/**
 *
 */
package org.gcube.datatransfer.resolver.services;

import java.net.URI;
import java.net.URLEncoder;
import java.util.Random;
import java.util.concurrent.ExecutionException;

import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.QueryParam;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;

import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.datatransfer.resolver.caches.LoadingGeoExplorerApplicationURLCache;
import org.gcube.datatransfer.resolver.caches.LoadingGeonetworkInstanceCache;
import org.gcube.datatransfer.resolver.caches.LoadingGisViewerApplicationURLCache;
import org.gcube.datatransfer.resolver.gis.GeonetworkInstance;
import org.gcube.datatransfer.resolver.gis.MetadataConverter;
import org.gcube.datatransfer.resolver.gis.entity.GisLayerItem;
import org.gcube.datatransfer.resolver.gis.exception.GeonetworkInstanceException;
import org.gcube.datatransfer.resolver.init.UriResolverSmartGearManagerInit;
import org.gcube.datatransfer.resolver.services.error.ExceptionManager;
import org.gcube.spatial.data.geonetwork.LoginLevel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.cache.CacheLoader.InvalidCacheLoadException;

/**
 * The Class GisResolver.
 *
 * @author Francesco Mangiacrapa at ISTI-CNR (francesco.mangiacrapa@isti.cnr.it)
 *         Dec 14, 2018
 */
@Path("gis")
public class GisResolver {

	private static Logger logger = LoggerFactory.getLogger(GisResolver.class);

	public static String help = "https://wiki.gcube-system.org/gcube/URI_Resolver#GIS_Resolver";

	public static final String UTF_8 = "UTF-8";

	public static final String GIS_UUID = "gis-UUID";
	public static final String SCOPE = "scope";
	public static final String GEO_EXPLORER_LAYER_UUID = "geo-exp";

	/**
	 * Submit get.
	 *
	 * @param req             the req
	 * @param scope           the scope
	 * @param gisUUID         the gis uuid
	 * @param geoExplorerUUID the geo explorer uuid
	 * @return the response
	 * @throws WebApplicationException the web application exception
	 */
	@GET
	@Path("")
	public Response submitGet(@Context HttpServletRequest req, @QueryParam(SCOPE) String scope,
			@QueryParam(GIS_UUID) String gisUUID, @QueryParam(GEO_EXPLORER_LAYER_UUID) String geoExplorerUUID)
			throws WebApplicationException {

		logger.info(this.getClass().getSimpleName() + " GET starts...");

		try {
			boolean isGisLink = false;
			boolean isGeoExplorerLink = false;

			if (scope == null || scope.isEmpty()) {
				logger.error("Query Parameter 'scope' not found");
				throw ExceptionManager.badRequestException(req, "Missing mandatory query parameter 'scope'",
						this.getClass(), help);
			}

			if (gisUUID == null || gisUUID.isEmpty()) {
				logger.error("Path Parameter 'gis-UUID' not found");
				throw ExceptionManager.badRequestException(req, "Missing mandatory query parameter 'gis-UUID'",
						this.getClass(), help);
			} else
				isGisLink = true;

			logger.info(SCOPE + " is: " + scope);
			logger.info(GIS_UUID + " is: " + gisUUID);

			if (geoExplorerUUID == null || geoExplorerUUID.isEmpty()) {
				logger.debug(GEO_EXPLORER_LAYER_UUID + " not found");
			} else
				isGeoExplorerLink = true;

			logger.info(GEO_EXPLORER_LAYER_UUID + " is: " + geoExplorerUUID);

			if (!isGisLink && !isGeoExplorerLink) {
				String err = GIS_UUID + " or " + GEO_EXPLORER_LAYER_UUID + " not found or empty in the query string";
				logger.error(err);
				throw ExceptionManager.badRequestException(req, err, this.getClass(), help);
			}

			if (isGisLink) {
				ScopeProvider.instance.set(scope);
				// ServerParameters geonetworkParams = getCachedServerParameters(scope);
				GisLayerItem gisLayerItem = getGisLayerForLayerUUID(req, scope, gisUUID);

				logger.info("wms url is: " + gisLayerItem.getFullWmsUrlRequest());
				String wmsRequest = URLEncoder.encode(gisLayerItem.getFullWmsUrlRequest(), UTF_8);
				logger.info("encoded WMS url is: " + wmsRequest);

				String layerTitle = null;
				if (gisLayerItem.getCitationTitle() != null && !gisLayerItem.getCitationTitle().isEmpty())
					layerTitle = URLEncoder.encode(gisLayerItem.getCitationTitle(), UTF_8);

				logger.info("layer Title encoded is: " + layerTitle);
				String gisViewerPortletUrl = null;
				try {
					gisViewerPortletUrl = LoadingGisViewerApplicationURLCache.get(scope);
				} catch (ExecutionException | InvalidCacheLoadException e) {
					logger.error("Error on getting the GisViewer Applicaton URL from cache for scope " + scope, e);
					throw ExceptionManager.wrongParameterException(req,
							"Error on getting the GisViewer Applicaton URL from cache for scope " + scope
									+ ".\nIs the Application Profile with APPID "
									+ UriResolverSmartGearManagerInit.getGisViewerProfile().getAppId()
									+ " registered for this scope: " + scope + "?",
							this.getClass(), help);
				}
				// CHECKING IF THE GisViewer Portlet URL is valid
				if (gisViewerPortletUrl == null || gisViewerPortletUrl.isEmpty())
					throw ExceptionManager.notFoundException(req,
							"GisViewer Portlet URL not found in the scope: " + scope + ". Please contact the support",
							this.getClass(), help);

				logger.info("Gis Viewer Application url is: " + gisViewerPortletUrl);
				gisViewerPortletUrl += "?rid=" + new Random().nextLong() + "&wmsrequest=" + wmsRequest + "&uuid="
						+ URLEncoder.encode(gisUUID, UTF_8);

				if (layerTitle != null)
					gisViewerPortletUrl += "&layertitle=" + layerTitle;

				logger.info("Redirecting to: " + gisViewerPortletUrl);
				return Response.seeOther(new URI(gisViewerPortletUrl)).build();

			}

			if (isGeoExplorerLink) {

				ScopeProvider.instance.set(scope);
				String geoExplorerPortletUrl = null;
				try {
					geoExplorerPortletUrl = LoadingGeoExplorerApplicationURLCache.get(scope);
				} catch (ExecutionException e) {
					logger.error("Error on getting the GeoExplorer Applicaton URL from cache for scope " + scope, e);
					throw ExceptionManager.wrongParameterException(req,
							"Error on getting the GeoExplorer Applicaton URL from cache for scope " + scope
									+ ".\nIs the Application Profile with APPID "
									+ UriResolverSmartGearManagerInit.getGeoExplorerProfile().getAppId()
									+ " registered for this scope: " + scope + "?",
							this.getClass(), help);
				}
				// CHECKING IF THE GeoExplorer Portlet URL is valid
				if (geoExplorerPortletUrl == null || geoExplorerPortletUrl.isEmpty())
					throw ExceptionManager.notFoundException(req,
							"GeoExplorer Portlet URL not found in the scope: " + scope + ". Please contact the support",
							this.getClass(), help);

				logger.info("GeoExplorer Application url is: " + geoExplorerPortletUrl);
				geoExplorerPortletUrl += "?rid=" + new Random().nextLong() + "&luuid="
						+ URLEncoder.encode(geoExplorerUUID, UTF_8);
				// urlRedirect(req, resp, geoExplorerPortletUrl);
				return Response.seeOther(new URI(geoExplorerPortletUrl)).build();
			}

			throw ExceptionManager.badRequestException(req,
					GIS_UUID + " or " + GEO_EXPLORER_LAYER_UUID + " not found or empty in the query string",
					this.getClass(), help);

		} catch (Exception e) {

			if (!(e instanceof WebApplicationException)) {
				// UNEXPECTED EXCEPTION managing it as WebApplicationException
				String error = "Sorry, an error occurred on resolving request with UUID " + gisUUID + " and scope "
						+ scope + ". Please, contact support!";
				if (e.getCause() != null)
					error += "\n\nCaused: " + e.getCause().getMessage();
				throw ExceptionManager.internalErrorException(req, error, this.getClass(), help);
			}
			// ALREADY MANAGED AS WebApplicationException
			logger.error("Exception:", e);
			throw (WebApplicationException) e;
		}

	}

	/**
	 * Gets the gis layer for layer uuid.
	 *
	 * @param req     the req
	 * @param scope   the scope
	 * @param gisUUID the gis uuid
	 * @return the gis layer for layer uuid
	 * @throws Exception the exception
	 */
	public GisLayerItem getGisLayerForLayerUUID(HttpServletRequest req, String scope, String gisUUID) throws Exception {

		try {
			GeonetworkInstance gi = null;
			try {
				gi = LoadingGeonetworkInstanceCache.get(scope);

			} catch (ExecutionException | InvalidCacheLoadException e) {
				logger.error("Error on getting the Geonetwork Instance from cache for scope " + scope, e);
				throw ExceptionManager.wrongParameterException(req,
						"Error on getting the Geonetwork Instance from cache for scope " + scope
								+ ". Is it registered for this scope: " + scope + "?",
						this.getClass(), help);
			}
			if (gi == null)
				throw new Exception("GeonetworkInstance not instanciable in the scope: " + scope);

			LoginLevel toLoginLevel = LoginLevel.SCOPE;
			logger.info(
					"Performing authentication on GN with " + LoginLevel.class.getSimpleName() + " " + toLoginLevel);
			gi.getGeonetworkPublisher().login(toLoginLevel);

			GisLayerItem gisLayerItem = MetadataConverter.getWMSOnLineResource(gi, gisUUID);
			return gisLayerItem;
			// TODO CREATE A BEAN ADDING WMS REQUEST AND LAYER TITLE MetadataConverter.
		} catch (GeonetworkInstanceException e) {
			logger.error("An error occurred when instancing geonetowrk gis layer with UUID " + gisUUID, e);
			throw new IllegalArgumentException(
					"Sorry, An error occurred when instancing geonetwork with UUID: " + gisUUID);
		} catch (Exception e) {
			logger.error("An error occurred when retrieving gis layer with UUID " + gisUUID, e);
			throw new IllegalArgumentException(
					"Sorry, An error occurred when retrieving gis layer with UUID " + gisUUID);
		}
	}

}