//
// This software is now distributed according to
// the Lesser Gnu Public License.  Please see
// http://www.gnu.org/copyleft/lesser.txt for
// the details.
//    -- Happy Computing!
//
package com.stevesoft.pat;

import java.util.*;

/**
 * A special optimization of multi that is used when the common subpattern ".*"
 * is encountered.
 */
class DotMulti extends PatternSub
{
  patInt fewestMatches, mostMatches;

  public patInt minChars()
  {
    return fewestMatches;
  }

  public patInt maxChars()
  {
    return mostMatches;
  }

  public boolean matchFewest = false;

  StringLike src = null;

  int srclength = 0;

  boolean dotDoesntMatchCR = true;

  DotMulti(patInt a, patInt b)
  {
    fewestMatches = a;
    mostMatches = b;
  }

  public String toString()
  {
    return ".{" + fewestMatches + "," + mostMatches + "}"
            + (matchFewest ? "?" : "") + "(?# <= dot multi)" + nextString();
  }

  final int submatchInternal(int pos, Pthings pt)
  {
    if (pos < srclength)
    {
      if (dotDoesntMatchCR)
      {
        if (src.charAt(pos) != '\n')
        {
          return 1 + pos;
        }
      }
      else
      {
        return 1 + pos;
      }
    }
    return -1;
  }

  final static int step = 1;

  static int idcount = 1;

  public int matchInternal(int pos, Pthings pt)
  {
    int m = -1;
    int i = pos;
    src = pt.src;
    srclength = src.length();
    dotDoesntMatchCR = pt.dotDoesntMatchCR;
    if (matchFewest)
    {
      int nMatches = 0;
      while (fewestMatches.intValue() > nMatches)
      {
        i = submatchInternal(i, pt);
        if (i < 0)
        {
          return -1;
        }
        nMatches++;
      }
      if (i < 0)
      {
        return -1;
      }
      int ii = nextMatch(i, pt);
      if (ii >= 0)
      {
        return ii;
      }
      if (!mostMatches.finite())
      {
        while (i >= 0)
        {
          i = submatchInternal(i, pt);
          if (i < 0)
          {
            return -1;
          }
          ii = nextMatch(i, pt);
          if (ii >= 0)
          {
            return ii;
          }
        }
      }
      else
      {
        while (i > 0)
        {
          i = submatchInternal(i, pt);
          if (i < 0)
          {
            return -1;
          }
          nMatches++;
          if (nMatches > mostMatches.intValue())
          {
            return -1;
          }
          ii = nextMatch(i, pt);
          if (ii >= 0)
          {
            return ii;
          }
        }
      }
      return -1;
    }
    int nMatches = 0;
    while (fewestMatches.intValue() > nMatches)
    {
      i = submatchInternal(i, pt);
      if (i >= 0)
      {
        nMatches++;
      }
      else
      {
        return -1;
      }
    }
    m = i;
    if (mostMatches.finite())
    {
      while (nMatches < mostMatches.intValue())
      {
        i = submatchInternal(i, pt);
        if (i >= 0)
        {
          m = i;
          nMatches++;
        }
        else
        {
          break;
        }
      }
    }
    else
    {
      while (true)
      {
        i = submatchInternal(i, pt);
        if (i >= 0)
        {
          m = i;
          nMatches++;
        }
        else
        {
          break;
        }
      }
    }
    while (m >= pos)
    {
      int r = nextMatch(m, pt);
      if (r >= 0)
      {
        return r;
      }
      m -= step;
      nMatches--;
      if (nMatches < fewestMatches.intValue())
      {
        return -1;
      }
    }
    return -1;
  }

  Pattern clone1(Hashtable h)
  {
    DotMulti dm = new DotMulti(fewestMatches, mostMatches);
    dm.matchFewest = matchFewest;
    return dm;
  }
}
