/***************************************************************************
 * Copyright (C) 2003-2008 eXo Platform SAS.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation; either version 3
 * 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, see<http://www.gnu.org/licenses/>.
 ***************************************************************************/

package org.exoplatform.forum.common;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang.StringUtils;

public class TransformHTML {
  
  public static final String EMPTY_STR = "";

  public static final String SPACE     = " ";

  public static String cleanHtmlCode(String sms, List<String> bbcs) {
    if (isEmpty(sms))
      return EMPTY_STR;
    sms = StringUtils.replace(sms, "\n", SPACE);
    // clean bbcode
    if (bbcs != null && bbcs.size() > 0) {
      List<String> bbcList = new ArrayList<String>();
      bbcList.addAll(bbcs);
      for (String bbc : bbcs) {
        bbcList.add(bbc.toLowerCase());
      }
      int lastIndex = 0;
      int tagIndex = 0;
      String start, end;
      for (String bbc : bbcList) {
        start = "[" + bbc;
        end = "[/" + bbc + "]";
        lastIndex = 0;
        tagIndex = 0;
        while ((tagIndex = sms.indexOf(start, lastIndex)) != -1) {
          lastIndex = tagIndex + 1;
          try {
            int clsIndex = sms.indexOf(end, tagIndex);
            String content = sms.substring(tagIndex, clsIndex);
            String content_ = content.substring(content.indexOf("]") + 1);
            sms = StringUtils.replace(sms, content + end, content_);
          } catch (Exception e) {
            continue;
          }
        }
      }
      sms = StringUtils.replace(sms, "[U]", EMPTY_STR);
      sms = StringUtils.replace(sms, "[/U]", EMPTY_STR);
      sms = StringUtils.replace(sms, "[u]", EMPTY_STR);
      sms = StringUtils.replace(sms, "[/u]", EMPTY_STR);
    }
    // Clean html code
    String scriptregex = "<(script|style)[^>]*>[^<]*</(script|style)>";
    Pattern p1 = Pattern.compile(scriptregex, Pattern.CASE_INSENSITIVE);
    Matcher m1 = p1.matcher(sms);
    sms = m1.replaceAll(EMPTY_STR);
    String tagregex = "<[^>]*>";
    Pattern p2 = Pattern.compile(tagregex);
    Matcher m2 = p2.matcher(sms);
    sms = m2.replaceAll(EMPTY_STR);
    String multiplenewlines = "(\\n{1,2})(\\s*\\n)+";
    sms = sms.replaceAll(multiplenewlines, "$1");
    return sms;
  }

  public static String getTitleInHTMLCode(String s, List<String> bbcs) {
    if (isEmpty(s))
      return EMPTY_STR;
    if (s.length() > 500)
      s = s.substring(0, 500);
    s = s.replace("&nbsp;", SPACE).replace("<br/>", SPACE).replaceAll("( \\s*)", SPACE);
    s = s.replace("'", "&#39;").replace("\"", "&#34;");
    s = cleanHtmlCode(s, bbcs);
    s = removeCharterStrange(s);
    return s.trim();
  }
  
  public static String getPlainText(String s) {
    if (isEmpty(s))
      return EMPTY_STR;
    s = s.replaceAll("&nbsp;", SPACE)
         .replaceAll("<br/>", "\n")
         .replaceAll("<br />", "\n")
         .replaceAll("<p>", EMPTY_STR)
         .replaceAll("</p>", EMPTY_STR);
    return s.trim();
  }

  public static String removeCharterStrange(String s) {
    if (s == null || s.length() <= 0)
      return EMPTY_STR;
    int i = 0;
    StringBuilder builder = new StringBuilder();
    while (i < s.length()) {
      if (s.codePointAt(i) > 31) {
        builder.append(s.charAt(i));
      }
      ++i;
    }
    return builder.toString();
  }
  
  public static String enCodeHTMLTitle(String s) {
    StringBuffer buffer = new StringBuffer();
    if (s != null) {
      s = s.replaceAll("(<p>((\\&nbsp;)*)(\\s*)?</p>)|(<p>((\\&nbsp;)*)?(\\s*)</p>)", "<br/>").trim();
      s = s.replaceFirst("(<br/>)*", EMPTY_STR);
      s = s.replaceAll("(\\w|\\$)(>?,?\\.?\\*?\\!?\\&?\\%?\\]?\\)?\\}?)(<br/><br/>)*", "$1$2");
      for (int j = 0; j < s.trim().length(); j++) {
        char c = s.charAt(j);
        if ((int) c == 60) {
          buffer.append("&lt;");
        } else if ((int) c == 62) {
          buffer.append("&gt;");
        } else if (c == '\'') {
          buffer.append("&#39");
        } else {
          buffer.append(c);
        }
      }
    }
    return buffer.toString().replaceFirst("(<br/>)*", EMPTY_STR);
  }

  public static String enCodeHTMLContent(String message) {
    StringBuilder buffer = new StringBuilder();
    for (int j = 0; j < message.length(); j++) {
      char c = message.charAt(j);
      if ((int) c == 9) {
        buffer.append("&nbsp; &nbsp; ");
      } else if ((int) c == 10) {
        buffer.append("<br/>");
      } else if ((int) c == 60) {
        buffer.append("&lt;");
      } else if ((int) c == 62) {
        buffer.append("&gt;");
      } else if (c == 39) {
        buffer.append("&#39;");
      } else if (c == '&') {
        buffer.append("&amp;");
      } else if (c == '"') {
        buffer.append("&quot;");
      } else {
        buffer.append(c);
      }
    }
    return buffer.toString();
  }

  public static String enCodeViewSignature(String s) {
    if (s != null && s.trim().length() > 0) {
      // replace enter key to <br/> tag html
      StringBuffer buffer = new StringBuffer();
      for (int j = 0; j < s.trim().length(); j++) {
        if (s.codePointAt(j) == 10) {
          buffer.append("<br/>");
        } else {
          buffer.append(s.charAt(j));
        }
      }
      s = buffer.toString();
    } else
      s = EMPTY_STR;
    return s;
  }

  public static String fixAddBBcodeAction(String b) {
    int tagIndex = 0;
    int lastIndex = 0;
    String start;
    String end;
    String text_ = EMPTY_STR;
    StringBuilder builder = new StringBuilder();
    String[] tagBBcode = new String[] { "quote", "code", "QUOTE", "CODE" };
    for (int i = 0; i < tagBBcode.length; i++) {
      start = "[" + tagBBcode[i];
      end = "[/" + tagBBcode[i] + "]";
      while ((tagIndex = b.indexOf(start, lastIndex)) != -1) {
        lastIndex = tagIndex + 1;
        try {
          int clsIndex = b.indexOf(end, tagIndex);
          String text = b.substring(tagIndex, clsIndex);
          if (text == null || text.trim().length() == 0)
            continue;
          text_ = text;
          builder = new StringBuilder();
          if (text.indexOf('<' + "p") > text.indexOf('<' + "/p")) {
            text = StringUtils.replaceOnce(text, "</p>", EMPTY_STR);
            int t = text.lastIndexOf('<' + "p>");
            builder.append(text.substring(0, t));
            if (text.length() > (t + 3)) {
              builder.append(text.substring(t + 3));
            }
          }
          text = builder.toString();
          if (text != null && text.length() > 0) {
            b = StringUtils.replace(b, text_, text);
            text_ = text;
          } else
            text = text_;

          builder = new StringBuilder();
          if (text.indexOf('<' + "span") > text.indexOf('<' + "/span")) {
            text = StringUtils.replaceOnce(text, "</span>", EMPTY_STR);
            int t = text.lastIndexOf('<' + "span");
            builder.append(text.substring(0, t));
            if (text.length() > (t + 6)) {
              builder.append(text.substring((t + 6)));
            }
          }
          text = builder.toString();
          if (text != null && text.length() > 0) {
            b = StringUtils.replace(b, text_, text);
          }
        } catch (Exception e) {
          continue;
        }
      }
    }
    return b;
  }
  
  /**
   * Check string is null or empty
   * @param String s
   * @return boolean
   */
  private static boolean isEmpty(String s) {
    return (s == null || s.trim().length() <= 0) ? true : false;
  }
  
}
