/*
 
* Java GPX Library (@__identifier__@).
 
* Copyright (c) @__year__@ Franz Wilhelmstötter
 
*
 
* 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.
 
*
 
* Author:
 
*
    
Franz Wilhelmstötter (franz.wilhelmstoetter@gmail.com)
 
*/
package io.jenetics.jpx.geom;

import static java.util.Objects.requireNonNull;

import io.jenetics.jpx.Length;
import io.jenetics.jpx.Length.Unit;
import io.jenetics.jpx.Point;

/**
 
* Helper class for collecting a stream of points to its length.
 
*
 
* @author<a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
 
* @version 1.0
 
* @since 1.0
 
*/

final class LengthCollector {

	
private final Geoid _geoid;
	
private final DoubleAdder _length = new DoubleAdder();

	
private Point _first;
	
private Point _start;

	
LengthCollector(final Geoid geoid) {
		
_geoid = requireNonNull(geoid);
	
}

	
LengthCollector combine(final LengthCollector other) {
		
throw new UnsupportedOperationException();
	
}

	
void add(final Point point) {
		
requireNonNull(point);

		
if (_first == null) {
			
_first = point;
		
}

		
final Point end = _start;
		
_start = point;

		
if (end != null) {
			
_length.add(_geoid.distance(end, _start).doubleValue());
		
}
	
}

	
Length pathLength() {
		
return Length.of(_length.doubleValue(), Unit.METER);
	
}

	
Length tourLength() {
		
if (_start != null && _first != null) {
			
_length.add(_geoid.distance(_start, _first).doubleValue());
		
}
		
return pathLength();
	
}
}