const note_sets = {

basic: ["A", "B", "C", "D", "E", "F", "G"],

sharps: ["A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"],

sharps_flats: ["A", "A#", "Bb", "B", "C", "C#", "Db", "D", "D#", "Eb", "E", "F", "F#", "Gb", "G", "G#","Ab"]

};

let current_set = null;

let current_index = null;

let current_notes = null;

function newCurrentSet() {

const selected_set = document.querySelector("#note_set").value;

current_set = selected_set;

// Shuffle notes from current set

current_notes = note_sets[current_set].slice().sort(() => Math.random() - 0.5);

current_index = 0;

}

document.querySelector("#note_set").addEventListener("change", newCurrentSet);

newCurrentSet();

function updateNote() {

const selected_strings = 6; //parseInt(document.querySelector("#string_set").value);

let selected_string = null;

if(selected_strings != 6) {

// Random string between selected string and 6

selected_string = Math.floor(Math.random() * (7 - selected_strings)) + selected_strings;

}

const contentDiv = document.querySelector("#content");

contentDiv.textContent = current_notes[current_index];

if(selected_string) {

contentDiv.innerHTML += "<br>(on " + selected_string + ")";

}

current_index++;

if (current_index >= current_notes.length) {

newCurrentSet();

}

setTimeout(updateNote, (document.querySelector("#duration").value || 5) * 1000);

}

updateNote();