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

/**
 * Hook that auto-tracks screen views from React Navigation.
 *
 * Attach the returned `onStateChange` and `ref` to your NavigationContainer:
 *
 * ```tsx
 * const { ref, onStateChange } = useReactNavigationTracking();
 *
 * <NavigationContainer ref={ref} onStateChange={onStateChange}>
 *   ...
 * </NavigationContainer>
 * ```
 */
export function useReactNavigationTracking(options?: {
  /** Custom function to extract screen name from navigation state */
  getActiveRouteName?: (state: any) => string | undefined;
  /** Extra properties to attach to every screen event */
  extraProperties?: Record<string, any>;
}) {
  const navigationRef = useRef<any>(null);
  const routeNameRef = useRef<string | undefined>(undefined);

  const getActiveRouteName = options?.getActiveRouteName ?? defaultGetActiveRouteName;

  const onStateChange = (state: any) => {
    const currentRoute = getActiveRouteName(state);
    const previousRoute = routeNameRef.current;

    if (currentRoute && currentRoute !== previousRoute) {
      try {
        getAnalytics().screen(currentRoute, {
          previous_screen: previousRoute,
          ...options?.extraProperties,
        });
      } catch {
        // Analytics not yet initialized — skip silently
      }
    }

    routeNameRef.current = currentRoute;
  };

  useEffect(() => {
    // Track initial screen on mount
    if (navigationRef.current) {
      const state = navigationRef.current.getRootState?.();
      if (state) {
        routeNameRef.current = getActiveRouteName(state);
        if (routeNameRef.current) {
          try {
            getAnalytics().screen(routeNameRef.current, options?.extraProperties);
          } catch {
            // ignore
          }
        }
      }
    }
  }, []);

  return { ref: navigationRef, onStateChange };
}

/**
 * Recursively finds the active route name from a navigation state object.
 */
function defaultGetActiveRouteName(state: any): string | undefined {
  if (!state) return undefined;

  const route = state.routes?.[state.index];
  if (!route) return undefined;

  if (route.state) {
    return defaultGetActiveRouteName(route.state);
  }

  return route.name;
}

/**
 * Standalone helper: get active screen name from navigation state.
 * Useful if you need to read the screen name outside of a hook.
 */
export { defaultGetActiveRouteName as getActiveRouteName };