//StateManager.cpp //<map>

#include "StateManager.h"
#include "GameState.h"

namespace Framework
{
	StateManager* StateManager::mInstance = 0;

	/**
	*	Function: Constructor
	*	Purpose: 
	**/
	StateManager::StateManager() 
	{
	}
	
	/**
	*	Function: Destructor
	*	Purpose:
	**/
	StateManager::~StateManager()
	{
	}

	/**
	*	Function: LoadState
	*	Purpose: Loads a State onto the Stack and calls its initialize function\
	**/
	void StateManager::LoadState(GameState* state)
	{
		state->Initalize();
		mStates.push_state(state);
	}
	
	/**
	*	Function: DestroyState
	*	Purpose: Destroys the state on top of the stack
	**/
	GameState* StateManager::DestroyState()
		{
			GameState* state = 0;

			if (mStates.size() > 0)
			{
				state = mStates[mStates.size()-1];
				mStates.pop_back();
				state->Shutdown();
			}

			return state;
		}

	/**
	*	Function: Destory All
	*	Purpose: Removes all states from stack
	**/
	void StateManager::DestroyAll()
	{
		while(DestroyState());
	}
	
	/**
	*	Function: Update
	*	Purpose:
	**/
	bool StateManager::Update()
	{
		if (mStates.size() > 0)
			return mStates[mStates.size()-1]->Update();
		 else
			return false;
	}
	/**
	*	Function: Render
	*	Purpose:
	**/
	void StateManager::Render()
	{
		if(mStates.size() > 0)
			mStates[mStates.size()-1]->Render();
	}

	/**
	*	Function: GetInstance
	*	Purpose:
	**/
	StateManager* StateManager::GetInstance()
	{
		if(mInstance == 0)
			mInstance = new StateManager();
		
		return mInstance;
	}

}