// ========== PARTICLES ANIMATION ==========
const particlesContainer = document.getElementById('particles');

function createParticle() {
    const particle = document.createElement('div');
    particle.className = 'particle';
    
    
    particle.style.left = Math.random() * 100 + '%';
    particle.style.top = Math.random() * 100 + '%';
    
    
    const size = 3 + Math.random() * 4;
    particle.style.width = size + 'px';
    particle.style.height = size + 'px';
    
    const duration = 3 + Math.random() * 5;
    const delay = Math.random() * 2;
    const moveX = (Math.random() - 0.5) * 200;
    
    const animationName = `float-${Date.now()}-${Math.random()}`;
    const keyframes = `
        @keyframes ${animationName} {
            0% { 
                transform: translateY(0) translateX(0); 
                opacity: 0; 
            }
            10% { 
                opacity: 1; 
            }
            90% { 
                opacity: 1; 
            }
            100% { 
                transform: translateY(-100vh) translateX(${moveX}px); 
                opacity: 0; 
            }
        }
    `;
    
    const style = document.createElement('style');
    style.innerHTML = keyframes;
    document.head.appendChild(style);
    
    particle.style.animation = `${animationName} ${duration}s ${delay}s ease-in-out forwards`;
    
    particlesContainer.appendChild(particle);
    
    setTimeout(() => {
        particle.remove();
        style.remove();
    }, (duration + delay) * 1000);
}

setInterval(createParticle, 300);

for (let i = 0; i < 25; i++) {
    setTimeout(createParticle, i * 100);
}

// ========== LEADERBOARD DATA MANAGEMENT ==========

// Get leaderboard data from localStorage
function getLeaderboardData() {
    const data = localStorage.getItem('leaderboard2048');
    return data ? JSON.parse(data) : [];
}

// Save leaderboard data to localStorage
function saveLeaderboardData(data) {
    localStorage.setItem('leaderboard2048', JSON.stringify(data));
}

// Get current logged-in user
function getCurrentUser() {
    return localStorage.getItem('currentUser') || null;
}

// Add or update score for a player
function addScore(playerName, score) {
    let leaderboard = getLeaderboardData();
    
    // Find if player already exists
    const existingIndex = leaderboard.findIndex(p => p.name === playerName);
    
    if (existingIndex >= 0) {
        // Update only if new score is higher
        if (score > leaderboard[existingIndex].score) {
            leaderboard[existingIndex].score = score;
            leaderboard[existingIndex].level = Math.floor(score / 100);
            leaderboard[existingIndex].date = new Date().toISOString();
        }
    } else {
        // Add new player
        leaderboard.push({
            name: playerName,
            score: score,
            level: Math.floor(score / 100),
            date: new Date().toISOString()
        });
    }
    
    saveLeaderboardData(leaderboard);
}

// ========== RENDER LEADERBOARD ==========
function renderLeaderboard() {
    let leaderboardData = getLeaderboardData();
    const currentUser = getCurrentUser();
    const list = document.getElementById('leaderboardList');
    const emptyState = document.getElementById('emptyState');
    
    // Sort by score (highest first)
    leaderboardData.sort((a, b) => b.score - a.score);
    
    // Update stats
    const totalPlayers = leaderboardData.length;
    const topScore = leaderboardData.length > 0 ? leaderboardData[0].score : 0;
    
    document.getElementById('totalPlayers').textContent = totalPlayers;
    document.getElementById('topScore').textContent = topScore.toLocaleString();
    
    // Find current user's rank
    let userRank = '--';
    if (currentUser) {
        const userIndex = leaderboardData.findIndex(p => p.name === currentUser);
        if (userIndex >= 0) {
            userRank = userIndex + 1;
        }
    }
    document.getElementById('yourRank').textContent = userRank;
    
    // Check if there's data
    if (leaderboardData.length === 0) {
        list.style.display = 'none';
        if (emptyState) emptyState.style.display = 'block';
        return;
    }
    
    list.style.display = 'flex';
    if (emptyState) emptyState.style.display = 'none';
    
    // Render top 10 players
    const top10 = leaderboardData.slice(0, 10);
    
    list.innerHTML = top10.map((player, index) => {
        const rank = index + 1;
        let rankClass = 'rank-other';
        
        if (rank === 1) rankClass = 'rank-1';
        else if (rank === 2) rankClass = 'rank-2';
        else if (rank === 3) rankClass = 'rank-3';
        
        const isCurrentUser = currentUser && player.name === currentUser;
        const yourRankClass = isCurrentUser ? 'your-rank' : '';
        
        return `
            <li class="leaderboard-item ${rankClass} ${yourRankClass}">
                <div class="rank-badge">${rank}</div>
                <div class="player-info">
                    <div class="player-name">${escapeHtml(player.name)}</div>
                    <div class="player-level">Level ${player.level || Math.floor(player.score / 100)}</div>
                </div>
                <div class="player-score">
                    <div class="score-value">${player.score.toLocaleString()}</div>
                    <div class="score-label">Points</div>
                </div>
            </li>
        `;
    }).join('');
}

// Escape HTML to prevent XSS
function escapeHtml(text) {
    const map = {
        '&': '&amp;',
        '<': '&lt;',
        '>': '&gt;',
        '"': '&quot;',
        "'": '&#039;'
    };
    return text.replace(/[&<>"']/g, m => map[m]);
}

// ========== SAMPLE DATA (FOR TESTING) ==========
function initSampleData() {
    const existingData = getLeaderboardData();
    
    // Only add sample data if leaderboard is empty
    if (existingData.length === 0) {
        const sampleData = [
            { name: "CyberKing", score: 9850, level: 98, date: new Date().toISOString() },
            { name: "NeonMaster", score: 8200, level: 82, date: new Date().toISOString() },
            { name: "PixelHunter", score: 6950, level: 69, date: new Date().toISOString() },
            { name: "StarGazer", score: 5420, level: 54, date: new Date().toISOString() },
            { name: "CodeNinja", score: 4890, level: 48, date: new Date().toISOString() },
            { name: "ByteWarrior", score: 4320, level: 43, date: new Date().toISOString() },
            { name: "DataDragon", score: 3850, level: 38, date: new Date().toISOString() },
            { name: "SyntaxSage", score: 3120, level: 31, date: new Date().toISOString() },
            { name: "LogicLord", score: 2780, level: 27, date: new Date().toISOString() },
            { name: "BugSlayer", score: 2340, level: 23, date: new Date().toISOString() }
        ];
        
        saveLeaderboardData(sampleData);
        console.log('Sample data initialized');
    }
}

// ========== CLEAR LEADERBOARD (FOR TESTING) ==========
function clearLeaderboard() {
    if (confirm('Are you sure you want to clear all leaderboard data?')) {
        localStorage.removeItem('leaderboard2048');
        renderLeaderboard();
        console.log('Leaderboard cleared');
    }
}

// ========== REFRESH LEADERBOARD ==========
function refreshLeaderboard() {
    renderLeaderboard();
    console.log('Leaderboard refreshed');
}

// ========== INITIALIZE ON PAGE LOAD ==========
window.addEventListener('DOMContentLoaded', function() {
    
    renderLeaderboard();
    
    console.log('Leaderboard initialized');
    console.log('Available functions:');
    console.log('- addScore(name, score) - Add/update a score');
    console.log('- clearLeaderboard() - Clear all data');
    console.log('- refreshLeaderboard() - Refresh display');
});

// ========== EXPOSE FUNCTIONS TO WINDOW (FOR EXTERNAL USE) ==========
window.leaderboard = {
    addScore: addScore,
    getLeaderboardData: getLeaderboardData,
    clearLeaderboard: clearLeaderboard,
    refreshLeaderboard: refreshLeaderboard,
    initSampleData: initSampleData
};