/**
 * pipesandfilters.cpp
 */

#include "pipesandfilters.h"

/**
 * Default constructor.
 */

Packet::Packet()
{
};

/**
 * Default constructor.
 */

Pipe::Pipe()
{
};

int Pipe::size()
{
	return (int) packets.size();
};

Packet& Pipe::read()
{
	if( size() == 0 ) 
	{
		throw new EmptyPipeException();
	}

	Packet packet = packets.back();
	packets.pop_back();
	return packet;
};

void Pipe::write( Packet& packet )
{
	packets.push_front( packet );
	observer -> notify();
};

void Pipe::setObserver( DataSink* observer )
{
	this -> observer = observer;
};

DataSink* Pipe::getObserver()
{
	return observer;
};

/**
 * Default constructor.
 */

DataSource::DataSource()
{
	output = (Pipe *) 0;
};

void DataSource::add( Packet& packet )
{
	if( output != (Pipe *) 0 )
	{
		output -> write( packet );
	}
	else
	{
		throw new NoOutputPipeException();
	}
};

void DataSource::setOutput( Pipe* output )
{
	this -> output = output;
};

Pipe* DataSource::getOutput()
{
	return output;
};

DataSink::DataSink()
{
	input = (Pipe *) 0;
	observer = (Filter *) 0;
};

int DataSink::size()
{
	return received.size();
};

Packet& DataSink::nextPacket()
{
	Packet packet = received.back();
	received.pop_back();
	return packet;
};

void DataSink::notify()
{
	while( input -> size() > 0 )
	{
		received.push_front( input -> read() );
	}
	if( observer )
	{
		observer -> notify();
	}
};

void DataSink::setInput( Pipe* newinput )
{
	input = newinput;
};

Pipe* DataSink::getInput()
{
	return input;
};

void DataSink::setObserver( Filter* filter )
{
	this -> observer = filter;
}

Filter* DataSink::getObserver()
{
	return observer;
}

/**
 * Default constructor.
 */

Filter::Filter()
{
};

void Filter::transform()
{
	while( input -> size() > 0 )
	{
		output -> add( input -> nextPacket() );
	}
}

void Filter::notify()
{
	transform();
}

void Filter::setDataSource( DataSource* ds )
{
	output = ds;
};

DataSource* Filter::getDataSource()
{
	return output;
};

void Filter::setDataSink( DataSink* ds )
{
	input = ds;
};

DataSink* Filter::getDataSink()
{
	return input;
};