package org.gcube.common.authorization.utils.socialservice;

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

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response.Status;

import org.gcube.com.fasterxml.jackson.databind.ObjectMapper;
import org.gcube.common.authorization.utils.manager.SecretManager;
import org.gcube.common.authorization.utils.manager.SecretManagerProvider;
import org.gcube.common.authorization.utils.secret.Secret;
import org.gcube.common.authorization.utils.user.GCubeUser;
import org.gcube.common.authorization.utils.user.User;
import org.gcube.common.gxhttp.request.GXHTTPStringRequest;
import org.gcube.common.resources.gcore.GCoreEndpoint;
import org.gcube.resources.discovery.client.api.DiscoveryClient;
import org.gcube.resources.discovery.client.queries.api.SimpleQuery;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Discover the Social Networking Service in the Infrastructure.
 * @author Luca Frosini (ISTI - CNR)
 */
public class SocialService {
	
	private static final String RESOURCE = "jersey-servlet";
	private static final String SERVICE_NAME = "SocialNetworking";
	private static final String SERVICE_CLASS = "Portal";
	
	private static Logger logger = LoggerFactory.getLogger(SocialService.class);
	private String serviceBasePath;
	
	// Map<String contextFullName, SocialService socialService>
	private static Map<String,SocialService> socialServicePerContext;
	
	static {
		socialServicePerContext = new HashMap<>();
	}
	
	public static SocialService getSocialService() throws Exception {
		SecretManager secretManager = SecretManagerProvider.instance.get();
		String context = secretManager.getContext();
		SocialService socialService = socialServicePerContext.get(context);
		if(socialService == null) {
			socialService = new SocialService();
			socialServicePerContext.put(context, socialService);
		}
		return socialService;
	}
	
	/**
	 * Discover the gcore endpoint for the social networking service.
	 * @throws Exception the exception
	 */
	private SocialService() throws Exception {
		getServiceBasePathViaGCoreEndpoint();
	}
	
	protected void getServiceBasePathViaGCoreEndpoint() throws Exception {
		SecretManager secretManager = SecretManagerProvider.instance.get();
		try {
			SimpleQuery query = queryFor(GCoreEndpoint.class);
			query.addCondition(String.format("$resource/Profile/ServiceClass/text() eq '%s'", SERVICE_CLASS));
			query.addCondition("$resource/Profile/DeploymentData/Status/text() eq 'ready'");
			query.addCondition(String.format("$resource/Profile/ServiceName/text() eq '%s'", SERVICE_NAME));
			query.setResult(
					"$resource/Profile/AccessPoint/RunningInstanceInterfaces//Endpoint[@EntryName/string() eq \""
							+ RESOURCE + "\"]/text()");
			
			DiscoveryClient<String> client = client();
			List<String> endpoints = client.submit(query);
			if(endpoints == null || endpoints.isEmpty()) {
				throw new Exception("Cannot retrieve the GCoreEndpoint SERVICE_NAME: " + SERVICE_NAME
						+ ", SERVICE_CLASSE: " + SERVICE_CLASS + ", in scope: " + secretManager.getContext());
			}
			
			this.serviceBasePath = endpoints.get(0);
			
			if(serviceBasePath == null)
				throw new Exception("Endpoint:" + RESOURCE + ", is null for SERVICE_NAME: " + SERVICE_NAME
						+ ", SERVICE_CLASSE: " + SERVICE_CLASS + ", in scope: " + secretManager.getContext());
			
			serviceBasePath = serviceBasePath.endsWith("/") ? serviceBasePath : serviceBasePath + "/";
			
		} catch(Exception e) {
			String error = "An error occurred during GCoreEndpoint discovery, SERVICE_NAME: " + SERVICE_NAME
					+ ", SERVICE_CLASSE: " + SERVICE_CLASS + ", in scope: " + secretManager.getContext() + ".";
			logger.error(error, e);
			throw new Exception(error);
		}
	}
	
	/**
	 * @return the base path of the service
	 */
	public String getServiceBasePath() {
		return serviceBasePath;
	}
	
	
	public StringBuilder getStringBuilder(InputStream inputStream) throws IOException {
		StringBuilder result = new StringBuilder();
		try(BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
			String line;
			while((line = reader.readLine()) != null) {
				result.append(line);
			}
		}
		
		return result;
	}
	
	public String getResultAsString(HttpURLConnection httpURLConnection) throws IOException {
		int responseCode = httpURLConnection.getResponseCode();
		if(responseCode >= Status.BAD_REQUEST.getStatusCode()) {
			Status status = Status.fromStatusCode(responseCode);
			InputStream inputStream = httpURLConnection.getErrorStream();
			StringBuilder result = getStringBuilder(inputStream);
			logger.trace(result.toString());
			throw new WebApplicationException(result.toString(), status);
		}
		InputStream inputStream = httpURLConnection.getInputStream();
		String ret = getStringBuilder(inputStream).toString();
		logger.trace("Got Respose is {}", ret);
		return ret;
	}
	
	protected static final String SOCIAL_SERVICE_GET_OAUTH_USER_PROFILE_PATH = "2/users/get-oauth-profile";
	
	protected static final String RESPONSE_SUCCESS_KEY = "success";
	protected static final String RESPONSE_MESSAGE_KEY = "message";
	protected static final String RESPONSE_RESULT_KEY = "result";
	
	
	public User getUser(Secret secret) throws Exception {
		try {
			String socialServiceBasePath = SocialService.getSocialService().getServiceBasePath();
			
			GXHTTPStringRequest gxhttpStringRequest = GXHTTPStringRequest.newRequest(socialServiceBasePath);
			gxhttpStringRequest.from("authorization-utils");
			gxhttpStringRequest.header(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON);
			Map<String,String> authzHeaders = secret.getHTTPAuthorizationHeaders();
			for(String key : authzHeaders.keySet()) {
				gxhttpStringRequest.header(key, authzHeaders.get(key));
			}
			gxhttpStringRequest.path(SOCIAL_SERVICE_GET_OAUTH_USER_PROFILE_PATH);
			HttpURLConnection httpURLConnection = gxhttpStringRequest.get();
			
			String ret = getResultAsString(httpURLConnection);
			ObjectMapper mapper = new ObjectMapper();
			return mapper.readValue(ret, GCubeUser.class);
		} catch(Exception e) {
			throw new Exception("Unable to retrive User from Social Service", e);
		}
		
	}
	
}