/*
    * Copyright 2004-2006 the Seasar Foundation and the Others.
    *
    * 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.isenshi.util;
  
  import java.util.Iterator;
  import java.util.Stack;
  
  /***
   * @author nishioka
   */
  public class XMLStringBuffer {
  
  	public static final String NEWLINE = "\n";
  
  	private static final String XML_VERSION = "1.0";
  
  	private StringBuffer buf_;
  
  	private Stack tagStack_;
  
  	private boolean isClosed_;
  
  	private boolean isNewline_ = true;
  
  	private boolean isTab_ = true;
  
  	public XMLStringBuffer() {
  		buf_ = new StringBuffer();
  		tagStack_ = new Stack();
  		isClosed_ = true;
  	}
  
  	/***
  	 * @throws IllegalStateException
  	 *             if called not in inital time of document
  	 * @throws IllegalArgumentException
  	 *             if called when standalone parameter is not "yes" or "no"
  	 */
  	public void appendXMLDeclaration(String encoding, String standalone) {
  
  		if (buf_.length() > 0)
  			throw new IllegalStateException(
  					"XML Declaration must appear at the start of document.");
  
  		// version declaration could not be ommitted
  		buf_.append("<?xml version=\"" + XML_VERSION + "\"");
  		if (encoding != null && !encoding.equals("")) {
  			buf_.append(" encoding=\"" + encoding + "\"");
  		}
  
  		if (standalone != null) {
  			if (standalone.equalsIgnoreCase("yes")
  					|| standalone.equalsIgnoreCase("no")) {
  				buf_.append(" standalone=\"" + standalone + "\"");
  			} else {
  				throw new IllegalArgumentException(
  						"Attribute \"standalone\" must be yes or no.");
  			}
  		}
  		buf_.append("?>");
  		appendNewLine();
  	}
  
  	public void appendAttribute(String name, String value) {
  		if (value != null) {
  			buf_.append(" ");
  			buf_.append(name);
  			buf_.append("=\"");
  			buf_.append(value);
  			buf_.append("\"");
  		}
  	}
  
  	public void appendBody(String body) {
  		if (body == null) {
  			return;
  		}
  		assertBody();
  		buf_.append(body);
  		if (isNewline_)
  			appendNewLine();
  	}
  
  	public void appendStartTag(String tag) {
  		assertBody();
  
 		buf_.append("<");
 		buf_.append(tag);
 		isClosed_ = false;
 
 		doTagPush(tag);
 	}
 
 	public void endTag() {
 		String tag = doTagPop();
 
 		if (isClosed_) {
 			if (isTab_)
 				doTab();
 			buf_.append("</");
 			buf_.append(tag);
 			closeTag(true);
 		} else {
 			closeTag(false);
 		}
 	}
 
 	public void endAllTags() {
 		Iterator itr = tagStack_.iterator();
 		while (itr.hasNext()) {
 			endTag();
 		}
 	}
 
 	private void assertBody() {
 		if (!isClosed_) {
 			closeTag(true);
 		}
 		if (isTab_)
 			doTab();
 	}
 
 	protected void doTab() {
 		for (int i = 0; i < tagStack_.size(); i++) {
 			buf_.append("\t");
 		}
 	}
 
 	private void doTagPush(String tag) {
 		tagStack_.push(tag);
 	}
 
 	private String doTagPop() {
 		if(tagStack_.size()>0){
 			return (String) tagStack_.pop();
 		}else{
 			return "nulldesu";
 		}
 	}
 
 	public void closeTag() {
 		closeTag(true);
 	}
 
 	private void closeTag(boolean onlyClose) {
 		if (!onlyClose) {
 			buf_.append("/");
 		}
 		isClosed_ = true;
 		buf_.append(">");
 		if (isNewline_)
 			buf_.append(NEWLINE);
 	}
 
 	public String toString() {
 		return buf_.toString();
 	}
 
 	public void setNewline(boolean isNewline) {
 		this.isNewline_ = isNewline;
 	}
 
 	public void setTab(boolean isTab) {
 		this.isTab_ = isTab;
 	}
 
 	public int nextIndex() {
 		int idx = buf_.length();
 		return (isClosed_) ? idx : idx + 1;
 	}
 
 	public String cut(int start, int end) {
 		String s = buf_.substring(start, end);
 		buf_.delete(start, end);
 		return s;
 	}
 
 	public boolean isTagEmpty() {
 		return tagStack_.empty();
 	}
 
 	public void appendBodyLine(String body) {
 		boolean tmpTab = isTab_;
 		boolean tmpNewLine = isNewline_;
 		
 		setTab(false);
 		setNewline(false);
 		
 		assertBody();
 		appendNewLine();
 		appendBody(body);
 		appendNewLine();
 		
 		setTab(tmpTab);
 		setNewline(tmpNewLine);
 	}
 	
 	public void appendNewLine(){
 		buf_.append(NEWLINE);
 	}
 }