import { useEffect, useRef } from 'react';
import { getAnalytics } from '../core/AnalyticsManager';

/**
 * Hook that auto-tracks screen views from Expo Router.
 *
 * Uses `usePathname` and `useSegments` from expo-router internally.
 * Drop it anywhere in your root layout:
 *
 * ```tsx
 * // app/_layout.tsx
 * import { useExpoRouterTracking } from 'react-native-analytics-bridge';
 *
 * export default function RootLayout() {
 *   useExpoRouterTracking();
 *   return <Stack />;
 * }
 * ```
 *
 * Note: expo-router is a peer dependency — install it separately.
 */
export function useExpoRouterTracking(options?: {
  /** Extra properties to attach to every screen event */
  extraProperties?: Record<string, any>;
  /**
   * Custom function to derive a human-readable screen name from the pathname.
   * Defaults to using the pathname directly.
   */
  getScreenName?: (pathname: string, segments: string[]) => string;
}) {
  // Dynamic imports so the package doesn't hard-require expo-router
  let usePathname: () => string;
  let useSegments: () => string[];

  try {
    // eslint-disable-next-line @typescript-eslint/no-var-requires
    const expoRouter = require('expo-router');
    usePathname = expoRouter.usePathname;
    useSegments = expoRouter.useSegments;
  } catch {
    console.warn(
      '[AnalyticsBridge] expo-router not found. Install it to use useExpoRouterTracking.'
    );
    return;
  }

  const pathname = usePathname();
  const segments = useSegments();
  const previousPathRef = useRef<string | undefined>(undefined);

  useEffect(() => {
    const screenName = options?.getScreenName
      ? options.getScreenName(pathname, segments)
      : pathname;

    if (screenName !== previousPathRef.current) {
      try {
        getAnalytics().screen(screenName, {
          pathname,
          segments: segments.join('/'),
          previous_screen: previousPathRef.current,
          ...options?.extraProperties,
        });
      } catch {
        // Analytics not yet initialized — skip silently
      }

      previousPathRef.current = screenName;
    }
  }, [pathname]);
}