script.js

// Constants
var BASE_VOLUME    =   0.100;
var TEST_VOLUME    =   0.050;
var BASE_LEN_SEC   =      40;
var TEST_GRACE_SEC =       6;
var PERIOD_FACTOR  =     1.3;

// Game States
var STATE_IDLE     = 0;
var STATE_RUNNING  = 1;
var STATE_ENDED    = 2;

// Global state
var rain     = document.getElementById('rain');
var bell     = document.getElementById('bell');
var rain_gain = null;
var timer     = null;
var test_is_ongoing  = false;
var session_start_time = 0;
var period_len_sec   = 0;
var current_state    = STATE_IDLE;

// Global input listener
document.addEventListener('keydown', function(event) {
    if (event.code === 'Space') {
        event.preventDefault();

        if (current_state === STATE_IDLE) {
            start_button_pressed();
        } else if (current_state === STATE_RUNNING) {
            key_was_pressed();
        } else if (current_state === STATE_ENDED) {
            restart_session();
        }
    }
});

function start_button_pressed()
{
    assert(current_state === STATE_IDLE, "start_button_pressed called while not IDLE");

    log_message('Start button was pressed');
    current_state = STATE_RUNNING;

    // Switch containers
    display_feedback('top_container',    false);
    display_feedback('bottom_container',  true);

    session_start();
}

function stop_session_early()
{
    assert(current_state === STATE_RUNNING, "stop_session_early called while not RUNNING");
    
    log_message('Session stopped manually by user');

    if (timer) {
        window.clearTimeout(timer);
        timer = null;
    }

    session_end(null);
}

function restart_session()
{
    assert(current_state === STATE_ENDED, "restart_session called while not ENDED");

    log_message('Restarting session...');
    
    // Hide buttons and messages
    toggle_display('restart_button', false);
    display_feedback('fb_theend', false);
    display_feedback('fb_wander', false);
    display_feedback('fb_eager',  false);
    display_feedback('fb_score',  false);

    current_state = STATE_RUNNING;
    
    session_start();
}

// Helper to show/hide elements without animation (mostly for buttons)
function toggle_display(id, show) {
    var el = document.getElementById(id);
    if (el) el.style.display = show ? 'block' : 'none';
}

function display_feedback(name, onoff)
{
    var elem = document.getElementById(name);

    if (onoff)
    {
        elem.style.animation = 'blurFadeIn 0.9s forwards';
        elem.style.animationDelay = '1s';
    }
    else
    {
        elem.style.animation = 'blurFadeOut 2s forwards';
        elem.style.animationDelay = '0s';
    }
}

function rain_begin_playing()
{
    if (!rain_gain) {
        var context = new AudioContext();
        var source  = context.createBufferSource();
        rain_gain   = context.createGain();
        
        rain_gain.gain.value = BASE_VOLUME;
        
        source.connect(rain_gain);
        rain_gain.connect(context.destination);

        var request = new XMLHttpRequest();
        request.open('GET', rain.innerHTML, true); 
        request.responseType = 'arraybuffer';
        request.onload = function()
        {
            context.decodeAudioData(request.response, function(response)
            {
                source.buffer = response;
                source.start(0);
                source.loop = true;
            }, function () { console.error('The request failed.'); } );
        };
        request.send();
    }
    rain_volume(BASE_VOLUME);
}

function rain_volume(vol, duration)
{
    assert(rain_gain !== null, "rain_volume called before rain_gain initialized");
    var now = rain_gain.context.currentTime;
    rain_gain.gain.cancelScheduledValues(now);
    rain_gain.gain.setValueAtTime(rain_gain.gain.value, now);

    if (duration && duration > 0) {
        rain_gain.gain.linearRampToValueAtTime(vol, now + duration);
    } else {
        rain_gain.gain.setValueAtTime(vol, now);
    }
}

function session_start()
{
    log_message('Meditation session begins...');

    timer  = null;
    session_start_time = Date.now();
    period_len_sec    = BASE_LEN_SEC;

    log_message(rain.currentSrc);
    rain_begin_playing();

    window.setTimeout(function() { bell.play(); }, 1000);

    // Feedback and Buttons
    display_feedback('fb_listen', true);
    
    // Show Stop and Trigger buttons
    toggle_display('stop_button', true);
    toggle_display('trigger_button', true);
    toggle_display('restart_button', false);

    period_begin_now(period_len_sec);
}

function period_begin_now(length_sec)
{
    log_message('Period of length ' + length_sec + ' begins...');

    rain_volume(BASE_VOLUME);
    test_is_ongoing = false;
    period_len_sec  = length_sec;
    
    display_feedback('fb_listen', true);
    
    // Ensure controls are visible
    toggle_display('stop_button', true);
    toggle_display('trigger_button', true);

    timer = window.setTimeout(test_begin_now, length_sec * 1000);
}

function test_begin_now()
{
    log_message('Test period started');
    test_is_ongoing = true;
    rain_volume(TEST_VOLUME, TEST_GRACE_SEC);
    timer = window.setTimeout(test_end_now, TEST_GRACE_SEC * 1000);
}

function test_end_now()
{
    log_message('Test period finished without user pressing any key');
    test_is_ongoing = false;
    session_end('fb_wander');
}

function session_end(feedback)
{
    current_state = STATE_ENDED;

    rain_volume(TEST_VOLUME);
    bell.pause();
    bell.currentTime = 0;
    bell.play();

    // HIDE active game elements
    display_feedback('fb_listen', false);
    toggle_display('stop_button', false);
    toggle_display('trigger_button', false); // Hide the interaction button
    
    // SHOW end game elements
    session_length = Math.ceil((Date.now() - session_start_time) / (60 * 1000));
    document.getElementById('score_value').innerHTML = (session_length == 1)? '1 minute' : session_length + ' minutes';
    
    if (feedback) {
        display_feedback(feedback, true);
    }
    display_feedback('fb_theend', true);
    display_feedback('fb_score', true);
    
    // Show restart button
    toggle_display('restart_button', true);
    display_feedback('restart_button', true);
}

function key_was_pressed()
{
    if (timer) {
        window.clearTimeout(timer);
        timer = null;
    }

    if (test_is_ongoing)
    {
        log_message('User passed the test')
        var goodjob = document.getElementById('fb_goodjob');
        var cloned  = goodjob.cloneNode(true);
        goodjob.parentNode.replaceChild(cloned, goodjob);
        cloned.style.animation = 'blurFadeInThenOut 4s forwards';

        period_len_sec *= PERIOD_FACTOR;
        period_begin_now(period_len_sec);
    }
    else
    {
        log_message('User pressed a key too early')
        session_end('fb_eager');
    }
}

function log_message(msg)
{
    console.log(msg);
}

function assert(condition, message)
{
    if (!condition) {
        throw new Error("Assertion failed: " + message);
    }
}