/*
* Copyright (c) 1997 - 2016
* Actelion Pharmaceuticals Ltd.
* Gewerbestrasse 16
* CH-4123 Allschwil, Switzerland
*
* All rights reserved.
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* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
*    list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
*    this list of conditions and the following disclaimer in the documentation
*    and/or other materials provided with the distribution.
* 3. Neither the name of the the copyright holder nor the
*    names of its contributors may be used to endorse or promote products
*    derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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package com.actelion.research.chem.properties.complexity;

import com.actelion.research.chem.Molecule;
import com.actelion.research.chem.StereoMolecule;

public class SymmetryCalculator {
	
	/**
	 * 
	 */
	public static double getRatioSymmetricAtoms(StereoMolecule mol) {
		
		mol.ensureHelperArrays(Molecule.cHelperNeighbours);
		
		// Only the biggest fragment remains
		mol.stripSmallFragments();
		
		mol.ensureHelperArrays(Molecule.cHelperSymmetrySimple);
				
		int nAtms = mol.getAtoms();
		
		int maxRank = 0;
		for (int i = 0; i < nAtms; i++) {
			int rank = mol.getSymmetryRank(i);
			
			if(rank > maxRank){
				maxRank=rank;
			}
		}
		
		
		int nSymmetricAtms = nAtms-maxRank;

		double ratio = nSymmetricAtms / (double)nAtms;
		
		return ratio;
		
	}

}
