43, the occurrence has 5/43 chance of being chosen
 */
function randomOccurance(chain, prefix) {
	var index = -1;
	var tracker = randint(1, chain[prefix]['total']);
	while (tracker >= 1) {
		index += 1;
		var currentOccurance = chain[prefix]['occurances'][index];
		tracker -= chain[prefix][currentOccurance];
	}

	return chain[prefix]['occurances'][index];
}

function randint(min, max) {
	return min + Math.floor((max - min) * Math.random());
}