/* EmptySequence.java
 * This file is part of Artemis
 *
 * Copyright (C) 2007  Genome Research Limited
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package uk.ac.sanger.artemis.io;

import org.biojava.bio.symbol.IllegalSymbolException;

import uk.ac.sanger.artemis.sequence.Bases;
import uk.ac.sanger.artemis.util.ReadOnlyException;

/**
 * Used when retrieving just part of a sequence with associated features.
 **/

public class PartialSequence implements Sequence 
{
  private char[] sequence;
  /** Count of the a bases in the sequence. */
  private int a_count = 0;

  /** Count of the c bases in the sequence. */
  private int c_count = 0;

  /** Count of the g bases in the sequence. */
  private int g_count = 0;

  /** Count of the t bases in the sequence. */
  private int t_count = 0;
  
  /** full sequence length */
  private int sequenceLength;

  /** start of this part of the sequence*/
  private int start;
  
  /** orientation/directionality of the location. Should be 0,-1 or +1 */
  private Short strand;
  
  /** values are 0,1,2 */
  private Integer phase;
  
  /**
   * Holds ony part of the sequence
   * @param sequence        part of the sequence to store
   * @param sequenceLength  full sequence length
   * @param start           start position of sequence
   * @param strand
   * @param phase
   */
  public PartialSequence(final char[] sequence, 
                         final int sequenceLength,
                         final int start,
                         final Short strand,
                         final Integer phase)
  {
    try
    {
      setFromChar(sequence);
      this.sequenceLength = sequenceLength;
      this.start = start;
      this.strand = strand;
      this.phase = phase;
    }
    catch(IllegalSymbolException e)
    {
      e.printStackTrace();
    }
    catch(ReadOnlyException e)
    {
      e.printStackTrace();
    }
  }
  
  public char charAt(int i)
  {
    return sequence[i];
  }

  public int getACount()
  {
    return a_count;
  }

  public int getCCount()
  {
    return c_count;
  }

  public char[] getCharSubSequence(int this_start, int this_end)
  {
    int subSeqLength = this_end-this_start+1;
    char subSequence[] = new char[subSeqLength];
    int count = 0;
    
    this_start -= start;
    this_end   -= start;
    
    for(int i=this_start;i<=this_end;i++)
    {
      subSequence[count] = sequence[i];
      count++;
    }

    if(isComplement())
      return Bases.reverseComplement(subSequence);
    
    return subSequence;
  }

  
  public int getGCount()
  {
    return g_count;
  }

  public int getOtherCount()
  {
    return
      sequence.length - (getCCount() + getACount() + getTCount() + getGCount());
  }

  public String getSubSequence(int start, int end)
  {
    return new String(getCharSubSequence(start, end));
  }
  
  public char[] getSequence()
  {
    return sequence;
  }

  public int getTCount()
  {
    return t_count;
  }

  public int length()
  {
    return sequenceLength;
  }

  public void setFromChar(char[] sequence) throws ReadOnlyException, IllegalSymbolException
  { 
    this.sequence = sequence;
    setCounts();
  }
  
  /**
   *  Set the a_count, c_count, t_count and g_count variables.
   **/
  private void setCounts() 
  {
    a_count = c_count = t_count = g_count = 0;

    for(int i = 0 ; i < length(); ++i) 
      counter(sequence[i]);
  }

  private void counter(char c)
  {
    switch(c)
    {
      case 'a':
        ++a_count;
        break;
      case 'c':
        ++c_count;
        break;
      case 'g':
        ++g_count;
        break;
      case 't':
        ++t_count;
        break;
      default:
        break;
    }
  }

  public Short getStrand()
  {
    return strand;
  }
  
  public boolean isComplement()
  {
    if(strand.intValue() == -1)
      return true;
    return false;
  }

  public Integer getPhase()
  {
    return phase;
  }
  
  public void clear()
  {
    sequence = null;
  }
}