//
// Urho3D Engine
// Copyright (c) 2008-2012 Lasse Öörni
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#pragma once

#include "Component.h"
#include "ScriptEventListener.h"

class Script;
class ScriptFile;
class asIScriptFunction;
class asIScriptObject;

/// Inbuilt scripted component methods.
enum ScriptInstanceMethod
{
    METHOD_START = 0,
    METHOD_STOP,
    METHOD_UPDATE,
    METHOD_POSTUPDATE,
    METHOD_FIXEDUPDATE,
    METHOD_FIXEDPOSTUPDATE,
    METHOD_LOAD,
    METHOD_SAVE,
    METHOD_FINISHUPDATE,
    MAX_SCRIPT_METHODS
};

/// Delay-executed method call.
struct DelayedMethodCall
{
    /// Delay time remaining until execution.
    float delay_;
    /// Method declaration.
    String declaration_;
    /// Parameters.
    VariantVector parameters_;
};

/// %Script object component.
class ScriptInstance : public Component, public ScriptEventListener
{
    OBJECT(ScriptInstance);
    
public:
    /// Construct.
    ScriptInstance(Context* context);
    /// Destruct.
    virtual ~ScriptInstance();
    /// Register object factory.
    static void RegisterObject(Context* context);
    
    /// Apply attribute changes that can not be applied immediately. Called after scene load or a network update.
    virtual void ApplyAttributes();
    /// Add an event handler. Called by script exposed version of SubscribeToEvent().
    virtual void AddEventHandler(StringHash eventType, const String& handlerName);
    /// Add an event handler for a specific sender. Called by script exposed version of SubscribeToEvent().
    virtual void AddEventHandler(Object* sender, StringHash eventType, const String& handlerName);
    
    /// Create object of certain class from the script file. Return true if successful.
    bool CreateObject(ScriptFile* scriptFile, const String& className);
    /// Set script file only. Recreate object if necessary.
    void SetScriptFile(ScriptFile* scriptFile);
    /// Set class name only. Recreate object if necessary.
    void SetClassName(const String& className);
    /// Enable or disable scripted updates and event handlers.
    void SetActive(bool active);
    /// Set fixed updates per second. 0 (default) uses the physics frame rate.
    void SetFixedUpdateFps(int fps);
    /// Query for a method by declaration and execute if found.
    bool Execute(const String& declaration, const VariantVector& parameters = VariantVector());
    /// Execute a method.
    bool Execute(asIScriptFunction* method, const VariantVector& parameters = VariantVector());
    /// Add a delay-executed method call.
    void DelayedExecute(float delay, const String& declaration, const VariantVector& parameters = VariantVector());
    /// Clear pending delay-executed method calls.
    void ClearDelayedExecute();
    
    /// Return script file.
    ScriptFile* GetScriptFile() const { return scriptFile_; }
    /// Return script object.
    asIScriptObject* GetScriptObject() const { return scriptObject_; }
    /// Return class name.
    const String& GetClassName() const { return className_; }
    /// Return whether scripted updates and event handlers are enabled.
    bool IsActive() const { return active_; }
    /// Return fixed updates per second.
    int GetFixedUpdateFps() const { return fixedUpdateFps_; }
    
    /// Set script file attribute.
    void SetScriptFileAttr(ResourceRef value);
    /// Set delayed method calls attribute.
    void SetDelayedMethodCallsAttr(PODVector<unsigned char> value);
    /// Set fixed update time accumulator attribute.
    void SetFixedUpdateAccAttr(float value);
    /// Set script data attribute by calling a script function.
    void SetScriptDataAttr(PODVector<unsigned char> data);
    /// Return script file attribute.
    ResourceRef GetScriptFileAttr() const;
    /// Return delayed method calls attribute.
    PODVector<unsigned char> GetDelayedMethodCallsAttr() const;
    /// Return fixed update time accumulator attribute.
    float GetFixedUpdateAccAttr() const;
    /// Get script data attribute by calling a script function.
    PODVector<unsigned char> GetScriptDataAttr() const;
    
private:
    /// (Re)create the script object and check for supported methods if successfully created.
    void CreateObject();
    /// Release the script object.
    void ReleaseObject();
    /// Clear supported methods.
    void ClearMethods();
    /// Check for supported methods.
    void GetSupportedMethods();
    /// Handle scene update event.
    void HandleSceneUpdate(StringHash eventType, VariantMap& eventData);
    /// Handle scene post-update event.
    void HandleScenePostUpdate(StringHash eventType, VariantMap& eventData);
    /// Handle physics pre-step event.
    void HandlePhysicsPreStep(StringHash eventType, VariantMap& eventData);
    /// Handle physics post-step event.
    void HandlePhysicsPostStep(StringHash eventType, VariantMap& eventData);
    /// Handle an event in script.
    void HandleScriptEvent(StringHash eventType, VariantMap& eventData);
    /// Handle script file reload start.
    void HandleScriptFileReload(StringHash eventType, VariantMap& eventData);
    /// Handle script file reload finished.
    void HandleScriptFileReloadFinished(StringHash eventType, VariantMap& eventData);
    
    /// Script subsystem.
    SharedPtr<Script> script_;
    /// Script file.
    WeakPtr<ScriptFile> scriptFile_;
    /// Script object.
    asIScriptObject* scriptObject_;
    /// Class name.
    String className_;
    /// Pointers to supported inbuilt methods.
    asIScriptFunction* methods_[MAX_SCRIPT_METHODS];
    /// Active flag.
    bool active_;
    /// Fixed update FPS.
    int fixedUpdateFps_;
    /// Fixed update time interval.
    float fixedUpdateInterval_;
    /// Fixed update time accumulator.
    float fixedUpdateAcc_;
    /// Fixed post update time accumulator.
    float fixedPostUpdateAcc_;
    /// Delayed method calls.
    Vector<DelayedMethodCall> delayedMethodCalls_;
};

/// Return the Urho3D context of the active script context.
Context* GetScriptContext();
/// Return the ScriptInstance of the active script context.
ScriptInstance* GetScriptContextInstance();
/// Return the scene node of the active script context.
Node* GetScriptContextNode();
/// Return the scene of the active script context.
Scene* GetScriptContextScene();
/// Return the event listener of the active script context.
ScriptEventListener* GetScriptContextEventListener();
/// Return the event listener of the active script context as an Object pointer.
Object* GetScriptContextEventListenerObject();