/*
  *  Copyright (C) 2022 github.com/REAndroid
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
  *  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
package com.reandroid.xml;

import java.util.regex.Pattern;

public class XMLUtil {
    public static String NEW_LINE="\n";
    public static boolean isEmpty(String s){
        if(s==null){
            return true;
        }
        return s.length()==0;
    }
    public static String escapeXmlChars(String str){
        if(str==null){
            return null;
        }
        if(str.indexOf('&')<0 && str.indexOf('<')<0 && str.indexOf('>')<0){
            return str;
        }
        str=str.replaceAll("&amp;", "&");
        str=str.replaceAll("&lt;", "<");
        str=str.replaceAll("&gt;", ">");
        str=str.replaceAll("&", "&amp;");
        str=str.replaceAll("<", "&lt;");
        str=str.replaceAll(">", "&gt;");
        return str;
    }
    public static String escapeQuote(String str){
        if(str==null){
            return null;
        }
        int i = str.indexOf('"');
        if(i<0){
            return str;
        }
        str=str.replaceAll("\"", "&quot;");
        return str;
    }
    public static String unEscapeXmlChars(String str){
        if(str==null){
            return null;
        }
        int i=str.indexOf('&');
        if(i<0){
            return str;
        }
        str=str.replaceAll("&amp;", "&");
        str=str.replaceAll("&lt;", "<");
        str=str.replaceAll("&gt;", ">");
        str=str.replaceAll("&quot;", "\"");
        return str;
    }
    public static String trimQuote(String txt){
        if(txt==null){
            return null;
        }
        String tmp=txt.trim();
        if(tmp.length()==0){
            return txt;
        }
        char c1=tmp.charAt(0);
        if(c1!='"'){
            return txt;
        }
        int end=tmp.length()-1;
        c1=tmp.charAt(end);
        if(c1!='"'){
            return txt;
        }
        if(end<=1){
            return "";
        }
        return tmp.substring(1,end);
    }


    private static final Pattern PATTERN_ESCAPE = Pattern.compile("^.*[><&].*$");

}