App.js

import React from 'react';
import { StyleSheet, SafeAreaView, Platform,AsyncStorage } from 'react-native';
import { ScreenOrientation } from 'expo';
import { ApplicationProvider, Layout, Text, BottomNavigation, BottomNavigationTab, IconRegistry, Drawer } from '@ui-kitten/components';
import { mapping, light as lightTheme, dark } from '@eva-design/eva';
import { EvaIconsPack } from '@ui-kitten/eva-icons';
import { NavigationContainer } from '@react-navigation/native';
import { createBottomTabNavigator } from '@react-navigation/bottom-tabs'
import * as Pages from './components/pages';
import { createDrawerNavigator } from '@react-navigation/drawer';
import * as Location from 'expo-location'
import * as BackgroundFetch from 'expo-background-fetch'
import * as Permissions from 'expo-permissions';
import * as TaskManager from 'expo-task-manager';
import Dev from './components/dev';
import * as api from './api';

const CACHED_LOCATION = '@EXPOSURE_APP_CACHED_PLACE_ID'
const TASK_ON_LOC_CHANGE = "@EXPOSURE_APP_TASK_ON_LOC_CHANGE";
const TASK_PERIODIC_UPDATE = "@EXPOSURE_APP_TASK_PERIODIC_UPDATE";

TaskManager.defineTask(TASK_ON_LOC_CHANGE, api.location.updateLocation)

TaskManager.defineTask(TASK_PERIODIC_UPDATE,api.location.updateContactedPeersWithCachedLocation)
//BackgroundFetch.unregisterTaskAsync(TASK_PERIODIC_UPDATE)
//BackgroundFetch.unRegisterTaskAsync(TASK_PERIODIC_UPDATE)
const ForeGroundBackGroundTask=()=>{
  AsyncStorage.getItem(CACHED_LOCATION)
  .then((place_id)=>api.location.updateContactedPeers(place_id)) 
  return setTimeout(_=>ForeGroundBackGroundTask(),600000)
}

ForeGroundBackGroundTask()

const handleBackgroundTasksIOs = async () => {
  console.log('SETTING UP')
  // Location.setApiKey()
await TaskManager.isTaskRegisteredAsync(TASK_ON_LOC_CHANGE).then(isRegistered => !isRegistered &&
    Location.startLocationUpdatesAsync(TASK_ON_LOC_CHANGE, {
      accuracy: Location.Accuracy.High,
      distanceInterval: 100,
      //timeInterval: 60000,
      pausesUpdatesAutomatically: true,
    })
  )
  
  await TaskManager.isTaskRegisteredAsync(TASK_PERIODIC_UPDATE).then((isRegistered)=> {

  //Location.stopLocationUpdatesAsync(TASK_PERIODIC_UPDATE)
  if(!isRegistered){
 // BackgroundFetch.registerTaskAsync(TASK_PERIODIC_UPDATE).then(()=>BackgroundFetch.setMinimumIntervalAsync())
  Location.startLocationUpdatesAsync(TASK_PERIODIC_UPDATE,{ accuracy: Location.Accuracy.High, distanceInterval:1, timeInterval: 600000, deferredUpdatesInterval: 600000 }) }
  }
    
    
    //pausesUpdatesAutomatically: true})
  
  )
  
}



const handleBackgroundTasksAndroid = () => {
  TaskManager.defineTassk(TASK_ON_LOC_CHANGE, api.location. updateLocation)
  TaskManager.defineTask(TASK_PERIODIC_UPDATE, api.location.updateContactedPeersWithCachedLocation)
  
  // Location.setApiKey()
  TaskManager.isTaskRegisteredAsync(TASK_ON_LOC_CHANGE).then(isRegistered => !isRegistered &&
    Location.startLocationUpdatesAsync(TASK_ON_LOC_CHANGE, {
      accuracy: Location.Accuracy.Balanced,
      pausesUpdatesAutomatically: true,
    })
  )
  

    BackgroundFetch.registerTaskAsync(TASK_PERIODIC_UPDATE, {
      minimumInterval: 600,
      stopOnTerminate: false,
     startOnBoot: true,
    })

    BackgroundFetch.setMinimumIntervalAsync(600)
}

const startPushNotificationsListener = () => {

}

// Find the user's OS and un appropriate background tasks callback
Permissions.askAsync(Permissions.LOCATION)
.then(({ status }) => status === 'granted'
  && ( // currently fails silently if not granted
    Platform.OS === 'ios'
    ? handleBackgroundTasksIOs()
    : handleBackgroundTasksAndroid()
  )
)



const BottomTabBar = ({navigation, state}) => {
  const onSelect = (index) => {
    navigation.navigate(state.routeNames[index]);
  };

  return (
    <SafeAreaView style={{backgroundColor: '#222B45'}}>
      <BottomNavigation selectedIndex={state.index} onSelect={onSelect}>
        <BottomNavigationTab title='HOME'/>
        <BottomNavigationTab title='MY SYMPTOMS'/>
        <BottomNavigationTab title='INVITE'/>
        <BottomNavigationTab title='EXPOSURE MAP'/>
      </BottomNavigation>
    </SafeAreaView>
  )

}

function TabScreen() {
  return (
    <Tab.Navigator tabBar={props => <BottomTabBar {...props} />}>
    <Tab.Screen name="Home" component={Pages.Home}/>
    <Tab.Screen name="Report Symptoms" component={Pages.Report}/>
    <Tab.Screen name="Invite" component={Pages.Invite}/>
    <Tab.Screen name="Exposure Map" component={Pages.Map}/>
  </Tab.Navigator>
  );
};


function DrawerScreen() {
  return (
    <DrawerNav.Navigator>
    <DrawerNav.Screen name="Main" component={TabScreen} />
    <DrawerNav.Screen name="About" component={Pages.About} />
    <DrawerNav.Screen name="DEV STUFF" component={Dev}/>
  </DrawerNav.Navigator>
  )
}


export default class App extends React.Component {
  state = { Screen: Pages.Loading}
  
  finishRegistration = () => {
    this.setState({Screen: DrawerScreen})
  }

  constructor(props) {
    super(props);
  }

  componentDidMount() {

    ScreenOrientation.lockAsync(ScreenOrientation.OrientationLock.PORTRAIT_UP);
    api.storage.getMyIdentifier()
    .then(res => {
      console.log(`IDENTIFIER: ${res}`);
      return res;
    })
    .then(res => this.setState({Screen: res ? DrawerScreen : Pages.Register }))
  }
  render() {
    const {Screen} = this.state;

    return (
      <React.Fragment>
      <ApplicationProvider mapping={mapping} theme={dark}>
      <IconRegistry icons={EvaIconsPack}/>
        <NavigationContainer>
          <Screen onSubmit={this.finishRegistration}/>   
        </NavigationContainer>
      </ApplicationProvider>
      </React.Fragment>
    );
  }
}

const Tab = createBottomTabNavigator();
const DrawerNav = createDrawerNavigator();
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
});