package org.geotools.data.geojson;
/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2015, 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.
 */
import java.awt.RenderingHints.Key;
import java.io.IOException;
import java.io.Serializable;
import java.net.URL;
import java.util.Collections;
import java.util.Map;

import org.apache.commons.io.FilenameUtils;
import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFactorySpi;
import org.geotools.util.KVP;

public class GeoJSONDataStoreFactory implements DataStoreFactorySpi {

	public static final String[] EXTS = { "geojson", "json" };
	public static final Param URLP = new Param("url", URL.class, "url to a .json file", true, null,
	    new KVP(Param.EXT, "json", Param.EXT, "geojson"));

	/** Confirm DataStore availability, null if unknown */
	Boolean isAvailable = null;

	public GeoJSONDataStoreFactory() {
		super();
	}

	@Override
	public String getDisplayName() {
		return "GeoJSON";
	}

	@Override
	public String getDescription() {
		return "GeoJSON files and URLsi containing feature collections.";
	}

	@Override
	public Param[] getParametersInfo() {
		return new Param[] { URLP };
	}

	@Override
	public boolean canProcess(Map<String, Serializable> params) {
		URL url;
		try {
			url = (URL) URLP.lookUp(params);
			if (url != null) {
				for (String ext : EXTS) {
					if (FilenameUtils.getExtension(url.toExternalForm()).equalsIgnoreCase(ext)) {
						return true;
					}
				}
			}
		} catch (IOException e) {
			// in fact we don't really care as we are merely testing
		}
		return false;
	}

	@Override
	/**
	 * Test to see if this DataStore is available, for example if it has all the
	 * appropriate libraries to construct an instance.
	 * 
	 * This method is used for interactive applications, so as to not advertise
	 * support for formats that will not function.
	 * 
	 * @return <tt>true</tt> if and only if this factory is available to create
	 *         DataStores.
	 */
	public synchronized boolean isAvailable() {
		if (isAvailable == null) {
			try {
				Class geoJSONReaderType = Class.forName("org.geotools.geojson.feature.FeatureJSON");
				isAvailable = true;
			} catch (ClassNotFoundException e) {
				isAvailable = false;
			}
		}
		return isAvailable;
	}

	@Override
	public Map<Key, ?> getImplementationHints() {
		// none required
		return Collections.emptyMap();
	}

	@Override
	public DataStore createDataStore(Map<String, Serializable> params) throws IOException {
		URL url = (URL) URLP.lookUp(params);
		return new GeoJSONDataStore(url);
	}

	@Override
	public DataStore createNewDataStore(Map<String, Serializable> params) throws IOException {
		URL url = (URL) URLP.lookUp(params);
		// We can only really write to local files
		String scheme = url.getProtocol();
		String host = url.getHost();
		if ("file".equalsIgnoreCase(scheme) && (host == null || host.isEmpty())) {
			return new GeoJSONDataStore(url);
		} else {
			throw new IllegalArgumentException("unable to write to remote URLs");
		}
	}

}