/*
 * [Deletions.java]
 *
 * Summary: Notice files that have been deleted since we last distributed.
 *
 * Copyright: (c) 2007-2017 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:
 *  8.4 2007-07-18
 */
package com.mindprod.replicatorsender;

import com.mindprod.sorted.Merge;
import com.mindprod.sorted.SortedArrayList;

/**
 * Notice files that have been deleted since we last distributed.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 8.4 2007-07-18
 * @since 2007
 */
final class Deletions
    {
    /**
     * Discover files that have either been deleted or updated
     * since the last distribution.  The old versions in the zip files are now deadwood. We
     * record the amount of new deadwood in each zip.
     */
    public static void process()
        {
        // obsolete includes both files newly replaced and newly deleted.
        SortedArrayList<MaxiFD> obsolete =
                Merge.allBut( ReplicatorSender.oldFilesDistributed,
                        ReplicatorSender.filesToDistribute,
                        MaxiFD.BY_DATE_AND_FILENAME );
        for ( MaxiFD fd : obsolete )
            {
            // deadwood accounting for files that have been been replaced or
            // deleted
            long fileLength = fd.getFileLength();
            MaxiZD zd = fd.getZip();
            assert zd != null : "unassigned file was distributed";
            zd.deadwood += fileLength;
            zd.livewood -= fileLength;
            // don't change timestamp or would disturb ordering.
            // don't bother to setFileLength or assignZip(null) since
            // most of these are replacements which will just be dropped anyway.
            }
        // split off the true deletions from the obsoletes, excluding old
        // deletions.
        final SortedArrayList<MaxiFD> deletions =
                Merge.allBut( obsolete,
                        ReplicatorSender.filesToDistribute,
                        MaxiFD.BY_FILENAME );
        StatsForSender.recentDeletedFilesCount = deletions.size();
        StatsForSender.recentUpdatedFilesCount = obsolete.size() - deletions.size();
        // stop tracking files we deleted long ago.
        final int size = ReplicatorSender.oldFilesDeleted.size();
        for ( int i = 0; i < size; i++ )
            {
            final MaxiFD fd = ReplicatorSender.oldFilesDeleted.get( i );
            if ( fd.getClumping() < ConfigForSender.KEEP_DELETED_CUTOFF_TIMESTAMP )
                {
                ReplicatorSender.oldFilesDeleted.set( i, null ); // effectively delete it.
                }
            }
        // physically delete nulled elements.
        ReplicatorSender.oldFilesDeleted = Merge.pruneNulls( ReplicatorSender.oldFilesDeleted );
        // new list of files to delete is old list minus files "undeleted",
        // re-emerged plus newly deleted files.
        ReplicatorSender.filesToDelete =
                Merge.allBut( ReplicatorSender.oldFilesDeleted,
                        ReplicatorSender.filesToDistribute,
                        MaxiFD.BY_FILENAME );
        // add newly discovered deletions.
        for ( MaxiFD fd : deletions )
            {
            // date effectively noticed it disappeared.
            fd.markAsDeleted();
            fd.setFileLength( 0 );
            fd.setTimestamp( ReplicatorSender.cutOffTimestamp );
            fd.setClumping( ReplicatorSender.cutOffTimestamp );
            fd.assignZip( null );
            ReplicatorSender.filesToDelete.add( fd );
            }
        // we have wrecked the order of any SortedArrayList one of the deletions
        // might have been in.
        ReplicatorSender.filesToDelete.invalidate();
        ReplicatorSender.oldFilesDistributed.invalidate();
        }
    }