// Globale state
let config = null;
let currentIndex = 0;
let audioContext = null;

// DOM elementen
const timerBorder = document.querySelector('.timer-border');
const startScreen = document.getElementById('startScreen');
const statementScreen = document.getElementById('statementScreen');
const overlay = document.getElementById('overlay');
const finishScreen = document.getElementById('finishScreen');
const leftStatement = document.getElementById('leftStatement');
const rightStatement = document.getElementById('rightStatement');
const leftText = document.getElementById('leftText');
const rightText = document.getElementById('rightText');
const startButton = document.getElementById('startButton');
const nextButton = document.getElementById('nextButton');
const finishText = document.getElementById('finishText');
const counterDisplay = document.getElementById('counterDisplay');
const fullscreenButton = document.getElementById('fullscreenButton');

// Laad configuratie bij start
async function loadConfig() {
    try {
        const response = await fetch('config.json');
        config = await response.json();
        initializeApp();
    } catch (error) {
        console.error('Fout bij laden config:', error);
        alert('Kan config.json niet laden. Zorg dat alle bestanden in dezelfde map staan.');
    }
}

// Initialiseer app met config
function initializeApp() {
    // Stel CSS variabelen in
    document.documentElement.style.setProperty('--timer-duration', `${config.timer}s`);

    // Pas font grootte toe
    document.querySelectorAll('.statement p').forEach(el => {
        el.style.fontSize = config.fontSize;
    });
    finishText.style.fontSize = config.fontSize;

    // Pas kleuren toe
    leftStatement.style.backgroundColor = config.colors.left;
    rightStatement.style.backgroundColor = config.colors.right;

    // Zet knop tekst
    nextButton.textContent = config.buttonText;
    finishText.textContent = config.finishText;

    // Toon startscherm (niet direct beginnen)
    showStartScreen();
}

// Toon startscherm
function showStartScreen() {
    startScreen.classList.remove('hidden');
    statementScreen.classList.add('hidden');
    overlay.classList.add('hidden');
    finishScreen.classList.add('hidden');
    counterDisplay.classList.add('hidden');
}

// Start het spel
function startGame() {
    startScreen.classList.add('hidden');
    showStatement(0);
}

// Toon stelling op index
function showStatement(index) {
    currentIndex = index;

    // Check of we klaar zijn
    if (index >= config.stellingen.length) {
        showFinish();
        return;
    }

    const stelling = config.stellingen[index];

    // Update teksten
    leftText.textContent = stelling.links;
    rightText.textContent = stelling.rechts;

    // Update counter (1-based index)
    counterDisplay.textContent = `${index + 1}/${config.stellingen.length}`;
    counterDisplay.classList.remove('hidden');

    // Toon stellingen scherm, verberg overlay en finish
    statementScreen.classList.remove('hidden');
    overlay.classList.add('hidden');
    finishScreen.classList.add('hidden');

    // Start timer
    startTimer();
}

// Start timer animatie
function startTimer() {
    // Reset timer
    timerBorder.classList.remove('timer-active');
    void timerBorder.offsetWidth; // Force reflow

    // Start timer
    timerBorder.classList.add('timer-active');

    // Wacht tot timer klaar is
    setTimeout(() => {
        playBeep();
        showOverlay();
    }, config.timer * 1000);
}

// Toon overlay met knop (stellingen blijven zichtbaar)
function showOverlay() {
    overlay.classList.remove('hidden');
    timerBorder.classList.remove('timer-active');
}

// Toon eind scherm
function showFinish() {
    statementScreen.classList.add('hidden');
    overlay.classList.add('hidden');
    finishScreen.classList.remove('hidden');
    counterDisplay.classList.add('hidden');
    timerBorder.classList.remove('timer-active');
}

// Initialiseer audio context (herbruikbaar)
function initAudioContext() {
    if (!audioContext) {
        try {
            audioContext = new (window.AudioContext || window.webkitAudioContext)();
        } catch (error) {
            console.error('Fout bij initialiseren audio context:', error);
        }
    }
}

// Speel beep geluid via Web Audio API
function playBeep() {
    try {
        // Zorg dat audioContext bestaat
        initAudioContext();
        if (!audioContext) return;

        const oscillator = audioContext.createOscillator();
        const gainNode = audioContext.createGain();

        // Configureer oscillator (beep geluid)
        oscillator.type = 'sine';
        oscillator.frequency.setValueAtTime(800, audioContext.currentTime); // 800 Hz

        // Configureer volume (fade out)
        gainNode.gain.setValueAtTime(0.3, audioContext.currentTime);
        gainNode.gain.exponentialRampToValueAtTime(0.01, audioContext.currentTime + 0.3);

        // Verbind nodes
        oscillator.connect(gainNode);
        gainNode.connect(audioContext.destination);

        // Speel beep (300ms)
        oscillator.start(audioContext.currentTime);
        oscillator.stop(audioContext.currentTime + 0.3);
    } catch (error) {
        console.error('Fout bij afspelen geluid:', error);
    }
}

// Toggle fullscreen modus
function toggleFullscreen() {
    if (!document.fullscreenElement) {
        // Ga naar fullscreen
        document.documentElement.requestFullscreen().then(() => {
            fullscreenButton.classList.add('is-fullscreen');
        }).catch((error) => {
            console.error('Fout bij activeren fullscreen:', error);
        });
    } else {
        // Verlaat fullscreen
        document.exitFullscreen().then(() => {
            fullscreenButton.classList.remove('is-fullscreen');
        }).catch((error) => {
            console.error('Fout bij verlaten fullscreen:', error);
        });
    }
}

// Event listeners
startButton.addEventListener('click', () => {
    startGame();
});

nextButton.addEventListener('click', () => {
    if (currentIndex === config.stellingen.length - 1) {
        showFinish();
    } else {
        showStatement(currentIndex + 1);
    }
});

fullscreenButton.addEventListener('click', () => {
    toggleFullscreen();
});

// Luister naar fullscreen veranderingen (bijv. via ESC toets)
document.addEventListener('fullscreenchange', () => {
    if (document.fullscreenElement) {
        fullscreenButton.classList.add('is-fullscreen');
    } else {
        fullscreenButton.classList.remove('is-fullscreen');
    }
});

// Spatiebalk voor volgende stelling EN startscherm
document.addEventListener('keydown', (e) => {
    if (e.code === 'Space') {
        e.preventDefault();
        // Start spel als we op startscherm zijn
        if (!startScreen.classList.contains('hidden')) {
            startGame();
        }
        // Volgende stelling als overlay zichtbaar is
        else if (!overlay.classList.contains('hidden')) {
            if (currentIndex === config.stellingen.length - 1) {
                showFinish();
            } else {
                showStatement(currentIndex + 1);
            }
        }
    }
});

// Start de app
loadConfig();