let array = [];
let arraySize = 20;
let selectedAlgorithm = 'bubble';
let sorting = false;
let comparisons = 0;
let swaps = 0;
let attempts = 0;

const asciiChars = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'];

// Audio context and sound system
let audioContext;
let isSoundEnabled = true;
let slideWhistleOscillator;
let slideWhistleGain;
let startTime;
let totalSortingTime = 10; // Will be dynamically adjusted

function initAudio() {
    if (!audioContext) {
        audioContext = new (window.AudioContext || window.webkitAudioContext)();
    }
}

function startSlideWhistle() {
    if (!isSoundEnabled || !audioContext) return;
    
    // Create oscillator and gain for slide whistle
    slideWhistleOscillator = audioContext.createOscillator();
    slideWhistleGain = audioContext.createGain();
    
    slideWhistleOscillator.type = 'sine';
    
    // Start at low frequency
    slideWhistleOscillator.frequency.setValueAtTime(200, audioContext.currentTime);
    
    // Estimate sorting time based on array size and algorithm
    totalSortingTime = estimateSortingTime();
    
    // Schedule a smooth frequency ramp over the estimated time
    slideWhistleOscillator.frequency.exponentialRampToValueAtTime(
        800, 
        audioContext.currentTime + totalSortingTime
    );
    
    slideWhistleGain.gain.setValueAtTime(0.15, audioContext.currentTime);
    
    slideWhistleOscillator.connect(slideWhistleGain);
    slideWhistleGain.connect(audioContext.destination);
    
    slideWhistleOscillator.start();
    startTime = audioContext.currentTime;
}

function estimateSortingTime() {
    // Estimate based on array size and algorithm complexity
    const baseTime = array.length * getDelay() / 1000;
    
    switch(selectedAlgorithm) {
        case 'bubble':
        case 'selection':
        case 'insertion':
        case 'cocktail':
            return baseTime * array.length * 0.5;
        case 'quick':
        case 'merge':
        case 'heap':
            return baseTime * Math.log2(array.length) * 2;
        case 'shell':
            return baseTime * array.length * 0.3;
        case 'radix':
            return baseTime * 3;
        case 'gnome':
            return baseTime * array.length * 0.7;
        case 'bogo':
            return baseTime * 10; // Who knows!
        default:
            return baseTime * array.length * 0.5;
    }
}

function updateSlideWhistle(progress) {
    // With exponential ramping, we don't need to update manually
    // The Web Audio API handles the smooth transition
}

function stopSlideWhistle() {
    if (!slideWhistleOscillator) return;
    
    // Cancel any scheduled frequency changes
    slideWhistleOscillator.frequency.cancelScheduledValues(audioContext.currentTime);
    
    // Set current frequency and fade out
    const currentFreq = slideWhistleOscillator.frequency.value;
    slideWhistleOscillator.frequency.setValueAtTime(currentFreq, audioContext.currentTime);
    
    // Smooth fade out
    slideWhistleGain.gain.exponentialRampToValueAtTime(0.001, audioContext.currentTime + 0.2);
    
    setTimeout(() => {
        if (slideWhistleOscillator) {
            slideWhistleOscillator.stop();
            slideWhistleOscillator = null;
            slideWhistleGain = null;
        }
    }, 200);
}

function playZoot() {
    if (!isSoundEnabled || !audioContext) return;
    
    // Create a fun "zoot" sound with multiple components
    const oscillator1 = audioContext.createOscillator();
    const oscillator2 = audioContext.createOscillator();
    const oscillator3 = audioContext.createOscillator();
    const gainNode = audioContext.createGain();
    const filter = audioContext.createBiquadFilter();
    
    // Three oscillators for a richer, more satisfying sound
    oscillator1.type = 'sawtooth';
    oscillator2.type = 'square';
    oscillator3.type = 'triangle';
    
    // Quick frequency sweep for "zoot" effect
    const now = audioContext.currentTime;
    
    // Main sweep
    oscillator1.frequency.setValueAtTime(800, now);
    oscillator1.frequency.exponentialRampToValueAtTime(1600, now + 0.05);
    oscillator1.frequency.exponentialRampToValueAtTime(400, now + 0.15);
    oscillator1.frequency.exponentialRampToValueAtTime(800, now + 0.25);
    
    // Harmonic sweep
    oscillator2.frequency.setValueAtTime(400, now);
    oscillator2.frequency.exponentialRampToValueAtTime(800, now + 0.05);
    oscillator2.frequency.exponentialRampToValueAtTime(200, now + 0.15);
    oscillator2.frequency.exponentialRampToValueAtTime(400, now + 0.25);
    
    // Sub bass sweep
    oscillator3.frequency.setValueAtTime(100, now);
    oscillator3.frequency.exponentialRampToValueAtTime(200, now + 0.1);
    oscillator3.frequency.exponentialRampToValueAtTime(50, now + 0.25);
    
    // Filter sweep for extra "zoot" character
    filter.type = 'bandpass';
    filter.frequency.setValueAtTime(400, now);
    filter.frequency.exponentialRampToValueAtTime(2000, now + 0.1);
    filter.frequency.exponentialRampToValueAtTime(800, now + 0.25);
    filter.Q.value = 5;
    
    // Envelope
    gainNode.gain.setValueAtTime(0, now);
    gainNode.gain.linearRampToValueAtTime(0.4, now + 0.02);
    gainNode.gain.linearRampToValueAtTime(0.3, now + 0.1);
    gainNode.gain.exponentialRampToValueAtTime(0.001, now + 0.4);
    
    // Connect
    oscillator1.connect(filter);
    oscillator2.connect(filter);
    oscillator3.connect(filter);
    filter.connect(gainNode);
    gainNode.connect(audioContext.destination);
    
    // Play
    oscillator1.start();
    oscillator2.start();
    oscillator3.start();
    oscillator1.stop(now + 0.4);
    oscillator2.stop(now + 0.4);
    oscillator3.stop(now + 0.4);
}

// Add a function to calculate sorting progress
function getSortingProgress() {
    let sortedCount = 0;
    const rows = document.querySelectorAll('.bar-row');
    rows.forEach(row => {
        if (row.classList.contains('sorted')) {
            sortedCount++;
        }
    });
    return sortedCount / array.length;
}

// Toggle sound on/off
function toggleSound() {
    isSoundEnabled = !isSoundEnabled;
    const soundBtn = document.getElementById('soundBtn');
    soundBtn.textContent = isSoundEnabled ? 'SOUND: ON' : 'SOUND: OFF';
    
    // If sound is turned off while playing, stop the whistle
    if (!isSoundEnabled && slideWhistleOscillator) {
        stopSlideWhistle();
    }
}

function generateArray() {
    // Use smaller array for Bogo Sort
    if (selectedAlgorithm === 'bogo') {
        arraySize = 5; // Much smaller for Bogo!
        document.getElementById('arraySize').textContent = arraySize;
    } else if (arraySize === 5 && selectedAlgorithm !== 'bogo') {
        arraySize = 20; // Reset to normal size
        document.getElementById('arraySize').textContent = arraySize;
    }
    
    array = [];
    for (let i = 0; i < arraySize; i++) {
        array.push(Math.floor(Math.random() * 90) + 10);
    }
    renderArray();
    resetStats();
}

function getAsciiBar(value, maxValue) {
    const normalized = value / maxValue;
    const maxBarLength = window.innerWidth < 768 ? 20 : 40;
    const barLength = Math.floor(normalized * maxBarLength);
    let bar = '';
    
    for (let i = 0; i < barLength; i++) {
        bar += asciiChars[Math.min(7, Math.floor(i / 5))];
    }
    
    return bar;
}

function renderArray() {
    const container = document.getElementById('visualization');
    const maxValue = Math.max(...array);
    const isMobile = window.innerWidth < 768;
    const borderLength = isMobile ? 30 : 50;
    const padLength = isMobile ? 20 : 40;
    let asciiDisplay = '';
    
    // Top border
    asciiDisplay += '┌' + '─'.repeat(borderLength) + '┐\n';
    
    // Array visualization
    array.forEach((value, index) => {
        const bar = getAsciiBar(value, maxValue);
        const paddedValue = String(value).padStart(3, '0');
        const paddedIndex = String(index).padStart(2, '0');
        if (isMobile) {
            asciiDisplay += `│${paddedIndex}:[${paddedValue}]${bar.padEnd(padLength, ' ')}│\n`;
        } else {
            asciiDisplay += `│ ${paddedIndex}: [${paddedValue}] ${bar.padEnd(padLength, ' ')}│\n`;
        }
    });
    
    // Bottom border
    asciiDisplay += '└' + '─'.repeat(borderLength) + '┘';
    
    container.innerHTML = asciiDisplay.split('\n').map((line, index) => {
        if (index > 0 && index <= array.length) {
            return `<span class="bar-row" data-index="${index-1}">${line}</span>`;
        }
        return `<span>${line}</span>`;
    }).join('\n');
}

function resetStats() {
    comparisons = 0;
    swaps = 0;
    attempts = 0;
    updateStats();
}

function updateStats() {
    document.getElementById('comparisons').textContent = String(comparisons).padStart(4, '0');
    document.getElementById('swaps').textContent = String(swaps).padStart(4, '0');
    document.getElementById('attempts').textContent = String(attempts).padStart(4, '0');
}

function selectAlgorithm(algo) {
    selectedAlgorithm = algo;
    document.querySelectorAll('.algorithm-btn').forEach(btn => {
        btn.classList.remove('active');
    });
    event.target.classList.add('active');
    
    // Show/hide attempts counter for Bogo Sort
    const attemptsContainer = document.getElementById('attemptsContainer');
    if (algo === 'bogo') {
        attemptsContainer.style.display = 'block';
        generateArray(); // Auto-generate smaller array for Bogo
    } else {
        attemptsContainer.style.display = 'none';
        if (arraySize === 5) {
            generateArray(); // Reset to normal size
        }
    }
}

async function startSort() {
    if (sorting) return;
    
    sorting = true;
    document.getElementById('startBtn').disabled = true;
    resetStats();
    
    // Initialize audio on user interaction
    initAudio();
    
    // Start slide whistle
    startSlideWhistle();
    
    switch (selectedAlgorithm) {
        case 'bubble':
            await bubbleSort();
            break;
        case 'selection':
            await selectionSort();
            break;
        case 'insertion':
            await insertionSort();
            break;
        case 'quick':
            await quickSort(0, array.length - 1);
            break;
        case 'merge':
            await mergeSort(0, array.length - 1);
            break;
        case 'heap':
            await heapSort();
            break;
        case 'shell':
            await shellSort();
            break;
        case 'cocktail':
            await cocktailSort();
            break;
        case 'radix':
            await radixSort();
            break;
        case 'gnome':
            await gnomeSort();
            break;
        case 'bogo':
            await bogoSort();
            break;
    }
    
    // Stop slide whistle and play zoot
    stopSlideWhistle();
    playZoot();
    
    markAllSorted();
    sorting = false;
    document.getElementById('startBtn').disabled = false;
}

function getDelay() {
    return 101 - document.getElementById('speedSlider').value;
}

async function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}

async function compare(i, j) {
    comparisons++;
    updateStats();
    const rows = document.querySelectorAll('.bar-row');
    if (rows[i]) rows[i].classList.add('comparing');
    if (rows[j]) rows[j].classList.add('comparing');
    
    // Subtle pitch update during comparisons for continuous glissando
    const progress = getSortingProgress();
    updateSlideWhistle(progress);
    
    await sleep(getDelay());
    if (rows[i]) rows[i].classList.remove('comparing');
    if (rows[j]) rows[j].classList.remove('comparing');
}

async function swap(i, j) {
    swaps++;
    updateStats();
    
    const temp = array[i];
    array[i] = array[j];
    array[j] = temp;
    
    renderArray();
    
    // Update slide whistle pitch based on progress
    const progress = getSortingProgress();
    updateSlideWhistle(progress);
    
    await sleep(getDelay());
}

async function bubbleSort() {
    for (let i = 0; i < array.length - 1; i++) {
        for (let j = 0; j < array.length - i - 1; j++) {
            await compare(j, j + 1);
            if (array[j] > array[j + 1]) {
                await swap(j, j + 1);
            }
        }
        document.querySelectorAll('.bar-row')[array.length - i - 1].classList.add('sorted');
        
        // Update slide whistle pitch
        const progress = getSortingProgress();
        updateSlideWhistle(progress);
    }
    document.querySelectorAll('.bar-row')[0].classList.add('sorted');
}

async function selectionSort() {
    for (let i = 0; i < array.length - 1; i++) {
        let minIdx = i;
        for (let j = i + 1; j < array.length; j++) {
            await compare(minIdx, j);
            if (array[j] < array[minIdx]) {
                minIdx = j;
            }
        }
        if (minIdx !== i) {
            await swap(i, minIdx);
        }
        document.querySelectorAll('.bar-row')[i].classList.add('sorted');
        
        // Update slide whistle pitch
        const progress = getSortingProgress();
        updateSlideWhistle(progress);
    }
    document.querySelectorAll('.bar-row')[array.length - 1].classList.add('sorted');
}

async function insertionSort() {
    for (let i = 1; i < array.length; i++) {
        let j = i - 1;
        let key = array[i];
        
        while (j >= 0 && array[j] > key) {
            await compare(j, j + 1);
            array[j + 1] = array[j];
            renderArray();
            j--;
            await sleep(getDelay());
        }
        
        array[j + 1] = key;
        renderArray();
        document.querySelectorAll('.bar-row')[j + 1].classList.add('sorted');
    }
    markAllSorted();
}

async function quickSort(low, high) {
    if (low < high) {
        let pi = await partition(low, high);
        await quickSort(low, pi - 1);
        await quickSort(pi + 1, high);
    }
}

async function partition(low, high) {
    let pivot = array[high];
    let i = low - 1;
    
    for (let j = low; j < high; j++) {
        await compare(j, high);
        if (array[j] < pivot) {
            i++;
            await swap(i, j);
        }
    }
    
    await swap(i + 1, high);
    return i + 1;
}

async function mergeSort(left, right) {
    if (left < right) {
        let mid = Math.floor((left + right) / 2);
        await mergeSort(left, mid);
        await mergeSort(mid + 1, right);
        await merge(left, mid, right);
    }
}

async function merge(left, mid, right) {
    let leftArr = array.slice(left, mid + 1);
    let rightArr = array.slice(mid + 1, right + 1);
    let i = 0, j = 0, k = left;
    
    while (i < leftArr.length && j < rightArr.length) {
        await compare(left + i, mid + 1 + j);
        if (leftArr[i] <= rightArr[j]) {
            array[k] = leftArr[i];
            i++;
        } else {
            array[k] = rightArr[j];
            j++;
        }
        k++;
        renderArray();
        await sleep(getDelay());
    }
    
    while (i < leftArr.length) {
        array[k] = leftArr[i];
        i++;
        k++;
        renderArray();
        await sleep(getDelay());
    }
    
    while (j < rightArr.length) {
        array[k] = rightArr[j];
        j++;
        k++;
        renderArray();
        await sleep(getDelay());
    }
}

// Heap Sort
async function heapSort() {
    // Build max heap
    for (let i = Math.floor(array.length / 2) - 1; i >= 0; i--) {
        await heapify(array.length, i);
    }
    
    // Extract elements from heap one by one
    for (let i = array.length - 1; i > 0; i--) {
        await swap(0, i);
        document.querySelectorAll('.bar-row')[i].classList.add('sorted');
        await heapify(i, 0);
        
        // Update slide whistle pitch
        const progress = getSortingProgress();
        updateSlideWhistle(progress);
    }
    document.querySelectorAll('.bar-row')[0].classList.add('sorted');
}

async function heapify(n, i) {
    let largest = i;
    let left = 2 * i + 1;
    let right = 2 * i + 2;
    
    if (left < n) {
        await compare(left, largest);
        if (array[left] > array[largest]) {
            largest = left;
        }
    }
    
    if (right < n) {
        await compare(right, largest);
        if (array[right] > array[largest]) {
            largest = right;
        }
    }
    
    if (largest !== i) {
        await swap(i, largest);
        await heapify(n, largest);
    }
}

// Shell Sort
async function shellSort() {
    let gap = Math.floor(array.length / 2);
    
    while (gap > 0) {
        for (let i = gap; i < array.length; i++) {
            let temp = array[i];
            let j = i;
            
            while (j >= gap) {
                await compare(j - gap, j);
                if (array[j - gap] > temp) {
                    array[j] = array[j - gap];
                    j -= gap;
                    renderArray();
                    await sleep(getDelay());
                } else {
                    break;
                }
            }
            
            array[j] = temp;
            renderArray();
            await sleep(getDelay());
        }
        
        gap = Math.floor(gap / 2);
    }
    
    // Mark all as sorted
    for (let i = 0; i < array.length; i++) {
        document.querySelectorAll('.bar-row')[i].classList.add('sorted');
    }
}

// Cocktail Sort (Bidirectional Bubble Sort)
async function cocktailSort() {
    let swapped = true;
    let start = 0;
    let end = array.length - 1;
    
    while (swapped) {
        swapped = false;
        
        // Forward pass (like bubble sort)
        for (let i = start; i < end; i++) {
            await compare(i, i + 1);
            if (array[i] > array[i + 1]) {
                await swap(i, i + 1);
                swapped = true;
            }
        }
        
        if (!swapped) break;
        
        document.querySelectorAll('.bar-row')[end].classList.add('sorted');
        end--;
        swapped = false;
        
        // Backward pass
        for (let i = end; i > start; i--) {
            await compare(i, i - 1);
            if (array[i] < array[i - 1]) {
                await swap(i, i - 1);
                swapped = true;
            }
        }
        
        document.querySelectorAll('.bar-row')[start].classList.add('sorted');
        start++;
    }
    
    // Mark remaining elements as sorted
    for (let i = start; i <= end; i++) {
        document.querySelectorAll('.bar-row')[i].classList.add('sorted');
    }
}

// Radix Sort (LSD - Least Significant Digit)
async function radixSort() {
    // Find the maximum number to know number of digits
    let max = Math.max(...array);
    
    // Do counting sort for every digit
    for (let exp = 1; Math.floor(max / exp) > 0; exp *= 10) {
        await countingSortByDigit(exp);
    }
    
    // Mark all as sorted
    for (let i = 0; i < array.length; i++) {
        document.querySelectorAll('.bar-row')[i].classList.add('sorted');
    }
}

async function countingSortByDigit(exp) {
    let output = new Array(array.length);
    let count = new Array(10).fill(0);
    
    // Store count of occurrences
    for (let i = 0; i < array.length; i++) {
        let digit = Math.floor(array[i] / exp) % 10;
        count[digit]++;
    }
    
    // Change count[i] so it contains actual position
    for (let i = 1; i < 10; i++) {
        count[i] += count[i - 1];
    }
    
    // Build the output array
    for (let i = array.length - 1; i >= 0; i--) {
        let digit = Math.floor(array[i] / exp) % 10;
        output[count[digit] - 1] = array[i];
        count[digit]--;
        
        // Visual comparison for the digit
        if (i < array.length - 1) {
            await compare(i, i + 1);
        }
    }
    
    // Copy the output array to arr[]
    for (let i = 0; i < array.length; i++) {
        array[i] = output[i];
        renderArray();
        await sleep(getDelay());
    }
}

// Gnome Sort (also called Stupid Sort)
async function gnomeSort() {
    let index = 0;
    
    while (index < array.length) {
        if (index == 0) {
            index++;
        } else {
            await compare(index, index - 1);
            if (array[index] >= array[index - 1]) {
                document.querySelectorAll('.bar-row')[index - 1].classList.add('sorted');
                index++;
            } else {
                await swap(index, index - 1);
                index--;
            }
        }
    }
    
    // Mark the last element as sorted
    if (array.length > 0) {
        document.querySelectorAll('.bar-row')[array.length - 1].classList.add('sorted');
    }
}

// Bogo Sort (Warning: This is intentionally terrible!)
async function bogoSort() {
    attempts = 0;
    const maxAttempts = 10000; // Safety limit to prevent infinite loops
    
    while (!isSorted() && attempts < maxAttempts) {
        // Shuffle the array randomly
        await shuffleArray();
        attempts++;
        updateStats();
    }
    
    if (attempts >= maxAttempts) {
        alert("Bogo Sort gave up after " + maxAttempts + " attempts! Try a smaller array.");
    }
    
    // Mark all as sorted
    for (let i = 0; i < array.length; i++) {
        document.querySelectorAll('.bar-row')[i].classList.add('sorted');
    }
}

function isSorted() {
    for (let i = 0; i < array.length - 1; i++) {
        if (array[i] > array[i + 1]) {
            return false;
        }
    }
    return true;
}

async function shuffleArray() {
    // Fisher-Yates shuffle with visualization
    for (let i = array.length - 1; i > 0; i--) {
        let j = Math.floor(Math.random() * (i + 1));
        await compare(i, j);
        await swap(i, j);
    }
}

function markAllSorted() {
    document.querySelectorAll('.bar-row').forEach(row => {
        row.classList.add('sorted');
    });
}

// Initialize
generateArray();
document.querySelector('.algorithm-btn').click();

// Re-render on window resize
let resizeTimeout;
window.addEventListener('resize', () => {
    clearTimeout(resizeTimeout);
    resizeTimeout = setTimeout(() => {
        renderArray();
    }, 250);
});