/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * See LICENSE.txt included in this distribution for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at LICENSE.txt.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
 */
package org.opensolaris.opengrok.analysis.plain;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.util.Arrays;

import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.opensolaris.opengrok.analysis.Definitions;
import org.opensolaris.opengrok.analysis.ExpandTabsReader;
import org.opensolaris.opengrok.analysis.FileAnalyzerFactory;
import org.opensolaris.opengrok.analysis.Hash2TokenStream;
import org.opensolaris.opengrok.analysis.TextAnalyzer;
import org.opensolaris.opengrok.analysis.XrefWriter;
import org.opensolaris.opengrok.configuration.Project;
import org.opensolaris.opengrok.history.Annotation;

/**
 * Analyzer for plain text files
 * Created on September 21, 2005
 *
 * @author Chandan
 */
public class PlainAnalyzer extends TextAnalyzer {

    /** buffer to store the content which needs to be tokenized/parsed */
    protected char[] content;
    /** the number of chars in {@link #content} representing the original source
     * read, i.e. the last {@code content.length - len} chars of content should
     * be ignored (contain garbage).*/
    protected int len;
    private final PlainFullTokenizer plainfull;
    private final PlainSymbolTokenizer plainref;
    private final PlainXref xref;
    private static final Reader dummy = new StringReader(" ");
    /** container, where found symbols get stored */
    protected Definitions defs;

    /** Creates a new instance of PlainAnalyzer 
     * @param factory   factory to use for fallback settings
     */
    protected PlainAnalyzer(FileAnalyzerFactory factory) {
        super(factory);
        content = new char[64 * 1024];
        len = 0;
        plainfull = new PlainFullTokenizer(dummy);
        plainref = new PlainSymbolTokenizer(dummy);
        xref = new PlainXref((Reader) null);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void analyze(Document doc, Reader in) throws IOException {
        @SuppressWarnings("resource")
        Reader inReader = ExpandTabsReader.wrap(in, project);
        len = 0;
        do {
            int rbytes = inReader.read(content, len, content.length - len);
            if (rbytes >= 0) {
                if (rbytes == (content.length - len)) {
                    content = Arrays.copyOf(content, content.length * 2);
                }
                len += rbytes;
            } else {
                break;
            }
        } while (true);

        doc.add(new Field("full", dummy));
        String fullpath;
        if ((fullpath = doc.get("fullpath")) != null && ctags != null) {
            defs = ctags.doCtags(fullpath + "\n");
            if (defs != null && defs.numberOfSymbols() > 0) {
                doc.add(new Field("defs", dummy));
                doc.add(new Field("refs", dummy)); //@FIXME adding a refs field only if it has defs?
                byte[] tags = defs.serialize();
                doc.add(new Field("tags", tags));
            }
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public TokenStream overridableTokenStream(String fieldName, Reader reader) {
        if ("full".equals(fieldName)) {
            plainfull.reInit(content, len);
            return plainfull;
        } else if ("refs".equals(fieldName)) {
            plainref.reInit(content, len);
            return plainref;
        } else if ("defs".equals(fieldName)) {
            return new Hash2TokenStream(defs.getSymbols());
        }
        return super.overridableTokenStream(fieldName, reader);
    }


    /**
     * {@inheritDoc}
     */
    @Override
    public void writeXref(XrefWriter out) throws IOException {
        xref.reInit(content, len);
        xref.project = project;
        xref.write(out);
    }

    /**
     * Write a cross referenced HTML file reads the source from in
     * @param in Input source
     * @param out Output xref writer
     * @param defs definitions for the file (could be null)
     * @param annotation annotation for the file (could be null)
     */
    static void writeXref(Reader in, XrefWriter out, Definitions defs, 
        Annotation annotation, Project project) throws IOException 
    {
        PlainXref xref = new PlainXref(in);
        xref.annotation = annotation;
        xref.project = project;
        xref.setDefs(defs);
        xref.write(out);
    }
}