$#include "Scene.h"

static const unsigned FIRST_REPLICATED_ID;
static const unsigned LAST_REPLICATED_ID;
static const unsigned FIRST_LOCAL_ID;
static const unsigned LAST_LOCAL_ID;

/// Root scene node, represents the whole scene.
class Scene : public Node
{
public:
    /// Construct.
    Scene(Context* context);
    /// Destruct.
    virtual ~Scene();
    
    /// Load from an XML file. Return true if successful.
    bool LoadXML(Deserializer& source);
    /// Save to an XML file. Return true if successful.
    bool SaveXML(Serializer& dest) const;
    /// Load from a binary file asynchronously. Return true if started successfully.
    bool LoadAsync(File* file);
    /// Load from an XML file asynchronously. Return true if started successfully.
    bool LoadAsyncXML(File* file);
    /// Stop asynchronous loading.
    void StopAsyncLoading();
    /// Clear.
    void Clear();
    /// Enable or disable scene update.
    void SetUpdateEnabled(bool enable);
    /// Set update time scale. 1.0 = real time (default.)
    void SetTimeScale(float scale);
    /// Set elapsed time in seconds. This can be used to prevent inaccuracy in the timer if the scene runs for a long time.
    void SetElapsedTime(float time);
    /// Set network client motion smoothing constant.
    void SetSmoothingConstant(float constant);
    /// Set network client motion smoothing snap threshold.
    void SetSnapThreshold(float threshold);
    
    /// Return node from the whole scene by ID, or null if not found.
    Node* GetNode(unsigned id) const;
    /// Return component from the whole scene by ID, or null if not found.
    Component* GetComponent(unsigned id) const;
    /// Return whether updates are enabled.
    bool IsUpdateEnabled() const { return updateEnabled_; }
    /// Return asynchronous loading flag.
    bool IsAsyncLoading() const { return asyncLoading_; }
    /// Return asynchronous loading progress between 0.0 and 1.0, or 1.0 if not in progress.
    float GetAsyncProgress() const;
    /// Return source file name.
    const String& GetFileName() const { return fileName_; }
    /// Return source file checksum.
    unsigned GetChecksum() const { return checksum_; }
    /// Return update time scale.
    float GetTimeScale() const { return timeScale_; }
    /// Return elapsed time in seconds.
    float GetElapsedTime() const { return elapsedTime_; }
    /// Return motion smoothing constant.
    float GetSmoothingConstant() const { return smoothingConstant_; }
    /// Return motion smoothing snap threshold.
    float GetSnapThreshold() const { return snapThreshold_; }
    /// Return a node user variable name, or empty if not registered.
    const String& GetVarName(ShortStringHash hash) const;

    /// Update scene. Called by HandleUpdate.
    void Update(float timeStep);
    /// Begin a threaded update. During threaded update components can choose to delay dirty processing.
    void BeginThreadedUpdate();
    /// End a threaded update. Notify components that marked themselves for delayed dirty processing.
    void EndThreadedUpdate();
    /// Add a component to the delayed dirty notify queue. Is thread-safe.
    void DelayedMarkedDirty(Component* component);
    /// Return threaded update flag.
    bool IsThreadedUpdate() const { return threadedUpdate_; }
    /// Get free node ID, either non-local or local.
    unsigned GetFreeNodeID(CreateMode mode);
    /// Get free component ID, either non-local or local.
    unsigned GetFreeComponentID(CreateMode mode);
    /// Node added. Assign scene pointer and add to ID map.
    void NodeAdded(Node* node);
    /// Node removed. Remove from ID map.
    void NodeRemoved(Node* node);
    /// Component added. Add to ID map.
    void ComponentAdded(Component* component);
    /// Component removed. Remove from ID map.
    void ComponentRemoved(Component* component);
    /// Set node user variable reverse mappings.
    void SetVarNamesAttr(String value);
    /// Return node user variable reverse mappings.
    String GetVarNamesAttr() const;
    /// Prepare network update by comparing attributes and marking replication states dirty as necessary.
    void PrepareNetworkUpdate();
    /// Clean up all references to a network connection that is about to be removed.
    void CleanupConnection(Connection* connection);
    /// Mark a node for attribute check on the next network update.
    void MarkNetworkUpdate(Node* node);
    /// Mark a comoponent for attribute check on the next network update.
    void MarkNetworkUpdate(Component* component);
    /// Mark a node dirty in scene replication states. The node does not need to have own replication state yet.
    void MarkReplicationDirty(Node* node);
};