/*
 * Copyright 2004-2009 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 org.seasar.mayaa.impl.util.xml;

import java.util.Stack;

import org.seasar.mayaa.impl.util.StringUtil;
import org.xml.sax.Attributes;

/**
 * @author Koji Suga (Gluegent, Inc.)
 */
public class TagHandlerStack {

    private String _rootName;

    private TagHandler _rootHandler;

    private Stack _stack;

    public TagHandlerStack(TagHandler rootHandler) {
        if (rootHandler == null) {
            throw new IllegalArgumentException();
        }
        _stack = new Stack();
        _rootName = rootHandler.getName();
        _rootHandler = rootHandler;
    }

    public void startElement(String name, Attributes attributes,
            String systemID, int lineNumber) {
        if (StringUtil.isEmpty(name)) {
            throw new IllegalArgumentException();
        }
        if (_stack.size() == 0) {
            if (_rootName.equalsIgnoreCase(name)) {
                _rootHandler.start(attributes, systemID, lineNumber);
                _stack.push(_rootHandler);
            } else {
                throw new IllegalStateException();
            }
        } else {
            TagHandler top = (TagHandler) _stack.peek();
            TagHandler handler = top.startElement(
                    name, attributes, systemID, lineNumber);
            _stack.push(handler);
        }
    }

    public void endElement() {
        if (_stack.size() > 0) {
            TagHandler top = (TagHandler) _stack.pop();
            if (top.isValid()) {
                top.endElement();
            }
        } else {
            throw new IllegalStateException();
        }
    }

    public void characters(char[] buffer, int offset, int length) {
        TagHandler top = (TagHandler) _stack.peek();
        top.characters(new String(buffer, offset, length).trim());
    }

    public TagHandler getRoot() {
        return _rootHandler;
    }

}
