package org.geotools.referencing.factory.gridshift;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.zip.GZIPInputStream;

import org.geotools.factory.AbstractFactory;
import org.geotools.metadata.iso.citation.Citations;
import org.geotools.util.logging.Logging;
import org.opengis.metadata.citation.Citation;

/**
 * Test helper that can load compressed grids
 */
public class TestGridShiftLocator  extends AbstractFactory implements GridShiftLocator {

    static final Logger LOGGER = Logging.getLogger(TestGridShiftLocator.class);

    @Override
    public Citation getVendor() {
        return Citations.GEOTOOLS;
    }

    @Override
    public URL locateGrid(String grid) {
        GZIPInputStream is = null;
        FileOutputStream fos = null;
        try {
            URL compressed = getClass().getResource(grid + ".gz");
            if (compressed != null) {
                is = new GZIPInputStream(compressed.openStream());
                File out = new File("./target/" + grid);
                fos = new FileOutputStream(out);
                byte[] buf = new byte[1024];
                int read;
                while ((read = is.read(buf)) > 0) {
                    fos.write(buf, 0, read);
                }

                return out.toURI().toURL();
            }
        } catch (IOException e) {
            LOGGER.log(Level.SEVERE, "Failed to unpack the grid", e);
        } finally {
            try {
                if (is != null) {
                    is.close();
                }
            } catch (IOException e) {
                //
            }

            try {
                if (fos != null) {
                    fos.close();
                }
            } catch (IOException e) {
                //
            }
        }

        return null;
    }

}