import { DarkTheme, DefaultTheme, ThemeProvider } from '@react-navigation/native';
import { Stack, router, useRootNavigationState, useSegments } from 'expo-router';
import * as SplashScreen from 'expo-splash-screen';
import { StatusBar } from 'expo-status-bar';
import { useEffect, useRef } from 'react';
import 'react-native-reanimated';
import { StripeProvider } from '@stripe/stripe-react-native';

import { LoadingSpinner } from '@/components/ui/LoadingSpinner';
import { AuthProvider, useAuth } from '@/contexts/AuthContext';
import { BeneficiaryProvider } from '@/contexts/BeneficiaryContext';
import { useColorScheme } from '@/hooks/use-color-scheme';

// Stripe publishable key (test mode) - must match backend STRIPE_PUBLISHABLE_KEY
const STRIPE_PUBLISHABLE_KEY = 'pk_test_51P3kdqP0gvUw6M9C7ixPQHqbPcvga4G5kAYx1h6QXQAt1psbrC2rrmOojW0fTeQzaxD1Q9RKS3zZ23MCvjjZpWLi00eCFWRHMk';

SplashScreen.preventAutoHideAsync();

function RootLayoutNav() {
  const colorScheme = useColorScheme();
  const { isAuthenticated, isInitializing } = useAuth();
  const segments = useSegments();
  const navigationState = useRootNavigationState();

  // Track if initial redirect was done
  const hasInitialRedirect = useRef(false);

  useEffect(() => {
    // Wait for navigation to be ready
    if (!navigationState?.key) {
      console.log('[Layout] Navigation not ready yet');
      return;
    }

    // Wait for INITIAL auth check to complete
    if (isInitializing) {
      console.log('[Layout] Still initializing auth state...');
      return;
    }

    // Hide splash screen safely
    SplashScreen.hideAsync().catch(() => { });

    const inAuthGroup = segments[0] === '(auth)';

    console.log('[Layout] Auth check:', { isAuthenticated, inAuthGroup, hasInitialRedirect: hasInitialRedirect.current });

    // INITIAL REDIRECT (only once after app starts):
    // - If not authenticated and not in auth → go to login
    if (!hasInitialRedirect.current) {
      hasInitialRedirect.current = true;

      if (!isAuthenticated && !inAuthGroup) {
        console.log('[Layout] Initial redirect → login');
        router.replace('/(auth)/login');
        return;
      }
    }

    // SUBSEQUENT REDIRECTS (only when isAuthenticated changes):
    // - If authenticated → go to tabs (user just logged in)
    if (isAuthenticated && inAuthGroup) {
      console.log('[Layout] User authenticated → tabs');
      router.replace('/(tabs)');
    }
    // If not authenticated, do NOTHING - let the auth screens handle their own navigation

  }, [isAuthenticated, isInitializing, navigationState?.key]);
  // IMPORTANT: isLoading NOT in deps - we don't want to react to loading state changes
  // segments also not in deps - we don't want to react to navigation changes

  if (isInitializing) {
    return <LoadingSpinner fullScreen message="Loading..." />;
  }

  return (
    <ThemeProvider value={colorScheme === 'dark' ? DarkTheme : DefaultTheme}>
      <Stack screenOptions={{ headerShown: false }}>
        <Stack.Screen name="(auth)" />
        <Stack.Screen name="(tabs)" />
        <Stack.Screen name="modal" options={{ presentation: 'modal', title: 'Modal' }} />
      </Stack>
      <StatusBar style="auto" />
    </ThemeProvider>
  );
}

export default function RootLayout() {
  return (
    <StripeProvider
      publishableKey={STRIPE_PUBLISHABLE_KEY}
      merchantIdentifier="merchant.com.wellnuo.app"
    >
      <AuthProvider>
        <BeneficiaryProvider>
          <RootLayoutNav />
        </BeneficiaryProvider>
      </AuthProvider>
    </StripeProvider>
  );
}