/*
 * 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, 2011, Oracle and/or its affiliates. All rights reserved.
 */
/* Portions Copyright 2008 Peter Bray */
package org.opensolaris.opengrok.history;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.opensolaris.opengrok.util.IOUtils;
import org.opensolaris.opengrok.util.StringUtils;

/**
 * A History Parser for Razor
 *
 * @author Peter Bray <Peter.Darren.Bray@gmail.com>
 */
class RazorHistoryParser {
    private static final Logger logger = 
        Logger.getLogger(RazorHistoryParser.class.getName());
    private RazorRepository repository = new RazorRepository();

    private static final Pattern ACTION_TYPE_PATTERN =
        Pattern.compile("^(INTRODUCE|CHECK-OUT|CHECK-IN|UN-CHECK-OUT|RENAME"
            + "|EDIT_PROPS|ALTERED|CHECK-POINT|REVERT|INTRODUCE_AND_EDIT|BRANCH"
            + "|BUMP|MERGE-CHECK-IN|PROMOTE)"
            + "\\s+(\\S*)\\s+([\\.0-9]+)?\\s+(\\S*)\\s+(\\S*)\\s*$");
    private static final Pattern ADDITIONAL_INFO_PATTERN =
        Pattern.compile("^##(TITLE|NOTES|AUDIT|ISSUE):\\s+(.*)\\s*$");
    private static final boolean DUMP_HISTORY_ENTRY_ADDITIONS = false;

    History parse(File file, Repository repos) throws HistoryException {
        try {
            return parseFile(file, repos);
        } catch (IOException ioe) {
            throw new HistoryException(ioe);
        }
    }

    private History parseFile(File file, Repository repos)
            throws IOException {

        repository = (RazorRepository) repos;
        File mappedFile = repository.getRazorHistoryFileFor(file);
        logger.log(Level.FINE, "Mapping ''{0}'' to ''{1}''", 
            new String[] { file.getPath(), mappedFile.getPath() });

        if (!mappedFile.exists()) {
            logger.warning("History File Mapping is NON-EXISTENT (" 
                + mappedFile.getAbsolutePath() + ")");
            return null;
        }

        if (mappedFile.isDirectory()) {
            logger.warning("History File Mapping is a DIRECTORY (" 
                + mappedFile.getAbsolutePath() + ")");
            return null;
        }

        FileReader contents = new FileReader(mappedFile.getAbsoluteFile());
        try {
            return parseContents(new BufferedReader(contents));
        } finally {
            IOUtils.close(contents);
        }
    }

    protected History parseContents(BufferedReader contents) throws IOException {
        DateFormat df = repository.getDateFormat();
        String line;

        ArrayList<HistoryEntry> entries = new ArrayList<HistoryEntry>();
        HistoryEntry entry = null;
        boolean lastWasTitle = true;

        Matcher actionMatcher = ACTION_TYPE_PATTERN.matcher("");
        Matcher infoMatcher = ADDITIONAL_INFO_PATTERN.matcher("");
        while ((line = contents.readLine()) != null) {
            logger.log(Level.FINE, "Processing [{0}]", line);
            if (StringUtils.isOnlyWhitespace(line)) {
                if (entry != null && entry.getDate() != null) {
                    entries.add(entry);
                    dumpEntry(entry);
                }
                entry = null;
                continue;
            } else if (entry != null) {
                infoMatcher.reset(line);
                if (infoMatcher.find()) {
                    String infoType = infoMatcher.group(1);
                    String details = infoMatcher.group(2);
                    if ("TITLE".equals(infoType)) {
                        logger.log(Level.FINE, "Setting Message ''{0}''", details);
                        entry.setMessage(details);
                        lastWasTitle = true;
                    } else if ("ISSUE".equals(infoType)) {
                        logger.log(Level.FINE, "Adding CR ''{0}''", details);
                        entry.addChangeRequest(details);
                    } else {
                        logger.log(Level.FINE, "Ignoring Info Type Line [{0}]", line);
                    }
                } else  if (!line.startsWith("##") && line.charAt(0) == '#') {
                    logger.log(Level.FINE, "Seen Comment [{0}]", line);
                    if (lastWasTitle) {
                        entry.appendMessage("");
                        lastWasTitle = false;
                    }
                    entry.appendMessage(line.substring(1));
                } else {
                   logger.warning("Expecting addlInfo and got [" + line + "]");
                }
            } else {
                actionMatcher.reset(line);
                if (actionMatcher.find()) {
                    entry = new HistoryEntry();
                    String actionType = actionMatcher.group(1);
                    String userName = actionMatcher.group(2);
                    String revision = actionMatcher.group(3);
                    String state = actionMatcher.group(4);
                    String dateTime = actionMatcher.group(5);
                    logger.log(Level.FINE, "New History Event Seen: actionType "
                        + "= {0}, userName = {1}, revision = {2}, state = {3}, "
                        + "dateTime = {4}",  new String[] { actionType, userName,
                        revision, state, dateTime });
                    if (actionType.startsWith("INTRODUCE")
                        || actionType.contains("CHECK-IN")
                        || "CHECK-POINT".equals(actionType)
                        || "REVERT".equals(actionType))
                    {
                        entry.setAuthor(userName);
                        entry.setRevision(revision);
                        entry.setActive("Active".equals(state));
                        Date date = null;
                        try {
                            date = df.parse(dateTime);
                        } catch (ParseException pe) {
                            logger.warning("Could not parse date " + dateTime 
                                + ": " + pe.getMessage());
                            logger.log(Level.FINE, "parseContents", pe);
                        }
                        entry.setDate(date);
                    }
                } else {
                    logger.warning("Expecting actionType and got [" + line + "]");
                }
            }
        }

        if (entry != null && entry.getDate() != null) {
            entries.add(entry);
            dumpEntry(entry);
        }

        History history = new History();
        history.setHistoryEntries(entries);
        return history;
    }

    private static void dumpEntry(HistoryEntry entry) {
        if (DUMP_HISTORY_ENTRY_ADDITIONS) {
            entry.dump();
        }
    }
}