/*
 * ome.io.nio.ThumbnailService
 *
 *   Copyright 2006 University of Dundee. All rights reserved.
 *   Use is subject to license terms supplied in LICENSE.txt
 */
package ome.io.nio;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import ome.conditions.ResourceError;
import ome.model.display.Thumbnail;
import ome.util.Utils;

/**
 * @author callan
 * 
 */
public class ThumbnailService extends AbstractFileSystemService {

    /* The logger for this class. */
    private transient static Logger log = LoggerFactory
            .getLogger(ThumbnailService.class);

    /**
     * Constructor
     * @param path
     */
    public ThumbnailService(String path) {
        super(path);
    }

    /**
     * Creates thumbnail on disk using byte array
     *
     * @param thumbnail
     * @param buf
     * @throws IOException
     */
    public void createThumbnail(Thumbnail thumbnail, byte[] buf)
            throws IOException {
        String path = getThumbnailPath(thumbnail.getId());
        createSubpath(path);

        FileOutputStream stream = new FileOutputStream(path);
        stream.write(buf);
        stream.close();
    }

    /**
     * Returns length of Thumbnail on disk
     *
     * @param thumbnail
     */
    public long getThumbnailLength(Thumbnail thumbnail) {
        File f = new File(getThumbnailPath(thumbnail.getId()));
        return f.length();
    }

    /**
     * Return byte array of Thumbnail
     *
     * @param thumbnail
     * @return a byte array
     * @throws IOException
     */
    public byte[] getThumbnail(Thumbnail thumbnail) throws IOException {
        byte[] buf = new byte[(int) getThumbnailLength(thumbnail)];
        return getThumbnail(thumbnail, buf);
    }

    /**
     * Return byte array of Thumbnail, providing byte array
     *
     * @param thumbnail
     * @param buf
     * @return a byte array
     * @throws IOException
     */
    public byte[] getThumbnail(Thumbnail thumbnail, byte[] buf)
            throws IOException {
        String path = getThumbnailPath(thumbnail.getId());
        FileInputStream stream = new FileInputStream(path);
        try {
            stream.read(buf, 0, buf.length);
        } finally {
            Utils.closeQuietly(stream);
        }
        return buf;
    }

    /**
     * Return FileOutputStream of Thumbnail
     * 
     * @param thumbnail
     * @return a {@link FileOutputStream}
     * @throws IOException
     */
    public FileOutputStream getThumbnailOutputStream(Thumbnail thumbnail)
            throws IOException {
        String path = getThumbnailPath(thumbnail.getId());
        createSubpath(path);
        return new FileOutputStream(path);
    }

    /**
     * Returns whether or not a thumbnail exists on disk.
     *
     * @param thumbnail The thumbnail metadata.
     * @return See above.
     */
    public boolean getThumbnailExists(Thumbnail thumbnail)
            throws IOException {
        String path = getThumbnailPath(thumbnail.getId());
        return new File(path).exists();
    }

    /**
     * Removes files from data repository based on a parameterized List of Long
     * thumbnail ids
     *
     * @param thumbnailIds -
     *            Long file keys to be deleted
     * @throws ResourceError If deletion fails.
     */
    public void removeThumbnails(List<Long> thumbnailIds) {
        File file;
        boolean success = false;

        for (Long id : thumbnailIds)
        {
            String thumbnailPath = getThumbnailPath(id);
            file = new File(thumbnailPath);
            if (file.exists())
            {
                success = file.delete();
                if (!success)
                {
                    throw new ResourceError("Thumbnail " + file.getName()
                            + " deletion failed");
                }
                else
                {
                    if (log.isInfoEnabled())
                    {
                        log.info("INFO: Thumbnail " + file.getName()
                                + " deleted.");
                    }
                }
            }
        }
    }
}