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

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

// Prevent auto-hiding splash screen
SplashScreen.preventAutoHideAsync();

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

  useEffect(() => {
    if (isLoading) return;

    // Hide splash screen once we know auth state
    SplashScreen.hideAsync();

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

    if (!isAuthenticated && !inAuthGroup) {
      // Redirect to login if not authenticated
      router.replace('/(auth)/login');
    } else if (isAuthenticated && inAuthGroup) {
      // Redirect to main app if authenticated
      router.replace('/(tabs)');
    }
  }, [isAuthenticated, isLoading, segments]);

  if (isLoading) {
    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="patients" />
        <Stack.Screen name="modal" options={{ presentation: 'modal', title: 'Modal' }} />
      </Stack>
      <StatusBar style="auto" />
    </ThemeProvider>
  );
}

export default function RootLayout() {
  return (
    <AuthProvider>
      <RootLayoutNav />
    </AuthProvider>
  );
}