/*
 *                    BioJava development code
 *
 * This code may be freely distributed and modified under the
 * terms of the GNU Lesser General Public Licence.  This should
 * be distributed with the code.  If you do not have a copy,
 * see:
 *
 *      http://www.gnu.org/copyleft/lesser.html
 *
 * Copyright for this code is held jointly by the individual
 * authors.  These should be listed in @author doc comments.
 *
 * For more information on the BioJava project and its aims,
 * or to join the biojava-l mailing list, visit the home page
 * at:
 *
 *      http://www.biojava.org/
 *
 * Created on June 17, 2010
 * Author: Mark Chapman
 */

package org.biojava.nbio.alignment.template;

import org.biojava.nbio.core.alignment.template.SequencePair;
import org.biojava.nbio.core.alignment.template.SubstitutionMatrix;
import org.biojava.nbio.core.sequence.template.Compound;
import org.biojava.nbio.core.sequence.template.CompoundSet;
import org.biojava.nbio.core.sequence.template.Sequence;

import java.util.ArrayList;
import java.util.List;

/**
 * Implements common code for an {@link Aligner} for a pair of {@link Sequence}s.
 *
 * @author Mark Chapman
 * @param <S> each {@link Sequence} of the alignment pair is of type S
 * @param <C> each element of an {@link AlignedSequence} is a {@link Compound} of type C
 */
public abstract class AbstractPairwiseSequenceAligner<S extends Sequence<C>, C extends Compound>
		extends AbstractMatrixAligner<S, C> implements PairwiseSequenceAligner<S, C> {

	// additional input fields
	private S query, target;

	// additional output field
	protected SequencePair<S, C> pair;

	/**
	 * Before running a pairwise global sequence alignment, data must be sent in via calls to
	 * {@link #setQuery(Sequence)}, {@link #setTarget(Sequence)}, {@link #setGapPenalty(GapPenalty)}, and
	 * {@link #setSubstitutionMatrix(SubstitutionMatrix)}.
	 */
	protected AbstractPairwiseSequenceAligner() {
	}

	/**
	 * Prepares for a pairwise global sequence alignment.
	 *
	 * @param query the first {@link Sequence} of the pair to align
	 * @param target the second {@link Sequence} of the pair to align
	 * @param gapPenalty the gap penalties used during alignment
	 * @param subMatrix the set of substitution scores used during alignment
	 */
	protected AbstractPairwiseSequenceAligner(S query, S target, GapPenalty gapPenalty,
			SubstitutionMatrix<C> subMatrix) {
		this(query, target, gapPenalty, subMatrix, false);
	}

	/**
	 * Prepares for a pairwise sequence alignment.
	 *
	 * @param query the first {@link Sequence} of the pair to align
	 * @param target the second {@link Sequence} of the pair to align
	 * @param gapPenalty the gap penalties used during alignment
	 * @param subMatrix the set of substitution scores used during alignment
	 * @param local if true, find a region of similarity rather than aligning every compound
	 */
	protected AbstractPairwiseSequenceAligner(S query, S target, GapPenalty gapPenalty,
			SubstitutionMatrix<C> subMatrix, boolean local) {
		super(gapPenalty, subMatrix, local);
		this.query = query;
		this.target = target;
		reset();
	}

	/**
	 * Sets the query {@link Sequence}.
	 *
	 * @param query the first {@link Sequence} of the pair to align
	 */
	public void setQuery(S query) {
		this.query = query;
		reset();
	}

	/**
	 * Sets the target {@link Sequence}.
	 *
	 * @param target the second {@link Sequence} of the pair to align
	 */
	public void setTarget(S target) {
		this.target = target;
		reset();
	}

	// method for PairwiseSequenceAligner

	@Override
	public SequencePair<S, C> getPair() {
		if (pair == null) {
			align();
		}
		return pair;
	}

	// methods for PairwiseSequenceScorer

	@Override
	public S getQuery() {
		return query;
	}

	@Override
	public S getTarget() {
		return target;
	}

	// methods for AbstractMatrixAligner

	@Override
	protected CompoundSet<C> getCompoundSet() {
		return (query == null) ? null : query.getCompoundSet();
	}

	@Override
	protected List<C> getCompoundsOfQuery() {
		return (query == null) ? new ArrayList<C>() : query.getAsList();
	}

	@Override
	protected List<C> getCompoundsOfTarget() {
		return (target == null) ? new ArrayList<C>() : target.getAsList();
	}

	@Override
	protected int[] getScoreMatrixDimensions() {
		return new int[] { (query == null) ? 1 : query.getLength() + 1, (target == null) ? 1 : target.getLength() + 1,
				(getGapPenalty() == null || getGapPenalty().getType() == GapPenalty.Type.LINEAR) ? 1 : 3 };
	}

	@Override
	protected int getSubstitutionScore(int queryColumn, int targetColumn) {
		return getSubstitutionMatrix().getValue(query.getCompoundAt(queryColumn), target.getCompoundAt(targetColumn));
	}

	@Override
	protected boolean isReady() {
		return query != null && target != null && getGapPenalty() != null && getSubstitutionMatrix() != null &&
				query.getCompoundSet().equals(target.getCompoundSet());
	}

	@Override
	protected void reset() {
		super.reset();
		pair = null;
		if (query != null && target != null && getGapPenalty() != null && getSubstitutionMatrix() != null &&
				query.getCompoundSet().equals(target.getCompoundSet())) {
			int maxq = 0, maxt = 0;
			for (C c : query) {
				maxq += getSubstitutionMatrix().getValue(c, c);
			}
			for (C c : target) {
				maxt += getSubstitutionMatrix().getValue(c, c);
			}
			max = Math.max(maxq, maxt);
			score = min = isLocal() ? 0 : (int) (2 * getGapPenalty().getOpenPenalty() + (query.getLength() +
					target.getLength()) * getGapPenalty().getExtensionPenalty());
		}
	}

}