/*
 * 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) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 */
package org.opensolaris.opengrok.history;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.text.DateFormat;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.opensolaris.opengrok.util.Executor;

/**
 * Parse source history for a AccuRev Repository
 *
 * @author Steven Haehn
 */
public class AccuRevHistoryParser implements Executor.StreamHandler {
    private static final Logger logger = 
        Logger.getLogger(AccuRevHistoryParser.class.getName());
    private AccuRevRepository repository;
    private History history;
    private boolean foundHistory;

    /**
     * Parse the history for the specified file.
     *
     * @param file the file to parse history for
     * @param repos Pointer to the {@code AccuRevRepository}
     * @return the file's history
     */
    History parse(File file, Repository repos) {
        repository = (AccuRevRepository) repos;
        history = null;
        foundHistory = false;
        String relPath = AccuRevRepository.getDepotRelativePath(file);

        /* When the path given is really just the root to the source workarea, 
         * no history is available, create fake. */
        if (relPath.equals("/./")) {
            List<HistoryEntry> entries = new ArrayList<HistoryEntry>();
            entries.add(new HistoryEntry("", null, new Date(), "OpenGrok", 
                "Workspace Root", true));
            history = new History(entries);
        } else {
            Executor executor = repository.getHistoryLogExecutor(file);
            executor.exec(true, this);
            /* Try again because there was no 'keep' history. */
            if (!foundHistory) {
                executor = repository.getHistoryLogExecutor(file);
                executor.exec(true, this);
            }
        }
        return history;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void processStream(InputStream input) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(input));
        List<HistoryEntry> entries = new ArrayList<HistoryEntry>();
        DateFormat df = repository.getDateFormat();
        String line;
        HistoryEntry entry = null;
        history = new History();

        /* Accurev history of an element (directory or file) looks like:
         *
         * element: /./path/to/element
         * eid: 238865
         * transaction 1486194; purge; 2012/02/28 12:46:55 ; user: tluksha
         *   version 2541/1 (2539/1)
         *
         * transaction 1476285; purge; 2012/02/03 12:16:25 ; user: shaehn
         *   version 4241/1 (4241/1)
         *
         * transaction 1317224; promote; 2011/05/03 11:37:56 ; user: mtrinh
         *   # changes to ngb to compile on windows
         *   version 13/93 (1000/2)
         * ...
         *
         * What is of interest then is: user (author), version (revision), date,
         * comment (message)
         *
         * Any lines not recognized are ignored.
         */
        while ((line = in.readLine()) != null) {
            if (line.startsWith("t")) {             // found transaction
                foundHistory = true;
                String data[] = line.split("; ");
                String user = data[3].replaceFirst("user: ", "");
                Date date = null;
                try {
                    date = df.parse(data[2]);
                } catch (ParseException pe) {
                    logger.log(Level.WARNING, "Could not parse date: " + line);
                    logger.log(Level.FINE, "processStream", pe);
                }
                entry = new HistoryEntry(null, null, date, user, "", false);
            } else if (entry != null) {
                if (line.startsWith("  #")) {  // found comment
                    entry.appendMessage(line.substring(3));
                } else if (line.startsWith("  v")) {  // found version
                    String data[] = line.split("\\s+");
                    entry.setRevision(data[2]);
                    entry.setActive(true);
                    entries.add(entry);
                    entry = null;
                }
            }
        }
        history.setHistoryEntries(entries);
    }
}