/*
 * Encog(tm) Unit Tests v2.5 - Java Version
 * http://www.heatonresearch.com/encog/
 * http://code.google.com/p/encog-java/
 
 * Copyright 2008-2010 Heaton Research, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *   
 * For more information on Heaton Research copyrights, licenses 
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */

package org.encog.persist.persistors;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

import org.encog.engine.network.rbf.RadialBasisFunction;
import org.encog.mathutil.rbf.GaussianFunction;
import org.encog.mathutil.rbf.RBFEnum;
import org.encog.neural.networks.layers.RadialBasisFunctionLayer;
import org.encog.parse.tags.read.ReadXML;
import org.encog.parse.tags.write.WriteXML;
import org.junit.Assert;
import org.junit.Test;

/**
 * Simple unit test for the radial basis function layer.
 * @author jheaton
 *
 */
public class TestRadialBasisFunctionLayerPersistor {

	/**
	 * Create a test RBF layer to save and load.
	 * @return The created test layer.
	 */
	private RadialBasisFunctionLayer createTestLayer() {
		final RadialBasisFunctionLayer layer = new RadialBasisFunctionLayer(1);
		double[] centers = { 1 };
		layer.setRBFFunction(0, RBFEnum.Gaussian, centers, 3);
		return layer;
	}

	/**
	 * 
	 * @param store A byte array that holds the stored object.
	 * @return The loaded object.
	 * @throws Exception If an exception happens, this is a unit test, so let
	 * the unit test runner report it.
	 */
	private RadialBasisFunctionLayer loadRadialFunctionLayer(final byte[] store)
			throws Exception {
		final ByteArrayInputStream input = new ByteArrayInputStream(store);
		final RadialBasisFunctionLayerPersistor p = 
			new RadialBasisFunctionLayerPersistor();
		final ReadXML readXML = new ReadXML(input);
		final RadialBasisFunctionLayer result = (RadialBasisFunctionLayer) p
				.load(readXML);
		input.close();
		return result;
	}

	/**
	 * Save a radial basis function layer to a byte array.
	 * @param layer The layer to be saved.
	 * @return The layer saved as a byte array.
	 * @throws Exception If an exception happens, this is a unit test, so let
	 * the unit test runner report it.
	 */
	private byte[] saveRadialFunctionLayer(final RadialBasisFunctionLayer layer)
			throws Exception {
		final ByteArrayOutputStream output = new ByteArrayOutputStream();
		final RadialBasisFunctionLayerPersistor p = 
			new RadialBasisFunctionLayerPersistor();
		final WriteXML xmlOutput = new WriteXML(output);
		xmlOutput.beginDocument();
		p.save(layer, xmlOutput);
		xmlOutput.endDocument();
		output.close();
		final byte[] array = output.toByteArray();

		return array;
	}

	/**
	 * Test saving and then loading a RBF layer.
	 * @throws Exception If an exception happens, this is a unit test, so let
	 * the unit test runner report it.
	 */
	@Test
	public void testPersistRBF() throws Exception {
		final RadialBasisFunctionLayer layer = createTestLayer();
		final byte[] store = saveRadialFunctionLayer(layer);
		final RadialBasisFunctionLayer layer2 = loadRadialFunctionLayer(store);
		Assert.assertEquals(layer.getNeuronCount(), layer2.getNeuronCount());

		RadialBasisFunction[] rbf = layer.getRadialBasisFunction();
		Assert.assertEquals(1, rbf.length);
	
		Assert.assertEquals( 1.0, rbf[0].getCenters()[0], 0.1);
		Assert.assertEquals( 3.0, rbf[0].getWidth(), 0.1);		
		Assert.assertEquals( 0.5, rbf[0].getPeak(), 0.1 );

		
	}

}