feat(property): best friends of the owner can build on the property

property_bff_build (off by default, as live): while the owner is in build mode, their best friends can join it and place, move and pick up models, build brick by brick and edit behaviors, each from their own inventory. Only the owner starts build mode; a best friend still in it when the owner leaves keeps building until they leave it. The client lets only the property's owner edit, so each player now gets their own DownloadPropertyData, with their own id as the owner while they can build, sent again whenever that changes. SetBuildModeConfirmed and GetModelsOnProperty go to each player instead of everyone. The first builder makes the property private and pauses the models; the last one restores them. Saving no longer needs the owner in the world. A model taken off the property goes to whoever placed it; if they aren't here it stays placed. Privacy and the property's name stay owner only (neither was checked before). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-13 08:13:46 +00:00 · 2026-09-28 12:08:29 -05:00
parent 6b7d95acbd
commit df922e3cd9
15 changed files with 555 additions and 88 deletions
--- a/dGame/dComponents/PropertyManagementComponent.cpp
+++ b/dGame/dComponents/PropertyManagementComponent.cpp
@@ -35,6 +35,8 @@
 #include "BrickByBrick.h"
 #include "eLootSourceType.h"
 #include "eKillType.h"
+#include "PropertyBuilders.h"
+#include "BuildingMessages.h"

 PropertyManagementComponent* PropertyManagementComponent::instance = nullptr;

@@ -91,6 +93,77 @@ PropertyManagementComponent::PropertyManagementComponent(Entity* parent, const i

 		Load();
 	}
+
+	// Turning property_bff_build on or off changes who can build right away
+	static bool configHandlerAdded = false;
+	if (!configHandlerAdded && Game::config) {
+		Game::config->AddConfigHandler([]() { if (instance) instance->UpdateBuildRights(); });
+		configHandlerAdded = true;
+	}
+}
+
+PropertyManagementComponent::~PropertyManagementComponent() {
+	if (instance == this) instance = nullptr;
+}
+
+bool PropertyManagementComponent::IsBestFriend(const LWOOBJID player) const {
+	if (owner == LWOOBJID_EMPTY || player == owner) return false;
+	const auto cached = bestFriends.find(player);
+	if (cached != bestFriends.end()) return cached->second;
+	const auto status = Database::Get()->GetBestFriendStatus(player, owner);
+	const bool isBestFriend = status && status->bestFriendStatus == 3;
+	bestFriends[player] = isBestFriend;
+	return isBestFriend;
+}
+
+bool PropertyManagementComponent::CanBuild(const Entity& player) const {
+	const bool bestFriendsBuild = PropertyBuilders::BestFriendsBuild();
+	PropertyBuilders::Player state{ .id = player.GetObjectID(), .isBuilding = builders.contains(player.GetObjectID()) };
+	// Only a best friend needs the lookup
+	if (bestFriendsBuild && state.id != owner) state.isBestFriend = IsBestFriend(state.id);
+	return PropertyBuilders::CanBuild(state, owner, builders.contains(owner), bestFriendsBuild);
+}
+
+void PropertyManagementComponent::OnPlayerLoaded(Entity& player) {
+	IsBestFriend(player.GetObjectID());
+}
+
+void PropertyManagementComponent::OnPlayerRemoved(Entity& player) {
+	const auto id = player.GetObjectID();
+	const bool wasBuilding = EndBuilding(player);
+	sentBuildRights.erase(id);
+	bestFriends.erase(id);
+	// The owner leaving build mode stops best friends who aren't building from joining
+	if (wasBuilding) UpdateBuildRights();
+}
+
+void PropertyManagementComponent::UpdateBuildRights() {
+	for (auto* player : PlayerManager::GetAllPlayers()) {
+		if (!player) continue;
+		const auto id = player->GetObjectID();
+		const auto sent = sentBuildRights.find(id);
+		// Never sent the property's data: the client has no rights to take away
+		const bool couldBuild = sent != sentBuildRights.end() && sent->second;
+		const bool canBuild = CanBuild(*player);
+		if (couldBuild == canBuild) continue;
+
+		if (!canBuild && builders.contains(id)) {
+			// Out of build mode, as when they leave it themselves
+			GameMessages::SetBuildModeConfirmed confirmed;
+			confirmed.target = id;
+			confirmed.start = false;
+			confirmed.warnVisitors = true;
+			confirmed.playerId = id;
+			confirmed.startPos = player->GetPosition();
+			confirmed.Send(player->GetSystemAddress());
+			if (player->GetCharacter()) player->GetCharacter()->SetBuildMode(false);
+			EndBuilding(*player);
+			Game::zoneManager->GetZoneControlObject()->OnZonePropertyEditEnd();
+			ChatPackets::SendSystemMessage(player->GetSystemAddress(), u"You can't build on this property any more.");
+		}
+
+		OnQueryPropertyData(player, player->GetSystemAddress());
+	}
 }

 LWOOBJID PropertyManagementComponent::GetOwnerId() const {
@@ -102,7 +175,7 @@ Entity* PropertyManagementComponent::GetOwner() const {
 }

 void PropertyManagementComponent::SetOwner(Entity* value) {
-	owner = value->GetObjectID();
+	SetOwnerId(value->GetObjectID());
 }

 std::vector<NiPoint3> PropertyManagementComponent::GetPaths() const {
@@ -190,7 +263,7 @@ void PropertyManagementComponent::UpdatePropertyDetails(std::string name, std::s
 	Database::Get()->UpdatePropertyDetails(info);
 	DashboardNotify::Changed("properties", propertyId);

-	OnQueryPropertyData(GetOwner(), UNASSIGNED_SYSTEM_ADDRESS);
+	OnQueryPropertyData(nullptr, UNASSIGNED_SYSTEM_ADDRESS);
 }

 bool PropertyManagementComponent::Claim(const LWOOBJID playerId) {
@@ -251,10 +324,20 @@ bool PropertyManagementComponent::Claim(const LWOOBJID playerId) {
 	return true;
 }

-void PropertyManagementComponent::OnStartBuilding() {
-	auto* ownerEntity = GetOwner();
+void PropertyManagementComponent::OnStartBuilding(Entity& builder) {
+	const bool first = builders.empty();
+	if (!builders.insert(builder.GetObjectID()).second) return;

-	if (ownerEntity == nullptr) return;
+	// The owner starting lets their best friends join
+	if (builder.GetObjectID() == owner) UpdateBuildRights();
+
+	auto inventoryComponent = builder.GetComponent<InventoryComponent>();
+
+	// Push equipped items
+	if (inventoryComponent) inventoryComponent->PushEquippedItems();
+
+	// Someone else is already building: the property is already private and paused
+	if (!first) return;

 	const auto players = PlayerManager::GetAllPlayers();

@@ -274,16 +357,13 @@ void PropertyManagementComponent::OnStartBuilding() {
 		}
 	}

+	// Everyone who can't build here leaves
 	for (auto* player : players) {
-		if (player == ownerEntity) continue;
+		if (!player || CanBuild(*player)) continue;

 		auto* characterComponent = player->GetComponent<CharacterComponent>();
 		if (characterComponent) characterComponent->SendToZone(zoneId);
 	}
-	auto inventoryComponent = ownerEntity->GetComponent<InventoryComponent>();
-
-	// Push equipped items
-	if (inventoryComponent) inventoryComponent->PushEquippedItems();

 	for (auto modelID : models | std::views::keys) {
 		auto* model = Game::entityManager->GetEntity(modelID);
@@ -302,13 +382,22 @@ void PropertyManagementComponent::OnStartBuilding() {
 	}
 }

-void PropertyManagementComponent::OnFinishBuilding() {
-	auto* ownerEntity = GetOwner();
+void PropertyManagementComponent::OnFinishBuilding(const Entity& builder) {
+	// A best friend who left can't come back until the owner builds; the owner leaving stops the others joining
+	if (EndBuilding(builder)) UpdateBuildRights();
+}

-	if (ownerEntity == nullptr) return;
+bool PropertyManagementComponent::EndBuilding(const Entity& builder) {
+	if (builders.erase(builder.GetObjectID()) == 0) return false;
+
+	// Others are still building: keep the property private and paused
+	if (!builders.empty()) {
+		Save();
+		return true;
+	}

 	UpdateApprovedStatus(false);
-	
+
 	SetPrivacyOption(originalPrivacyOption);

 	Save();
@@ -328,9 +417,10 @@ void PropertyManagementComponent::OnFinishBuilding() {
 	for (auto* const entity : Game::entityManager->GetEntitiesInGroup("SpawnedPropertyEnemies")) {
 		if (entity) entity->Smash();
 	}
+	return true;
 }

-Entity* PropertyManagementComponent::SpawnModel(const LOT lot, const LWOOBJID modelId, const NiPoint3& position, const NiQuaternion& rotation, const LwoNameValue& config) {
+Entity* PropertyManagementComponent::SpawnModel(const LOT lot, const LWOOBJID modelId, const NiPoint3& position, const NiQuaternion& rotation, const LwoNameValue& config, const LWOOBJID placer) {
 	auto* node = new SpawnerNode();
 	node->position = position;
 	node->rotation = rotation;
@@ -361,15 +451,17 @@ Entity* PropertyManagementComponent::SpawnModel(const LOT lot, const LWOOBJID mo
 	auto* model = spawner->Spawn();
 	if (!model) return nullptr;

-	// Placed while the owner is editing: stays still until they finish (OnFinishBuilding resumes every model)
+	// Placed while someone is building: stays still until the last builder finishes (OnFinishBuilding resumes every
+	// model)
 	auto* modelComponent = model->GetComponent<ModelComponent>();
 	if (modelComponent) modelComponent->Pause();

 	models.insert_or_assign(model->GetObjectID(), spawnerId);
+	placedBy.insert_or_assign(modelId, placer);
 	return model;
 }

-LWOOBJID PropertyManagementComponent::PlaceModelFromItem(Item& item, const NiPoint3& position, const NiQuaternion& rotation) {
+LWOOBJID PropertyManagementComponent::PlaceModelFromItem(const Entity& builder, Item& item, const NiPoint3& position, const NiQuaternion& rotation) {
 	LWOOBJID modelId = LWOOBJID_EMPTY;
 	Entity* model = nullptr;

@@ -389,35 +481,38 @@ LWOOBJID PropertyManagementComponent::PlaceModelFromItem(Item& item, const NiPoi
 		modelConfig.Insert<LWOOBJID>(u"blueprintid", blueprintId);
 		const auto behaviors = config.find(u"userModelBehaviors");
 		if (behaviors != config.end() && behaviors->second) modelConfig.Insert<std::string>(u"userModelBehaviors", behaviors->second->GetValueAsString());
-		model = SpawnModel(BrickByBrick::MODEL_OBJECT_LOT, modelId, position, rotation, modelConfig);
+		model = SpawnModel(BrickByBrick::MODEL_OBJECT_LOT, modelId, position, rotation, modelConfig, builder.GetObjectID());
 	} else {
 		// A premade model gets a new UGID each time it is placed (live: the placed model's id, then a new item id
 		// when it is picked up)
 		modelId = ObjectIDManager::GetPersistentID();
 		GeneralUtils::SetBit(modelId, eObjectBits::CLIENT);
-		model = SpawnModel(item.GetLot(), modelId, position, rotation, {});
+		model = SpawnModel(item.GetLot(), modelId, position, rotation, {}, builder.GetObjectID());
 	}

 	if (!model) return LWOOBJID_EMPTY;

 	item.SetCount(item.GetCount() - 1, false, false, false, eLootSourceType::PROPERTY);
-	// Straight to the database: the model must not be lost if the server stops before the owner finishes editing
+	// Straight to the database: the model must not be lost if the server stops before the builder finishes editing
 	Save();
 	return modelId;
 }

 void PropertyManagementComponent::SendModelsOnProperty() const {
 	GameMessages::GetModelsOnProperty msg;
-	msg.target = owner;
 	msg.models = { models.begin(), models.end() };
-	msg.Send(UNASSIGNED_SYSTEM_ADDRESS);
+	// Each player's own character, as PropertyContentsFromClient answers: the owner may not be here to target
+	for (const auto* player : PlayerManager::GetAllPlayers()) {
+		if (!player) continue;
+		msg.target = player->GetObjectID();
+		msg.Send(player->GetSystemAddress());
+	}
 }

-void PropertyManagementComponent::UpdateModelPosition(const LWOOBJID id, const NiPoint3 position, NiQuaternion rotation) {
+void PropertyManagementComponent::UpdateModelPosition(Entity& builder, const LWOOBJID id, const NiPoint3 position, NiQuaternion rotation) {
 	LOG("Placing model <%f, %f, %f>", position.x, position.y, position.z);

-	auto* entity = GetOwner();
-	if (entity == nullptr) return;
+	auto* entity = &builder;

 	auto* inventoryComponent = entity->GetComponent<InventoryComponent>();
 	if (inventoryComponent == nullptr) return;
@@ -433,7 +528,7 @@ void PropertyManagementComponent::UpdateModelPosition(const LWOOBJID id, const N
 		rotation = { rotation.w, rotation.z, rotation.y, rotation.x };
 	}

-	const auto modelId = PlaceModelFromItem(*item, position, rotation);
+	const auto modelId = PlaceModelFromItem(builder, *item, position, rotation);
 	if (modelId == LWOOBJID_EMPTY) return;

 	// As a live server answered a placed model
@@ -464,15 +559,9 @@ void PropertyManagementComponent::UpdateModelPosition(const LWOOBJID id, const N
 	if (missionComponent != nullptr) missionComponent->Progress(eMissionTaskType::PLACE_MODEL, 0);
 }

-void PropertyManagementComponent::DeleteModel(const LWOOBJID id, const int deleteReason) {
+void PropertyManagementComponent::DeleteModel(Entity& builder, const LWOOBJID id, const int deleteReason) {
 	LOG("Delete model: (%llu) (%i)", id, deleteReason);

-	auto* entity = GetOwner();
-	if (entity == nullptr) return;
-
-	auto* inventoryComponent = entity->GetComponent<InventoryComponent>();
-	if (inventoryComponent == nullptr) return;
-
 	auto* model = Game::entityManager->GetEntity(id);
 	if (model == nullptr) {
 		LOG("Failed to find model entity");
@@ -486,6 +575,32 @@ void PropertyManagementComponent::DeleteModel(const LWOOBJID id, const int delet
 	}

 	const auto modelId = index->second;
+
+	// The model goes back to whoever placed it
+	const auto placer = GetPlacedBy(modelId);
+	auto* placerEntity = placer == builder.GetObjectID() ? &builder : PlayerManager::GetPlayer(placer);
+	const auto placerName = [&]() -> std::string {
+		if (placerEntity && placerEntity->GetCharacter()) return placerEntity->GetCharacter()->GetName();
+		const auto info = Database::Get()->GetCharacterInfo(placer);
+		return info ? info->name : "another player";
+	};
+	switch (PropertyBuilders::PlanModelReturn(builder.GetObjectID(), placer, placerEntity != nullptr, deleteReason)) {
+	case PropertyBuilders::eModelReturn::PLACER_AWAY:
+		LOG("%llu picked up model %llu placed by %llu, who isn't here; leaving it on the property", builder.GetObjectID(), modelId, placer);
+		ChatPackets::SendSystemMessage(builder.GetSystemAddress(), "This model is " + placerName() + "'s. It stays on the property until they are here to get it back.");
+		return;
+	case PropertyBuilders::eModelReturn::NOT_THEIRS:
+		ChatPackets::SendSystemMessage(builder.GetSystemAddress(), "This model is " + placerName() + "'s. Only they can take it apart.");
+		return;
+	default:
+		break;
+	}
+	auto& receiver = *placerEntity;
+	const bool toBuilder = &receiver == &builder;
+
+	auto* inventoryComponent = receiver.GetComponent<InventoryComponent>();
+	if (inventoryComponent == nullptr) return;
+
 	const auto removal = BrickByBrick::PlanModelRemoval(deleteReason);

 	// Every way off the property puts the model in MODELS; taking it apart then opens it in brick by brick building
@@ -498,14 +613,17 @@ void PropertyManagementComponent::DeleteModel(const LWOOBJID id, const int delet
 		subKey = modelId;
 	}

+	// Only the player picking it up carries it
 	const auto received = inventoryComponent->ReceiveItem(LWOOBJID_EMPTY, itemLot, 1, eLootSourceType::PROPERTY, config, subKey, false,
-		{ .inventory = eInventoryType::MODELS, .showFlyingLoot = false, .equip = removal.equip });
+		{ .inventory = eInventoryType::MODELS, .showFlyingLoot = false, .equip = toBuilder && removal.equip });
 	if (received.id == LWOOBJID_EMPTY) {
-		LOG("Could not give model %llu back to %llu, leaving it on the property", modelId, entity->GetObjectID());
+		LOG("Could not give model %llu back to %llu, leaving it on the property", modelId, receiver.GetObjectID());
+		if (!toBuilder) ChatPackets::SendSystemMessage(builder.GetSystemAddress(), "This model is " + placerName() + "'s, and they have no room for it. It stays on the property.");
 		return;
 	}

 	models.erase(index);
+	placedBy.erase(modelId);
 	Game::entityManager->DestructEntity(model);
 	auto* spawner = Game::zoneManager->GetSpawner(modelId);
 	if (spawner != nullptr) {
@@ -517,36 +635,47 @@ void PropertyManagementComponent::DeleteModel(const LWOOBJID id, const int delet
 	// Straight to the database, as for placing
 	Save();

-	if (removal.notifyPostDelete) {
+	if (removal.notifyPostDelete && toBuilder) {
 		auto* item = inventoryComponent->FindItemById(received.id);
 		GameMessages::HandleUGCEquipPostDeleteBasedOnEditMode msg;
-		msg.target = entity->GetObjectID();
+		msg.target = builder.GetObjectID();
 		msg.invItem = received.id;
 		msg.itemsTotal = item ? item->GetCount() : 1;
-		msg.Send(entity->GetSystemAddress());
+		msg.Send(builder.GetSystemAddress());
+	}
+
+	if (!toBuilder) {
+		const auto builderName = builder.GetCharacter() ? builder.GetCharacter()->GetName() : "Another player";
+		ChatPackets::SendSystemMessage(builder.GetSystemAddress(), "This model is " + placerName() + "'s, so it went back to them.");
+		ChatPackets::SendSystemMessage(receiver.GetSystemAddress(), builderName + " picked up one of your models. It is back in your models.");
 	}

 	SendModelsOnProperty();

 	{
 		GameMessages::PlaceModelResponse msg;
-		msg.target = entity->GetObjectID();
+		msg.target = builder.GetObjectID();
 		msg.response = BrickByBrick::PLACE_MODEL_REMOVED;
-		msg.Send(entity->GetSystemAddress());
+		msg.Send(builder.GetSystemAddress());
 	}

 	switch (static_cast<BrickByBrick::eDeleteReason>(deleteReason)) {
 	case BrickByBrick::eDeleteReason::PICKING_MODEL_UP:
-		Game::entityManager->GetZoneControlEntity()->OnZonePropertyModelPickedUp(entity);
+		Game::entityManager->GetZoneControlEntity()->OnZonePropertyModelPickedUp(&builder);
 		break;
 	case BrickByBrick::eDeleteReason::RETURNING_MODEL_TO_INVENTORY:
-		Game::entityManager->GetZoneControlEntity()->OnZonePropertyModelRemoved(entity);
+		Game::entityManager->GetZoneControlEntity()->OnZonePropertyModelRemoved(&builder);
 		break;
 	default:
 		break;
 	}
 }

+LWOOBJID PropertyManagementComponent::GetPlacedBy(const LWOOBJID modelId) const {
+	const auto placer = placedBy.find(modelId);
+	return PropertyBuilders::Placer(placer != placedBy.end() ? placer->second : LWOOBJID_EMPTY, owner);
+}
+
 void PropertyManagementComponent::UpdateApprovedStatus(const bool value, const std::string& rejectionReason) {
 	if (owner == LWOOBJID_EMPTY) return;

@@ -627,20 +756,16 @@ void PropertyManagementComponent::Load() {
 		auto* model = spawner->Spawn();

 		models.insert_or_assign(model->GetObjectID(), spawnerId);
+		if (databaseModel.placedBy != LWOOBJID_EMPTY) placedBy.insert_or_assign(databaseModel.id, databaseModel.placedBy);
 	}
 }

 void PropertyManagementComponent::Save() {
-	if (propertyId == LWOOBJID_EMPTY) {
+	// From the property's own ids: it saves whoever is here (the owner may not be)
+	if (propertyId == LWOOBJID_EMPTY || owner == LWOOBJID_EMPTY) {
 		return;
 	}

-	const auto* const owner = GetOwner();
-	if (!owner) return;
-
-	const auto* const character = owner->GetCharacter();
-	if (!character) return;
-
 	auto present = Database::Get()->GetPropertyModels(propertyId);

 	std::vector<LWOOBJID> modelIds;
@@ -659,12 +784,13 @@ void PropertyManagementComponent::Save() {
 		if (!modelComponent) continue;
 		const auto modelBehaviors = modelComponent->GetBehaviorsForSave();

-		// save the behaviors of the model
+		// save the behaviors of the model, as the model's placer's
+		const auto placer = GetPlacedBy(id);
 		for (const auto& [behaviorId, behaviorStr] : modelBehaviors) {
 			if (behaviorStr.empty() || behaviorId == -1 || behaviorId == 0) continue;
 			IBehaviors::Info info{
 				.behaviorId = behaviorId,
-				.characterId = character->GetID(),
+				.characterId = placer,
 				.behaviorInfo = behaviorStr
 			};
 			Database::Get()->AddBehavior(info);
@@ -685,6 +811,7 @@ void PropertyManagementComponent::Save() {
 			for (auto i = 0; i < model.behaviors.size(); i++) {
 				model.behaviors[i] = modelBehaviors[i].first;
 			}
+			model.placedBy = placer;

 			Database::Get()->InsertNewPropertyModel(propertyId, model, "Objects_" + std::to_string(model.lot) + "_name");
 		} else {
@@ -795,10 +922,29 @@ void PropertyManagementComponent::OnQueryPropertyData(Entity* originator, const
 	message.pathPositions = GetPaths();

 	LOG("(%llu) sending property data (%d)", author, true);
-	message.Send(UNASSIGNED_SYSTEM_ADDRESS);
+	// Each player gets their own: it tells builders they own the property
+	if (sysAddr == UNASSIGNED_SYSTEM_ADDRESS) {
+		for (auto* player : PlayerManager::GetAllPlayers()) {
+			if (player) SendPropertyData(*player, message);
+		}
+	} else {
+		auto* player = PlayerManager::GetPlayer(sysAddr);
+		if (player) SendPropertyData(*player, message);
+	}
 	// send rejection here?
 }

+void PropertyManagementComponent::SendPropertyData(const Entity& player, const GameMessages::DownloadPropertyData& message) {
+	const bool canBuild = CanBuild(player);
+	sentBuildRights[player.GetObjectID()] = canBuild;
+
+	// The client lets only the property's owner build (ownerId == its character); a best friend who can build is told
+	// they own it, while ownerName stays the owner's
+	auto forPlayer = message;
+	if (canBuild) forPlayer.ownerId = player.GetObjectID();
+	forPlayer.Send(player.GetSystemAddress());
+}
+
 void PropertyManagementComponent::OnUse(Entity* originator) {
 	OnQueryPropertyData(originator, UNASSIGNED_SYSTEM_ADDRESS);
 	GameMessages::OpenPropertyManagement msg;
@@ -807,6 +953,7 @@ void PropertyManagementComponent::OnUse(Entity* originator) {
 }

 void PropertyManagementComponent::SetOwnerId(const LWOOBJID value) {
+	if (owner != value) bestFriends.clear();
 	owner = value;
 }

@@ -829,5 +976,5 @@ void PropertyManagementComponent::ApplyModeration(const bool approved, const std
 	rejectionReason = approved ? "" : reason;
 	// The dashboard makes rejected properties private; don't let a later save here publish it again
 	if (!approved) privacyOption = PropertyPrivacyOption::Private;
-	OnQueryPropertyData(GetOwner(), UNASSIGNED_SYSTEM_ADDRESS);
+	OnQueryPropertyData(nullptr, UNASSIGNED_SYSTEM_ADDRESS);
 }
--- a/dGame/dComponents/PropertyManagementComponent.h
+++ b/dGame/dComponents/PropertyManagementComponent.h
@@ -2,6 +2,8 @@

 #include "ePropertyPrivacyOption.h"
 #include <chrono>
+#include <map>
+#include <set>
 #include "Entity.h"
 #include "Component.h"
 #include "eReplicaComponentType.h"
@@ -9,6 +11,10 @@

 class Item;

+namespace GameMessages {
+	struct DownloadPropertyData;
+}
+
 /**
 * Main component that handles interactions with a property, generally the plaques you see on properties.
 */
@@ -16,8 +22,24 @@ class PropertyManagementComponent final : public Component {
 public:
 	static constexpr eReplicaComponentType ComponentType = eReplicaComponentType::PROPERTY_MANAGEMENT;
 	PropertyManagementComponent(Entity* parent, const int32_t componentID);
+	~PropertyManagementComponent() override;
 	static PropertyManagementComponent* Instance();

+	/**
+	 * Whether the player can build on this property: its owner, or with property_bff_build a best friend of the owner
+	 * while the owner is building (and, once in build mode, until they leave it)
+	 */
+	bool CanBuild(const Entity& player) const;
+
+	// A player finished loading into this world: looks up whether they are a best friend of the owner
+	void OnPlayerLoaded(Entity& player);
+
+	// A player left this world: ends their building and updates who else can build
+	void OnPlayerRemoved(Entity& player);
+
+	// Tells every player whose right to build changed (CanBuild) and ends building for those who lost it
+	void UpdateBuildRights();
+
 	/**
 	 * Event handler for when an entity requests information about this property, will send back whether it's owned, etc.
 	 * @param originator the entity that triggered the event
@@ -90,44 +112,51 @@ public:
 	bool Claim(LWOOBJID playerId);

 	/**
-	 * Event triggered when the owner of the property starts building, will kick other entities out
+	 * Event triggered when a player who can build starts building. The first one to start (the owner) makes the property
+	 * private, pauses the models and sends away the players who can't build.
 	 */
-	void OnStartBuilding();
+	void OnStartBuilding(Entity& builder);

 	/**
-	 * Event triggered when the owner of the property finished building, will re-apply this property for moderation
-	 * request.
+	 * Event triggered when a builder finished building. When the last one finishes the property is re-applied for
+	 * moderation, gets its privacy back and the models run again.
 	 */
-	void OnFinishBuilding();
+	void OnFinishBuilding(const Entity& builder);

 	/**
-	 * Updates the position of a model on the property
-	 * @param id the ID of the model to reposition
+	 * Places a model from the builder's inventory on the property
+	 * @param builder the player placing the model
+	 * @param id the ID of the model item to place
 	 * @param position the position to place the model on
 	 * @param rotation the rotation to place the model on
 	 */
-	void UpdateModelPosition(LWOOBJID id, NiPoint3 position, NiQuaternion rotation);
+	void UpdateModelPosition(Entity& builder, LWOOBJID id, NiPoint3 position, NiQuaternion rotation);

 	/**
-	 * Deletes a model for a property
+	 * Takes a model off the property, into the inventory of the player who placed it
+	 * @param builder the player taking the model off
 	 * @param id the ID of the model to delete
 	 * @param deleteReason the reason of the deletion, e.g. picked up or destroyed (in case of UGC)
 	 */
-	void DeleteModel(LWOOBJID id, int deleteReason);
+	void DeleteModel(Entity& builder, LWOOBJID id, int deleteReason);

 	/**
 	 * Spawns a model on the property and records it in the property's models (not yet saved)
 	 * @param lot the model object's LOT (14 for a brick built model)
 	 * @param modelId the model's id in properties_contents (its UGID)
 	 * @param config extra config for the model object
+	 * @param placedBy the player who placed it
 	 */
-	Entity* SpawnModel(LOT lot, LWOOBJID modelId, const NiPoint3& position, const NiQuaternion& rotation, const LwoNameValue& config);
+	Entity* SpawnModel(LOT lot, LWOOBJID modelId, const NiPoint3& position, const NiQuaternion& rotation, const LwoNameValue& config, LWOOBJID placedBy);

 	/**
-	 * Places a model item on the property, uses the item up and saves the property
+	 * Places a model item of the builder's on the property, uses the item up and saves the property
 	 * @return the placed model's id, or LWOOBJID_EMPTY if it could not be placed
 	 */
-	LWOOBJID PlaceModelFromItem(Item& item, const NiPoint3& position, const NiQuaternion& rotation);
+	LWOOBJID PlaceModelFromItem(const Entity& builder, Item& item, const NiPoint3& position, const NiQuaternion& rotation);
+
+	// The player who placed a model (by its id in properties_contents); the owner for models placed before this was kept
+	LWOOBJID GetPlacedBy(LWOOBJID modelId) const;

 	// GetModelsOnProperty with every model on the property
 	void SendModelsOnProperty() const;
@@ -175,6 +204,16 @@ public:

 	void OnChatMessageReceived(const std::string& sMessage) const;
 private:
+	// Sends the property's data to one player; a player who can build is told they own it, which is the client's only
+	// check before editing (the owner's name stays the owner's)
+	void SendPropertyData(const Entity& player, const GameMessages::DownloadPropertyData& message);
+
+	// Whether the player is a best friend of the owner (looked up the first time)
+	bool IsBestFriend(LWOOBJID player) const;
+
+	// OnFinishBuilding without updating who can build; false if they weren't building
+	bool EndBuilding(const Entity& builder);
+
 	/**
 	 * This
 	 */
@@ -249,4 +288,17 @@ private:
 	 * The privacy setting before it was changed, saved to set back after a player finishes building
 	 */
 	PropertyPrivacyOption originalPrivacyOption = PropertyPrivacyOption::Private;
+
+	// Whether each player on the property is a best friend of the owner, looked up once per player (again when the
+	// owner changes)
+	mutable std::map<LWOOBJID, bool> bestFriends;
+
+	// Whether each player on the property was last told they can build (see SendPropertyData)
+	std::map<LWOOBJID, bool> sentBuildRights;
+
+	// Players building right now
+	std::set<LWOOBJID> builders;
+
+	// Who placed each model, by its id in properties_contents (LWOOBJID_EMPTY: the owner)
+	std::map<LWOOBJID, LWOOBJID> placedBy;
 };