/*
 * $Header: /cvsroot/mvnforum/mvnforum/src/com/mvnforum/admin/importexport/mvnforum/ImportMvnForum.java,v 1.12 2006/04/14 17:36:29 minhnn Exp $
 * $Author: minhnn $
 * $Revision: 1.12 $
 * $Date: 2006/04/14 17:36:29 $
 *
 * ====================================================================
 *
 * Copyright (C) 2002-2006 by MyVietnam.net
 *
 * All copyright notices regarding mvnForum MUST remain 
 * intact in the scripts and in the outputted HTML.
 * The "powered by" text/logo with a link back to
 * http://www.mvnForum.com and http://www.MyVietnam.net in 
 * the footer of the pages MUST remain visible when the pages
 * are viewed on the internet or intranet.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Support can be obtained from support forums at:
 * http://www.mvnForum.com/mvnforum/index
 *
 * Correspondence and Marketing Questions can be sent to:
 * info at MyVietnam net
 *
 * @author: Igor Manic   
 */
package com.mvnforum.admin.importexport.mvnforum;

import java.io.*;
import java.util.Calendar;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.mvnforum.MVNForumConfig;
import com.mvnforum.MVNForumGlobal;
import com.mvnforum.admin.ImportWebHelper;
import com.mvnforum.admin.importexport.SetParentRule;
import net.myvietnam.mvncore.exception.*;
import org.apache.commons.digester.Digester;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xml.sax.SAXException;

/**
 * @author Igor Manic
 * @version $Revision: 1.12 $, $Date: 2006/04/14 17:36:29 $
 * <br/>
 * <code>ImportMvnForum</code> class encapsulates processing
 * of MVN Forum's XML or ZIP backups, and imports all the data into MVN Forum.
 * For details see {@link #importXml(File, HttpServletRequest, HttpServletResponse, int, String, Calendar, String, boolean, int)}
 * and {@link #importZip(File, HttpServletRequest, HttpServletResponse, int, String, Calendar, String, boolean, int)}
 * <br/>
 * This class cannot be instantiated.
 */
public class ImportMvnForum extends ImportWebHelper {

    /** Message log. */
    private static Log log = LogFactory.getLog(ImportMvnForum.class);

    /** Cannot instantiate. */
    private ImportMvnForum() {
    }


// =================================================================
// ===================== MAIN PUBLIC METHODS =======================
// =================================================================
    /**
     * This method performs processing of MVN Forum's XML backup file <code>importFile</code>
     * and imports the data into the MVN Forum system. It clears the database
     * and files, does neccessary setup (including startup of message output),
     * and calls {@link #processXml(File, Calendar)} to do actual processing.<br/>
     *
     * @param importFile MVN Forum XML backup file to be imported.
     * @param request Current session's <code>HttpServletRequest</code> object.
     * @param response Current session's <code>HttpServletResponse</code> object.
     * @param logonMemberID MemberID of user who is logged in, and who initiated import process.
     * @param logonMemberName MemberName of user who is logged in, and who initiated import process.
     * @param importTime The moment when import process was started.
     * @param importIP From this IP address admin requested import.
     * @param clearIfError Should it clear/reset the database in case of error.
     * @param messageLevel What messages should be written to output during the process.
     *                     For details see {@link com.mvnforum.MVNForumConfig#MESSAGE_LEVEL_ALL_MESSAGES},
     *                     {@link com.mvnforum.MVNForumConfig#MESSAGE_LEVEL_IMPORTANT_MESSAGES} and
     *                     {@link com.mvnforum.MVNForumConfig#MESSAGE_LEVEL_ONLY_ERRORS}.
     *
     * @exception ImportException If there is an error during the process. See {@link net.myvietnam.mvncore.exception.ImportException}.
     */
    public static void importXml(File importFile,
           HttpServletRequest request, HttpServletResponse response,
           int logonMemberID, String logonMemberName,
           Calendar importTime, String importIP,
           boolean clearIfError, int messageLevel)
    throws ImportException {
        try {
            response.setContentType("text/html; charset=utf-8");
            setOutputHtmlWriter(response.getWriter());
            setMessageOutputLevel(messageLevel);
            startHtml(request);
            clearDatabase();
            clearFiles(request.getSession().getServletContext());
        } catch (DatabaseException e) {
            handleFatalError("Database error while clearing previous contents.",
                             e, clearIfError, request);
        } catch (IOException e) {
            handleFatalError("I/O error while clearing previous contents.",
                             e, clearIfError, request);
        }

        try {
            processXml(importFile, importTime);
            handleSuccess(request);
        } catch (ImportException e) {
            handleFatalError(e.getMessage(), e.getException(),
                             clearIfError, request);
        } catch (IOException e) {
            handleFatalError("I/O error while reading XML file.",
                             e, clearIfError, request);
        } catch (SAXException e) {
            if (e.getException()==null) {
                handleFatalError("Error while parsing uploaded XML file.",
                                 e, clearIfError, request);
            } else {
                handleFatalError("Error while parsing uploaded XML file. Detail: "+
                                 e.getException().getMessage(), e.getException(),
                                 clearIfError, request);
            }
        } finally {
            /* Don't delete this XML since this method was maybe started from the
             * command-line, which means this file is not temporary (uploaded)
             * //if ((importFile!=null) && (importFile.exists())) importFile.delete();
             * Anyway, if neccessary, this XML will be deleted in calling WebHandler
             */
        }
    }

    /**
     * This method performs processing of MVN Forum's ZIP backup file <code>importFile</code>
     * and imports the data into the MVN Forum system. It clears the database
     * and files, does neccessary setup (including startup of message output),
     * extracts the files from ZIP, and calls {@link #processXml(File, Calendar)}
     * to do actual processing of the main XML file (found in ZIP).<br/>
     *
     * @param importFile MVN Forum ZIP backup file to be imported.
     * @param request Current session's <code>HttpServletRequest</code> object.
     * @param response Current session's <code>HttpServletResponse</code> object.
     * @param logonMemberID MemberID of user who is logged in, and who initiated import process.
     * @param logonMemberName MemberName of user who is logged in, and who initiated import process.
     * @param importTime The moment when import process was started.
     * @param importIP From this IP address admin requested import.
     * @param clearIfError If <code>true</code>, the database will be cleared/reset
     *                     in case of error rises during the import. Default <code>Guest</code>
     *                     and <code>Admin</code> users will be created.
     * @param messageLevel What amount of messages (informational, important, error)
     *                     will be written to output.
     *
     * @exception ImportException If there is an error during the process. See {@link net.myvietnam.mvncore.exception.ImportException}.
     */
    public static void importZip(File importFile,
           HttpServletRequest request, HttpServletResponse response,
           int logonMemberID, String logonMemberName,
           Calendar importTime, String importIP,
           boolean clearIfError, int messageLevel)
    throws ImportException {
        File importXml=null;
        try {
            response.setContentType("text/html; charset=utf-8");
            setOutputHtmlWriter(response.getWriter());
            setMessageOutputLevel(messageLevel);
            startHtml(request);
            clearDatabase();
            clearFiles(request.getSession().getServletContext());
        } catch (DatabaseException e) {
            handleFatalError("Database error while clearing previous contents.",
                             e, clearIfError, request);
        } catch (IOException e) {
            handleFatalError("I/O error while clearing previous contents.",
                             e, clearIfError, request);
        }

       /* Now extract ZIP file into mvnForumHome, and give me back only XML file.
        * IMPORTANT: DON'T CALL clearFiles() AFTER THE EXTRACTION OF THE ZIP!
        * Otherwise, all extracted files will be deleted too
        */
       try {
           addImportantMessage("Extracting the ZIP file.");
           importXml=extractImportZip(importFile, request);
           if (importXml==null) {
               handleFatalError("Error while extracting the file: can't find IMPORT.xml in ZIP file.",
                                null/*error*/, clearIfError, request);
           }
       } catch (IOException e) {
           handleFatalError("I/O error while extracting the file.",
                            e, clearIfError, request);
       } finally {
           importFile.delete(); importFile=null;
       }

       //from this point on, use only importXml file (importFile is deleted)
       try {
           processXml(importXml, importTime);
           handleSuccess(request);
       } catch (ImportException e) {
           handleFatalError(e.getMessage(), e.getException(),
                            clearIfError, request);
       } catch (IOException e) {
           handleFatalError("I/O error while reading XML file.",
                            e, clearIfError, request);
       } catch (SAXException e) {
           if (e.getException()==null) {
               handleFatalError("Error while parsing uploaded XML file.",
                                e, clearIfError, request);
           } else {
               handleFatalError("Error while parsing uploaded XML file. Detail: "+
                                e.getException().getMessage(), e.getException(),
                                clearIfError, request);
           }
       } finally {
           //now delete temporary XML file (extracted from ZIP, and already imported to database)
           if ((importFile!=null) && (importFile.exists())) importFile.delete();
           if ((importXml!=null) && (importXml.exists())) importXml.delete();
       }
    }

    /**
     * This method should unpack the zip into mvnForumHome.
     * It should also return importXml file (which was also extracted)
     */
    private static File extractImportZip(File importZipFile, HttpServletRequest request)
    throws IOException {
        String avatarsDir = request.getSession().getServletContext().getRealPath(MVNForumGlobal.UPLOADED_AVATAR_DIR);