package org.gcube.datacatalogue.ckanutillibrary.server;

import static org.gcube.resources.discovery.icclient.ICFactory.client;
import static org.gcube.resources.discovery.icclient.ICFactory.clientFor;
import static org.gcube.resources.discovery.icclient.ICFactory.queryFor;

import java.io.StringReader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.gcube.common.encryption.StringEncrypter;
import org.gcube.common.resources.gcore.ServiceEndpoint;
import org.gcube.common.resources.gcore.ServiceEndpoint.AccessPoint;
import org.gcube.common.resources.gcore.ServiceEndpoint.Property;
import org.gcube.common.resources.gcore.utils.XPathHelper;
import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.datacatalogue.ckanutillibrary.server.exceptions.ApplicationProfileNotFoundException;
import org.gcube.datacatalogue.ckanutillibrary.server.exceptions.NoApplicationProfileMasterException;
import org.gcube.datacatalogue.ckanutillibrary.server.exceptions.NoDataCatalogueRuntimeResourceException;
import org.gcube.datacatalogue.ckanutillibrary.server.exceptions.ServiceEndPointException;
import org.gcube.resources.discovery.client.api.DiscoveryClient;
import org.gcube.resources.discovery.client.queries.api.Query;
import org.gcube.resources.discovery.client.queries.api.SimpleQuery;
import org.gcube.resources.discovery.client.queries.impl.QueryBox;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Node;
import org.xml.sax.InputSource;

/**
 * Retrieve ckan running instance information in the infrastructure (for both its database and data catalogue url)
 * @author Costantino Perciante at ISTI-CNR (costantino.perciante@isti.cnr.it)
 */
public class DataCatalogueRunningCluster {

	//logger
	private static final Logger logger = LoggerFactory.getLogger(DataCatalogueRunningCluster.class);

	// database of the datacatalogue info
	private final static String RUNTIME_DB_RESOURCE_NAME = "CKanDatabase";
	private final static String PLATFORM_DB_NAME = "postgres";
	private final static String APPLICATION_PROFILE_NAME = "CkanPortlet";

	// data catalogue info
	private final static String RUNTIME_CATALOGUE_RESOURCE_NAME = "CKanDataCatalogue";
	private final static String PLATFORM_CATALOGUE_NAME = "Tomcat"; 

	// api key property
	private final static String API_KEY_PROPERTY = "API_KEY";

	// property to retrieve the master service endpoint into the /root scope
	private final static String IS_MASTER_ROOT_KEY_PROPERTY = "IS_ROOT_MASTER"; // true, false.. missing means false as well
	private final static String IS_MANAGE_PRODUCT_ENABLED = "IS_MANAGE_PRODUCT_ENABLED"; // true, false.. missing means false as well (for GRSF records)

	// url of the http uri for this scope
	private final static String URL_RESOLVER = "URL_RESOLVER";
	
	// retrieved data
	private List<String> datacatalogueUrls = new ArrayList<String>();
	private List<String> hostsDB = new ArrayList<String>();
	private List<Integer> portsDB = new ArrayList<Integer>();
	private String nameDB;
	private String userDB;
	private String passwordDB;
	private String portletUrl;
	private boolean manageProductEnabled;
	private String urlResolver;

	// this token is needed in order to assign roles to user
	private String sysAdminToken;

	public DataCatalogueRunningCluster(String scope) throws Exception{

		if(scope == null || scope.isEmpty())
			throw new Exception("Invalid scope!!");

		// retrieve the current scope and save it (it will be reset later)
		String currentScope = ScopeProvider.instance.get();

		logger.info("Retrieving ckan database service end point information for scope " + scope);
		try {

			// set the scope
			ScopeProvider.instance.set(scope);

			List<ServiceEndpoint> resources = getConfigurationFromISFORDB();

			if (resources.size() == 0){
				throw new NoDataCatalogueRuntimeResourceException("There is no Runtime Resource having name " + RUNTIME_DB_RESOURCE_NAME +" and Platform " + PLATFORM_DB_NAME + " in this scope.");
			}
			else {
				try{

					if(resources.size() > 1){
						boolean oneWasMaster = false;

						logger.info("Too many Runtime Resource having name " + RUNTIME_DB_RESOURCE_NAME +" in this scope.. Looking for the one that has the property " + IS_MASTER_ROOT_KEY_PROPERTY);

						for (ServiceEndpoint res : resources) {

							Iterator<AccessPoint> accessPointIterator = res.profile().accessPoints().iterator();

							while (accessPointIterator.hasNext()) {
								ServiceEndpoint.AccessPoint accessPoint = (ServiceEndpoint.AccessPoint) accessPointIterator
										.next();

								// get the is master property
								Property entry = accessPoint.propertyMap().get(IS_MASTER_ROOT_KEY_PROPERTY);
								String isMaster = entry != null ?  entry.value() : null;

								if(isMaster == null || !isMaster.equals("true"))
									continue;

								// set this variable
								oneWasMaster = true;

								// add this host
								hostsDB.add(accessPoint.address().split(":")[0]);

								// save the port
								int port = Integer.parseInt(accessPoint.address().split(":")[1]);
								portsDB.add(port);

								// save the name of the cluster (this should be unique)
								nameDB = accessPoint.name();

								// save user and password
								passwordDB = StringEncrypter.getEncrypter().decrypt(accessPoint.password());
								userDB = accessPoint.username();

								// now break
								break;
							}
						}

						// if none of them was master, throw an exception
						if(!oneWasMaster)
							throw new NoApplicationProfileMasterException("There is no application profile with MASTER property");
					}else{
						logger.debug(resources.toString());
						for (ServiceEndpoint res : resources) {

							Iterator<AccessPoint> accessPointIterator = res.profile().accessPoints().iterator();

							while (accessPointIterator.hasNext()) {
								ServiceEndpoint.AccessPoint accessPoint = (ServiceEndpoint.AccessPoint) accessPointIterator
										.next();

								// add this host
								hostsDB.add(accessPoint.address().split(":")[0]);

								// save the port
								int port = Integer.parseInt(accessPoint.address().split(":")[1]);
								portsDB.add(port);

								// save the name of the cluster (this should be unique)
								nameDB = accessPoint.name();

								// save user and password
								passwordDB = StringEncrypter.getEncrypter().decrypt(accessPoint.password());
								userDB = accessPoint.username();
								
							}
						}
					}
				}catch(Exception e ){
					throw new ServiceEndPointException(e.toString());
				}
			}

			logger.debug("Retrieving ckan data catalogue service end point information and sysadmin token.");
			resources = getConfigurationFromISFORCatalogueUrl();

			if (resources.size() == 0){
				logger.error("There is no Runtime Resource having name " + RUNTIME_CATALOGUE_RESOURCE_NAME +" and Platform " + PLATFORM_CATALOGUE_NAME + " in this scope.");
				throw new NoDataCatalogueRuntimeResourceException();
			}
			else {
				logger.debug(resources.toString());
				try{
					if(resources.size() > 1){
						boolean oneWasMaster = false;

						logger.info("Too many Runtime Resource having name " + RUNTIME_CATALOGUE_RESOURCE_NAME +" in this scope.. Looking for the one that has the property " + IS_MASTER_ROOT_KEY_PROPERTY);

						for (ServiceEndpoint res : resources) {

							Iterator<AccessPoint> accessPointIterator = res.profile().accessPoints().iterator();

							while (accessPointIterator.hasNext()) {
								ServiceEndpoint.AccessPoint accessPoint = (ServiceEndpoint.AccessPoint) accessPointIterator
										.next();

								// get the is master property
								Property entry = accessPoint.propertyMap().get(IS_MASTER_ROOT_KEY_PROPERTY);
								String isMaster = entry != null ?  entry.value() : null;

								if(isMaster == null || !isMaster.equals("true"))
									continue;

								// set this variable
								oneWasMaster = true;

								// add this host
								datacatalogueUrls.add(accessPoint.address());

								// retrieve sys admin token
								sysAdminToken = accessPoint.propertyMap().get(API_KEY_PROPERTY).value();
								sysAdminToken = StringEncrypter.getEncrypter().decrypt(sysAdminToken);
								
								// retrieve URL_RESOLVER
								if(accessPoint.propertyMap().containsKey(URL_RESOLVER))
									urlResolver = accessPoint.propertyMap().get(URL_RESOLVER).value();

								// break now
								break;
							}
						}

						// if none of them was master, throw an exception
						if(!oneWasMaster)
							throw new NoApplicationProfileMasterException("There is no application profile with MASTER property");

					}else{
						for (ServiceEndpoint res : resources) {

							Iterator<AccessPoint> accessPointIterator = res.profile().accessPoints().iterator();

							while (accessPointIterator.hasNext()) {
								ServiceEndpoint.AccessPoint accessPoint = (ServiceEndpoint.AccessPoint) accessPointIterator
										.next();

								// add this host
								datacatalogueUrls.add(accessPoint.address());

								// retrieve sys admin token
								sysAdminToken = accessPoint.propertyMap().get(API_KEY_PROPERTY).value();
								sysAdminToken = StringEncrypter.getEncrypter().decrypt(sysAdminToken);
								
								// get the is manage product property
								Property entry = accessPoint.propertyMap().get(IS_MANAGE_PRODUCT_ENABLED);
								String isManageProduct = entry != null ?  entry.value() : null;

								if(isManageProduct != null && isManageProduct.equals("true")){
									logger.info("Manage product is enabled in this scope");
									manageProductEnabled = true;
								}
								
								// retrieve URL_RESOLVER
								if(accessPoint.propertyMap().containsKey(URL_RESOLVER))
									urlResolver = accessPoint.propertyMap().get(URL_RESOLVER).value();
							}
						}
					}
				}catch(Exception e){
					throw new ServiceEndPointException("There is no service end point for such information");
				}
			}


			// finally get the url in which the ckan portlet is deployed
			logger.debug("Looking for portlet url in " + ScopeProvider.instance.get() + " scope" );
			portletUrl = getPortletUrlFromInfrastrucure();

		}catch(Exception e) {
			logger.warn("The following error occurred: " + e.toString());
		}finally{
			ScopeProvider.instance.set(currentScope);
		}
	}

	/**
	 * Retrieve endpoints information from IS for DB
	 * @return list of endpoints for ckan database
	 * @throws Exception
	 */
	private List<ServiceEndpoint> getConfigurationFromISFORDB() throws Exception{

		SimpleQuery query = queryFor(ServiceEndpoint.class);
		query.addCondition("$resource/Profile/Name/text() eq '"+ RUNTIME_DB_RESOURCE_NAME +"'");
		query.addCondition("$resource/Profile/Platform/Name/text() eq '"+ PLATFORM_DB_NAME +"'");
		DiscoveryClient<ServiceEndpoint> client = clientFor(ServiceEndpoint.class);
		List<ServiceEndpoint> toReturn = client.submit(query);
		return toReturn;

	}

	/**
	 * Retrieve endpoints information from IS for DataCatalogue URL
	 * @return list of endpoints for ckan data catalogue
	 * @throws Exception
	 */
	private List<ServiceEndpoint> getConfigurationFromISFORCatalogueUrl() throws Exception{

		SimpleQuery query = queryFor(ServiceEndpoint.class);
		query.addCondition("$resource/Profile/Name/text() eq '"+ RUNTIME_CATALOGUE_RESOURCE_NAME +"'");
		query.addCondition("$resource/Profile/Platform/Name/text() eq '"+ PLATFORM_CATALOGUE_NAME +"'");
		DiscoveryClient<ServiceEndpoint> client = clientFor(ServiceEndpoint.class);
		List<ServiceEndpoint> toReturn = client.submit(query);
		return toReturn;

	}	

	/**
	 * Retrieve the url of the ckan portlet deployed into this scope
	 * @return
	 */
	private String getPortletUrlFromInfrastrucure() {

		String scope = ScopeProvider.instance.get();
		logger.debug("Trying to fetch applicationProfile profile from the infrastructure for " + APPLICATION_PROFILE_NAME + " scope: " +  scope);

		try {
			Query q = new QueryBox("for $profile in collection('/db/Profiles/GenericResource')//Resource " +
					"where $profile/Profile/SecondaryType/string() eq 'ApplicationProfile' and  $profile/Profile/Name/string() " +
					" eq '" + APPLICATION_PROFILE_NAME + "'" +
					"return $profile");

			DiscoveryClient<String> client = client();
			List<String> appProfile = client.submit(q);

			if (appProfile == null || appProfile.size() == 0) 
				throw new ApplicationProfileNotFoundException("Your applicationProfile is not registered in the infrastructure");
			else {
				String elem = appProfile.get(0);
				DocumentBuilder docBuilder =  DocumentBuilderFactory.newInstance().newDocumentBuilder();
				Node node = docBuilder.parse(new InputSource(new StringReader(elem))).getDocumentElement();
				XPathHelper helper = new XPathHelper(node);

				List<String> currValue = null;
				currValue = helper.evaluate("/Resource/Profile/Body/url/text()");
				if (currValue != null && currValue.size() > 0) {
					logger.debug("Portlet url found is " + currValue.get(0));
					return currValue.get(0);
				} 

			}

		} catch (Exception e) {
			logger.error("Error while trying to fetch applicationProfile profile from the infrastructure", e);
		} 

		return null;

	}

	/** Retrieve the ckan portlet url
	 * @return the portletUrl
	 */
	public String getPortletUrl() {
		return portletUrl;
	}

	/**
	 * Retrieve data catalogue url
	 */
	public List<String> getDataCatalogueUrl() {
		return datacatalogueUrls;
	}

	/**
	 * Get the hosts for such resource.
	 * @return
	 */
	public List<String> getDatabaseHosts() {
		return hostsDB;
	}

	/**
	 * Get the ports for such resource.
	 * @return
	 */
	public List<Integer> getDatabasePorts() {
		return portsDB;
	}

	/**
	 * Get the database name.
	 * @return
	 */
	public String getDataBaseName() {
		return nameDB;
	}

	/**
	 * Get the database's user.
	 * @return
	 */
	public String getDataBaseUser() {
		return userDB;
	}

	/**
	 * Get the database's password.
	 * @return
	 */
	public String getDataBasePassword() {
		return passwordDB;
	}

	/**
	 * @return the sysAdminToken
	 */
	public String getSysAdminToken() {
		return sysAdminToken;
	}

	/**
	 * Is manager product enabled (e.g., for GRSF records)
	 * @return
	 */
	public boolean isManageProductEnabled() {
		return manageProductEnabled;
	}

	/**
	 * Get the url of the uri resolver for this instance/scope
	 * @return
	 */
	public String getUrlResolver() {
		return urlResolver;
	}

}