make event signups only show people who don't have a carpool

src/components/Event/EventCarpools.tsx

@@ -122,11 +122,17 @@ export default function Carpools() {
 	return (
 		<div style={{ display: 'flex', flexDirection: 'column' }}>
 			<h3 style={{ marginBottom: '0' }}>Carpools</h3>
-			{alreadyInCarpool ? (
+			{creationStatus === 'completed' ? (
-				<span>You are already in a carpool for this event</span>
+				<span>
+					Created{' '}
+					<UILink href={`/carpools/${createdCarpoolId}`}>your carpool</UILink>!
+				</span>
+			) : myCarpool ? (
+				<span>
+					You are already in a carpool for this event:{' '}
+					<UILink href={`/carpools/${myCarpool.id}`}>{myCarpool.name}</UILink>
+				</span>
 			) : (
-				<>
-					{creationStatus !== 'completed' ? (
 				<>
 					<span>Available to drive?</span>
 					<UIButton
@@ -140,16 +146,6 @@ export default function Carpools() {
 							: 'Errored'}
 					</UIButton>
 				</>
-					) : (
-						<span>
-							Created{' '}
-							<UILink href={`/carpools/${createdCarpoolId}`}>
-								your carpool
-							</UILink>
-							!
-						</span>
-					)}
-				</>
 			)}
 			{event.carpools.map((carpool) => (
 				<CarpoolRow

src/components/Event/EventSignups.tsx

@@ -3,6 +3,7 @@ import { useMe } from '../hooks';
 import latlongdist, { R_miles } from '../../lib/latlongdist';
 import { IEventSignup, IEvent } from '../types';
 import usePlace from '../usePlace';
+import { useMemo } from 'react';
 
 export default function EventSignups({
 	event,
@@ -13,15 +14,24 @@ export default function EventSignups({
 	signups: IEventSignup[];
 	myPlaceId: string | null;
 }) {
+	const carpools = event.carpools;
 	const placeDetails = usePlace(myPlaceId);
 	const locationLongitude = event.latitude;
 	const locationLatitude = event.longitude;
 	const me = useMe();
 
+	const signupsWithoutCarpool = useMemo(() => {
+		// A list of users not in any carpool
+		const members = carpools.map((c) => c.members);
+		const allMembers = members.reduce((a, b) => a.concat(b), []);
+		const allMembersIds = allMembers.map((m) => m.id);
+		return signups.filter((s) => !allMembersIds.includes(s.user.id));
+	}, [signups, carpools]);
+
 	return (
 		<div style={{ display: 'flex', flexDirection: 'column' }}>
-			<h3 style={{ marginBlockEnd: '0' }}>People</h3>
+			<h3 style={{ marginBlockEnd: '0' }}>People without a carpool</h3>
-			{signups.map(({ latitude, longitude, user }) => {
+			{signupsWithoutCarpool.map(({ latitude, longitude, user }) => {
 				if (user.id === me?.id) {
 					return null;
 				}