/*
 * 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.
 */
package org.apache.tika.parser.wordperfect;

import java.io.IOException;

import org.apache.tika.sax.XHTMLContentHandler;
import org.xml.sax.SAXException;

/**
 * Extracts WordPerfect Document Area text from a WordPerfect document.
 * @author Pascal Essiembre
 */
abstract class WPDocumentAreaExtractor {

    boolean startedP = false;
    public void extract(WPInputStream in, XHTMLContentHandler xhtml) 
            throws IOException, SAXException {
        int chunk = 4096;
        StringBuilder out = new StringBuilder(chunk);
        int c;
        while ((c = in.read()) != -1) {
            extract(c, in, out, xhtml);
            if (out.length() >= chunk) {
                xhtml.characters(out.toString());
                out.setLength(0);
            }
        }
        endParagraph(out, xhtml);
    }
 
    protected abstract void extract(
            int c, WPInputStream in, StringBuilder out, XHTMLContentHandler xhtml) throws IOException, SAXException;


    protected void lazilyStartParagraph(XHTMLContentHandler xhtml) throws SAXException {
        if (! startedP) {
            xhtml.startElement("p");
        }
        startedP = true;
    }

    /**
     * This assumes that the <p> was started before you get here.
     * And the user is required to close the <p> at the end of the document.
     *
     * These are currently handled by {@link #extract(WPInputStream, XHTMLContentHandler)}.
     *
     * @param xhtml
     * @throws SAXException
     */
    protected void endParagraph(StringBuilder buffer, XHTMLContentHandler xhtml) throws SAXException {
        lazilyStartParagraph(xhtml);

        xhtml.characters(buffer.toString());
        buffer.setLength(0);
        xhtml.endElement("p");
        startedP = false;
    }

    // Skips until the given character is encountered.
    protected int skipUntilChar(WPInputStream in, int targetChar)
            throws IOException {
        int count = 0;
        int c;
        while ((c = in.read()) != -1) {
            count++;
            if (c == targetChar) {
                return count;
            }
        }
        return count;
    }
}