/*
 * [RSSFeedLog.java]
 *
 * Summary: Logs the XML for all feeds.
 *
 * Copyright: (c) 2008-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2008-07-31
 */
package com.mindprod.htmlmacros.support;

import com.mindprod.common18.EIO;

import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;

import static com.mindprod.htmlmacros.macro.Global.configuration;
import static java.lang.System.*;

/**
 * Logs the XML for all feeds.
 * <p/>
 * it will be expanded in line if there were any feeds.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2008-07-31
 * @since 2008-07-31
 */
public final class RSSFeedLog
    {
    /**
     * count of RSS items
     */
    static int count;

    static File rssBinaryLogFile;

    /**
     * where we log all feeds in binary format for later sorting and collecting into separate feeds.
     * Opened on first encounter with RSS macro .
     * Stays open until shutdown.
     */
    private static DataOutputStream rssBinaryLogStream;

    /**
     * close binary log of feeds we will later format
     */
    private static void endAllFeeds() throws IOException
        {
        if ( rssBinaryLogStream != null )
            {
            rssBinaryLogStream.close();
            rssBinaryLogStream = null;
            }
        }

    /**
     * start recording binary stream of rss items that will will later format
     */
    private static void startAllFeeds()
        {
        try
            {
            // first time we have encountered an RSS macro expansion in this batch, open file and leave open till shutdown.
            rssBinaryLogFile = new File( configuration.getLocalWebrootWithSlashes() + "/rss/temprssfeedlog.bin" );
            rssBinaryLogStream = EIO.getDataOutputStream( rssBinaryLogFile, 32 * 1024 );
            }
        catch ( IOException e )
            {
            err.println( "Unable to open " + rssBinaryLogFile.getAbsolutePath() );
            System.exit( 2 );
            }
        }

    /**
     * done at start
     */
    public static void fireup()
        {
        startAllFeeds();
        }

    /**
     * emit the XML for one RSS-2 feed item to a binary log file.
     *
     * @param feedItem item to log
     */
    public static void logFeedItem( RSSSortableItem feedItem )
        {
        try
            {
            // we have to automatically handle start/end. Caller won't invoke them.
            // log item in computer-friendly BigEndian binary format for processing later.
            feedItem.write( rssBinaryLogStream );
            count++;
            }
        catch ( IOException e )
            {
            throw new IllegalArgumentException( "problem writing an RSS feed item file" );
            }
        }

    /**
     * generate various export files to download with formatted xml
     */
    public static void shutdown()
        {
        try
            {
            // sends all results to files, nothing to expandNoRef inline.
            endAllFeeds();
            RSSFeedExport.exportAllFeeds();
            }
        catch ( IOException e )
            {
            throw new IllegalArgumentException( "problem closing/exporting a RSS feed item file" );
            }
        }
    }