feat: add ranked season rollover policy

server/domain/teams.go

@@ -28,10 +28,14 @@ func PartitionTeams(players []Candidate) (Teams, error) {
 	var visit func(int)
 	visit = func(start int) {
 		if len(chosen) == teamSize {
-			if !containsPlayer(chosen, anchor) { return }
+			if !containsPlayer(chosen, anchor) {
+				return
+			}
 			team1 := make([]Candidate, 0, teamSize)
 			for _, player := range ordered {
-				if !containsPlayer(chosen, player.PlayerID) { team1 = append(team1, player) }
+				if !containsPlayer(chosen, player.PlayerID) {
+					team1 = append(team1, player)
+				}
 			}
 			if !found || betterTeams(chosen, team1, best) {
 				best = Teams{Team0: append([]Candidate(nil), chosen...), Team1: team1}
@@ -46,16 +50,24 @@ func PartitionTeams(players []Candidate) (Teams, error) {
 		}
 	}
 	visit(0)
-	if !found { return Teams{}, fmt.Errorf("no balanced team partition") }
+	if !found {
+		return Teams{}, fmt.Errorf("no balanced team partition")
+	}
 	return best, nil
 }
 
 func betterTeams(team0, team1 []Candidate, best Teams) bool {
-	if best.Team0 == nil { return true }
+	if best.Team0 == nil {
+		return true
+	}
 	meanDelta, maxOpposing := teamScore(team0, team1)
 	bestMean, bestMaxOpposing := teamScore(best.Team0, best.Team1)
-	if meanDelta != bestMean { return meanDelta < bestMean }
-	if maxOpposing != bestMaxOpposing { return maxOpposing < bestMaxOpposing }
+	if meanDelta != bestMean {
+		return meanDelta < bestMean
+	}
+	if maxOpposing != bestMaxOpposing {
+		return maxOpposing < bestMaxOpposing
+	}
 	return playerIDs(team0) < playerIDs(best.Team0)
 }
 
@@ -65,7 +77,9 @@ func teamScore(team0, team1 []Candidate) (float64, float64) {
 	for _, left := range team0 {
 		for _, right := range team1 {
 			delta := abs(left.Rating - right.Rating)
-			if delta > maxOpposing { maxOpposing = delta }
+			if delta > maxOpposing {
+				maxOpposing = delta
+			}
 		}
 	}
 	return abs(mean0 - mean1), maxOpposing
@@ -73,20 +87,30 @@ func teamScore(team0, team1 []Candidate) (float64, float64) {
 
 func meanRating(players []Candidate) float64 {
 	total := 0.0
-	for _, player := range players { total += player.Rating }
+	for _, player := range players {
+		total += player.Rating
+	}
 	return total / float64(len(players))
 }
 
 func containsPlayer(players []Candidate, playerID string) bool {
-	for _, player := range players { if player.PlayerID == playerID { return true } }
+	for _, player := range players {
+		if player.PlayerID == playerID {
+			return true
+		}
+	}
 	return false
 }
 
 func playerIDs(players []Candidate) string {
 	ids := make([]string, 0, len(players))
-	for _, player := range players { ids = append(ids, player.PlayerID) }
+	for _, player := range players {
+		ids = append(ids, player.PlayerID)
+	}
 	sort.Strings(ids)
 	result := ""
-	for _, id := range ids { result += id + "\x00" }
+	for _, id := range ids {
+		result += id + "\x00"
+	}
 	return result
 }