#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "buffer.hpp"
#include <stdlib.h>

/******************************************************************
 *	Remove entries from FIFO buffer list, if their DTS is less than
 *	actual SCR. These packet data have been already decoded and have
 *	been removed from the system target decoder's elementary stream
 *	buffer.
 *****************************************************************/

void BufferModel::Cleaned(clockticks SCR)
{
    BufferQueue *pointer;

    while ((first != NULL) && first->DTS < SCR)
    {
	  pointer = first;
	  first = first->next;
	  delete pointer;	
    }
}

/******************************************************************
 * Return the SCR when there will next be some change in the
 * buffer.
 * If the buffer is empty return a zero timestamp.
 *****************************************************************/

clockticks BufferModel::NextChange()
{
	if( first == NULL )
		return static_cast<clockticks>(0);
	else
		return first->DTS;
}


/******************************************************************
 *
 *	Remove all entries from FIFO buffer list, if their DTS is less
 *	than actual SCR. These packet data have been already decoded and
 *	have been removed from the system target decoder's elementary
 *	stream buffer.
 *****************************************************************/

void BufferModel::Flushed ()
{
    BufferQueue *pointer;

    while (first != NULL)
    {
	  pointer = first;
	  first = first->next;
	  delete pointer;	
    }
}

/******************************************************************
	BufferModel::Space

	returns free space in the buffer
******************************************************************/

unsigned int BufferModel::Space ()
{
    unsigned int used_bytes;
    BufferQueue *pointer;

    pointer=first;
    used_bytes=0;

    while (pointer != NULL)
    {
		used_bytes += pointer->size;
		pointer = pointer->next;
    }

    return (max_size - used_bytes);

}

/******************************************************************
	Queue_Buffer

	adds entry into the buffer FIFO queue
******************************************************************/

void BufferModel::Queued (unsigned int bytes,
					clockticks TS)
{
    BufferQueue *pointer;

    pointer=first;
    if (pointer==NULL)
    {
		first = new BufferQueue;
		first->size = bytes;
		first->next=NULL;
		first->DTS = TS;
    } 
	else
    {
		while ((pointer->next)!=NULL)
		{
			pointer = pointer->next;
		}

		pointer->next = new BufferQueue;
		pointer->next->size = bytes;
		pointer->next->next = NULL;
		pointer->next->DTS = TS;
    }
}


void BufferModel::Init ( unsigned int size)
{
    max_size = size;
    first = 0;
}