/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2015 - 2016, Open Source Geospatial Foundation (OSGeo)
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *    Lesser General Public License for more details.
 */
package org.geotools.gce.imagemosaic.catalog;

import it.geosolutions.imageio.maskband.DatasetLayout;

import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.geotools.coverage.grid.io.AbstractGridCoverage2DReader;
import org.geotools.coverage.grid.io.AbstractGridFormat;
import org.geotools.coverage.grid.io.GridFormatFinder;
import org.geotools.coverage.grid.io.footprint.MultiLevelROI;
import org.geotools.coverage.grid.io.footprint.MultiLevelROIProvider;
import org.geotools.coverage.grid.io.footprint.MultiLevelROIRaster;
import org.geotools.coverage.grid.io.footprint.SidecarFootprintProvider;
import org.geotools.factory.Hints;
import org.geotools.gce.imagemosaic.Utils;
import org.geotools.util.logging.Logging;
import org.opengis.feature.simple.SimpleFeature;

/**
 * {@link MultiLevelROIProvider} implementation returning a {@link MultiLevelROIRaster} instance
 * 
 * @author Nicola Lagomarsini
 */
public class MultiLevelROIRasterProvider implements MultiLevelROIProvider {

    /** Logger used for logging exceptions */
    static final Logger LOGGER = Logging.getLogger(SidecarFootprintProvider.class);

    /** Hints to use for avoiding to search for the imagemosaic format */
    public static final Hints EXCLUDE_MOSAIC = new Hints(Utils.EXCLUDE_MOSAIC, true);

    /** Mosaic Folder used as root folder */
    private File mosaicFolder;

    public MultiLevelROIRasterProvider(File mosaicFolder) {
        this.mosaicFolder = mosaicFolder;
    }

    @Override
    public MultiLevelROI getMultiScaleROI(SimpleFeature sf) throws IOException {
        if (sf == null) {
            // Feature is not defined
            return null;
        }
        // Extracting File from feature
        Object value = sf.getAttribute("location");
        if (value != null && value instanceof String) {
            String strValue = (String) value;
            File file = getFile(strValue);
            MultiLevelROI result = null;
            if (file.exists() && file.canRead()) {
                try {
                    // When looking for formats which may parse this file, make sure to exclude the ImageMosaicFormat as return
                    AbstractGridFormat format = (AbstractGridFormat) GridFormatFinder
                            .findFormat(file, EXCLUDE_MOSAIC);
                    AbstractGridCoverage2DReader reader = format.getReader(file);
                    // Getting Dataset Layout
                    DatasetLayout layout = reader.getDatasetLayout();
                    // If present use it
                    if (layout != null) {
                        // Getting Total Number of masks
                        int numExternalMasks = layout.getNumExternalMasks() > 0
                                ? layout.getNumExternalMasks() : 0;
                        int numInternalMasks = layout.getNumInternalMasks() > 0
                                ? layout.getNumInternalMasks() : 0;
                        int numExternalMaskOverviews = layout.getNumExternalMaskOverviews() > 0
                                ? layout.getNumExternalMaskOverviews() : 0;
                        int totalMasks = numExternalMasks + numInternalMasks
                                + numExternalMaskOverviews;
                        // Check if masks are present
                        // NOTE No Mask: Outside ROI
                        if (totalMasks > 0) {
                            return new MultiLevelROIRaster(layout, file, sf);
                        }
                    }
                } catch (Exception e) {
                    throw new IOException("Failed to load the footprint for granule " + strValue,
                            e);
                }
            }
            return result;
        } else {
            if (LOGGER.isLoggable(Level.FINE)) {
                LOGGER.fine("Could not use the location attribute value to search for "
                        + "the file, the value was: " + value);
            }
            return null;
        }
    }

    /** Returns the File associated to the imagemosaic feature location */
    private File getFile(String strValue) throws IOException {
        File file = new File(strValue);
        if (!file.isAbsolute()) {
            file = new File(mosaicFolder, strValue);
        }
        return file;
    }

    @Override
    public void dispose() {
    }

}