/*
 * Copyright (c) 2003, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.util;


import java.util.Vector;
import java.util.Hashtable;
import java.util.Date;
import java.util.StringTokenizer;

/**
 * Misc static text utility methods.
 */
public class Text {

  /**
   * Retrieves a parameter value from a parameter string. If the parameter
   * is not found the default value is returned.
   *
   * @param s Parameter string, format '<param1>=data1::<param2>=data2'
   * @param param Parameter to retrieve.
   * @param def Default value to return, if the parameter is not found.
   * @return parameter value or default value.
   */
  public static String getParam(String s, String param, String def) {
    if (s == null || param == null) return def;
    int ix  = s.indexOf(param+"=");
    if (ix < 0) return def;

    int startIdx = ix + param.length()+1;
    int endIdx = s.indexOf("::", startIdx);
    if (endIdx < 0) endIdx = s.length();

    try {
      return s.substring(startIdx, endIdx);
    } catch (Exception e) {
      return def;
    }
  }

  // String replace functions below by Erik Wistrand

  /**
   * Replace all occurances of a substring with another string.
   *
   * <p>
   * The returned string will shrink or grow as necessary, depending on
   * the lengths of <tt>v1</tt> and <tt>v2</tt>.
   * </p>
   *
   * <p>
   * Implementation note: This method avoids using the standard String
   * manipulation methods to increase execution speed. 
   * Using the <tt>replace</tt> method does however
   * include two <tt>new</tt> operations in the case when matches are found.
   * </p>
   *
   *
   * @param s  Source string.
   * @param v1 String to be replaced with <code>v2</code>.
   * @param v2 String replacing <code>v1</code>. 
   * @return Modified string. If any of the input strings are <tt>null</tt>,
   *         the source string <tt>s</tt> will be returned unmodified. 
   *         If <tt>v1.length == 0</tt>, <tt>v1.equals(v2)</tt> or
   *         no occurances of <tt>v1</tt> is found, also 
   *         return <tt>s</tt> unmodified.
   */
  public static String replace(final String s, 
			       final String v1, 
			       final String v2) {
    
    // return quick when nothing to do
    if(s == null 
       || v1 == null 
       || v2 == null 
       || v1.length() == 0 
       || v1.equals(v2)) {
      return s;
    }

    int ix       = 0;
    int v1Len    = v1.length(); 
    int n        = 0;

    // count number of occurances to be able to correctly size
    // the resulting output char array
    while(-1 != (ix = s.indexOf(v1, ix))) {
      n++;
      ix += v1Len;
    }

    // No occurances at all, just return source string
    if(n == 0) {
      return s;
    }

    // Set up an output char array of correct size
    int     start  = 0;
    int     v2Len  = v2.length();
    char[]  r      = new char[s.length() + n * (v2Len - v1Len)];
    int     rPos   = 0;

    // for each occurance, copy v2 where v1 used to be
    while(-1 != (ix = s.indexOf(v1, start))) {
      while(start < ix) r[rPos++] = s.charAt(start++);
      for(int j = 0; j < v2Len; j++) {
	r[rPos++] = v2.charAt(j);
      }
      start += v1Len;
    }

    // ...and add all remaining chars
    ix = s.length(); 
    while(start < ix) r[rPos++] = s.charAt(start++);
    
    // ..ouch. this hurts.
    return new String(r);
  }


  /**
   * Utility method for replacing substrings with an integer.
   *
   * <p>
   * Equivalent to <tt>replace(s, v1, Integer.toString(v2))</tt>
   * </p>
   */
  public static String replace(String s, String v1, int v2) {
    return replace(s, v1, Integer.toString(v2));
  }

  /**
   * Utility method for replacing substrings with a boolean.
   *
   * <p>
   * Equivalent to <tt>replace(s, v1, v2 ? "true" : "false")</tt>
   * </p>
   */
  public static String replace(String s, String v1, boolean v2) {
    return replace(s, v1, v2 ? "true" : "false");
  }


  /**
   * Expand all tabs in a string. Tab stop positions are placed
   * at the columns which are multiples of <code>tabSize</code>.
   *
   * @param s String to untabify.
   * @param tabSize Tab stop interval.
   * @return String with expanded tabs.
   */
  public static String untabify(String s, int tabSize) {
    StringBuffer sb = new StringBuffer( s );
    for(int i = 0; i < sb.length(); i++) {
      if(sb.charAt(i)=='\t') {
	String toinsert = "        ".substring( 0, tabSize-(i%tabSize) );
	if (toinsert.length() == 0) {
	  sb = new StringBuffer(sb.toString().substring(0, i) + sb.toString().substring(i + 1));
	} else {
	  sb.setCharAt(i,' ');
	  if (toinsert.length() > 1) {
	    sb.insert(i, toinsert.substring(1));
	  }
	}
      }
    }
    return sb.toString();
  }

  /**
   * Format a java type in human readable way.
   *
   * @param s Type string to format.
   * @param prefixIgnore Prefix strings to ignore in output.
   * @return Nice-to-read string.
   */
  public static String formatJavaType(String s, String[] prefixIgnore) {
    for(int i = 0; i < prefixIgnore.length; i++) {
      if(s.startsWith(prefixIgnore[i])) {
	return s.substring(prefixIgnore[i].length());
      }
    }

    // Handle array types
    if(s.startsWith("[L") && s.endsWith(";")) {
      return formatJavaType(s.substring(2, s.length()-1), prefixIgnore) + "[]";
    }
    return s;
  }

  /**
   * Make first (and only) character in string upper case.
   * 
   * @param s String to capitalize.
   * @return Capitalized string. If <tt>s</tt> is <tt>null</tt> or equals the
   *         empty string, return <tt>s</tt>.
   */
  public static String  capitalize(String s) {
    return (s.equals("") || s == null) 
      ? s 
      : s.substring(0,1).toUpperCase() + s.substring(1).toLowerCase();
  }


  /** 
   * Default whitespace string for splitwords().
   * Value is <tt>" \t\n\r"</tt>)
   */
  protected static String  WHITESPACE = " \t\n\r";

  /**
   * Default citation char for splitwords().
   * Value is <tt>'"'</tt>
   */
  protected static char   CITCHAR    = '"';
  
  
  /**
   * Utility method to split a string into words separated by whitespace.
   *
   * <p>
   * Equivalent to <tt>splitwords(s, Text.WHITESPACE)</tt>
   * </p>
   */
  public static String [] splitwords(String s) {
    return splitwords(s, Text.WHITESPACE);
  }

  /**
   * Utility method to split a string into words separated by whitespace.
   *
   * <p>
   * Equivalent to <tt>splitwords(s, Text.WHITESPACE, Text.CITCHAR)</tt>
   * </p>
   */
  public static String [] splitwords(String s, String whiteSpace) {
    return splitwords(s, Text.WHITESPACE, Text.CITCHAR);
  }

  
  /**
   * Split a string into words separated by whitespace.
   * <p>
   * Citation chars may be used to group words with embedded
   * whitespace.
   * </p>
   *
   * @param s          String to split.
   * @param whiteSpace whitespace to use for splitting. Any of the
   *                   characters in the whiteSpace string are considered
   *                   whitespace between words and will be removed
   *                   from the result. If no words are found, return an
   *                   array of length zero.
   * @param citChar    Citation character used for grouping words with 
   *                   embedded whitespace. Typically '"'
   */
  public static String [] splitwords(String s, 
				     String whiteSpace,
				     char   citChar) {
    boolean       bCit  = false;        // true when inside citation chars.
    Vector        v     = new Vector(); // (String) individual words after splitting
    StringBuffer  buf   = null; 
    int           i     = 0; 
    
    while(i < s.length()) {
      char c = s.charAt(i);

      if(bCit || whiteSpace.indexOf(c) == -1) {
	// Build up word until we breaks on either a citation char or whitespace
	if(c == citChar) {
	  bCit = !bCit;
	} else {
	  if(buf == null) {
	    buf = new StringBuffer();
	  }
	  buf.append(c);
	}
	i++;
      } else {	
	// found whitespace or end of citation, append word if we have one
	if(buf != null) {
	  v.addElement(buf.toString());
	  buf = null;
	}

	// and skip whitespace so we start clean on a word or citation char
	while((i < s.length()) && (-1 != whiteSpace.indexOf(s.charAt(i)))) {
	  i++;
	}
      }
    }

    // Add possible remaining word
    if(buf != null) {
      v.addElement(buf.toString());
    }
    
    // Copy back into an array
    String [] r = new String[v.size()];
    v.copyInto(r);
    
    return r;
  }


  /**
   * Splits a string into words, using the <code>StringTokenizer</code> class.
   */
  public static String[] split(String s, String sep) {
    StringTokenizer st = new StringTokenizer(s, sep);
    int ntok = st.countTokens();
    String[] res = new String[ntok];
    for (int i = 0; i < ntok; i++) {
      res[i] = st.nextToken();
    }
    return res;
  }
  
  /**
   * Join an array into a single string with a given separator.
   */
  public static String join(Object[] s, String sep) {
    StringBuffer buf = new StringBuffer();
    int l = s.length;
    if (l > 0) {
      buf.append(s[0].toString());
    }

    for (int i = 1; i < l; i++) {
      buf.append(sep);
      buf.append(s[i].toString());
    }
    return buf.toString();
  }
  
  public static Object[] toArray(Vector v) {
    int size = v.size();
    Object[] o = new Object[size];

    // Why not v.copyInto(o) ??

    for (int i = 0; i < size; i++) {
      o[i] = v.elementAt(i);
    }
    return o;
  }
  

  /*

  // Testing purposes
  static public void main(String[] argv) {
    String[] s = splitwords(argv[0], " ,");
    for(int i = 0; i < s.length; i++) {
      System.out.println(s[i]);
    }

    int n = 100000;
    

    {
      Hashtable h = new Hashtable();
      long start = System.currentTimeMillis();
      for(int i = 0; i < n; i++) {
	String ss = replace(argv[0], argv[1], argv[2]);
	h.put(ss, ss);
      }
      long stop = System.currentTimeMillis();
      double delta = ((double)stop - start) / 1000;
      
      System.out.println("total = " + delta + ", replace/sec=" + (n / delta));
    }

  }
  */

}