App.tsx

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 *
 * @format
 */

import React, {useState} from 'react';
import type {PropsWithChildren} from 'react';
import {
  SafeAreaView,
  ScrollView,
  StatusBar,
  StyleSheet,
  Text,
  useColorScheme,
  View,
  Alert,
  Button,
} from 'react-native';

import {
  Colors,
  DebugInstructions,
  Header,
  LearnMoreLinks,
  ReloadInstructions,
} from 'react-native/Libraries/NewAppScreen';
import * as Updates from 'expo-updates';

type SectionProps = PropsWithChildren<{
  title: string;
}>;

function Section({children, title}: SectionProps): JSX.Element {
  const isDarkMode = useColorScheme() === 'dark';
  return (
    <View style={styles.sectionContainer}>
      <Text
        style={[
          styles.sectionTitle,
          {
            color: isDarkMode ? Colors.white : Colors.black,
          },
        ]}>
        {title}
      </Text>
      <Text
        style={[
          styles.sectionDescription,
          {
            color: isDarkMode ? Colors.light : Colors.dark,
          },
        ]}>
        {children}
      </Text>
    </View>
  );
}

function App(): JSX.Element {
  const [isUpdateAvailable, setIsUpdateAvailable] = useState(false);

  const isDarkMode = useColorScheme() === 'dark';

  const backgroundStyle = {
    backgroundColor: isDarkMode ? Colors.darker : Colors.lighter,
  };

  async function onCheckIfUpdateAvailableAsync() {
    const update = await Updates.checkForUpdateAsync();
    setIsUpdateAvailable(update.isAvailable);
  }

  async function onFetchUpdateAsync() {
    try {
      const update = await Updates.checkForUpdateAsync();

      if (update.isAvailable) {
        await Updates.fetchUpdateAsync();
        await Updates.reloadAsync();
      }
    } catch (error) {
      Alert.alert(`Error fetching latest Expo update: ${error}`);
    }
  }

  return (
    <SafeAreaView style={backgroundStyle}>
      <StatusBar
        barStyle={isDarkMode ? 'light-content' : 'dark-content'}
        backgroundColor={backgroundStyle.backgroundColor}
      />
      <ScrollView
        contentInsetAdjustmentBehavior="automatic"
        style={backgroundStyle}>
        <Header />
        <View
          style={{
            backgroundColor: isDarkMode ? Colors.black : Colors.white,
          }}>
          <View style={styles.sectionContainer}>
            <Text
              style={[
                styles.sectionTitle,
                {
                  color: isDarkMode ? Colors.white : Colors.black,
                },
              ]}>
              Updates
            </Text>
            <Text
              style={[
                styles.sectionDescription,
                {
                  color: isDarkMode ? Colors.light : Colors.dark,
                },
              ]}>
              Current update ID: {Updates.updateId}
            </Text>
            {isUpdateAvailable && (
              <Text
                style={[
                  styles.sectionDescription,
                  {
                    color: 'green',
                  },
                ]}>
                Update available!
              </Text>
            )}
            <Button
              title="Check if update available"
              onPress={onCheckIfUpdateAvailableAsync}
            />
            <Button title="Fetch update" onPress={onFetchUpdateAsync} />
          </View>
          <Section title="See Your Changes">
            <ReloadInstructions />
          </Section>
          <Section title="Debug">
            <DebugInstructions />
          </Section>
          <Section title="Learn More">
            Read the docs to discover what to do next:
          </Section>
          <LearnMoreLinks />
        </View>
      </ScrollView>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  sectionContainer: {
    marginTop: 32,
    paddingHorizontal: 24,
  },
  sectionTitle: {
    fontSize: 24,
    fontWeight: '600',
  },
  sectionDescription: {
    marginTop: 8,
    fontSize: 18,
    fontWeight: '400',
  },
  highlight: {
    fontWeight: '700',
  },
});

export default App;