package org.gcube.informationsystem.resourceregistry.schema;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import org.gcube.common.authorization.library.AuthorizationEntry;
import org.gcube.common.authorization.library.provider.SecurityTokenProvider;
import org.gcube.common.resources.gcore.GCoreEndpoint;
import org.gcube.common.resources.gcore.ServiceEndpoint;
import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.informationsystem.resourceregistry.api.Constants;
import org.gcube.resources.discovery.client.queries.api.SimpleQuery;
import org.gcube.resources.discovery.icclient.ICFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Luca Frosini (ISTI - CNR)
 */
public class ResourceRegistrySchemaClientFactory {
	
	private static final Logger logger = LoggerFactory.getLogger(ResourceRegistrySchemaClientFactory.class);
	
protected static List<String> addresses;
	
	static {
		addresses = new ArrayList<>();
	}
	
	private static String FORCED_URL = null;
	
	protected static void forceToURL(String url){
		FORCED_URL = url;
	}
	
	private static String classFormat = "$resource/Profile/ServiceClass/text() eq '%1s'";
	private static String nameFormat = "$resource/Profile/ServiceName/text() eq '%1s'";
	private static String statusFormat = "$resource/Profile/DeploymentData/Status/text() eq 'ready'";
	private static String containsFormat = "$entry/@EntryName eq '%1s'";
	
	
	private static String serviceEndpointCategoryFormat = "$resource/Profile/Category/text() eq '%1s'";
	private static String serviceEndpointNameFormat = "$resource/Profile/Name/text() eq '%1s'";
	private static String serviceEndpointstatusFormat = "$resource/Profile/RunTime/Status/text() eq 'READY'";

	public static String getCurrentContextFullName() {
		String token = SecurityTokenProvider.instance.get();
		AuthorizationEntry authorizationEntry = null;
		try {
			authorizationEntry = org.gcube.common.authorization.client.Constants.authorizationService().get(token);
		} catch(Exception e) {
			return ScopeProvider.instance.get();
		}
		return authorizationEntry.getContext();
	}
	
	private static SimpleQuery queryForService(){
		return ICFactory.queryFor(GCoreEndpoint.class)
				.addCondition(String.format(classFormat, Constants.SERVICE_CLASS))
				.addCondition(String.format(nameFormat, Constants.SERVICE_NAME))
				.addCondition(String.format(statusFormat))
				.addVariable("$entry","$resource/Profile/AccessPoint/RunningInstanceInterfaces/Endpoint")
				.addCondition(String.format(containsFormat, Constants.SERVICE_ENTRY_NAME))
				.setResult("$entry/text()");
	}
	
	private static SimpleQuery queryForProxy(){
		return ICFactory.queryFor(ServiceEndpoint.class)
				.addCondition(String.format(serviceEndpointCategoryFormat, Constants.SERVICE_CLASS))
				.addCondition(String.format(serviceEndpointNameFormat, Constants.SERVICE_NAME))
				.addCondition(String.format(serviceEndpointstatusFormat))
				.addVariable("$entry","$resource/Profile/AccessPoint/Interface/Endpoint")
				.addCondition(String.format(containsFormat, Constants.SERVICE_ENTRY_NAME))
				.setResult("$entry/text()");
	}
	
	
	protected static List<String> getAddresses(){
		List<String> addresses = new ArrayList<>();
		
		try {
			SimpleQuery proxyQuery = queryForProxy();
			addresses = ICFactory.client().submit(proxyQuery);
			if(addresses==null || addresses.isEmpty()){
				throw new Exception("No ResourceRegistry Proxy Found");
			}
		} catch (Exception e) {
			logger.debug("{}. Looking for RunningInstance.", e.getMessage());
			SimpleQuery serviceQuery = queryForService();
			addresses = ICFactory.client().submit(serviceQuery);
		}
		
		return addresses;
	}
	
	public static ResourceRegistrySchemaClient create() {
		String address = null;
		
		if(FORCED_URL!=null){
			address = FORCED_URL;
		}else {
		
			if(addresses==null) {
				addresses = getAddresses();
			}
				
			if(addresses==null || addresses.isEmpty()){
				String error = String.format("No %s:%s found in the current context %s", Constants.SERVICE_CLASS, Constants.SERVICE_NAME, getCurrentContextFullName());
				throw new RuntimeException(error);
			}
				
			Random random = new Random();
			int index = random.nextInt(addresses.size());
			address = addresses.get(index);
		}
		
		return new ResourceRegistrySchemaClientImpl(address);
	}
	
}