// Analytics utilities for Umami with Performance Tracking
declare global {
  interface Window {
    umami?: {
      track: (event: string, data?: Record<string, unknown>) => void;
    };
  }
}

export interface PerformanceMetric {
  name: string;
  value: number;
  url: string;
  timestamp: number;
  userAgent?: string;
}

export interface WebVitalsMetric {
  name: 'CLS' | 'FID' | 'FCP' | 'LCP' | 'TTFB';
  value: number;
  delta: number;
  id: string;
  url: string;
}

// Track custom events to Umami
export const trackEvent = (event: string, data?: Record<string, unknown>) => {
  if (typeof window !== 'undefined' && window.umami) {
    window.umami.track(event, {
      ...data,
      timestamp: Date.now(),
      url: window.location.pathname,
    });
  }
};

// Track performance metrics
export const trackPerformance = (metric: PerformanceMetric) => {
  trackEvent('performance', {
    metric: metric.name,
    value: Math.round(metric.value),
    url: metric.url,
    userAgent: metric.userAgent,
  });
};

// Track Web Vitals
export const trackWebVitals = (metric: WebVitalsMetric) => {
  trackEvent('web-vitals', {
    name: metric.name,
    value: Math.round(metric.value),
    delta: Math.round(metric.delta),
    id: metric.id,
    url: metric.url,
  });
};

// Track page load performance
export const trackPageLoad = () => {
  if (typeof window === 'undefined' || typeof performance === 'undefined') return;

  try {
    const navigationEntries = performance.getEntriesByType('navigation');
    const navigation = navigationEntries[0] as PerformanceNavigationTiming | undefined;
    
    if (navigation && navigation.loadEventEnd && navigation.fetchStart) {
      trackPerformance({
        name: 'page-load',
        value: navigation.loadEventEnd - navigation.fetchStart,
        url: window.location.pathname,
        timestamp: Date.now(),
        userAgent: navigator.userAgent,
      });

      // Track individual timing phases
      trackEvent('page-timing', {
        dns: navigation.domainLookupEnd && navigation.domainLookupStart 
          ? Math.round(navigation.domainLookupEnd - navigation.domainLookupStart) 
          : 0,
        tcp: navigation.connectEnd && navigation.connectStart 
          ? Math.round(navigation.connectEnd - navigation.connectStart) 
          : 0,
        request: navigation.responseStart && navigation.requestStart 
          ? Math.round(navigation.responseStart - navigation.requestStart) 
          : 0,
        response: navigation.responseEnd && navigation.responseStart 
          ? Math.round(navigation.responseEnd - navigation.responseStart) 
          : 0,
        dom: navigation.domContentLoadedEventEnd && navigation.responseEnd 
          ? Math.round(navigation.domContentLoadedEventEnd - navigation.responseEnd) 
          : 0,
        load: navigation.loadEventEnd && navigation.domContentLoadedEventEnd 
          ? Math.round(navigation.loadEventEnd - navigation.domContentLoadedEventEnd) 
          : 0,
        url: window.location.pathname,
      });
    }
  } catch (error) {
    // Silently fail - performance tracking is not critical
    if (process.env.NODE_ENV === 'development') {
      console.warn('Error tracking page load:', error);
    }
  }
};

// Track API response times
export const trackApiCall = (endpoint: string, duration: number, status: number) => {
  if (typeof window === 'undefined') return;
  trackEvent('api-call', {
    endpoint,
    duration: Math.round(duration),
    status,
    url: window.location.pathname,
  });
};

// Track user interactions
export const trackInteraction = (action: string, element?: string) => {
  if (typeof window === 'undefined') return;
  trackEvent('interaction', {
    action,
    element,
    url: window.location.pathname,
  });
};

// Track errors
export const trackError = (error: string, context?: string) => {
  if (typeof window === 'undefined') return;
  trackEvent('error', {
    error,
    context,
    url: window.location.pathname,
  });
};