package org.apache.maven.doxia.sink.impl;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import javax.swing.text.MutableAttributeSet;
import javax.swing.text.html.HTML.Tag;

import org.apache.maven.doxia.markup.XmlMarkup;

/**
 * An abstract <code>Sink</code> for xml markup syntax.
 *
 * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
 * @version $Id$
 * @since 1.0
 */
public abstract class AbstractXmlSink
    extends SinkAdapter
    implements XmlMarkup
{
    /** Default namespace prepended to all tags */
    private String nameSpace;

    private boolean firstTag  = true;

    private boolean insertNewline = true;

    public void setInsertNewline( boolean insertNewline )
    {
        this.insertNewline = insertNewline;
    }

    /**
     * Sets the default namespace that is prepended to all tags written by this sink.
     *
     * @param ns the default namespace.
     * @since 1.1
     */
    public void setNameSpace( String ns )
    {
        this.nameSpace = ns;
    }

    /**
     * Return the default namespace that is prepended to all tags written by this sink.
     *
     * @return the current default namespace.
     * @since 1.1
     */
    public String getNameSpace()
    {
        return this.nameSpace;
    }

    /**
     * Starts a Tag. For instance:
     * <pre>
     * &lt;tag&gt;
     * </pre>
     *
     * @param t a non null tag
     * @see #writeStartTag(javax.swing.text.html.HTML.Tag, javax.swing.text.MutableAttributeSet)
     */
    protected void writeStartTag( Tag t )
    {
        writeStartTag ( t, null );
    }

    /**
     * Starts a Tag with attributes. For instance:
     * <pre>
     * &lt;tag attName="attValue"&gt;
     * </pre>
     *
     * @param t a non null tag.
     * @param att a set of attributes. May be null.
     * @see #writeStartTag(javax.swing.text.html.HTML.Tag, javax.swing.text.MutableAttributeSet, boolean).
     */
    protected void writeStartTag( Tag t, MutableAttributeSet att )
    {
        writeStartTag ( t, att, false );
    }

    /**
     * Starts a Tag with attributes. For instance:
     * <pre>
     * &lt;tag attName="attValue"&gt;
     * </pre>
     *
     * @param t a non null tag.
     * @param att a set of attributes. May be null.
     * @param isSimpleTag boolean to write as a simple tag.
     */
    protected void writeStartTag( Tag t, MutableAttributeSet att, boolean isSimpleTag )
    {
        if ( t == null )
        {
            throw new IllegalArgumentException( "A tag is required" );
        }

        StringBuilder sb = new StringBuilder();

        if ( insertNewline && t.isBlock() && !firstTag )
        {
            sb.append( EOL );
        }
        firstTag = false;

        sb.append( LESS_THAN );

        if ( nameSpace != null )
        {
            sb.append( nameSpace ).append( ':' );
        }

        sb.append( t.toString() );

        sb.append( SinkUtils.getAttributeString( att ) );

        if ( isSimpleTag )
        {
            sb.append( SPACE ).append( SLASH );
        }

        sb.append( GREATER_THAN );

        write( sb.toString() );
    }

    /**
     * Writes a system EOL.
     *
     * @since 1.1
     */
    protected void writeEOL()
    {
        write( EOL );
    }

    /**
     * Ends a Tag without writing an EOL. For instance: <pre>&lt;/tag&gt;</pre>.
     *
     * @param t a tag.
     */
    protected void writeEndTag( Tag t )
    {
        if ( t == null )
        {
            throw new IllegalArgumentException( "A tag is required" );
        }

        StringBuilder sb = new StringBuilder();
        sb.append( LESS_THAN );
        sb.append( SLASH );

        if ( nameSpace != null )
        {
            sb.append( nameSpace ).append( ':' );
        }

        sb.append( t.toString() );
        sb.append( GREATER_THAN );

        write( sb.toString() );
    }

    /**
     * Starts a simple Tag. For instance:
     * <pre>
     * &lt;tag /&gt;
     * </pre>
     *
     * @param t a non null tag
     * @see #writeSimpleTag(javax.swing.text.html.HTML.Tag, javax.swing.text.MutableAttributeSet)
     */
    protected void writeSimpleTag( Tag t )
    {
        writeSimpleTag( t, null );
    }

    /**
     * Starts a simple Tag with attributes. For instance:
     * <pre>
     * &lt;tag attName="attValue" /&gt;
     * </pre>
     *
     * @param t a non null tag.
     * @param att a set of attributes. May be null.
     * @see #writeStartTag(javax.swing.text.html.HTML.Tag, javax.swing.text.MutableAttributeSet, boolean).
     */
    protected void writeSimpleTag( Tag t, MutableAttributeSet att )
    {
        writeStartTag ( t, att, true );
    }

    /**
     * Write a text to the sink.
     *
     * @param text the given text to write
     */
    protected abstract void write( String text );
}