package org.gcube.datatransfer.resolver.services;

import java.net.URI;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutionException;

import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.common.scope.impl.ScopeBean;
import org.gcube.common.scope.impl.ScopeBean.Type;
import org.gcube.datacatalogue.ckanutillibrary.server.DataCatalogueRunningCluster.ACCESS_LEVEL_TO_CATALOGUE_PORTLET;
import org.gcube.datatransfer.resolver.ConstantsResolver;
import org.gcube.datatransfer.resolver.caches.LoadingMapOfDetachedVRE;
import org.gcube.datatransfer.resolver.caches.LoadingMapOfScopeCache;
import org.gcube.datatransfer.resolver.catalogue.CatalogueRequest;
import org.gcube.datatransfer.resolver.catalogue.ItemCatalogueURLs;
import org.gcube.datatransfer.resolver.catalogue.ResourceCatalogueCodes;
import org.gcube.datatransfer.resolver.catalogue.resource.CatalogueStaticConfigurations;
import org.gcube.datatransfer.resolver.catalogue.resource.CkanCatalogueConfigurationsReader;
import org.gcube.datatransfer.resolver.catalogue.resource.GatewayCKANCatalogueReference;
import org.gcube.datatransfer.resolver.catalogue.resource.GetAllInfrastructureScopes;
import org.gcube.datatransfer.resolver.services.error.ExceptionManager;
import org.gcube.datatransfer.resolver.util.Util;
import org.gcube.infrastructure.detachedres.detachedreslibrary.shared.re.VRE;
import org.gcube.smartgears.utils.InnerMethodName;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

import eu.trentorise.opendata.jackan.model.CkanDataset;

/**
 * The CatalogueResolver is able to get/resolve a link to a "Catalogue Entity"
 * stored in one of the D4Science Catalogue's instances. A Catalogue Entity is
 * either a "group" or an "organization" or a "product" of D4Science Data
 * Catalogue.
 *
 * See more at
 * https://gcube.wiki.gcube-system.org/gcube/URI_Resolver#CATALOGUE_Resolver
 * 
 * @author Francesco Mangiacrapa at ISTI-CNR (francesco.mangiacrapa@isti.cnr.it)
 *         Nov 16, 2018
 */
@Path("{entityContext:ctlg(-(o|g|p|d))?}")
public class CatalogueResolver {

	private static Logger logger = LoggerFactory.getLogger(CatalogueResolver.class);
	private static String helpURI = "https://wiki.gcube-system.org/gcube/URI_Resolver#CATALOGUE_Resolver";

	/**
	 * The Enum SCOPE_STATUS.
	 *
	 * @author Francesco Mangiacrapa at ISTI-CNR francesco.mangiacrapa@isti.cnr.it
	 * 
	 *         Mar 24, 2022
	 */
	private static enum SCOPE_STATUS {
		ACTIVE, DETACHED
	}

	/**
	 * Resolve an entity of the Catalogue
	 * 
	 * Request format:
	 * [URI_RESOLVER_SERVICE_ENDPOINT]/[ctlg|ctlg-d|ctlg-o|ctlg-g]/[VRE_NAME]/[entity_name]
	 *
	 * @param req           the req
	 * @param entityName    the entity name
	 * @param vreName       the vre name
	 * @param entityContext the entity context
	 * @return the response
	 * @throws WebApplicationException the web application exception
	 */
	@GET
	@Path("/{vreName}/{entityName}")
	public Response resolveCatalogue(@Context HttpServletRequest req, @PathParam("entityName") String entityName,
			@PathParam("vreName") String vreName, @PathParam("entityContext") String entityContext)
			throws WebApplicationException {

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

		try {
			InnerMethodName.instance.set("resolveCataloguePublicLink");
			ItemCatalogueURLs itemCatalogueURLs = getItemCatalogueURLs(req, vreName, entityContext, entityName);

			String itemCatalogueURL;

			if (itemCatalogueURLs.isPublicItem()) {
				logger.info("The dataset " + itemCatalogueURLs.getItemName()
						+ " was detected as public item (not private to VRE)");
				if (itemCatalogueURLs.getPublicVRECataloguePortletURL() != null
						&& !itemCatalogueURLs.getPublicVRECataloguePortletURL().isEmpty()) {
					itemCatalogueURL = itemCatalogueURLs.getPublicVRECataloguePortletURL();
					logger.info(
							"I found the public VRE catalogue URL, so using public access to it: " + itemCatalogueURL);
				} else {
					itemCatalogueURL = itemCatalogueURLs.getPublicGatewayCataloguePortletURL();
					logger.info("No public VRE catalogue URL found, so using public access to gateway CKAN portlet: "
							+ itemCatalogueURL);
				}
			} else {
				itemCatalogueURL = itemCatalogueURLs.getPrivateVRECataloguePortletURL();
				logger.info("The dataset " + itemCatalogueURLs.getItemName()
						+ " is a private item (to VRE) so using protected access to CKAN portlet: " + itemCatalogueURL);
			}

			return Response.seeOther(new URL(itemCatalogueURL).toURI()).build();
		} catch (Exception e) {

			if (!(e instanceof WebApplicationException)) {
				// UNEXPECTED EXCEPTION managing it as WebApplicationException
				String error = "Error occurred on resolving the Catalgoue URL. Please, contact the support!";
				if (e.getCause() != null)
					error += "\n\nCaused: " + e.getCause().getMessage();
				throw ExceptionManager.internalErrorException(req, error, this.getClass(), helpURI);
			}
			// ALREADY MANAGED AS WebApplicationException
			logger.error("Exception:", e);
			throw (WebApplicationException) e;
		}
	}

	/**
	 * Create a Catalogue Link
	 * 
	 *
	 * @param req         the req
	 * @param jsonRequest the json request
	 * @return the response
	 * @throws WebApplicationException the web application exception
	 */
	@POST
	@Path("")
	@Consumes(MediaType.APPLICATION_JSON)
	@Produces(MediaType.TEXT_PLAIN)
	public Response postCatalogue(@Context HttpServletRequest req, CatalogueRequest jsonRequest)
			throws WebApplicationException {
		logger.info(this.getClass().getSimpleName() + " POST starts...");

		try {

			InnerMethodName.instance.set("postCataloguePublicLink");
			logger.info("The body contains the request: " + jsonRequest.toString());

			// CHECK IF INPUT SCOPE IS VALID
			String scope = jsonRequest.getGcube_scope();
			if (!scope.startsWith(ConstantsResolver.SCOPE_SEPARATOR)) {
				logger.info("Scope not start with char '{}' adding it", ConstantsResolver.SCOPE_SEPARATOR);
				scope += ConstantsResolver.SCOPE_SEPARATOR + scope;
			}

			String serverUrl = Util.getServerURL(req);

			final String vreName = scope.substring(scope.lastIndexOf(ConstantsResolver.SCOPE_SEPARATOR) + 1,
					scope.length());
			ScopeBean fullScope = null;

			// CHECK IF THE vreName has a valid scope, so it is a valid VRE
			try {
				fullScope = LoadingMapOfScopeCache.get(vreName);
			} catch (ExecutionException e) {
				logger.error("Error on getting the fullscope from cache for vreName " + vreName, e);
				throw ExceptionManager.wrongParameterException(req,
						"Error on getting full scope for the VRE name " + vreName
								+ ". Is it registered as VRE in the D4Science Infrastructure System?",
						this.getClass(), helpURI);
			}

			if (fullScope == null)
				throw ExceptionManager.notFoundException(req,
						"The scope '" + scope + "' does not matching any scope in the infrastructure. Is it valid?",
						this.getClass(), helpURI);

			ResourceCatalogueCodes rc = ResourceCatalogueCodes.valueOfCodeValue(jsonRequest.getEntity_context());
			if (rc == null) {
				logger.error("Entity context is null/malformed");
				throw ExceptionManager.badRequestException(req, "Entity context is null/malformed", this.getClass(),
						helpURI);
			}

			String linkURL = String.format("%s/%s/%s/%s", serverUrl, rc.getId(), vreName, jsonRequest.getEntity_name());
			logger.info("Returining Catalogue URL: " + linkURL);
			return Response.ok(linkURL).header("Location", linkURL).build();

		} catch (Exception e) {

			if (!(e instanceof WebApplicationException)) {
				// UNEXPECTED EXCEPTION managing it as WebApplicationException
				String error = "Error occurred on resolving the Analytics URL. Please, contact the support!";
				throw ExceptionManager.internalErrorException(req, error, this.getClass(), helpURI);
			}
			// ALREADY MANAGED AS WebApplicationExceptiongetItemCatalogueURLs
			logger.error("Exception:", e);
			throw (WebApplicationException) e;
		}
	}

	/**
	 * Gets the item catalogue UR ls.
	 *
	 * @param req           the req
	 * @param scopeName     the scope name
	 * @param entityContext the entity context
	 * @param entityName    the entity name
	 * @return the item catalogue UR ls
	 * @throws Exception the exception
	 */
	protected static ItemCatalogueURLs getItemCatalogueURLs(HttpServletRequest req, String scopeName,
			String entityContext, String entityName) throws Exception {

		try {
			String entityContextValue = ResourceCatalogueCodes.valueOfCodeId(entityContext).getValue();
			ScopeBean scopeBean = null;
			SCOPE_STATUS scopeStatus = SCOPE_STATUS.ACTIVE;
			VRE vreDetached = null;
			try {
				scopeBean = LoadingMapOfScopeCache.get(scopeName);
			} catch (ExecutionException | InvalidCacheLoadException e) {
				logger.error(
						"Error on getting the fullscope from cache for scopeName {}. Tryng to load it from DetachedRE",
						scopeName);

				boolean isScopeDetached = false;
				try {
					vreDetached = LoadingMapOfDetachedVRE.get(scopeName);
					scopeBean = new ScopeBean(vreDetached.getScope());
					scopeStatus = SCOPE_STATUS.DETACHED;
					logger.info("I loaded a valid VRE obj for scope name {}", scopeName);
					isScopeDetached = true;
				} catch (Exception e1) {
					logger.warn("I was not able to load a detached VRE for vreName {}. Going to error for wrong scope",
							scopeName);
				}

				// If is not a cas of scope detached, going to error for wrong scope
				if (!isScopeDetached) {
					logger.error("Error on getting the fullscope from cache for scopeName " + scopeName, e);
					throw ExceptionManager.wrongParameterException(req,
							"Error on getting full scope for the scope name '" + scopeName
									+ "'. Is it registered as a valid Scope in the D4Science Infrastructure System?",
							CatalogueResolver.class, helpURI);
				}
			}

			String fullScope = scopeBean.toString();
			logger.info("Read fullScope: " + fullScope + " for SCOPE name: " + scopeName + " from cache created by: "
					+ GetAllInfrastructureScopes.class.getSimpleName());

			if (scopeBean.is(Type.VO)) {
				logger.info("It is a {} scope", Type.VO);
				logger.warn("The Catalogue can't work at {} level, I'm overriding the scope to {} level", Type.VO,
						Type.INFRASTRUCTURE);
				String[] splitScope = fullScope.split(ConstantsResolver.SCOPE_SEPARATOR);
				fullScope = ConstantsResolver.SCOPE_SEPARATOR + splitScope[1]; // THIS IS THE INFRASTRUCTURE SCOPE
				logger.info("Overriden the input scope {} with {} as type: {}", scopeBean.toString(),
						Type.INFRASTRUCTURE, fullScope);
			}

			ScopeProvider.instance.set(fullScope);
			GatewayCKANCatalogueReference ckanCatalogueReference = null;
			logger.info("Managing scope status: {}", scopeStatus);

			switch (scopeStatus) {
			case DETACHED:

				String privatePortletURL = vreDetached.getCatalogPortletURL();
				// The private portlet URL
				Map<ACCESS_LEVEL_TO_CATALOGUE_PORTLET, String> mapAccessURLToCatalogue = new HashMap<ACCESS_LEVEL_TO_CATALOGUE_PORTLET, String>(
						3);
				mapAccessURLToCatalogue.put(ACCESS_LEVEL_TO_CATALOGUE_PORTLET.PRIVATE_VRE, privatePortletURL);

				// Building the gateway catalogue public URL from private VRE Portlet URL
				URI toURL = new URI(privatePortletURL);
				String publicURL = privatePortletURL.startsWith("https://") ? "https://" + toURL.getHost()
						: "http://" + toURL.getHost();
				// It returns the string "catalogue"
				CatalogueStaticConfigurations staticConf = new CatalogueStaticConfigurations();
				// Replacing for example "ckan-bb" with "[PREFIXES-TO-CATALOGUE-URL]-bb" (e.g
				// catalogue-bb)
				String relativeURLWithCatalogueName = staticConf
						.buildRelativeURLToPublicCatalogueGateway(vreDetached.getCatalogUrl());
				String toGatewayPortletURL = String.format("%s/%s", publicURL, relativeURLWithCatalogueName);
				mapAccessURLToCatalogue.put(ACCESS_LEVEL_TO_CATALOGUE_PORTLET.PUBLIC_GATEWAY, toGatewayPortletURL);

				ckanCatalogueReference = new GatewayCKANCatalogueReference(fullScope, vreDetached.getCatalogUrl(),
						mapAccessURLToCatalogue);
				break;
			case ACTIVE:
			default:

				ckanCatalogueReference = CkanCatalogueConfigurationsReader.loadCatalogueEndPoints();
				break;
			}

			logger.info("For scope " + fullScope + " loaded end points: " + ckanCatalogueReference);

			// IS THE PRODUCT PLUBLIC OR PRIVATE?
			String datasetName = entityName;
			boolean isPublicItem = false;
			if (ckanCatalogueReference.getCkanURL() != null) {
				try {
					CkanDataset dataset = CkanCatalogueConfigurationsReader.getDataset(datasetName,
							ckanCatalogueReference.getCkanURL());
					if (dataset != null) {
						isPublicItem = true;
						// ckanPorltetUrl = ckanCatalogueReference.getPublicPortletURL();
						logger.info("The dataset " + datasetName + " is a public item");
					}
				} catch (Exception e) {
					logger.warn("Error on checking if dataset: " + datasetName + " is private or not", e);
					isPublicItem = true;
				}
			}

			String publicGatewayPorltetURL = String.format("%s?path=/%s/%s",
					ckanCatalogueReference.getCatalogueURL(ACCESS_LEVEL_TO_CATALOGUE_PORTLET.PUBLIC_GATEWAY),
					entityContextValue, entityName);

			String privateVREPortletURL = String.format("%s?path=/%s/%s",
					ckanCatalogueReference.getCatalogueURL(ACCESS_LEVEL_TO_CATALOGUE_PORTLET.PRIVATE_VRE),
					entityContextValue, entityName);

			// Checking if the public VRE portlet URL is available (so it was read from GR)
			String publicVREPortletURL = null;
			String toCheckPublicVREPortletURL = ckanCatalogueReference
					.getCatalogueURL(ACCESS_LEVEL_TO_CATALOGUE_PORTLET.PUBLIC_VRE);
			if (toCheckPublicVREPortletURL != null && !toCheckPublicVREPortletURL.isEmpty()) {
				// here the catalogue is available/deployed as public at VRE level
				publicVREPortletURL = String.format("%s?path=/%s/%s", toCheckPublicVREPortletURL, entityContextValue,
						entityName);
			}
			return new ItemCatalogueURLs(entityName, isPublicItem, privateVREPortletURL, publicVREPortletURL,
					publicGatewayPorltetURL);
		} catch (Exception e) {
			logger.error("Error when resolving CatalogueURL:", e);
			throw e;
		}

	}

}