Improve match merge logic

app/features/scanner-ingest/core/Matches.test.ts

@@ -92,6 +92,48 @@ describe("isSameMatch", () => {
 		expect(Matches.isSameMatch(a, b)).toBe(true);
 	});
 
+	test("close play times do not identify back-to-back games against different opponents", () => {
+		const playedAt = 1_700_000_000_000;
+		const nextSet = scannerMatch({ playedAt: playedAt + 5 * 60 * 1000 });
+		nextSet.teams[1] = {
+			players: ["o1", "o2", "o3", "o4"].map((name, i) =>
+				scannerMatchPlayer(name, (100 + 10 * i) as MainWeaponId),
+			),
+		};
+		expect(Matches.isSameMatch(scannerMatch({ playedAt }), nextSet)).toBe(
+			false,
+		);
+	});
+
+	test("close play times still identify a match with a couple of misread names per team", () => {
+		const playedAt = 1_700_000_000_000;
+		const b = scannerMatch({ playedAt: playedAt + 60 * 1000 });
+		b.teams[0].players[0] = scannerMatchPlayer("misread1", WEAPONS[0]!);
+		b.teams[0].players[1] = scannerMatchPlayer("misread2", WEAPONS[1]!);
+		b.teams[1].players[2] = scannerMatchPlayer("misread3", WEAPONS[6]!);
+		expect(Matches.isSameMatch(scannerMatch({ playedAt }), b)).toBe(true);
+	});
+
+	test("contradicting weapons rule out close play times when names are unread", () => {
+		const playedAt = 1_700_000_000_000;
+		const minimap = scannerMatch({
+			playedAt: playedAt + 5 * 60 * 1000,
+			teams: [
+				{
+					players: WEAPONS.slice(0, 4).map((w) => scannerMatchPlayer(null, w)),
+				},
+				{
+					players: [100, 110, 120, 130].map((w) =>
+						scannerMatchPlayer(null, w as MainWeaponId),
+					),
+				},
+			],
+		});
+		expect(Matches.isSameMatch(scannerMatch({ playedAt }), minimap)).toBe(
+			false,
+		);
+	});
+
 	test("far-apart play times contradict identity even with equal rosters", () => {
 		const a = scannerMatch({ playedAt: 1_700_000_000_000 });
 		const b = scannerMatch({ playedAt: 1_700_000_000_000 + 60 * 60 * 1000 });

app/features/scanner-ingest/core/Matches.ts

@@ -22,6 +22,11 @@ const MIN_NAME_OVERLAP = 6;
 const MIN_WEAPON_OVERLAP = 7;
 const MIN_WEAPON_SLOTS_READ = 7;
 
+/** A team pair with at least this many names (else weapons) read on both sides can contradict identity... */
+const MIN_SLOTS_READ_TO_CONTRADICT = 3;
+/** ...when at most this many of them align: different players, so a different game. */
+const MAX_CONTRADICTING_OVERLAP = 1;
+
 const PLAYERS_PER_TEAM = 4;
 
 /** Rebuilds a match with a fixed key order so `JSON.stringify` is stable — the hashing and change-detection representation. */
@@ -66,7 +71,8 @@ export function canonicalMatch(match: ScannerMatch): ScannerMatch {
 /**
  * Whether two (possibly partial) matches describe the same game; callers pre-scope to the same
  * tournament + POV user. Contradicting lobby/mode/stage/replay-code/play-time rules identity out; then a
- * matching replay code, close play times, or an aligning roster (names, else weapons) rules it in.
+ * matching replay code rules it in, contradicting rosters (a team pair of different players) rule it out,
+ * and close play times or an aligning roster (names, else weapons) rule it in.
  */
 export function isSameMatch(a: ScannerMatch, b: ScannerMatch): boolean {
 	if (a.lobby !== null && b.lobby !== null && a.lobby !== b.lobby) return false;
@@ -85,14 +91,16 @@ export function isSameMatch(a: ScannerMatch, b: ScannerMatch): boolean {
 	}
 
 	if (codeDiff !== null) return true;
-	if (playedDiff !== null && playedDiff <= PLAYED_AT_AFFINITY_MS) return true;
 
 	const aligned = bestAlignment(a, b);
+	if (rostersContradict(a, b, aligned.orientation)) return false;
+	if (playedDiff !== null && playedDiff <= PLAYED_AT_AFFINITY_MS) return true;
+
 	if (aligned.nameOverlap >= MIN_NAME_OVERLAP) return true;
 	if (
 		aligned.weaponOverlap >= MIN_WEAPON_OVERLAP &&
-		weaponSlotsRead(a) >= MIN_WEAPON_SLOTS_READ &&
-		weaponSlotsRead(b) >= MIN_WEAPON_SLOTS_READ
+		matchWeaponSlotsRead(a) >= MIN_WEAPON_SLOTS_READ &&
+		matchWeaponSlotsRead(b) >= MIN_WEAPON_SLOTS_READ
 	) {
 		return true;
 	}
@@ -268,12 +276,47 @@ function weaponOverlap(a: ScannerMatchTeam, b: ScannerMatchTeam): number {
 	return overlap;
 }
 
-function weaponSlotsRead(match: ScannerMatch): number {
-	return match.teams.flatMap((team) =>
-		team.players.filter((player) => player.weaponId !== null),
+function rostersContradict(
+	a: ScannerMatch,
+	b: ScannerMatch,
+	orientation: Alignment["orientation"],
+): boolean {
+	const [bFirst, bSecond] =
+		orientation === "straight"
+			? [b.teams[0], b.teams[1]]
+			: [b.teams[1], b.teams[0]];
+	return (
+		teamsContradict(a.teams[0], bFirst) || teamsContradict(a.teams[1], bSecond)
+	);
+}
+
+function teamsContradict(a: ScannerMatchTeam, b: ScannerMatchTeam): boolean {
+	if (Math.min(namesRead(a), namesRead(b)) >= MIN_SLOTS_READ_TO_CONTRADICT) {
+		return nameOverlap(a, b) <= MAX_CONTRADICTING_OVERLAP;
+	}
+	if (
+		Math.min(weaponSlotsRead(a), weaponSlotsRead(b)) >=
+		MIN_SLOTS_READ_TO_CONTRADICT
+	) {
+		return weaponOverlap(a, b) <= MAX_CONTRADICTING_OVERLAP;
+	}
+	return false;
+}
+
+function namesRead(team: ScannerMatchTeam): number {
+	return team.players.filter(
+		(player) => player.name && normalizeInGameName(player.name),
 	).length;
 }
 
+function weaponSlotsRead(team: ScannerMatchTeam): number {
+	return team.players.filter((player) => player.weaponId !== null).length;
+}
+
+function matchWeaponSlotsRead(match: ScannerMatch): number {
+	return weaponSlotsRead(match.teams[0]) + weaponSlotsRead(match.teams[1]);
+}
+
 function swapSides(match: ScannerMatch): ScannerMatch {
 	return {
 		...match,