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/*
 *  streams library
 *
 *  Copyright (C) 2011-2014 by Christian Bockermann, Hendrik Blom
 * 
 *  streams is a library, API and runtime environment for processing high
 *  volume data streams. It is composed of three submodules "stream-api",
 *  "stream-core" and "stream-runtime".
 *
 *  The streams library (and its submodules) 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.
 *
 *  The stream.ai library (and its submodules) 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 stream.data;

import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

/**
 * This is a generic utility class that holds a map of keys to double values.
 * Instance of this class can be added, subtracted and multiplied with a scalar.
 * 
 * @author Christian Bockermann <[email protected]>
 */
public class Statistics extends LinkedHashMap {

	/** The unique class ID */
	private static final long serialVersionUID = 5994452860264445162L;

	String name = "";
	String key = "";

	public Statistics() {
	}

	public Statistics(String name) {
		this.name = name;
	}

	public Statistics(Statistics stats) {
		this(stats.getName());
		this.add(stats);
	}

	public String getName() {
		return this.name;
	}

	public Statistics setName(String name) {
		this.name = name;
		return this;
	}

	/**
	 * @return the key
	 */
	public String getKey() {
		return key;
	}

	/**
	 * @param key
	 *            the key to set
	 */
	public Statistics setKey(String key) {
		this.key = key;
		return this;
	}

	/**
	 * Adds the given statistics vector to this instance.
	 * 
	 * @param st
	 */
	public synchronized void add(Map st) {
		for (String key : st.keySet()) {
			Double d = get(key);
			if (d == null)
				d = st.get(key);
			else
				d += st.get(key);

			put(key, d);
		}
	}

	public synchronized void add(Statistics st) {
		for (String key : st.keySet()) {
			Double d = get(key);
			if (d == null)
				d = st.get(key);
			else
				d += st.get(key);

			put(key, d);
		}
	}

	public synchronized void substract(Map st) {
		for (String key : st.keySet()) {
			Double d = get(key);
			if (d == null)
				d = -st.get(key);
			else
				d -= st.get(key);

			put(key, d);
		}
	}

	public synchronized void max(Map st) {

		List keys = new LinkedList(this.keySet());
		for (String k : st.keySet())
			if (!keys.contains(k))
				keys.add(k);

		for (String key : keys)
			this.put(key, max(get(key), st.get(key)));
	}

	protected Double max(Double d1, Double d2) {
		if (d1 == null && d2 == null)
			return Double.NaN;

		if (d1 == null)
			return d2;

		if (d2 == null)
			return d1;

		return Math.max(d1, d2);
	}

	public Statistics divideBy(String key) {
		Statistics st = new Statistics();
		st.putAll(this);

		Double x = get(key);
		if (x == null || x == 0.0d)
			return st;

		for (String k : keySet()) {
			if (!k.equals(key)) {
				Double val = get(k);
				st.put(k, val / x);
			}
		}
		return st;
	}

	public Statistics divideBy(Double val) {
		Statistics st = new Statistics();
		for (String k : keySet())
			st.put(k, get(k) / val);

		return st;
	}

	public void add(String key, Double val) {
		if (this.containsKey(key)) {
			Double d = get(key) + val;
			put(key, d);
		} else
			put(key, val);
	}
}