/*
 * MapTileSet.java        Jan 2, 2012 10:57:59 PM
 */

package com.bbn.openmap.maptileservlet;

import java.io.IOException;
import java.util.Properties;

import com.bbn.openmap.dataAccess.mapTile.ServerMapTileFactory;
import com.bbn.openmap.io.BinaryBufferedFile;
import com.bbn.openmap.io.FormatException;
import com.bbn.openmap.util.PropUtils;

/**
 * The RelayMapTileSet contains all the information for handling a specific set
 * of tiles. It contains a description, key to use in the request, the location
 * of the data directory or jar. This MapTileSet is able to contact a remote
 * server for tiles if the tile file isn't found locally.
 * <p>
 * These properties should be in the properties file referenced in the web.xml
 * file for this tile set:
 * 
 * <pre>
 * name=the-name-of-dataset
 * class=com.bbn.openmap.maptileservlet.RelayMapTileSet
 * rootDir=the formatted URL for remote tiles, i.e. http://server.com/{z}/{x}/{y}.png
 * localCacheRootDir=the local path of the cached tiles, i.e. /data/tiles/{z}/{x}/{y}.png
 * </pre>
 * 
 * As an example, a url for accessing a tile from this server would be:
 * <pre>
 * http://your.machine/ommaptile/the-name-of-dataset/z/x/y.png
 * </pre>
 * where ommaptile is the name of the servlet.  You can change that in the web.xml and in glassfish/tomcat.
 * 
 * @author dietrick
 */
public class RelayMapTileSet extends ServerMapTileFactory implements MapTileSet {

    public final static String NAME_ATTRIBUTE = "name";

    protected String name;
    protected String description = null;

    // To allow the component factory to create it.
    public RelayMapTileSet() {
    }

    public boolean allGood() {
        return name != null && rootDir != null;
    }

    public void setProperties(String prefix, Properties props) {
        super.setProperties(prefix, props);
        prefix = PropUtils.getScopedPropertyPrefix(prefix);

        name = props.getProperty(prefix + NAME_ATTRIBUTE, name);
    }

    public Properties getProperties(Properties props) {
        props = super.getProperties(props);
        String prefix = PropUtils.getScopedPropertyPrefix(this);
        props.put(prefix + NAME_ATTRIBUTE, PropUtils.unnull(name));
        return props;
    }

    public byte[] getImageData(String pathInfo) throws IOException, FormatException {
        byte[] imageData = null;

        // We're assuming that all queries are coming in with the name in front,
        // along with a slash
        if (name != null) {
            int index = pathInfo.indexOf(name, 1);
            pathInfo = pathInfo.substring(index + name.length());
        }

        // We need to build and check for local file. If not found, then call
        // getImageBytes to fetch from other server and cache locally

        String localFilePath = null;
        TileInfo tInfo = new TileInfo(pathInfo);

        if (!tInfo.valid) {
            return imageData;
        }

        if (localCacheDir != null) {
            localFilePath = buildLocalFilePath(tInfo.x, tInfo.y, tInfo.zoomLevel, fileExt);

            try {

                BinaryBufferedFile file = new BinaryBufferedFile(localFilePath);
                imageData = file.readBytes(100000, true);
                file.close();
                return imageData;

            } catch (IOException ioe) {
                // Didn't find local version of file, that's OK. Continue on...
            }
        }

        // The file wasn't found.

        String remoteFilePath = buildFilePath(tInfo.x, tInfo.y, tInfo.zoomLevel, fileExt);
        imageData = getImageBytes(remoteFilePath, localFilePath);

        return imageData;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}