/**
 * Prefetching Configuration Examples
 * 
 * Use these configurations with startRouter() or directly with LinkPrefetcher
 */

// Default configuration - balanced performance
export const defaultConfig = {
    strategies: ['hover', 'visible'],  // Prefetch on hover and when visible
    hoverDelay: 150,                  // Wait 150ms before prefetching on hover
    observerMargin: '50px',           // Start prefetching when link is 50px from viewport
    maxCacheSize: 20,                 // Cache up to 20 pages
    cacheTTL: 60000,                  // Cache for 60 seconds
    priority: 'low'                   // Use low priority for network requests
};

// Aggressive prefetching - for fast networks
export const aggressiveConfig = {
    strategies: ['hover', 'visible', 'eager'],
    hoverDelay: 50,                   // Faster hover response
    observerMargin: '200px',          // Prefetch earlier
    maxCacheSize: 50,                 // Larger cache
    cacheTTL: 300000,                 // Cache for 5 minutes
    priority: 'high'                  // High priority requests
};

// Conservative prefetching - for slow networks or mobile
export const conservativeConfig = {
    strategies: ['hover'],            // Only prefetch on hover
    hoverDelay: 300,                 // Wait longer before prefetching
    observerMargin: '0px',           // Don't use intersection observer
    maxCacheSize: 10,                // Smaller cache
    cacheTTL: 30000,                 // Cache for 30 seconds
    priority: 'low'                  // Low priority
};

// Minimal prefetching - disabled by default
export const minimalConfig = {
    strategies: [],                   // No automatic prefetching
    maxCacheSize: 5,                 // Minimal cache
    cacheTTL: 15000,                 // Short cache duration
};

// Adaptive configuration based on connection
export function getAdaptiveConfig() {
    // Use Network Information API if available
    const connection = navigator.connection || navigator.mozConnection || navigator.webkitConnection;
    
    if (!connection) {
        return defaultConfig;
    }
    
    // Check effective connection type
    if (connection.effectiveType === '4g' && !connection.saveData) {
        return aggressiveConfig;
    } else if (connection.effectiveType === '3g' || connection.saveData) {
        return conservativeConfig;
    } else if (connection.effectiveType === '2g' || connection.effectiveType === 'slow-2g') {
        return minimalConfig;
    }
    
    return defaultConfig;
}

// Custom configuration for specific pages
export function getPageSpecificConfig(pathname) {
    // Disable prefetching on certain pages
    if (pathname.includes('/admin') || pathname.includes('/checkout')) {
        return minimalConfig;
    }
    
    // Aggressive prefetching on landing pages
    if (pathname === '/' || pathname === '/products') {
        return aggressiveConfig;
    }
    
    return defaultConfig;
}