import React, { useEffect, useState } from 'react';
import { StatusBar } from 'expo-status-bar';
import { NavigationContainer } from '@react-navigation/native';
import { createNativeStackNavigator } from '@react-navigation/native-stack';
import { createBottomTabNavigator } from '@react-navigation/bottom-tabs';
import { ActivityIndicator, View, Text, TouchableOpacity } from 'react-native';
import { registerRootComponent } from 'expo';
import * as WebBrowser from 'expo-web-browser';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { ThemeProvider, useTheme } from './src/services/ThemeContext';
import DatabaseService from './src/services/DatabaseService';
import { getStoredUserId } from './src/services/AuthSession';
import LoginScreen from './src/screens/LoginScreen';
import RegisterScreen from './src/screens/RegisterScreen';
import OnboardingScreen from './src/screens/OnboardingScreen';
import HomeScreen from './src/screens/HomeScreen';
import SearchScreen from './src/screens/SearchScreen';
import CollectionsScreen from './src/screens/AlbumsScreen';
import SettingsScreen from './src/screens/SettingsScreen';
import FolderIcon from './assets/icons/folder.svg';
import LibraryGridIcon from './assets/icons/library-grid.svg';
import SearchIcon from './assets/icons/search.svg';
WebBrowser.maybeCompleteAuthSession();

const Stack = createNativeStackNavigator();
const Tab = createBottomTabNavigator();
function MainTabs({ route }) {
  const { userId } = route.params || {};
  const { theme } = useTheme();
  const insets = useSafeAreaInsets();
  const bottomInset = Math.max(insets.bottom, 8);

  return (
    <Tab.Navigator
      screenOptions={{
        headerShown: false,
        tabBarActiveTintColor: theme.tabActive,
        tabBarInactiveTintColor: theme.tabInactive,
        tabBarStyle: {
          backgroundColor: theme.tabBar,
          borderTopColor: theme.tabBarBorder,
          borderTopWidth: 1,
          height: 56 + bottomInset,
          paddingBottom: bottomInset,
          paddingTop: 6,
        },
        tabBarLabelStyle: { fontSize: 11, fontWeight: '500' },
      }}
    >
      <Tab.Screen
        name="Library"
        component={HomeScreen}
        initialParams={{ userId }}
        options={{
          tabBarLabel: 'Library',
          tabBarIcon: ({ color }) => <LibraryGridIcon width={20} height={20} color={color} />,
        }}
      />
      <Tab.Screen
        name="Search"
        component={SearchScreen}
        initialParams={{ userId }}
        options={{
          tabBarLabel: 'Search',
          tabBarIcon: ({ color }) => <SearchIcon width={20} height={20} color={color} />,
        }}
      />
      <Tab.Screen
        name="Collections"
        component={CollectionsScreen}
        initialParams={{ userId }}
        options={{
          tabBarLabel: 'Collections',
          tabBarIcon: ({ color }) => <FolderIcon width={20} height={20} color={color} />,
        }}
      />
    </Tab.Navigator>
  );
}
// App navigation is initialized inside AppInner.

function AppInner() {
  const { theme } = useTheme();
  const [isReady, setIsReady] = useState(false);
  const [error, setError] = useState(null);
  const [bootUserId, setBootUserId] = useState(null);
  const [bootChecked, setBootChecked] = useState(false);

  useEffect(() => { initializeApp(); }, []);

  const initializeApp = async () => {
    try {
      setError(null);
      await DatabaseService.initDatabase();
      const stored = await getStoredUserId();
      setBootUserId(stored);
      setBootChecked(true);
      setIsReady(true);
    } catch (err) {
      console.error('Database initialization failed:', err);
      setError(err.message || 'Database initialization failed');
      setIsReady(false);
    }
  };

  if ((!isReady || !bootChecked) && !error) {
    return (
      <View style={{ flex: 1, justifyContent: 'center', alignItems: 'center', backgroundColor: theme.background }}>
        <ActivityIndicator size="large" color={theme.primary} />
      </View>
    );
  }

  if (error) {
    return (
      <View style={{ flex: 1, justifyContent: 'center', alignItems: 'center', paddingHorizontal: 20, backgroundColor: theme.background }}>
        <Text style={{ fontSize: 16, color: theme.text, marginBottom: 12, textAlign: 'center' }}>{error}</Text>
        <TouchableOpacity
          onPress={initializeApp}
          style={{ backgroundColor: theme.primary, paddingHorizontal: 16, paddingVertical: 10, borderRadius: 6 }}
        >
          <Text style={{ color: '#fff', fontWeight: '600' }}>Retry</Text>
        </TouchableOpacity>
      </View>
    );
  }

  return (
    <>
      <NavigationContainer>
        <Stack.Navigator
          screenOptions={{ headerShown: false }}
          initialRouteName={bootUserId ? 'MainTabs' : 'Login'}
        >
          <Stack.Screen name="Login" component={LoginScreen} />
          <Stack.Screen name="Register" component={RegisterScreen} />
          <Stack.Screen name="Onboarding" component={OnboardingScreen} />
          <Stack.Screen
            name="MainTabs"
            component={MainTabs}
            initialParams={bootUserId ? { userId: bootUserId } : undefined}
          />
          <Stack.Screen name="Settings" component={SettingsScreen} />
        </Stack.Navigator>
      </NavigationContainer>
      <StatusBar style={theme.statusBarStyle} backgroundColor={theme.background} />
    </>
  );
}

function App() {
  return (
    <ThemeProvider>
      <AppInner />
    </ThemeProvider>
  );
}

registerRootComponent(App);

export default App;