/*
 * PairedSitePatterns.java
 *
 * Copyright (C) 2002-2006 Alexei Drummond and Andrew Rambaut
 *
 * This file is part of BEAST.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership and licensing.
 *
 * BEAST is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 *  BEAST 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with BEAST; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

package dr.evolution.alignment;

import dr.evolution.datatype.*;
import dr.evolution.util.Taxon;

import java.util.*;

/**
 * Stores a set of site patterns. This differs from the simple Patterns
 * class because it stores the pattern index for each site. Thus it has
 * a connection to a single alignment.
 *
 * @author Andrew Rambaut
 * @author Alexei Drummond
 *
 * @version $Id: PairedSitePatterns.java,v 1.3 2005/06/23 13:53:41 rambaut Exp $
 */
public class PairedSitePatterns implements SiteList {

	private final SiteList siteList;

	private final PairedDataType dataType;

	public PairedSitePatterns(SiteList siteList) {
		this.siteList = siteList;
		dataType = new PairedDataType(siteList.getDataType());
	}

	// **************************************************************
	// SiteList IMPLEMENTATION
	// **************************************************************

	/**
	 * @return number of sites
	 */
	public int getSiteCount() {
		int n = siteList.getSiteCount();
		return ((n - 1) * n) / 2;
	}

	/**
	 * Gets the pattern of site as an array of state numbers (one per sequence)
	 * @return the site pattern at siteIndex
	 */
	public int[] getSitePattern(int siteIndex) {
		int n = siteList.getSiteCount();
		int index1 = 0;
		int index2 = 0;
		int site = 0;
		for (int i = 0; i < n; i++) {
			for (int j = i + 1; j < n; j++) {
				if (site == siteIndex) {
					index1 = i;
					index2 = j;
					break;
				}
				site++;
			}
			if (site == siteIndex) {
				break;
			}
		}

		int[] pattern = new int[siteList.getTaxonCount()];

		int[] pattern1 = siteList.getSitePattern(index1);
		int[] pattern2 = siteList.getSitePattern(index2);

		for (int k = 0; k < pattern.length; k ++) {
			pattern[k] = dataType.getState(pattern1[k], pattern2[k]);
		}

		return pattern;
	}

	/**
	 * Gets the pattern index at a particular site
	 * @return the patternIndex
	 */
	public int getPatternIndex(int siteIndex) {
		return siteIndex;
	}

	/**
	 * @return the sequence state at (taxon, site)
	 */
	public int getState(int taxonIndex, int siteIndex) {
		return getSitePattern(siteIndex)[taxonIndex];
	}

	// **************************************************************
	// PatternList IMPLEMENTATION
	// **************************************************************

	/**
	 * @return number of patterns
	 */
	public int getPatternCount() {
		return getSiteCount();
	}

	/**
	 * @return number of states for this siteList
	 */
	public int getStateCount() {
		return dataType.getStateCount();
	}

	/**
	 * Gets the length of the pattern strings which will usually be the
	 * same as the number of taxa
	 * @return the length of patterns
	 */
	public int getPatternLength() {
		return getTaxonCount();
	}

	/**
	 * Gets the pattern as an array of state numbers (one per sequence)
	 * @return the pattern at patternIndex
	 */
	public int[] getPattern(int patternIndex) {
		return getSitePattern(patternIndex);
	}

	/**
	 * @return state at (taxonIndex, patternIndex)
	 */
	public int getPatternState(int taxonIndex, int patternIndex) {
		return getSitePattern(patternIndex)[taxonIndex];
	}

	/**
	 * Gets the weight of a site pattern
	 */
	public double getPatternWeight(int patternIndex) {
		return 1.0;
	}

	/**
	 * @return the array of pattern weights
	 */
	public double[] getPatternWeights() {
		double[] weights = new double[getSiteCount()];
		for (int i = 0; i < getSiteCount(); i++) {
			weights[i] = 1.0;
		}
		return weights;
	}

	/**
	 * @return the DataType of this siteList
	 */
	public DataType getDataType() {
		return dataType;
	}

	/**
	 * @return the frequency of each state
	 */
	public double[] getStateFrequencies() {
		return Utils.empiricalStateFrequencies(this);
	}

	// **************************************************************
	// TaxonList IMPLEMENTATION
	// **************************************************************

	/**
	 * @return a count of the number of taxa in the list.
	 */
	public int getTaxonCount() {
		if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
		return siteList.getTaxonCount();
	}

	/**
	 * @return the ith taxon.
	 */
	public Taxon getTaxon(int taxonIndex) {
		if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
		return siteList.getTaxon(taxonIndex);
	}

	/**
	 * @return the ID of the ith taxon.
	 */
	public String getTaxonId(int taxonIndex) {
		if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
		return siteList.getTaxonId(taxonIndex);
	}

	/**
	 * returns the index of the taxon with the given id.
	 */
	public int getTaxonIndex(String id) {
		if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
		return siteList.getTaxonIndex(id);
	}

	/**
	 * returns the index of the given taxon.
	 */
	public int getTaxonIndex(Taxon taxon) {
		if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
		return siteList.getTaxonIndex(taxon);
	}

    public List<Taxon> asList() {
        if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
        return siteList.asList();
    }

    public Iterator<Taxon> iterator() {
        if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
        return siteList.iterator();
    }

    /**
	 * @return an object representing the named attributed for the given taxon.
	 * @param taxonIndex the index of the taxon whose attribute is being fetched.
	 * @param name the name of the attribute of interest.
	 */
	public Object getTaxonAttribute(int taxonIndex, String name) {
		if (siteList == null) throw new RuntimeException("SitePatterns has no alignment");
		return siteList.getTaxonAttribute(taxonIndex, name);
	}

	// **************************************************************
	// Identifiable IMPLEMENTATION
	// **************************************************************

	protected String id = null;

	/**
	 * @return the id.
	 */
	public String getId() {
		return id;
	}

	/**
	 * Sets the id.
	 */
	public void setId(String id) {
		this.id = id;
	}
}
