/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2008 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.example;

import java.util.Arrays;

import com.rapidminer.tools.LogService;

/** Attribute statistics object for nominal attributes. 
 * 
 *  @author Ingo Mierswa
 *  @version $Id: NominalStatistics.java,v 1.10 2008/05/09 19:22:42 ingomierswa Exp $
 */
public class NominalStatistics implements Statistics {

    private static final long serialVersionUID = -7644523717916796701L;

    private long mode = -1;
    
    private long maxCounter = 0;

    private long[] scores;
    
    public NominalStatistics() {}
    
    /** Clone constructor. */
    private NominalStatistics(NominalStatistics other) {
        this.mode = other.mode;
        this.maxCounter = other.maxCounter;
        if (other.scores != null) {
            this.scores = new long[other.scores.length];
            for (int i = 0; i < this.scores.length; i++)
                this.scores[i] = other.scores[i];
        }
    }
    
    /** Returns a clone of this statistics object. The attribute is only cloned by reference. */
    public Object clone() {
        return new NominalStatistics(this);
    }
    
    public void startCounting(Attribute attribute) {
        this.scores = new long[attribute.getMapping().size()];
        this.mode = -1;
        this.maxCounter = 0;
    }
    
    public void count(double doubleIndex) {
        if (!Double.isNaN(doubleIndex)) {
            int index = (int)doubleIndex;
            if (index >= 0) {
            	// more values than before? Increase Array size...
            	if (index >= scores.length) {
            		long[] newScores = new long[index + 1];
            		System.arraycopy(scores, 0, newScores, 0, scores.length);
            		scores = newScores;
            	}
            	scores[index]++;
            	if (scores[index] > maxCounter) {
            		maxCounter = scores[index];
            		mode = index;
            	}
            }
        }
    }
    
    public boolean handleStatistics(String name) {
        return 
            MODE.equals(name) ||
            COUNT.equals(name) ||
            LEAST.equals(name);
    }

    public double getStatistics(Attribute attribute, String name, String parameter) {
        if (MODE.equals(name)) {
            return this.mode;
        } else if (COUNT.equals(name)) {
            if (parameter != null) {
                return getValueCount(attribute, parameter);
            } else {
                LogService.getGlobal().log("Cannot calculate statistics COUNT, no value given...", LogService.WARNING);
                return Double.NaN;
            }
        } if (LEAST.equals(name)) {
            long minCounter = Integer.MAX_VALUE;
            long least = 0;
            for (int i = 0; i < scores.length; i++) {
                if (scores[i] < minCounter) {
                    minCounter = scores[i];
                    least = i;
                }
            }
            return least;
        } else {
            LogService.getGlobal().log("Cannot calculate statistics, unknown type: " + name, LogService.WARNING);
            return Double.NaN;
        }
    }
    
    private long getValueCount(Attribute attribute, String value) {
    	if ((attribute != null) && (attribute.getMapping() != null)) {
    		int index = attribute.getMapping().getIndex(value);
    		if (index < 0) {
    			return -1;
    		} else {
    			return scores[index];
    		}
    	} else {
    		return -1;
    	}
    }
    
    public String toString() {
        return "Counts: " + Arrays.toString(scores);
    }
}