/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.xml.internal.txw2.output;

import javax.xml.stream.XMLStreamException;

import javax.xml.stream.XMLStreamWriter;

import java.util.Stack;

/**

 * @author Kohsuke Kawaguchi

 */

public class IndentingXMLStreamWriter extends DelegatingXMLStreamWriter {

    private final static Object SEEN_NOTHING = new Object();

    private final static Object SEEN_ELEMENT = new Object();

    private final static Object SEEN_DATA = new Object();

    private Object state = SEEN_NOTHING;

    private Stack<Object> stateStack = new Stack<Object>();

    private String indentStep = "  ";

    private int depth = 0;

    public IndentingXMLStreamWriter(XMLStreamWriter writer) {

        super(writer);

    }

    /**

     * Return the current indent step.

     *

     * <p>Return the current indent step: each start tag will be

     * indented by this number of spaces times the number of

     * ancestors that the element has.</p>

     *

     * @return The number of spaces in each indentation step,

     *         or 0 or less for no indentation.

     * @see #setIndentStep(int)

     *

     * @deprecated

     *      Only return the length of the indent string.

     */

    public int getIndentStep() {

        return indentStep.length();

    }

    /**

     * Set the current indent step.

     *

     * @param indentStep The new indent step (0 or less for no

     *        indentation).

     * @see #getIndentStep()

     *

     * @deprecated

     *      Should use the version that takes string.

     */

    public void setIndentStep(int indentStep) {

        StringBuilder s = new StringBuilder();

        for (; indentStep > 0; indentStep--) s.append(' ');

        setIndentStep(s.toString());

    }

    public void setIndentStep(String s) {

        this.indentStep = s;

    }

    private void onStartElement() throws XMLStreamException {

        stateStack.push(SEEN_ELEMENT);

        state = SEEN_NOTHING;

        if (depth > 0) {

            super.writeCharacters("\n");

        }

        doIndent();

        depth++;

    }

    private void onEndElement() throws XMLStreamException {

        depth--;

        if (state == SEEN_ELEMENT) {

            super.writeCharacters("\n");

            doIndent();

        }

        state = stateStack.pop();

    }

    private void onEmptyElement() throws XMLStreamException {

        state = SEEN_ELEMENT;

        if (depth > 0) {

            super.writeCharacters("\n");

        }

        doIndent();

    }

    /**

     * Print indentation for the current level.

     *

     * @exception org.xml.sax.SAXException If there is an error

     *            writing the indentation characters, or if a filter

     *            further down the chain raises an exception.

     */

    private void doIndent() throws XMLStreamException {

        if (depth > 0) {

            for (int i = 0; i < depth; i++)

                super.writeCharacters(indentStep);

        }

    }

    public void writeStartDocument() throws XMLStreamException {

        super.writeStartDocument();

        super.writeCharacters("\n");

    }

    public void writeStartDocument(String version) throws XMLStreamException {

        super.writeStartDocument(version);

        super.writeCharacters("\n");

    }

    public void writeStartDocument(String encoding, String version) throws XMLStreamException {

        super.writeStartDocument(encoding, version);

        super.writeCharacters("\n");

    }

    public void writeStartElement(String localName) throws XMLStreamException {

        onStartElement();

        super.writeStartElement(localName);

    }

    public void writeStartElement(String namespaceURI, String localName) throws XMLStreamException {

        onStartElement();

        super.writeStartElement(namespaceURI, localName);

    }

    public void writeStartElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {

        onStartElement();

        super.writeStartElement(prefix, localName, namespaceURI);

    }

    public void writeEmptyElement(String namespaceURI, String localName) throws XMLStreamException {

        onEmptyElement();

        super.writeEmptyElement(namespaceURI, localName);

    }

    public void writeEmptyElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {

        onEmptyElement();

        super.writeEmptyElement(prefix, localName, namespaceURI);

    }

    public void writeEmptyElement(String localName) throws XMLStreamException {

        onEmptyElement();

        super.writeEmptyElement(localName);

    }

    public void writeEndElement() throws XMLStreamException {

        onEndElement();

        super.writeEndElement();

    }

    public void writeCharacters(String text) throws XMLStreamException {

        state = SEEN_DATA;

        super.writeCharacters(text);

    }

    public void writeCharacters(char[] text, int start, int len) throws XMLStreamException {

        state = SEEN_DATA;

        super.writeCharacters(text, start, len);

    }

    public void writeCData(String data) throws XMLStreamException {

        state = SEEN_DATA;

        super.writeCData(data);

    }

}