From ce06c277c5c5eedc69751a0909163225a73fe18e Mon Sep 17 00:00:00 2001
From: Kerry Archibald <kerrya@element.io>
Date: Mon, 21 Mar 2022 13:11:07 +0100
Subject: [PATCH] sort beacons util

Signed-off-by: Kerry Archibald <kerrya@element.io>
---
 src/utils/beacon/duration.ts       | 11 ++++++
 test/test-utils/beacon.ts          |  4 +-
 test/utils/beacon/duration-test.ts | 60 ++++++++++++++++++++++++------
 3 files changed, 62 insertions(+), 13 deletions(-)

diff --git a/src/utils/beacon/duration.ts b/src/utils/beacon/duration.ts
index 6be934b909a1..b85e2ff85f68 100644
--- a/src/utils/beacon/duration.ts
+++ b/src/utils/beacon/duration.ts
@@ -1,3 +1,5 @@
+import { Beacon } from "matrix-js-sdk/src/matrix";
+
 /**
  * Get ms until expiry
  * Returns 0 when expiry is already passed
@@ -7,3 +9,12 @@
  */
 export const msUntilExpiry = (startTimestamp: number, durationMs: number): number =>
     Math.max(0, (startTimestamp + durationMs) - Date.now());
+
+export const getBeaconMsUntilExpiry = (beacon: Beacon): number =>
+    msUntilExpiry(beacon.beaconInfo.timestamp, beacon.beaconInfo.timeout);
+
+export const getBeaconExpiryTimestamp = (beacon: Beacon): number =>
+    beacon.beaconInfo.timestamp + beacon.beaconInfo.timeout;
+
+export const sortBeaconsByLatestExpiry = (left: Beacon, right: Beacon): number =>
+    getBeaconExpiryTimestamp(right) - getBeaconExpiryTimestamp(left);
diff --git a/test/test-utils/beacon.ts b/test/test-utils/beacon.ts
index dffdfaf2510f..fbce6459b1d4 100644
--- a/test/test-utils/beacon.ts
+++ b/test/test-utils/beacon.ts
@@ -24,6 +24,7 @@ type InfoContentProps = {
     isLive?: boolean;
     assetType?: LocationAssetType;
     description?: string;
+    timestamp?: number;
 };
 const DEFAULT_INFO_CONTENT_PROPS: InfoContentProps = {
     timeout: 3600000,
@@ -45,6 +46,7 @@ export const makeBeaconInfoEvent = (
 ): MatrixEvent => {
     const {
         timeout, isLive, description, assetType,
+        timestamp,
     } = {
         ...DEFAULT_INFO_CONTENT_PROPS,
         ...contentProps,
@@ -53,7 +55,7 @@ export const makeBeaconInfoEvent = (
         type: `${M_BEACON_INFO.name}.${sender}.${eventTypeSuffix || ++count}`,
         room_id: roomId,
         state_key: sender,
-        content: makeBeaconInfoContent(timeout, isLive, description, assetType),
+        content: makeBeaconInfoContent(timeout, isLive, description, assetType, timestamp),
     });
 
     // live beacons use the beacon_info event id
diff --git a/test/utils/beacon/duration-test.ts b/test/utils/beacon/duration-test.ts
index 82247890dfd8..f5398e2bf8af 100644
--- a/test/utils/beacon/duration-test.ts
+++ b/test/utils/beacon/duration-test.ts
@@ -1,6 +1,9 @@
-import { msUntilExpiry } from "../../../src/utils/beacon";
+import { Beacon } from "matrix-js-sdk/src/matrix";
 
-describe('msUntilExpiry', () => {
+import { msUntilExpiry, sortBeaconsByLatestExpiry } from "../../../src/utils/beacon";
+import { makeBeaconInfoEvent } from "../../test-utils";
+
+describe('beacon utils', () => {
     // 14.03.2022 16:15
     const now = 1647270879403;
     const HOUR_MS = 3600000;
@@ -13,19 +16,52 @@ describe('msUntilExpiry', () => {
         jest.spyOn(global.Date, 'now').mockRestore();
     });
 
-    it('returns remaining duration', () => {
-        const start = now - HOUR_MS;
-        const durationMs = HOUR_MS * 3;
+    describe('msUntilExpiry', () => {
+        it('returns remaining duration', () => {
+            const start = now - HOUR_MS;
+            const durationMs = HOUR_MS * 3;
+
+            expect(msUntilExpiry(start, durationMs)).toEqual(HOUR_MS * 2);
+        });
+
+        it('returns 0 when expiry has already passed', () => {
+            // created 3h ago
+            const start = now - HOUR_MS * 3;
+            // 1h durations
+            const durationMs = HOUR_MS;
 
-        expect(msUntilExpiry(start, durationMs)).toEqual(HOUR_MS * 2);
+            expect(msUntilExpiry(start, durationMs)).toEqual(0);
+        });
     });
 
-    it('returns 0 when expiry has already passed', () => {
-        // created 3h ago
-        const start = now - HOUR_MS * 3;
-        // 1h durations
-        const durationMs = HOUR_MS;
+    describe('sortBeaconsByLatestExpiry()', () => {
+        const roomId = '!room:server';
+        const aliceId = '@alive:server';
+
+        // 12h old, 12h left
+        const beacon1 = new Beacon(makeBeaconInfoEvent(aliceId,
+            roomId,
+            { timeout: HOUR_MS * 24, timestamp: now - 12 * HOUR_MS },
+            '$1',
+        ));
+        // 10h left
+        const beacon2 = new Beacon(makeBeaconInfoEvent(aliceId,
+            roomId,
+            { timeout: HOUR_MS * 10, timestamp: now },
+            '$2',
+        ));
+
+        // 1ms left
+        const beacon3 = new Beacon(makeBeaconInfoEvent(aliceId,
+            roomId,
+            { timeout: HOUR_MS + 1, timestamp: now - HOUR_MS },
+            '$3',
+        ));
 
-        expect(msUntilExpiry(start, durationMs)).toEqual(0);
+        it('sorts beacons by descending expiry time', () => {
+            expect([beacon2, beacon3, beacon1].sort(sortBeaconsByLatestExpiry)).toEqual([
+                beacon1, beacon2, beacon3,
+            ]);
+        });
     });
 });