From 0069cae9b2b55cc406d80fedbec34783865fe14a Mon Sep 17 00:00:00 2001
From: corentin <corentin.girard@datadoghq.com>
Date: Tue, 8 Aug 2023 00:22:08 +0200
Subject: [PATCH] Fix bug with `get.nextMatches()` for winner of WB final

---
 src/find.ts       | 78 ++++++++++++++++++++++++++++++++++++++++-------
 src/helpers.ts    | 11 +++++++
 test/find.spec.js |  9 ++++++
 3 files changed, 87 insertions(+), 11 deletions(-)

diff --git a/src/find.ts b/src/find.ts
index 66bfcf5..f9367d0 100644
--- a/src/find.ts
+++ b/src/find.ts
@@ -105,27 +105,42 @@ export class Find extends BaseGetter {
         );
 
         if (participantId !== undefined) {
+            if (!helpers.isParticipantInMatch(match, participantId))
+                throw Error('The participant does not belong to this match.');
+
+            if (!helpers.isMatchStale(match))
+                throw Error('The match is not stale yet, so it is not possible to conclude the next matches for this participant.');
+
             const loser = helpers.getLoser(match);
             if (stage.type === 'single_elimination' && loser?.id === participantId)
                 return []; // Eliminated.
 
             if (stage.type === 'double_elimination') {
-                const [upperBracketMatch, lowerBracketMatch] = nextMatches;
+                const { winnerBracketMatch, loserBracketMatch, finalGroupMatch } = await this.getMatchesByGroupDoubleElimination(nextMatches, new Map([[group.id, group]]));
+                const winner = helpers.getWinner(match);
 
-                if (loser?.id === participantId) {
-                    if (lowerBracketMatch)
-                        return [lowerBracketMatch];
-                    else
+                if (matchLocation === 'loser_bracket') {
+                    if (participantId === loser?.id)
                         return []; // Eliminated from lower bracket.
-                }
 
-                const winner = helpers.getWinner(match);
-                if (winner?.id === participantId)
-                    return [upperBracketMatch];
+                    if (participantId === winner?.id)
+                        return loserBracketMatch ? [loserBracketMatch] : [];
+                } else if (matchLocation === 'winner_bracket') {
+                    if (!loserBracketMatch)
+                        throw Error('All matches of winner bracket should lead to loser bracket.');
 
-                throw Error('The participant does not belong to this match.');
-            }
+                    if (participantId === loser?.id)
+                        return [loserBracketMatch]; // Eliminated from upper bracket, going to lower bracket.
+
+                    if (participantId === winner?.id)
+                        return winnerBracketMatch ? [winnerBracketMatch] : [];
+                } else if (matchLocation === 'final_group') {
+                    if (!finalGroupMatch)
+                        throw Error('All matches of a final group should also lead to the final group.');
 
+                    return [finalGroupMatch];
+                }
+            }
         }
 
         return nextMatches;
@@ -152,4 +167,45 @@ export class Find extends BaseGetter {
     public async matchGame(game: Partial<MatchGame>): Promise<MatchGame> {
         return this.findMatchGame(game);
     }
+
+    /**
+     * Returns an object with 1 match per group type. Only supports double elimination.
+     *
+     * @param matches A list of matches.
+     * @param fetchedGroups A map of groups which were already fetched.
+     */
+    private async getMatchesByGroupDoubleElimination(matches: Match[], fetchedGroups: Map<Id, Group>): Promise<{
+        winnerBracketMatch?: Match;
+        loserBracketMatch?: Match;
+        finalGroupMatch?: Match;
+    }> {
+        const getGroup = async (groupId: Id): Promise<Group> => {
+            const existing = fetchedGroups.get(groupId);
+            if (existing)
+                return existing;
+
+            const group = await this.storage.select('group', groupId);
+            if (!group) throw Error('Group not found.');
+            fetchedGroups.set(groupId, group);
+            return group;
+        };
+
+        let matchByGroupType: {
+            winnerBracketMatch?: Match
+            loserBracketMatch?: Match
+            finalGroupMatch?: Match
+        } = {};
+
+        for (const match of matches) {
+            const group = await getGroup(match.group_id);
+
+            matchByGroupType = {
+                winnerBracketMatch: matchByGroupType['winnerBracketMatch'] ?? (helpers.isWinnerBracket('double_elimination', group.number) ? match : undefined),
+                loserBracketMatch: matchByGroupType['loserBracketMatch'] ?? (helpers.isLoserBracket('double_elimination', group.number) ? match : undefined),
+                finalGroupMatch: matchByGroupType['finalGroupMatch'] ?? (helpers.isFinalGroup('double_elimination', group.number) ? match : undefined),
+            };
+        }
+
+        return matchByGroupType;
+    }
 }
diff --git a/src/helpers.ts b/src/helpers.ts
index 2d14e69..c4feac5 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -621,6 +621,17 @@ export function isMatchOngoing(match: MatchResults): boolean {
     return [Status.Ready, Status.Running].includes(match.status);
 }
 
+/**
+ * Checks if a match is stale (i.e. it should not change anymore).
+ * 
+ * [Locked - BYE] > Waiting > Ready > Running > [Completed > Archived]
+ * 
+ * @param match Partial match results.
+ */
+export function isMatchStale(match: MatchResults): boolean {
+    return match.status >= Status.Completed || isMatchByeCompleted(match);
+}
+
 /**
  * Checks if a match is completed because of a forfeit.
  * 
diff --git a/test/find.spec.js b/test/find.spec.js
index 0cb81cb..7a298b4 100644
--- a/test/find.spec.js
+++ b/test/find.spec.js
@@ -232,6 +232,15 @@ describe('Find previous and next matches in double elimination', () => {
         assert.strictEqual(afterLowerBracketContinued.length, 1);
         assert.strictEqual(afterLowerBracketContinued[0].id, 4);
 
+        await assert.isRejected(manager.find.nextMatches(2, 1), 'The match is not stale yet, so it is not possible to conclude the next matches for this participant.');
+
+        await manager.update.match({ id: 2, opponent1: { result: 'win' } });
+        const afterFinalWBForWinner = await manager.find.nextMatches(2, 1);
+        assert.strictEqual(afterFinalWBForWinner.length, 0);
+        const afterFinalWBForLoser = await manager.find.nextMatches(2, 2);
+        assert.strictEqual(afterFinalWBForLoser.length, 1);
+        assert.strictEqual(afterFinalWBForLoser[0].id, 4);
+
         await assert.isRejected(manager.find.nextMatches(3, 42), 'The participant does not belong to this match.');
     });
 });