"use strict";

const vowels = "aeiou".split("");
const consonants = "bcdfghjklmnpqrstvwxyz".split("");

function random_item(arr) {
	return arr[Math.floor(Math.random() * arr.length)];
}

export default function(word) {
	console.log(`***** MUTATE *****`)
	const chars = word.toLowerCase().split("");
	const targetpos = Math.floor(Math.random() * word.length);
	const targetchar = chars[targetpos];
	console.log("TARGET", targetchar, "POS", targetpos);
	let pool = consonants.concat(vowels);
	if(vowels.includes(targetchar))
		pool = vowels;
	if(consonants.includes(targetchar))
		pool = consonants;
	
	pool = [...pool]; // Shallow copy to avoid splice mutating the original array
	console.log("POOL BEFORE", pool);
	if(pool.includes(targetchar)) {
		console.log("REMOVING TARGET");
		pool.splice(pool.indexOf(targetchar), 1);
	}
	console.log("POOL AFTER", pool);
	
	let newchar = random_item(pool);
	chars.splice(targetpos, 1, newchar);
	return chars.join("");
}