package org.gcube.gcat.persistence.ckan;

import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.ws.rs.BadRequestException;
import javax.ws.rs.ForbiddenException;
import javax.ws.rs.InternalServerErrorException;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response.Status;

import org.gcube.common.resources.gcore.GenericResource;
import org.gcube.common.scope.impl.ScopeBean;
import org.gcube.common.scope.impl.ScopeBean.Type;
import org.gcube.gcat.api.GCatConstants;
import org.gcube.gcat.oldutils.Validator;
import org.gcube.gcat.profile.MetadataUtility;
import org.gcube.gcat.social.SocialPost;
import org.gcube.gcat.utils.ContextUtility;
import org.gcube.gcat.utils.URIResolver;
import org.gcube.resources.discovery.client.api.DiscoveryClient;
import org.gcube.resources.discovery.client.queries.api.SimpleQuery;
import org.gcube.resources.discovery.icclient.ICFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.NodeList;

import org.gcube.com.fasterxml.jackson.databind.JsonNode;
import org.gcube.com.fasterxml.jackson.databind.node.ArrayNode;
import org.gcube.com.fasterxml.jackson.databind.node.ObjectNode;

/**
 * @author Luca Frosini (ISTI - CNR)
 */
public class CKANPackage extends CKAN {
	
	private static final Logger logger = LoggerFactory.getLogger(CKANPackage.class);
	/*
	// see https://docs.ckan.org/en/latest/api/#ckan.logic.action.get.package_list
	public static final String ITEM_LIST = CKAN.CKAN_API_PATH + "package_list";
	*/
	// see https://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.get.package_search
	public static final String ITEM_LIST = CKAN.CKAN_API_PATH + "package_search";
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.create.package_create
	public static final String ITEM_CREATE = CKAN.CKAN_API_PATH + "package_create";
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.get.package_show
	public static final String ITEM_SHOW = CKAN.CKAN_API_PATH + "package_show";
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.update.package_update
	public static final String ITEM_UPDATE = CKAN.CKAN_API_PATH + "package_update";
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.patch.package_patch
	public static final String ITEM_PATCH = CKAN.CKAN_API_PATH + "package_patch";
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.delete.package_delete
	public static final String ITEM_DELETE = CKAN.CKAN_API_PATH + "package_delete";
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.delete.dataset_purge
	public static final String ITEM_PURGE = CKAN.CKAN_API_PATH + "dataset_purge";
	
	// limit in https://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.get.package_search
	protected static final String ROWS_KEY = "rows";
	// offset in https://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.get.package_search
	protected static final String START_KEY = "start";
	
	protected static final String ORGANIZATION_FILTER_TEMPLATE = GCatConstants.ORGANIZATION_PARAMETER + ":%s";
	
	protected static final String ORGANIZATION_REGEX = GCatConstants.ORGANIZATION_PARAMETER + ":[a-zA-Z0-9_\"]*";
	
	protected static final Pattern ORGANIZATION_REGEX_PATTERN;
	
	static {
		ORGANIZATION_REGEX_PATTERN = Pattern.compile(ORGANIZATION_REGEX);
	}
	
	public static final String GENERIC_RESOURCE_SECONDARY_TYPE_FOR_ORGANIZATIONS = "ApplicationProfile";
	public static final String GENERIC_RESOURCE_NAME_FOR_ORGANIZATIONS = "Supported CKAN Organizations";
	public static final String GENERIC_RESOURCE_TAG_NAME = "CKANOrganization";
	public static final String GENERIC_RESOURCE_TAG_NAME_PLURAL = "CKANOrganizations";
	
	protected static final String LICENSE_KEY = "license_id";
	
	protected static final String EXTRAS_ITEM_URL_KEY = "Item URL";
	
	protected static final String AUTHOR_KEY = "author";
	protected static final String AUTHOR_EMAIL_KEY = "author_email";
	protected static final String OWNER_ORG_KEY = "owner_org";
	protected static final String RESOURCES_KEY = "resources";
	protected static final String TITLE_KEY = "title";
	
	public static final String EXTRAS_KEY = "extras";
	public static final String EXTRAS_KEY_KEY = "key";
	public static final String EXTRAS_KEY_VALUE_SYSTEM_TYPE = "system:type";
	public static final String EXTRAS_VALUE_KEY = "value";
	
	// The 'results' array is included in the 'result' object for package_search
	private static final String RESULTS_KEY = "results";
	
	protected static final String PRIVATE_KEY = "private";
	protected static final String SEARCHABLE_KEY = "searchable";
	protected static final String CAPACITY_KEY = "capacity";
	
	// protected static final String INCLUDE_PRIVATE_KEY = "include_private";
	// protected static final String INCLUDE_DRAFTS_KEY = "include_drafts";
	
	public static final String GROUPS_KEY = "groups";
	public static final String TAGS_KEY = "tags";
	
	protected final List<CKANResource> managedResources;
	
	protected String itemID;
	
	protected ScopeBean currentScopeBean;
	protected String currentContext;
	
	protected String currentOrganizationName;
	protected Set<String> supportedOrganizations;
	
	public CKANPackage() {
		super();
		LIST = ITEM_LIST;
		CREATE = ITEM_CREATE;
		READ = ITEM_SHOW;
		UPDATE = ITEM_UPDATE;
		PATCH = ITEM_PATCH;
		DELETE = ITEM_DELETE;
		PURGE = ITEM_PURGE;
		managedResources = new ArrayList<CKANResource>();
		getCurrentContext();
		getSupportedOrganizationsFromIS();
	}
	
	protected Set<String> getSupportedOrganizationsFromIS() {
		if(supportedOrganizations == null) {
			
			supportedOrganizations = new HashSet<>();
			
			SimpleQuery query = ICFactory.queryFor(GenericResource.class);
			query.addCondition(String.format("$resource/Profile/SecondaryType/text() eq '%s'",
					GENERIC_RESOURCE_SECONDARY_TYPE_FOR_ORGANIZATIONS));
			query.addCondition(
					String.format("$resource/Profile/Name/text() eq '%s'", GENERIC_RESOURCE_NAME_FOR_ORGANIZATIONS));
			
			DiscoveryClient<GenericResource> client = ICFactory.clientFor(GenericResource.class);
			List<GenericResource> resources = client.submit(query);
			
			if(resources == null || resources.size() == 0) {
				logger.info(
						"{} with SecondaryType {} and Name %s not found. Item will be only be created in {} CKAN organization",
						GenericResource.class.getSimpleName(), GENERIC_RESOURCE_SECONDARY_TYPE_FOR_ORGANIZATIONS,
						GENERIC_RESOURCE_NAME_FOR_ORGANIZATIONS, getOrganizationName());
				supportedOrganizations.add(getOrganizationName());
			} else {
				GenericResource genericResource = resources.get(0);
				NodeList nodeList = genericResource.profile().body().getChildNodes();
				if(nodeList != null && nodeList.getLength() > 0) {
					for(int i = 0; i < nodeList.getLength(); i++) {
						NodeList nl = nodeList.item(i).getChildNodes();
						String organization = nl.item(0).getNodeValue();
						supportedOrganizations.add(organization);
					}
				}
			}
			
		}
		
		CKANUser ckanUser = CKANUserCache.getCurrrentCKANUser();
		for(String supportedOrganization : supportedOrganizations) {
			ckanUser.addUserToOrganization(supportedOrganization);
		}
		
		logger.debug("Supported CKAN Organization for current Context ({}) are {}", getCurrentContext(),
				supportedOrganizations);
		return supportedOrganizations;
	}
	
	/*
	 * Return the CKAN organization name using the current context name
	 */
	protected static String getOrganizationName(ScopeBean scopeBean) {
		String contextName = scopeBean.name();
		return contextName.toLowerCase().replace(" ", "_");
	}
	
	protected String getCurrentContext() {
		if(currentContext == null) {
			currentContext = ContextUtility.getCurrentContext();
			currentScopeBean = new ScopeBean(currentContext);
		}
		return currentContext;
	}
	
	protected String getOrganizationName() {
		if(currentOrganizationName == null) {
			this.currentOrganizationName = CKANPackage.getOrganizationName(currentScopeBean);
		}
		return currentOrganizationName;
	}
	
	protected CKANOrganization checkGotOrganization(String gotOrganization) throws ForbiddenException {
		if(!supportedOrganizations.contains(gotOrganization)) {
			String error = String.format(
					"IS Configuration does not allow to publish in %s organizations. Allowed organization are: %s",
					gotOrganization, supportedOrganizations);
			throw new ForbiddenException(error);
		}
		
		CKANOrganization ckanOrganization = new CKANOrganization();
		ckanOrganization.setName(gotOrganization);
		ckanOrganization.read();
		
		return ckanOrganization;
	}
	
	protected CKANOrganization getPublishingOrganization(ObjectNode objectNode) throws ForbiddenException {
		CKANOrganization ckanOrganization = null;
		if(objectNode.has(OWNER_ORG_KEY)) {
			String gotOrganizationName = objectNode.get(OWNER_ORG_KEY).asText();
			ckanOrganization = checkGotOrganization(gotOrganizationName);
		}
		
		if(ckanOrganization == null) {
			// owner organization must be specified if the token belongs to a VRE
			String organizationFromContext = getOrganizationName();
			ckanOrganization = checkGotOrganization(organizationFromContext);
			objectNode.put(OWNER_ORG_KEY, organizationFromContext);
		}
		
		return ckanOrganization;
	}
	
	public ObjectNode checkBaseInformation(String json) throws Exception {
		return checkBaseInformation(json, false);
	}
	
	/**
	 * @param json The json to check
	 * @param allowPartialInfo used for patch method which provide only partial information (i.e. the info to patch) 
	 * @return ObjectNode from json
	 * @throws Exception
	 */
	public ObjectNode checkBaseInformation(String json, boolean allowPartialInfo) throws Exception {
		ObjectNode objectNode = (ObjectNode) mapper.readTree(json);
		
		try {
			objectNode = (ObjectNode) checkName(objectNode);
		}catch (Exception e) {
			if(!allowPartialInfo) {
				throw e;
			}
		}
		
		// We need to enforce the itemID to properly manage resource persistence
		if(objectNode.has(ID_KEY)) {
			itemID = objectNode.get(ID_KEY).asText();
		}
		
		// To include private item in search result (e.g. listing) a private package must be searchable
		// The package it is just included in the search and listing results but remain private and cannot be accessed
		// if not authorized
		if(objectNode.has(PRIVATE_KEY)) {
			boolean privatePackage = objectNode.get(PRIVATE_KEY).asBoolean();
			if(privatePackage) {
				objectNode.put(SEARCHABLE_KEY, true);
			}
		}
		
		// check license
		String licenseId = null;
		if(objectNode.has(LICENSE_KEY)) {
			licenseId = objectNode.get(LICENSE_KEY).asText();
		}
		
		if(licenseId!=null && !licenseId.isEmpty()) {
			try {
				CKANLicense.checkLicenseId(licenseId);
			} catch(Exception e) {
				throw new BadRequestException(
						"You must specify an existing license identifier for the item. License list can be retrieved using licence collection");
			}
		}else if(!allowPartialInfo) {
			throw new BadRequestException(
					"You must specify a license identifier for the item. License list can be retrieved using licence collection");
		}
		
		if(objectNode.has(CAPACITY_KEY)) {
			/*
			 * When a client provides the 'capacity' field as 'private', the item is not counted in the 
			 * total number of items in the GUI. We want to avoid such a behavior
			 *  See https://support.d4science.org/issues/16410
			 */
			objectNode.remove(CAPACITY_KEY);
		}
		
		CKANUser ckanUser = CKANUserCache.getCurrrentCKANUser();
		
		objectNode.put(AUTHOR_KEY, ckanUser.getName());
		objectNode.put(AUTHOR_EMAIL_KEY, ckanUser.getPortalUser().getEMail());
		
		getPublishingOrganization(objectNode);
		
		return objectNode;
	}
	
	protected JsonNode validateJson(String json) {
		try {
			// check base information (and set them if needed)
			ObjectNode objectNode = checkBaseInformation(json);
			
			// Validating against profiles if any
			MetadataUtility metadataUtility = new MetadataUtility();
			if(!metadataUtility.getMetadataProfiles().isEmpty()) {
				Validator validator = new Validator(mapper);
				objectNode = validator.validateAgainstProfile(objectNode, metadataUtility);
			}
			
			return objectNode;
		} catch(BadRequestException e) {
			throw e;
		} catch(Exception e) {
			throw new BadRequestException(e);
		}
	}
	
	@Override
	public String list(int limit, int offset) {
		Map<String,String> parameters = new HashMap<>();
		if(limit <= 0) {
			// According to CKAN documentation
			// the number of matching rows to return. There is a hard limit of 1000 datasets per query.
			// see https://docs.ckan.org/en/2.6/api/index.html#ckan.logic.action.get.package_search
			limit = 1000;
		}
		parameters.put(ROWS_KEY, String.valueOf(limit));
		
		if(offset < 0) {
			offset = 0;
		}
		parameters.put(START_KEY, String.valueOf(offset * limit));
		
		if(uriInfo != null) {
			MultivaluedMap<String,String> queryParameters = uriInfo.getQueryParameters();
			parameters = checkListParameters(queryParameters, parameters);
		}
		
		return list(parameters);
	}

	protected Set<String> checkOrganizationFilter(String q) {
		Matcher m = ORGANIZATION_REGEX_PATTERN.matcher(q);
		
		Set<String> matches = new HashSet<>();
		while(m.find()) {
			matches.add(q.substring(m.start(), m.end()).replace(GCatConstants.ORGANIZATION_PARAMETER+":", ""));
		}
		
		return matches;
	}
	
	protected static String[] allowedListQueryParameters = new String[] {"q", "fq", "fq_list", "sort",
			/* "facet", "facet.mincount", "facet.limit", "facet.field", */
			"include_drafts", "include_private", "ext_bbox"};
	
	protected String getFilterForOrganizations() {
		StringWriter stringWriter = new StringWriter();
		int i=1;
		for(String organizationName : supportedOrganizations) {
			stringWriter.append(String.format(GCatConstants.ORGANIZATION_FILTER_TEMPLATE, organizationName));
			if(i!=supportedOrganizations.size()) {
				// Please note that an item can only belong to a single organization. 
				// Hence the query must put supported organizations in OR.
				stringWriter.append(" OR ");
			}
			i++;
		}
		return stringWriter.toString();
	}
	
	protected Map<String,String> checkListParameters(MultivaluedMap<String,String> queryParameters,
			Map<String,String> parameters) {
		
		String q = null;
		if(queryParameters.containsKey(GCatConstants.Q_KEY)) {
			q = queryParameters.getFirst(GCatConstants.Q_KEY);
		}
		
		if(q != null) {
			Set<String> organizations = checkOrganizationFilter(q);
			
			if(organizations.size()==0) {
				// Adding organization filter to q
				String filter = getFilterForOrganizations();
				parameters.put(GCatConstants.Q_KEY,	String.format("%s AND %s", q, filter));
			}else {
				organizations.removeAll(this.supportedOrganizations);
				if(organizations.size()>0) {
					String error = String.format("It is not possible to query the following organizations %s. Supported organization in this context are %s", organizations.toString(), supportedOrganizations.toString());
					throw new ForbiddenException(error);
				}
			}
			
		} else {
			String filter = getFilterForOrganizations();
			parameters.put(GCatConstants.Q_KEY, filter);
		}
			
		
		for(String key : allowedListQueryParameters) {
			if(queryParameters.containsKey(key)) {
				parameters.put(key, queryParameters.getFirst(key));
			}
		}
		
		// parameters.put(INCLUDE_PRIVATE_KEY, String.valueOf(true));
		
		// By default not including draft
		// parameters.put(INCLUDE_DRAFTS_KEY, String.valueOf(false));
		
		return parameters;
	}
	
	public String list(Map<String,String> parameters) {
		
		sendGetRequest(LIST, parameters);
		
		ArrayNode results = (ArrayNode) result.get(RESULTS_KEY);
		
		ArrayNode arrayNode = mapper.createArrayNode();
		for(JsonNode node : results) {
			try {
				String name = node.get(NAME_KEY).asText();
				arrayNode.add(name);
			} catch(Exception e) {
				try {
					logger.error("Unable to get the ID of {}. the result will not be included in the result",
							mapper.writeValueAsString(node));
				} catch(Exception ex) {
					logger.error("", ex);
				}
			}
		}
		
		return getAsString(arrayNode);
	}
	
	protected void rollbackManagedResources() {
		for(CKANResource ckanResource : managedResources) {
			try {
				ckanResource.rollback();
			} catch(Exception e) {
				logger.error("Unable to rollback resource {} to the original value", ckanResource.getResourceID());
			}
			
		}
	}
	
	protected ArrayNode createResources(ArrayNode resourcesToBeCreated) {
		ArrayNode created = mapper.createArrayNode();
		for(JsonNode resourceNode : resourcesToBeCreated) {
			CKANResource ckanResource = new CKANResource(itemID);
			String json = ckanResource.create(getAsString(resourceNode));
			created.add(getAsJsonNode(json));
			managedResources.add(ckanResource);
		}
		return created;
	}
	
	protected JsonNode addExtraField(JsonNode jsonNode, String key, String value) {
		ArrayNode extras = null;
		boolean found = false;
		if(jsonNode.has(EXTRAS_KEY)) {
			extras = (ArrayNode) jsonNode.get(EXTRAS_KEY);
			for(JsonNode extra : extras) {
				if(extra.has(EXTRAS_KEY_KEY) && extra.get(EXTRAS_KEY_KEY).asText().compareTo(key) == 0) {
					((ObjectNode) extra).put(EXTRAS_VALUE_KEY, value);
					found = true;
					break;
				}
			}
		} else {
			extras = mapper.createArrayNode();
		}
		
		if(!found) {
			ObjectNode extra = mapper.createObjectNode();
			extra.put(EXTRAS_KEY_KEY, key);
			extra.put(EXTRAS_VALUE_KEY, value);
			extras.add(extra);
		}
		
		return jsonNode;
	}
	
	protected String addItemURLViaResolver(JsonNode jsonNode) {
		// Adding Item URL via Resolver
		URIResolver uriResolver = new URIResolver();
		String catalogueItemURL = uriResolver.getCatalogueItemURL(name);
		addExtraField(jsonNode, EXTRAS_ITEM_URL_KEY, catalogueItemURL);
		return catalogueItemURL;
	}
	
	protected void sendSocialPost(String title, String catalogueItemURL) {
		try {
			boolean socialPost = false;
			try {
				MultivaluedMap<String,String> queryParameters = uriInfo.getQueryParameters();
				if(queryParameters.containsKey(GCatConstants.SOCIAL_POST_PARAMETER)) {
					socialPost = Boolean.parseBoolean(queryParameters.getFirst(GCatConstants.SOCIAL_POST_PARAMETER));
				}
			} catch(Exception e) {
				socialPost = false;
			}
			
			if(socialPost) {
				ArrayNode arrayNode = (ArrayNode) result.get(TAGS_KEY);
				SocialPost socialService = new SocialPost();
				socialService.setItemID(itemID);
				socialService.setItemURL(catalogueItemURL);
				socialService.setTags(arrayNode);
				socialService.setItemTitle(title);
				socialService.start();
			} else {
				logger.info("The request explicitly disabled the Social Post.");
			}
		} catch(Exception e) {
			logger.warn(
					"error dealing with Social Post. The service will not raise the exception belove. Please contact the administrator to let him know about this message.",
					e);
		}
	}
	
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.create.package_create
	@Override
	public String create(String json) {
		try {
			logger.debug("Going to create Item {}", json);
			
			JsonNode jsonNode = validateJson(json);
			
			ArrayNode resourcesToBeCreated = mapper.createArrayNode();
			if(jsonNode.has(RESOURCES_KEY)) {
				resourcesToBeCreated = (ArrayNode) jsonNode.get(RESOURCES_KEY);
				((ObjectNode) jsonNode).remove(RESOURCES_KEY);
			}
			
			String catalogueItemURL = "";
			if(currentScopeBean.is(Type.VRE)) {
				catalogueItemURL = addItemURLViaResolver(jsonNode);
			}
			
			super.create(getAsString(jsonNode));
			
			this.itemID = result.get(ID_KEY).asText();
			ArrayNode created = createResources(resourcesToBeCreated);
			((ObjectNode) result).replace(RESOURCES_KEY, created);
			
			// Adding Item URL via Resolver as
			// ((ObjectNode) result).put(ITEM_URL_KEY, catalogueItemURL);
			
			// Actions performed after a package has been correctly created on ckan.
			String title = result.get(TITLE_KEY).asText();
			
			if(currentScopeBean.is(Type.VRE)) {
				sendSocialPost(title, catalogueItemURL);
			}
			
			return getAsString(result);
		} catch(WebApplicationException e) {
			rollbackManagedResources();
			throw e;
		} catch(Exception e) {
			rollbackManagedResources();
			throw new InternalServerErrorException(e);
		}
	}
	
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.update.package_update
	@Override
	public String update(String json) {
		try {
			JsonNode jsonNode = validateJson(json);
			
			read();
			this.itemID = result.get(ID_KEY).asText();
			
			Map<String,CKANResource> originalResources = new HashMap<>();
			ArrayNode originalResourcesarrayNode = (ArrayNode) result.get(RESOURCES_KEY);
			if(originalResources != null) {
				for(JsonNode resourceNode : originalResourcesarrayNode) {
					CKANResource ckanResource = new CKANResource(itemID);
					ckanResource.setPreviousRepresentation(resourceNode);
					String resourceID = ckanResource.getResourceID();
					originalResources.put(resourceID, ckanResource);
				}
			}
			
			if(jsonNode.has(RESOURCES_KEY)) {
				ArrayNode resourcesToBeSend = mapper.createArrayNode();
				ArrayNode receivedResources = (ArrayNode) jsonNode.get(RESOURCES_KEY);
				for(JsonNode resourceNode : receivedResources) {
					CKANResource ckanResource = new CKANResource(itemID);
					String resourceId = CKANResource.extractResourceID(resourceNode);
					if(resourceId != null) {
						if(originalResources.containsKey(resourceId)) {
							ckanResource = originalResources.get(resourceId);
							originalResources.remove(resourceId);
						} else {
							throw new BadRequestException(
									"The content contains a resource with id " + resourceId + " which does not exists");
						}
					}
					if(originalResources.get(resourceId) != null
							&& (!originalResources.get(resourceId).getPreviousRepresentation().equals(resourceNode))) {
						resourceNode = ckanResource.createOrUpdate(resourceNode);
					}
					resourcesToBeSend.add(resourceNode);
					managedResources.add(ckanResource);
					
				}
				((ObjectNode) jsonNode).replace(RESOURCES_KEY, resourcesToBeSend);
			}
			
			addItemURLViaResolver(jsonNode);
			
			sendPostRequest(ITEM_UPDATE, getAsString(jsonNode));
			
			for(String resourceId : originalResources.keySet()) {
				CKANResource ckanResource = originalResources.get(resourceId);
				ckanResource.deleteFile();
			}
			
			/*
			// Adding Item URL via Resolver
			URIResolver uriResolver = new URIResolver();
			String catalogueItemURL = uriResolver.getCatalogueItemURL(name);
			((ObjectNode) result).put(ITEM_URL_KEY, catalogueItemURL);
			*/
			
			return getAsString(result);
		} catch(WebApplicationException e) {
			rollbackManagedResources();
			throw e;
		} catch(Exception e) {
			rollbackManagedResources();
			throw new InternalServerErrorException(e);
		}
	}
	
	// see http://docs.ckan.org/en/latest/api/#ckan.logic.action.patch.package_patch
	@Override
	public String patch(String json) {
		try {
			JsonNode jsonNode = checkBaseInformation(json, true);
			
			read();
			
			this.itemID = result.get(ID_KEY).asText();
			((ObjectNode)jsonNode).put(ID_KEY, this.itemID);
			
			Map<String,CKANResource> originalResources = new HashMap<>();
			ArrayNode originalResourcesarrayNode = (ArrayNode) result.get(RESOURCES_KEY);
			if(originalResources != null) {
				for(JsonNode resourceNode : originalResourcesarrayNode) {
					CKANResource ckanResource = new CKANResource(itemID);
					ckanResource.setPreviousRepresentation(resourceNode);
					String resourceID = ckanResource.getResourceID();
					originalResources.put(resourceID, ckanResource);
				}
			}
			
			if(jsonNode.has(RESOURCES_KEY)) {
				ArrayNode resourcesToBeSend = mapper.createArrayNode();
				ArrayNode receivedResources = (ArrayNode) jsonNode.get(RESOURCES_KEY);
				for(JsonNode resourceNode : receivedResources) {
					CKANResource ckanResource = new CKANResource(itemID);
					String resourceId = CKANResource.extractResourceID(resourceNode);
					if(resourceId != null) {
						if(originalResources.containsKey(resourceId)) {
							ckanResource = originalResources.get(resourceId);
							originalResources.remove(resourceId);
						} else {
							throw new BadRequestException(
									"The content contains a resource with id " + resourceId + " which does not exists");
						}
					}
					if(originalResources.get(resourceId) != null
							&& (!originalResources.get(resourceId).getPreviousRepresentation().equals(resourceNode))) {
						resourceNode = ckanResource.createOrUpdate(resourceNode);
					}
					resourcesToBeSend.add(resourceNode);
					managedResources.add(ckanResource);
					
				}
				((ObjectNode) jsonNode).replace(RESOURCES_KEY, resourcesToBeSend);
			}
			
			addItemURLViaResolver(jsonNode);
			
			sendPostRequest(ITEM_PATCH, getAsString(jsonNode));
			
			for(String resourceId : originalResources.keySet()) {
				CKANResource ckanResource = originalResources.get(resourceId);
				ckanResource.deleteFile();
			}
			
			/*
			// Adding Item URL via Resolver
			URIResolver uriResolver = new URIResolver();
			String catalogueItemURL = uriResolver.getCatalogueItemURL(name);
			((ObjectNode) result).put(ITEM_URL_KEY, catalogueItemURL);
			*/
			
			return getAsString(result);
		} catch(WebApplicationException e) {
			rollbackManagedResources();
			throw e;
		} catch(Exception e) {
			rollbackManagedResources();
			throw new InternalServerErrorException(e);
		}
	}
	
	@Override
	protected void delete() {
		super.delete();
	}
	
	@Override
	public void purge() {
		try {
			delete();
		} catch(WebApplicationException e) {
			// If the item was deleted but not purged we obtain Not Found. This is accepted. The item has to be purged
			// with SysAdmin right.
			Status status = Status.fromStatusCode(e.getResponse().getStatusInfo().getStatusCode());
			if(status != Status.NOT_FOUND) {
				throw e;
			}
		}
		setApiKey(CKANUtility.getSysAdminAPI());
		read();
		if(result.has(RESOURCES_KEY)) {
			itemID = result.get(ID_KEY).asText();
			ArrayNode arrayNode = (ArrayNode) result.get(RESOURCES_KEY);
			for(JsonNode jsonNode : arrayNode) {
				CKANResource ckanResource = new CKANResource(itemID);
				ckanResource.setPreviousRepresentation(jsonNode);
				ckanResource.deleteFile(); // Only delete file is required because the item has been deleted
			}
		}
		super.purge();
	}
	
}