// CryptoVista Dashboard Pro - Enhanced JavaScript

// API Configuration with fallbacks
const COINGECKO_API = 'https://api.coingecko.com/api/v3';
const CRYPTO_NEWS_API = 'https://min-api.cryptocompare.com/data/v2/news/';
const ALTERNATIVE_API = 'https://api.coincap.io/v2/assets?limit=5';

// Global State with enhanced monitoring
let cryptoData = {
    marketData: null,
    topGainers: [],
    news: [],
    userPreferences: {
        currency: 'usd',
        theme: 'dark',
        refreshInterval: 30000,
        notifications: true
    },
    performance: {
        lastUpdate: null,
        apiLatency: {},
        errors: []
    }
};

let selectedCurrency = localStorage.getItem('preferredCurrency') || 'usd';
let theme = localStorage.getItem('theme') || 'dark';
let isInitialized = false;

// Performance monitoring
const perfMonitor = {
    start: (label) => {
        if (window.performance) {
            perfMonitor[label] = performance.now();
        }
    },
    end: (label) => {
        if (window.performance && perfMonitor[label]) {
            const duration = performance.now() - perfMonitor[label];
            console.log(`⏱️ ${label}: ${duration.toFixed(2)}ms`);
            return duration;
        }
        return 0;
    }
};

// Initialize Dashboard with enhanced UX
async function initializeDashboard() {
    if (isInitialized) {
        console.warn('Dashboard already initialized');
        return;
    }
    
    perfMonitor.start('init');
    
    try {
        console.log('🚀 Initializing CryptoVista Dashboard Pro...');
        
        // Set initial theme
        applyTheme(theme);
        
        // Show loading state
        showLoadingState();
        
        // Load critical data first
        await Promise.allSettled([
            loadTopGainers(),
            loadNews(),
            loadMarketData()
        ]);
        
        // Setup enhanced auto-refresh
        setupAutoRefresh();
        
        // Setup enhanced event listeners
        setupEventListeners();
        
        // Initialize UI components
        initializeUIComponents();
        
        // Mark as initialized
        isInitialized = true;
        
        // Hide loading state
        hideLoadingState();
        
        perfMonitor.end('init');
        
        // Show welcome message
        setTimeout(() => {
            showToast('Dashboard loaded successfully!', 'success');
        }, 500);
        
        console.log('✅ Dashboard initialized successfully');
        
    } catch (error) {
        console.error('❌ Dashboard initialization failed:', error);
        showError('global', 'Failed to initialize dashboard. Please refresh.');
        hideLoadingState();
    }
}
// Load Top Gainers from CoinGecko API
async function loadTopGainers() {
    try {
        const response = await fetch(`${COINGECKO_API}/coins/markets?vs_currency=${selectedCurrency}&order=market_cap_desc&per_page=5&sparkline=false&price_change_percentage=24h`);
        const gainers = await response.json();
        
        const container = document.getElementById('topGainers');
        container.innerHTML = '';
        
        gainers.forEach((coin, index) => {
            const isPositive = coin.price_change_percentage_24h > 0;
            const changeClass = isPositive ? 'positive' : 'negative';
            
            const coinElement = `
                <div class="flex items-center justify-between p-4 bg-dark-900 rounded-xl hover:bg-dark-700 transition-colors cursor-pointer" 
                     onclick="window.location.href='/coin/${coin.id}'">
                    <div class="flex items-center gap-3">
                        <div class="w-10 h-10 rounded-full bg-gradient-to-r from-primary-600 to-secondary-600 flex items-center justify-center">
                            <span class="font-bold">${coin.symbol.toUpperCase()}</span>
                        </div>
                        <div>
                            <p class="font-medium">${coin.name}</p>
                            <p class="text-sm text-gray-400">$${coin.current_price.toLocaleString()}</p>
                        </div>
                    </div>
                    <div class="text-right">
                        <span class="price-change ${changeClass}">
                            ${isPositive ? '+' : ''}${coin.price_change_percentage_24h?.toFixed(2) || 0}%
                        </span>
                    </div>
                </div>
            `;
            
            container.innerHTML += coinElement;
        });
        
    } catch (error) {
        console.error('Error loading top gainers:', error);
        showError('topGainers', 'Failed to load top gainers data');
    }
}

// Load Crypto News from CryptoCompare API
async function loadNews() {
    try {
        // Note: In production, you'd use your actual API key
        const response = await fetch(CRYPTO_NEWS_API);
        const data = await response.json();
        const news = data.Data?.slice(0, 3) || [];
        
        const container = document.getElementById('newsFeed');
        container.innerHTML = '';
        
        news.forEach((article, index) => {
            const imageUrl = article.imageurl || `http://static.photos/technology/640x360/${index + 1}`;
            
            const newsElement = `
                <a href="${article.url}" target="_blank" rel="noopener noreferrer" 
                   class="block bg-dark-900 rounded-xl overflow-hidden hover-lift group">
                    <div class="relative overflow-hidden">
                        <img src="${imageUrl}" 
                             alt="${article.title}"
                             class="w-full h-48 object-cover group-hover:scale-105 transition-transform duration-300">
                        <div class="absolute inset-0 bg-gradient-to-t from-dark-900/80 to-transparent"></div>
                    </div>
                    <div class="p-4">
                        <h4 class="font-semibold mb-2 line-clamp-2 group-hover:text-primary-400 transition-colors">
                            ${article.title}
                        </h4>
                        <div class="flex items-center justify-between text-sm text-gray-400">
                            <span>${article.source}</span>
                            <span>${formatTimeAgo(article.published_on)}</span>
                        </div>
                    </div>
                </a>
            `;
            
            container.innerHTML += newsElement;
        });
        
    } catch (error) {
        console.error('Error loading news:', error);
        showError('newsFeed', 'Failed to load news feed');
        
        // Fallback to static news
        const container = document.getElementById('newsFeed');
        container.innerHTML = `
            <div class="col-span-3 text-center py-12">
                <i data-feather="wifi-off" class="w-12 h-12 text-gray-600 mx-auto mb-4"></i>
                <p class="text-gray-400">News feed temporarily unavailable</p>
                <p class="text-sm text-gray-500">Check back soon for updates</p>
            </div>
        `;
        feather.replace();
    }
}

// Load Market Overview Data
async function loadMarketData() {
    try {
        const response = await fetch(`${COINGECKO_API}/global`);
        const data = await response.json();
        cryptoData.marketData = data.data;
        
        // Update market stats
        updateMarketStats(data.data);
        
    } catch (error) {
        console.error('Error loading market data:', error);
    }
}

// Update Market Stats Display
function updateMarketStats(marketData) {
    const elements = {
        totalMarketCap: document.querySelector('[data-market-cap]'),
        totalVolume: document.querySelector('[data-volume]'),
        btcDominance: document.querySelector('[data-btc-dominance]'),
        activeCryptos: document.querySelector('[data-active-cryptos]')
    };
    
    if (marketData && marketData.total_market_cap) {
        Object.keys(elements).forEach(key => {
            if (elements[key] && marketData[key]) {
                const value = marketData[key];
                let formattedValue;
                
                switch(key) {
                    case 'total_market_cap':
                    case 'total_volume':
                        formattedValue = `$${(value.usd / 1e12).toFixed(2)}T`;
                        break;
                    case 'btc_dominance':
                        formattedValue = `${value.toFixed(2)}%`;
                        break;
                    case 'active_cryptocurrencies':
                        formattedValue = value.toLocaleString();
                        break;
                    default:
                        formattedValue = value;
                }
                
                elements[key].textContent = formattedValue;
            }
        });
    }
}

// Setup Auto Refresh
function setupAutoRefresh() {
    // Refresh specific components at different intervals
    setInterval(() => {
        loadTopGainers();
        console.log('🔄 Refreshed top gainers');
    }, 30000); // 30 seconds
    
    setInterval(() => {
        loadMarketData();
        console.log('📊 Refreshed market data');
    }, 60000); // 1 minute
    
    setInterval(() => {
        loadNews();
        console.log('📰 Refreshed news feed');
    }, 120000); // 2 minutes
}

// Setup Event Listeners
function setupEventListeners() {
    // Currency selector
    const currencyButtons = document.querySelectorAll('[data-currency]');
    currencyButtons.forEach(button => {
        button.addEventListener('click', () => {
            selectedCurrency = button.dataset.currency;
            currencyButtons.forEach(btn => btn.classList.remove('active'));
            button.classList.add('active');
            loadTopGainers();
        });
    });
    
    // Theme toggle
    const themeToggle = document.getElementById('themeToggle');
    if (themeToggle) {
        themeToggle.addEventListener('click', toggleTheme);
    }
    
    // Search functionality
    const searchInput = document.getElementById('cryptoSearch');
    if (searchInput) {
        searchInput.addEventListener('input', debounce(handleSearch, 300));
    }
    
    // Time range buttons
    const timeRangeButtons = document.querySelectorAll('[data-time-range]');
    timeRangeButtons.forEach(button => {
        button.addEventListener('click', () => {
            timeRangeButtons.forEach(btn => btn.classList.remove('active'));
            button.classList.add('active');
            // In production, update chart time range here
        });
    });
    
    // Mobile menu toggle
    const mobileMenuButton = document.getElementById('mobileMenuButton');
    const mobileMenu = document.getElementById('mobileMenu');
    if (mobileMenuButton && mobileMenu) {
        mobileMenuButton.addEventListener('click', () => {
            mobileMenu.classList.toggle('hidden');
        });
    }
}

// Handle Search Functionality
async function handleSearch(event) {
    const query = event.target.value.toLowerCase().trim();
    
    if (query.length < 2) {
        hideSearchResults();
        return;
    }
    
    try {
        const response = await fetch(`${COINGECKO_API}/search?query=${query}`);
        const data = await response.json();
        
        displaySearchResults(data.coins || []);
    } catch (error) {
        console.error('Search error:', error);
    }
}

// Display Search Results
function displaySearchResults(coins) {
    const container = document.getElementById('searchResults');
    if (!container) return;
    
    container.innerHTML = coins.slice(0, 5).map(coin => `
        <a href="/coin/${coin.id}" class="flex items-center gap-3 p-3 hover:bg-dark-700 rounded-lg transition-colors">
            <img src="${coin.thumb}" alt="${coin.name}" class="w-8 h-8 rounded-full">
            <div>
                <p class="font-medium">${coin.name}</p>
                <p class="text-sm text-gray-400">${coin.symbol.toUpperCase()}</p>
            </div>
        </a>
    `).join('');
    
    container.classList.remove('hidden');
}

// Hide Search Results
function hideSearchResults() {
    const container = document.getElementById('searchResults');
    if (container) {
        container.classList.add('hidden');
    }
}

// Toggle Theme
function toggleTheme() {
    const html = document.documentElement;
    
    if (theme === 'dark') {
        theme = 'light';
        html.classList.remove('dark');
        html.classList.add('light');
    } else {
        theme = 'dark';
        html.classList.remove('light');
        html.classList.add('dark');
    }
    
    // Save preference
    localStorage.setItem('theme', theme);
    
    // Update UI
    updateThemeUI();
}

// Update Theme UI
function updateThemeUI() {
    const themeToggle = document.getElementById('themeToggle');
    if (!themeToggle) return;
    
    const icon = themeToggle.querySelector('i[data-feather]');
    if (icon) {
        const newIcon = theme === 'dark' ? 'sun' : 'moon';
        icon.setAttribute('data-feather', newIcon);
        feather.replace();
    }
}

// Show Error Message
function showError(elementId, message) {
    const element = document.getElementById(elementId);
    if (element) {
        element.innerHTML = `
            <div class="text-center py-8">
                <i data-feather="alert-circle" class="w-12 h-12 text-red-500 mx-auto mb-4"></i>
                <p class="text-gray-400">${message}</p>
            </div>
        `;
        feather.replace();
    }
}

// Format Time Ago
function formatTimeAgo(timestamp) {
    const seconds = Math.floor((Date.now() - timestamp * 1000) / 1000);
    
    const intervals = [
        { label: 'year', seconds: 31536000 },
        { label: 'month', seconds: 2592000 },
        { label: 'day', seconds: 86400 },
        { label: 'hour', seconds: 3600 },
        { label: 'minute', seconds: 60 },
        { label: 'second', seconds: 1 }
    ];
    
    for (const interval of intervals) {
        const count = Math.floor(seconds / interval.seconds);
        if (count >= 1) {
            return `${count} ${interval.label}${count !== 1 ? 's' : ''} ago`;
        }
    }
    
    return 'just now';
}

// Debounce Function
function debounce(func, wait) {
    let timeout;
    return function executedFunction(...args) {
        const later = () => {
            clearTimeout(timeout);
            func(...args);
        };
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);
    };
}

// Load saved preferences
function loadPreferences() {
    const savedTheme = localStorage.getItem('theme');
    const savedCurrency = localStorage.getItem('currency');
    
    if (savedTheme) {
        theme = savedTheme;
        document.documentElement.classList.add(theme);
    }
    
    if (savedCurrency) {
        selectedCurrency = savedCurrency;
    }
}

// Format Currency
function formatCurrency(amount, currency = 'usd') {
    return new Intl.NumberFormat('en-US', {
        style: 'currency',
        currency: currency.toUpperCase(),
        minimumFractionDigits: 2,
        maximumFractionDigits: 6
    }).format(amount);
}

// Copy to Clipboard
function copyToClipboard(text) {
    navigator.clipboard.writeText(text).then(() => {
        showToast('Copied to clipboard!', 'success');
    }).catch(err => {
        console.error('Copy failed:', err);
        showToast('Copy failed', 'error');
    });
}

// Show Toast Notification
function showToast(message, type = 'info') {
    const toast = document.createElement('div');
    toast.className = `fixed bottom-4 right-4 px-6 py-3 rounded-lg shadow-lg z-50 transition-all duration-300 transform translate-y-0 opacity-100 ${
        type === 'success' ? 'bg-green-900 text-green-100' :
        type === 'error' ? 'bg-red-900 text-red-100' :
        'bg-dark-800 text-gray-100'
    }`;
    toast.textContent = message;
    
    document.body.appendChild(toast);
    
    setTimeout(() => {
        toast.style.transform = 'translateY(100%)';
        toast.style.opacity = '0';
        setTimeout(() => document.body.removeChild(toast), 300);
    }, 3000);
}

// Initialize when DOM is loaded
document.addEventListener('DOMContentLoaded', () => {
    loadPreferences();
    initializeDashboard();
    
    // Handle clicks outside search to close results
    document.addEventListener('click', (event) => {
        if (!event.target.closest('#searchContainer')) {
            hideSearchResults();
        }
    });
});

// Export functions for use in templates
window.cryptoUtils = {
    formatCurrency,
    formatTimeAgo,
    copyToClipboard,
    showToast,
    loadTopGainers,
    loadNews
};

// Simplex noise for chart background (placeholder)
class CryptoChartSimulator {
    constructor(canvasId) {
        this.canvas = document.getElementById(canvasId);
        if (!this.canvas) return;
        
        this.ctx = this.canvas.getContext('2d');
        this.width = this.canvas.width;
        this.height = this.canvas.height;
        
        this.setupChart();
        this.animate();
    }
    
    setupChart() {
        // Chart setup logic would go here
        this.ctx.lineWidth = 2;
        this.ctx.strokeStyle = '#0ea5e9';
    }
    
    animate() {
        // Animation logic for demo chart
        requestAnimationFrame(() => this.animate());
    }
}