/*
 * 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.
 * Use is subject to license terms.
 */
package org.opensolaris.opengrok.analysis;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.logging.Logger;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.document.Document;
import org.opensolaris.opengrok.configuration.Project;
import org.opensolaris.opengrok.configuration.RuntimeEnvironment;
import org.opensolaris.opengrok.util.IOUtils;

/**
 * Base class for all different File Analyzers
 *
 * An Analyzer for a filetype provides
 *<ol>
 * <li>the file extentions and magic numbers it analyzes</li>
 * <li>a lucene document listing the fields it can support</li>
 * <li>TokenStreams for each of the field it said requires tokenizing in 2</li>
 * <li>cross reference in HTML format</li>
 * <li>the type of file data, plain text etc.</li>
 *</ol>
 *
 * Created on September 21, 2005
 *
 * @author Chandan
 */
public class FileAnalyzer extends Analyzer {
    private static final Logger logger = 
        Logger.getLogger(FileAnalyzer.class.getName());
    /** the project to which this analyzer is related to */
    protected Project project;
    private final FileAnalyzerFactory factory;

    /**
     * What kind of file is this?
     */
    public static enum Genre {
        /** xrefed - line numbered context */
        PLAIN("p"),
        /** xrefed - summarizer context */
        XREFABLE("x"),
        /** not xrefed - no context - used by diff/list */
        IMAGE("i"),
        /** not xrefed - no context */
        DATA("d"),
        /** not xrefed - summarizer context from original file */
        HTML("h")
        ;
        private String typeName;
        private Genre(String typename) {
            this.typeName = typename;
        }

        /**
         * Get the type name value used to tag lucence documents.
         * @return a none-null string.
         */
        public String typeName() {
            return typeName;
        }

        /**
         * Get the Genre for the given type name.
         * @param typeName name to check
         * @return {@code null} if it doesn't match any genre, the genre otherwise.
         * @see #typeName()
         */
        public static Genre get(String typeName) {
            if (typeName == null) {
                return null;
            }
            for (Genre g : values()) {
                if (g.typeName.equals(typeName)) {
                    return g;
                }
            }
            return null;
        }
    }
    
    /**
     * Ctags instance to use for tagging.
     */
    protected Ctags ctags;

    /**
     * Set the ctag instance to use for tagging this repo's files.
     * @param ctags instance to set.
     */
    public void setCtags(Ctags ctags) {
        this.ctags = ctags;
    }

    /**
     *Set the project, to which this instance is related to.
     * @param project   project to set.
     */
    public void setProject(Project project) {
        this.project = project;
    }

    /**
     * Get the factory which created this analyzer.
     * @return the {@code FileAnalyzerFactory} which created this analyzer
     */
    public final FileAnalyzerFactory getFactory() {
        return factory;
    }

    /**
     * Get the genre, which this analyzer usually handles.
     * @return the genre this analyzer handles.
     * @see FileAnalyzerFactory#getGenre()
     */
    public Genre getGenre() {
        return factory.getGenre();
    }
    private final HistoryAnalyzer hista;

    /** Creates a new instance of FileAnalyzer 
     * @param factory the factory to use to obtain default settings */
    public FileAnalyzer(FileAnalyzerFactory factory) {
        this.factory = factory;
        hista = new HistoryAnalyzer();
    }

    /**
     * Read the given input, analyze it and store the result into the given 
     * document. NOTE: This method does not close given input stream on return!
     * 
     * @param doc   where to store results.
     * @param in    source to read.
     * @throws IOException
     */
    @SuppressWarnings("unused") // yes, hybrid: [not] a interface, [not] abstract
    public void analyze(Document doc, InputStream in) throws IOException {
        // not used
    }

    /**
     * Get the TokenStream for the given fieldname.
     * @param fieldName filed name in question {@code path | project | hist}
     * @param reader reader to use.
     * @return {@code null} for unknown field names, a new corresponding 
     *  TokenStream otherwise.
     */
    public TokenStream overridableTokenStream(String fieldName, Reader reader) {
        if ("path".equals(fieldName) || "project".equals(fieldName)) {
            return new PathTokenizer(reader);
        } else if ("hist".equals(fieldName)) {
            return hista.tokenStream(fieldName, reader);
        }
        logger.warning("Have no analyzer for '" + fieldName + "'");
        return null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final TokenStream tokenStream(String fieldName, Reader reader) {
        return this.overridableTokenStream(fieldName, reader);
    }        
        
    /**
     * {@inheritDoc}
     */
    @Override    
    public final TokenStream reusableTokenStream(String fieldName, Reader reader) {
        //TODO needs refactoring to get more speed and less ram usage for indexer
        return this.tokenStream(fieldName, reader);
    }           

    /**
     * Write out current results html formatted to the given writer.
     * 
     * @param out to writer HTML cross-reference
     * @throws java.io.IOException if an error occurs
     */
    @SuppressWarnings("static-method")
    public void writeXref(XrefWriter out) throws IOException {
        out.write("Error General File X-Ref writer!");
    }

    /**
     * Write out current results html formatted to the given destination.
     * @param xrefDir   the parent directory of the file to write.
     * @param path      the relative path wrt. <var>xrefDir</var> of the file to write.
     * @throws IOException
     */
    public void writeXref(File xrefDir, String path) throws IOException {
        @SuppressWarnings("resource")
        XrefWriter w = null;
        try {
            w = new XrefWriter(new File(xrefDir, path), factory.getGenre(), 
                RuntimeEnvironment.getConfig().isCompressXref());
            writeXref(w);
        } finally {
            IOUtils.close(w);
        }
    }
}