/*
 *                    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.phred;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintStream;
import java.io.Serializable;
import java.util.NoSuchElementException;
import java.util.Vector;

import org.biojava.bio.seq.Sequence;
import org.biojava.bio.seq.io.ParseException;
import org.biojava.bio.seq.io.SeqIOListener;
import org.biojava.bio.seq.io.SequenceFormat;
import org.biojava.bio.seq.io.StreamParser;
import org.biojava.bio.seq.io.SymbolTokenization;
import org.biojava.bio.symbol.IllegalSymbolException;
import org.biojava.bio.symbol.IntegerAlphabet;
import org.biojava.utils.ParseErrorSource;
import org.biojava.utils.ParseErrorListener;
import org.biojava.utils.ParseErrorEvent;

/**
 * Format object representing Phred Quality files.
 * The only `sequence property' reported by this parser
 * is PROPERTY_DESCRIPTIONLINE, which is the contents of the
 * sequence's description line (the line starting with a '>'
 * character).
 *
 * Essentially a rework of FastaFormat to cope with the quirks of Phred Quality data.<p>
 * Copyright (c) 2001<p>
 * Company:      AgResearch<p>
 *
 * @author Mark Schreiber
 * @author Greg Cox
 * @author Frans Verhoef
 * @since 1.1
 */

public class PhredFormat implements SequenceFormat, ParseErrorSource, ParseErrorListener, Serializable {
  
  public static final String DEFAULT = "PHRED";
  
  private Vector mListeners = new Vector();
  
  /**
   * Constant string which is the property key used to notify
   * listeners of the description lines of Phred sequences.
   */
  
  public final static String PROPERTY_DESCRIPTIONLINE = "description_line";
  
  /**
   * The line width for output.
   */
  private int lineWidth = 60;
  
  /**
   * Retrive the current line width.
   *
   * @return the line width
   */
  
  public int getLineWidth() {
    return lineWidth;
  }
  
  /**
   * Set the line width.
   * <p>
   * When writing, the lines of sequence will never be longer than the line
   * width.
   *
   * @param width the new line width
   */
  
  public void setLineWidth(int width) {
    this.lineWidth = width;
  }
  
  public boolean readSequence(BufferedReader reader,
  SymbolTokenization symParser,
  SeqIOListener siol)
  throws IllegalSymbolException, IOException, ParseException {
    String line = reader.readLine();
    if (line == null) {
      throw new IOException("Premature stream end");
    }
    if (!line.startsWith(">")) {
      throw new IOException("Stream does not appear to contain Phred formatted data: " + line);
    }
    
    siol.startSequence();
    
    String description = line.substring(1).trim();
    siol.addSequenceProperty(PROPERTY_DESCRIPTIONLINE, description);
    
    boolean seenEOF = readSequenceData(reader, symParser, siol);
    siol.endSequence();
    
    return !seenEOF;
  }
  
  private boolean readSequenceData(BufferedReader br,
  SymbolTokenization parser,
  SeqIOListener listener)
  throws IOException, IllegalSymbolException {
    char[] buffer = new char[256];
    StreamParser sparser = parser.parseStream(listener);
    boolean seenEOF = false; //reached the end of the file
    boolean reachedEnd = false; //reached the end of this sequence
    
    while(reachedEnd == false){// while more sequence
      br.mark(buffer.length); // mark the read ahead limit
      int bytesRead = br.read(buffer,0,buffer.length); // read into the buffer
      while(Character.isDigit(buffer[buffer.length -1])){// may have ended halfway through a number
        br.reset();// if so reset
        buffer = new char[buffer.length+64]; //make the buffer a little bigger
        br.mark(buffer.length); //mark the new read ahead limit
        bytesRead = br.read(buffer,0,buffer.length); //read into buffer
      }
      if(bytesRead < 0){ //ie -1 indicates end of file
        seenEOF = reachedEnd = true;
      }else{ // otherwise
        
        int parseEnd = 0;
        
        // while more sequence and more chars in the buffer and not a new sequence
        while(!reachedEnd && parseEnd < bytesRead && buffer[parseEnd] != '>'){
          ++parseEnd;
        }
        sparser.characters(buffer,0,parseEnd);
        
        //If found the start of a new sequence
        if(parseEnd < bytesRead && buffer[parseEnd] == '>'){
          br.reset(); // reset the reader
          // then skip the file reading pointer to the start of the new sequence ready for the
          //next read (if required).
          if(br.skip(parseEnd) != parseEnd) throw new IOException("Couldn't reset to start of next sequence");
          reachedEnd = true; //found the end of this sequence.
        }
      }
    }
    
    sparser.close();
    return seenEOF;
  }
  
  /**
   * Return a suitable description line for a Sequence. If the
   * sequence's annotation bundle contains PROPERTY_DESCRIPTIONLINE,
   * this is used verbatim.  Otherwise, the sequence's name is used.
   */
  
  protected String describeSequence(Sequence seq) {
    String description = null;
    try {
      description = seq.getAnnotation().getProperty(PROPERTY_DESCRIPTIONLINE).toString();
    } catch (NoSuchElementException ex) {
      description = seq.getName();
    }
    return description;
  }
  
  /**
   * This method will print symbols to the line width followed by a
   * new line etc.  NOTE that an integer symbol does not always
   * correspond to one character therefore a line width of sixty
   * will print sixty characters followed by a new line. Not
   * necessarily sixty integers.
   */
  public void writeSequence(Sequence seq, PrintStream os)
  throws IOException {
    os.print(">");
    os.println(describeSequence(seq));
    
    StringBuffer line = new StringBuffer();
    int seqLen = seq.length();
    
    for (int i = 1, linesPrinted = 1; i <= seqLen; i++) {
      int val = ((IntegerAlphabet.IntegerSymbol)seq.symbolAt(i)).intValue();
      String s = Integer.toString(val);
      if ((line.length() + s.length()) > lineWidth) {
        os.println(line.substring(0));
        line = new StringBuffer();
      }
      line.append(s + " ");
    }
  }
  
  /**
   * <code>writeSequence</code> writes a sequence to the specified
   * <code>PrintStream</code>, using the specified format.
   *
   * @param seq a <code>Sequence</code> to write out.
   * @param format a <code>String</code> indicating which sub-format
   * of those available from a particular
   * <code>SequenceFormat</code> implemention to use when
   * writing.
   * @param os a <code>PrintStream</code> object.
   *
   * @exception IOException if an error occurs.
   * @deprecated use writeSequence(Sequence seq, PrintStream os)
   */
  public void writeSequence(Sequence seq, String format, PrintStream os)
  throws IOException {
    if (! format.equalsIgnoreCase(getDefaultFormat()))
      throw new IllegalArgumentException("Unknown format '"
      + format
      + "'");
    writeSequence(seq, os);
  }
  
  /**
   * <code>getDefaultFormat</code> returns the String identifier for
   * the default format.
   *
   * @return a <code>String</code>.
   * @deprecated
   */
  public String getDefaultFormat() {
    return DEFAULT;
  }
  
  /**
   * Adds a parse error listener to the list of listeners if it isn't already
   * included.
   *
   * @param theListener Listener to be added.
   */
  public synchronized void addParseErrorListener(ParseErrorListener theListener) {
    if (mListeners.contains(theListener) == false) {
      mListeners.addElement(theListener);
    }
  }
  
  /**
   * Removes a parse error listener from the list of listeners if it is
   * included.
   *
   * @param theListener Listener to be removed.
   */
  public synchronized void removeParseErrorListener(ParseErrorListener theListener) {
    if (mListeners.contains(theListener) == true) {
      mListeners.removeElement(theListener);
    }
  }
  
  /**
   * This method determines the behaviour when a bad line is processed.
   * Some options are to log the error, throw an exception, ignore it
   * completely, or pass the event through.
   * <p>
   * This method should be overwritten when different behavior is desired.
   *
   * @param theEvent The event that contains the bad line and token.
   */
  public void BadLineParsed(org.biojava.utils.ParseErrorEvent theEvent) {
    notifyParseErrorEvent(theEvent);
  }
  
  // Protected methods
  /**
   * Passes the event on to all the listeners registered for ParseErrorEvents.
   *
   * @param theEvent The event to be handed to the listeners.
   */
  protected void notifyParseErrorEvent(ParseErrorEvent theEvent) {
    Vector listeners;
    synchronized(this) {
      listeners = (Vector)mListeners.clone();
    }
    
    for (int index = 0; index < listeners.size(); index++) {
      ParseErrorListener client = (ParseErrorListener)listeners.elementAt(index);
      client.BadLineParsed(theEvent);
    }
  }
  
}