#include "entitybank.h"

EntityBank::EntityBank()
{
	m_first = NULL;
	m_last = NULL;
	m_current = NULL;

	m_NumOfEntities = 0;
}

EntityBank::~EntityBank()
{

}

int EntityBank::AddToEntityList( void* entity, EntityType entType )
{
	EntityNode* entNode = new EntityNode();

	entNode->m_entity = entity;
	entNode->m_entType = entType;
	entNode->m_previous = NULL;
	entNode->m_next = NULL;

	if( m_first == NULL )
	{
		m_first = entNode;
		m_last = m_first;

		m_NumOfEntities++;
		return 1;
	}
	else
	{
		// Link last node to new node
		m_last->m_next = entNode;
		entNode->m_previous = m_last;

		// Swap last node wtih new node
		m_last = entNode;

		m_NumOfEntities++;
		return 1;
	}

	return 0;
}

int EntityBank::RemoveEntity( void* entity )
{
	if( m_first->m_entity == entity )
	{
		m_first = m_first->m_next;
		m_first->m_previous = NULL;
		// delete m_first->m_previous;
		m_NumOfEntities--;
		return 1;
	}

	if( m_last->m_entity == entity )
	{
		m_last = m_last->m_previous;
		m_last->m_next = NULL;
		// delete m_last->m_next;
		m_NumOfEntities--;
		return 1;
	}

	EntityNode* counter = m_first;
	while( counter != NULL )
	{
		if( counter->m_entity == entity )
		{
			EntityNode* tempPtr = counter->m_previous;
		
			// Link previous pointer to next, and next to previous
			tempPtr->m_next = counter->m_next;
			tempPtr->m_next->m_previous = tempPtr;

			// delete counter;

			m_NumOfEntities--;
			return 1;
		}

		counter = counter->m_next;
	}

	return 0;
}

int EntityBank::RemoveAllOfType( EntityType entType )
{
	ResetCurrent();
	void* entity = GetEntityOfType( entType );

	while( entity != NULL )
	{
		RemoveEntity( entity );	
	
		entity = GetEntityOfType( entType );
	}

	return 1;
}

EntityNode* EntityBank::GetNextEntity( void )
{
	if( m_current == NULL )
	{ return NULL; }

	m_current = m_current->m_next;
	return m_current;
}

EntityNode* EntityBank::GetAt( int index )
{
	EntityNode* iterator = m_first;
	for( int i = 0; i < m_NumOfEntities; i++ )
	{
		if( i == index )
		{
			return iterator;
		}

		iterator = iterator->m_next;
	}

	return NULL;
}

void EntityBank::ResetCurrent( void )
{
	m_current = m_first;
}

int EntityBank::GetNumOfEntities( void )
{
	return m_NumOfEntities;
}

void* EntityBank::GetEntityOfType( EntityType entType )
{
	void* temp = NULL;
	while( temp == NULL )
	{
		if( m_current == NULL )
		{ return NULL; }

		if( m_current->m_entType == entType )
		{ temp = m_current->m_entity; }

		m_current = m_current->m_next;
	}

	return temp;
}