/*
 *                    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/
 *
 */

package org.biojava.bio.program.gff;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.biojava.bio.Annotation;
import org.biojava.bio.BioException;
import org.biojava.bio.SmallAnnotation;
import org.biojava.bio.seq.Feature;
import org.biojava.bio.seq.FramedFeature;
import org.biojava.bio.seq.Sequence;
import org.biojava.bio.seq.SequenceAnnotator;
import org.biojava.bio.seq.StrandedFeature;
import org.biojava.bio.symbol.RangeLocation;
import org.biojava.utils.ChangeVetoException;

/**
 * A set of entries and comments as a representation of a GFF file.
 * <p>
 * This is an intermediate storage solution for GFF stuff. It lets you
 * collect together an arbitrary set of GFF records and comments, and then
 * do something with them later.
 *
 * @author Matthew Pocock
 * @author Keith James (docs)
 * @author Len Trigg
 */
public class GFFEntrySet {
  public static final String PROPERTY_GFF_SCORE = "org.biojava.bio.program.gff.gff_feature_score";

  /**
   * All of the lines - comments & records
   */
  private List lines;

  /**
   * Make an empty <span class="type">GFFEntrySet</span>.
   */
  public GFFEntrySet() {
    lines = new ArrayList();
  }

  /**
   * Loop over all lines in the set.
   * <p>
   * The <span class="type">Iterator</span>
   * will return <span class="type">String</span> and <span class="type">
   * GFFRecord</span> objects in the order that they were added to this set.
   * It is your responsibility to check the type of
   * <span class="method">hasNext()</span> before casting it.
   */
  public Iterator lineIterator() {
    return lines.iterator();
  }

  /**
   * Add a comment to the end of this set.
   * <p>
   * This should be the text of the comment, without the leading
   * '<code>#</code>'.
   *
   * @param comment a <span class="type">String</span> giving the comment
   */
  public void add(String comment) {
    lines.add(comment);
  }

  /**
   * Add a <span class="type">GFFRecord</span> to the end of this set.
   *
   * @param record a <span class="type">GFFRecord</span> to append
   */
  public void add(GFFRecord record) {
    lines.add(record);
  }

  /**
   * Return how many lines are in this set.
   *
   * @return the size
   */
  public int size() {
    return lines.size();
  }

  /**
   * Get an annotator that can add GFF features to a
   * <span class="type">Sequence</span> using the features in this
   * <span class="type">GFFEntrySet</span>.  The SequenceAnnotator
   * returned by this method currently adds new features to an
   * existing sequence (assuming it implements MutableFeatureHolder).
   *
   * <p>
   * Sequences are only annotated if their getName() method returns
   * a name equal to the sequence name field of one or more records
   * in this GFFEntrySet.
   * </p>
   *
   * @return an <span class="type">SequenceAnnotator</span> that adds GFF features
   */
  public SequenceAnnotator getAnnotator() {
    return getAnnotator(true);
  }

  /**
   * Get an annotator that can add GFF features to a
   * <span class="type">Sequence</span> using the features in this
   * <span class="type">GFFEntrySet</span>.  The SequenceAnnotator
   * returned by this method currently adds new features to an
   * existing sequence (assuming it implements MutableFeatureHolder).
   *
   * <p>
   * If checkSeqName is set to true,
   * Sequences are only annotated if their getName() method returns
   * a name equal to the sequence name field of one or more records
   * in this GFFEntrySet. If checkSeqName is false, then all features are
   * added to the sequence regardless of name.
   * </p>
   *
   * @param checkSeqName  boolean to indicate if only records with names
   *        matching the sequences name should be added
   * @return an <span class="type">SequenceAnnotator</span> that adds GFF featur
   es
   */
  public SequenceAnnotator getAnnotator(final boolean checkSeqName) {
    return new SequenceAnnotator() {
      public Sequence annotate(Sequence seq) throws BioException, ChangeVetoException {
        Feature.Template plain = new Feature.Template();
        StrandedFeature.Template stranded = new StrandedFeature.Template();
        FramedFeature.Template framed = new FramedFeature.Template();
        plain.annotation = Annotation.EMPTY_ANNOTATION;
        stranded.annotation = Annotation.EMPTY_ANNOTATION;
        framed.annotation = Annotation.EMPTY_ANNOTATION;
        for (Iterator i = lineIterator(); i.hasNext();) {
          Object o = i.next();
          if (o instanceof GFFRecord) {
            GFFRecord rec = (GFFRecord) o;
            if (!checkSeqName || rec.getSeqName().equals(seq.getName())) {
              Feature.Template thisTemplate;

              if (rec.getStrand() == StrandedFeature.UNKNOWN) {
                plain.location = new RangeLocation(rec.getStart(), rec.getEnd());
                plain.type = rec.getFeature();
                plain.source = rec.getSource();
                thisTemplate = plain;
              } else if (rec.getFrame() == GFFTools.NO_FRAME) {
                stranded.location = new RangeLocation(rec.getStart(), rec.getEnd());
                stranded.type = rec.getFeature();
                stranded.source = rec.getSource();
                stranded.strand = rec.getStrand();
                thisTemplate = stranded;
              } else {
                framed.location = new RangeLocation(rec.getStart(), rec.getEnd());
                framed.type = rec.getFeature();
                framed.source = rec.getSource();
                framed.strand = rec.getStrand();
                switch (rec.getFrame()) {
                  case 0:
                    framed.readingFrame = FramedFeature.FRAME_0;
                    break;
                  case 1:
                    framed.readingFrame = FramedFeature.FRAME_1;
                    break;
                  case 2:
                    framed.readingFrame = FramedFeature.FRAME_2;
                    break;
                }
                thisTemplate = framed;
              }

              thisTemplate.annotation = new SmallAnnotation();
              if (rec.getScore() != GFFTools.NO_SCORE) {
                thisTemplate.annotation.setProperty(PROPERTY_GFF_SCORE, new Double(rec.getScore()));
              }
              Map attributes = rec.getGroupAttributes();
              Iterator it = attributes.keySet().iterator();
              while (it.hasNext()) {
                String key = (String) it.next();
                thisTemplate.annotation.setProperty(key, attributes.get(key));
              }
              seq.createFeature(thisTemplate);
            }
          }
        }
        return seq;
      }
    };
  }

  /**
   * Filter this entry set into another set.
   *
   * @param filter the <span class="type">GFFRecordFilter</span> to filter with
   * @return  a new <span class="type">GFFEntrySet</span> containing only the
   *          items filtered in by the filter
   */
  public GFFEntrySet filter(GFFRecordFilter filter) {
    GFFEntrySet accepted = new GFFEntrySet();
    for (Iterator i = lineIterator(); i.hasNext();) {
      Object o = i.next();
      if (o instanceof GFFRecord) {
        GFFRecord record = (GFFRecord) o;
        if (filter.accept(record)) {
          accepted.add(record);
        }
      }
    }

    return accepted;
  }

  /**
   * Get the <span class="type">GFFDocumentHandler</span> for adding to this
   * set.
   *
   * @return  a <span class="type">GFFDocumentHandler</span> that adds everything
   *          that it recieves to this set
   */
  public GFFDocumentHandler getAddHandler() {
    return new EntrySetBuilder();
  }

  /**
   * Write all records in this set out to a handler.
   *
   * @param handler  the GFFDocumentHandler to inform of the records
   */
  public void streamRecords(GFFDocumentHandler handler) {
    handler.startDocument("");

    for (Iterator i = lineIterator(); i.hasNext();) {
      Object line = i.next();
      if (line instanceof String) {
        handler.commentLine((String) line);
      } else {
        handler.recordLine((GFFRecord) line);
      }
    }

    handler.endDocument();
  }

  /**
   * The type of object returned by <span class="method">getAddHandler</span>.
   *
   * @author Matthew Pocock
   * @author Thomas Down
   */
  private class EntrySetBuilder implements GFFDocumentHandler {
    public void startDocument(String locator) {
    }

    public void endDocument() {
    }

    public void commentLine(String comment) {
      lines.add(comment);
    }

    public void recordLine(GFFRecord record) {
      lines.add(record);
    }
  }
}