fix room rocket in-room reward spread

services/room-service/internal/room/service/room_rocket.go

@@ -1053,13 +1053,6 @@ func (s *Service) settleRoomRocketRewards(ctx context.Context, now time.Time, cu
 		})
 		return nil
 	}
-	addRandomReward := func(role string, userID int64, pool []RoomRocketRewardItem) error {
-		item, ok := selectRoomRocketReward(launch.RocketID, role, userID, pool)
-		if !ok {
-			return nil
-		}
-		return addRewardItem(role, userID, item)
-	}
 	addAllRewards := func(role string, userID int64, pool []RoomRocketRewardItem) error {
 		for _, item := range pool {
 			if err := addRewardItem(role, userID, item); err != nil {
@@ -1069,9 +1062,14 @@ func (s *Service) settleRoomRocketRewards(ctx context.Context, now time.Time, cu
 		return nil
 	}
 
+	inRoomRewards := selectRoomRocketRewardsForUsers(launch.RocketID, roomRocketRewardInRoom, inRoomUserIDs, levelCfg.InRoomRewards)
 	for _, userID := range inRoomUserIDs {
-		// 在房奖励是大面积发放池，每个在线用户只按权重抽一个奖项，避免房间人数放大单次火箭成本。
-		if err := addRandomReward(roomRocketRewardInRoom, userID, levelCfg.InRoomRewards); err != nil {
+		// 在房奖励是大面积发放池，每个在线用户只拿一个奖项；同一枚火箭内按无放回周期分配，避免配置了金币和麦位声波时整房都落到同一个奖项。
+		item, ok := inRoomRewards[userID]
+		if !ok {
+			continue
+		}
+		if err := addRewardItem(roomRocketRewardInRoom, userID, item); err != nil {
 			return nil, err
 		}
 	}
@@ -1111,7 +1109,56 @@ func (s *Service) grantRoomRocketReward(ctx context.Context, _ time.Time, curren
 	return resp.GetGrant().GetGrantId(), nil
 }
 
+func validRoomRocketRewardPool(pool []RoomRocketRewardItem) []RoomRocketRewardItem {
+	valid := make([]RoomRocketRewardItem, 0, len(pool))
+	for _, item := range pool {
+		if item.Weight <= 0 || item.ResourceGroupID <= 0 {
+			continue
+		}
+		valid = append(valid, item)
+	}
+	return valid
+}
+
+func selectRoomRocketRewardsForUsers(rocketID string, role string, userIDs []int64, pool []RoomRocketRewardItem) map[int64]RoomRocketRewardItem {
+	assignments := make(map[int64]RoomRocketRewardItem, len(userIDs))
+	if len(userIDs) == 0 {
+		return assignments
+	}
+	basePool := validRoomRocketRewardPool(pool)
+	if len(basePool) == 0 {
+		return assignments
+	}
+	available := append([]RoomRocketRewardItem(nil), basePool...)
+	cycle := 0
+	for index, userID := range userIDs {
+		if userID <= 0 {
+			continue
+		}
+		if len(available) == 0 {
+			// 一轮内每个配置项最多发一次；房间人数超过奖池大小时再开启下一轮，让大房间仍可继续按配置重复分配。
+			available = append([]RoomRocketRewardItem(nil), basePool...)
+			cycle++
+		}
+		selectedIndex, ok := selectRoomRocketRewardIndex(rocketID, role, userID, available, fmt.Sprintf("cycle:%d:index:%d", cycle, index))
+		if !ok {
+			continue
+		}
+		assignments[userID] = available[selectedIndex]
+		available = append(available[:selectedIndex], available[selectedIndex+1:]...)
+	}
+	return assignments
+}
+
 func selectRoomRocketReward(rocketID string, role string, userID int64, pool []RoomRocketRewardItem) (RoomRocketRewardItem, bool) {
+	index, ok := selectRoomRocketRewardIndex(rocketID, role, userID, pool, "")
+	if !ok {
+		return RoomRocketRewardItem{}, false
+	}
+	return pool[index], true
+}
+
+func selectRoomRocketRewardIndex(rocketID string, role string, userID int64, pool []RoomRocketRewardItem, salt string) (int, bool) {
 	total := int64(0)
 	for _, item := range pool {
 		if item.Weight > 0 && item.ResourceGroupID > 0 {
@@ -1119,21 +1166,26 @@ func selectRoomRocketReward(rocketID string, role string, userID int64, pool []R
 		}
 	}
 	if total <= 0 {
-		return RoomRocketRewardItem{}, false
+		return -1, false
 	}
-	hash := sha256.Sum256([]byte(fmt.Sprintf("%s|%s|%d", rocketID, role, userID)))
+	hash := sha256.Sum256([]byte(fmt.Sprintf("%s|%s|%d|%s", rocketID, role, userID, salt)))
 	pick := int64(binary.BigEndian.Uint64(hash[:8]) % uint64(total))
 	cursor := int64(0)
-	for _, item := range pool {
+	fallback := -1
+	for index, item := range pool {
 		if item.Weight <= 0 || item.ResourceGroupID <= 0 {
 			continue
 		}
+		fallback = index
 		cursor += item.Weight
 		if pick < cursor {
-			return item, true
+			return index, true
 		}
 	}
-	return pool[len(pool)-1], true
+	if fallback >= 0 {
+		return fallback, true
+	}
+	return -1, false
 }
 
 func roomRocketGrantCommandID(rocketID string, role string, userID int64, rewardItemID string) string {

services/room-service/internal/room/service/room_rocket_test.go

@@ -566,6 +566,9 @@ func TestRoomRocketLaunchStacksAllSpecialPoolsAndRandomInRoomReward(t *testing.T
 	if countRocketRewards(rewards, igniterID, "in_room") != 1 {
 		t.Fatalf("top1 igniter must still receive exactly one random in-room reward: %+v", rewards)
 	}
+	if countRocketRewardsByRoleAndGroup(rewards, "in_room", 1001) != 1 || countRocketRewardsByRoleAndGroup(rewards, "in_room", 1101) != 1 {
+		t.Fatalf("in-room rewards must spread across the configured pool before repeating an item: %+v", rewards)
+	}
 	if countRocketRewards(rewards, igniterID, "top1") != 2 || countRocketRewards(rewards, igniterID, "igniter") != 2 {
 		t.Fatalf("top1 igniter must receive every configured special reward: %+v", rewards)
 	}
@@ -828,6 +831,16 @@ func countRocketRewards(rewards []*roomv1.RoomRocketRewardGrant, userID int64, r
 	return count
 }
 
+func countRocketRewardsByRoleAndGroup(rewards []*roomv1.RoomRocketRewardGrant, role string, groupID int64) int {
+	count := 0
+	for _, reward := range rewards {
+		if reward.GetRewardRole() == role && reward.GetResourceGroupId() == groupID {
+			count++
+		}
+	}
+	return count
+}
+
 func rocketRewardUserIDs(rewards []*roomv1.RoomRocketRewardGrant) []int64 {
 	userIDs := make([]int64, 0, len(rewards))
 	for _, reward := range rewards {