$/**$

$*$ TM$35223$J TMA$02$ Q$1,$ code

$*$

$*26/10/2023$ Intial version Chris Thomson

$*14/12/2023$ Line $74$ modified to getDate rather than getDay Chris Thomson

$*$

$*$ This is the main application code for the React Native application.

$*$ It is a simple application that allows a user to register a userid

$*$ and then make a taxi request or offer.

$*$

$*$ The application uses the Expo framework to provide access to the

$*$ device GPS and to provide a simple UI$.$

$*$

$*$ The application uses the TaxiService library to access the taxi

$*$ service API.

$*$

$*$ The application uses the NominatimService library to access the

$*$ Nominatim service to lookup the address of the current GPS location.

$*$

$*$ The application uses the TimePicker, AddressPicker and WaitTime

$*$ components to provide a simple UI$.$

$**/$

import $\{$ Text, TextInput, Button, SafeAreaView, View, StyleSheet $\}$ from 'react$-$native';

import $\{$ useState $\}$ from 'react';

import TimePicker from $\text{'}./$components$/$TimePicker$\text{'}$;

import AddressPicker from $\text{'}./$components$/$AddressPicker$\text{'}$;

import WaitTime from $\text{'}./$components$/$WaitTime$\text{'}$;

import $\{$ getLocationAddress $\}$ from $\text{'}./$libraries$/$NominatimService$\text{'}$;

import $*$ as Taxi from $\text{'}./$libraries$/$TaxiService$\text{'}$;

import $*$ as Location from 'expo$-$location';

import StackNav from $\text{'}./$components$/$StackNav$\text{'}$;

$/**$

$*$ Requests user permission to get the GPS location of the device.

$*$ This needs to be called before the GPS is read.

$*$

$*$ @returns true if permission is granted, otherwise throws an error.

$*/$

async function getUserPermission$()$: Promise $\{$

let $\{$ status $\}=$ await Location.requestForegroundPermissionsAsync$()$;

if $($status $!==$ 'granted'$)\{$

throw$(\text{'}$Permission to access location was denied, please check your device settings.$\text{'})$;

$\}$ else $\{$

return true;

$\}$

$\}$

export default function App$()\{$

$//$ State variables to hold the data entered by the user.

const $[$ownerAddress$,$ setOwnerAddress$]=$ useState$("")$;

const $[$customerAddress$,$ setCustomerAddress$]=$ useState$("")$;

const $[$ownerHours$,$ setOwnerHours$]=$ useState$("0")$;

const $[$ownerMinutes$,$ setOwnerMinutes$]=$ useState$("0")$;

const $[$ownerMatches$,$ setOwnerMatches$]=$ useState$("")$;

const $[$customerHours$,$ setCustomerHours$]=$ useState$("0")$;

const $[$customerMinutes$,$ setCustomerMinutes$]=$ useState$("0")$;

const $[$ownerWait$,$ setOwnerWait$]=$ useState$("0")$;

const $[$userid$,$setUserid$]=$ useState$("")$;

const $[$ownerOrderid$,$setOwnerOrderid$]=$ useState$("")$;

const $[$customerMatches$,$ setCustomerMatches$]=$ useState$("")$;

$//$Make sure we can get the GPS location when required.

getUserPermission$()$;

const getOwnerData $=$ async $()=>\{$

$//$ fetch the current location.

const location $=$ await Location.getCurrentPositionAsync$(\{\})$;

setOwnerAddress$("$location found"$)$;

$\}$

const transportOwnerMake $=$ async $()=>\{$

const now $=$ new Date$()$;

$//$ Create a start and end time for the order.

const start $=$ new Date$($now$.$getFullYear$(),$ now.getMonth$(),$ now.getDate$(),$ parseInt$($ownerHours$),$ parseInt$($ownerMinutes$))$;

const end $=$ new Date$($start$.$getTime$()+$ parseInt$($ownerWait$)*60000)$;

const order $=$ await Taxi.postOrders$($userid$,$ start.toISOString$(),$ end.toISOString$(),"0",$ ownerAddress$)$;

setOwnerOrderid$($order$.$id$)$;

$\}$

const transportOwnerCancel $=()=>\{$

if $($ownerOrderid $!="")$

Taxi.deleteOrders$($userid$,$ ownerOrderid$)$;

setOwnerOrderid$("")$;

$\}$

const transportOwnerMatches $=$ async $()=>\{$

const matches $=$ await Taxi.getMatches$($userid$)$;

setOwnerMatches$($JSON$.$stringify$($matches$))$;

$\}$

$$

$//$ The UI for the application.

return $($

Owner Offer

Matches: $\{$ownerMatches$\}$

Customer Request

Matches: $\{$customerMatche