package org.gcube.datacatalogue.grsf_manage_widget.server.manage;

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

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.gcube.common.authorization.library.provider.SecurityTokenProvider;
import org.gcube.common.resources.gcore.GCoreEndpoint;
import org.gcube.common.scope.api.ScopeProvider;
import org.gcube.datacatalogue.ckanutillibrary.server.DataCatalogue;
import org.gcube.datacatalogue.common.Constants;
import org.gcube.datacatalogue.grsf_manage_widget.server.manage.RevertOperationUrl.Operation;
import org.gcube.datacatalogue.grsf_manage_widget.shared.ManageProductBean;
import org.gcube.resources.discovery.client.api.DiscoveryClient;
import org.gcube.resources.discovery.client.queries.api.SimpleQuery;
import org.gcube.vomanagement.usermanagement.RoleManager;
import org.gcube.vomanagement.usermanagement.UserManager;
import org.gcube.vomanagement.usermanagement.impl.LiferayRoleManager;
import org.gcube.vomanagement.usermanagement.impl.LiferayUserManager;
import org.gcube.vomanagement.usermanagement.model.GCubeTeam;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.databind.ObjectMapper;

import eu.trentorise.opendata.jackan.internal.org.apache.http.HttpEntity;
import eu.trentorise.opendata.jackan.internal.org.apache.http.HttpResponse;
import eu.trentorise.opendata.jackan.internal.org.apache.http.client.methods.HttpPost;
import eu.trentorise.opendata.jackan.internal.org.apache.http.entity.StringEntity;
import eu.trentorise.opendata.jackan.internal.org.apache.http.impl.client.CloseableHttpClient;
import eu.trentorise.opendata.jackan.internal.org.apache.http.impl.client.HttpClientBuilder;
import eu.trentorise.opendata.jackan.internal.org.apache.http.impl.client.LaxRedirectStrategy;
import eu.trentorise.opendata.jackan.internal.org.apache.http.util.EntityUtils;


/**
 * For managing the different interactions with social channels (posts and mails)
 * @author Costantino Perciante at ISTI-CNR (costantino.perciante@isti.cnr.it)
 */
public class SocialCommunications {

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

	// for discovering social networking service
	private static final String resource = "jersey-servlet";
	private static final String serviceName = "SocialNetworking";
	private static final String serviceClass = "Portal";

	// social operations
	private static final String SOCIAL_SERVICE_APPLICATION_TOKEN = "/2/tokens/generate-application-token/";
	private static final String SOCIAL_SERVICE_WRITE_APPLICATION_POST = "/2/posts/write-post-app/";
	private static final String SOCIAL_SEND_EMAIL = "/2/messages/write-message/";
	private static final String MEDIATYPE_JSON = "application/json";

	// for writing a post in the GRSF admin context
	private static final String APPLICATION_ID_CATALOGUE_MANAGER = "org.gcube.datacatalogue.GRSFNotifier"; 

	// emails to be sent to editors and reviewers and post to be written into the grsf admin vre
	private static final String POST_MESSAGE = "Dear members,"
			+ "<br>The record 'PRODUCT_TITLE' has been just updated by USER_FULLNAME."
			+ "<br>You can inspect it here: PRODUCT_URL<br>";

	private static final String EMAIL_MESSAGE_REVIEWER = "Dear GRSF Reviewer,"
			+ "<br>an update on the record named 'PRODUCT_TITLE' has been requested by USER_FULLNAME."
			+ "<br>It is available here LINK_RECORD.";

	private static final String EMAIL_MESSAGE_EDITOR = "Dear USER_FULLNAME,"
			+ "<br>your request for the record 'PRODUCT_TITLE' has been accepted."
			+ "<br>It is available here LINK_RECORD.";

	private static final String REVERT_LINK_PIECE = "<br>The request involves a merge operation. You can reject the merge by exploiting this link LINK in the following 24 hours.";

	/**
	 * 
	 * @param context
	 * @return
	 */
	private static String getBaseUrlSocialService(String context){

		if(context == null || context.isEmpty())
			throw new IllegalArgumentException("A valid context is needed to discover the service");

		String oldContext = ScopeProvider.instance.get();
		ScopeProvider.instance.set(context);

		String basePath = null;
		try{

			SimpleQuery query = queryFor(GCoreEndpoint.class);
			query.addCondition(String.format("$resource/Profile/ServiceClass/text() eq '%s'",serviceClass));
			query.addCondition("$resource/Profile/DeploymentData/Status/text() eq 'ready'");
			query.addCondition(String.format("$resource/Profile/ServiceName/text() eq '%s'",serviceName));
			query.setResult("$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 serviceName: "+serviceName +", serviceClass: " +serviceClass +", in scope: "+context);


			basePath = endpoints.get(0);
			if(basePath==null)
				throw new Exception("Endpoint:"+resource+", is null for serviceName: "+serviceName +", serviceClass: " +serviceClass +", in scope: "+context);

		}catch(Exception e){
			logger.error("Unable to retrieve such service endpoint information!", e);
		}finally{
			if(oldContext != null && !oldContext.equals(context))
				ScopeProvider.instance.set(oldContext);
		}
		logger.info("Found base path " + basePath + " for the service");
		return basePath;
	}

	/**
	 * Notify the users about the required changes.
	 * @param bean
	 * @param url
	 * @param username
	 * @param fullName
	 * @param hashtags
	 * @param enablePostNotification
	 */
	@SuppressWarnings("unchecked")
	public static void writeProductPost(ManageProductBean bean, String username, String fullName, List<String> hashtags, boolean enablePostNotification){

		// discover service endpoint for the social networking library
		String currentScope = ScopeProvider.instance.get();
		String tokenUser = SecurityTokenProvider.instance.get();

		logger.info("Current scope for writeProductPost is " + currentScope + " and token is " + tokenUser.substring(0, 10) + "***************");
		String basePath = getBaseUrlSocialService(currentScope);

		if(basePath == null){

			logger.error("Unable to write a post because there is no social networking service available");

		}else{

			basePath = basePath.endsWith("/") ? basePath : basePath + "/";

			try(CloseableHttpClient client = HttpClientBuilder.create().setRedirectStrategy(new LaxRedirectStrategy()).build();){

				// ask token application
				HttpPost postRequest = new HttpPost(basePath + SOCIAL_SERVICE_APPLICATION_TOKEN + "?gcube-token=" + tokenUser);
				StringEntity input = new StringEntity("{\"app_id\":\"" + APPLICATION_ID_CATALOGUE_MANAGER + "\"}");
				input.setContentType(MEDIATYPE_JSON);
				postRequest.setEntity(input);
				HttpResponse response = client.execute(postRequest);

				logger.debug("Url is " + basePath + SOCIAL_SERVICE_APPLICATION_TOKEN + "?gcube-token=" + tokenUser);

				if (response.getStatusLine().getStatusCode() != 201) {
					throw new RuntimeException("Failed to retrieve application token : HTTP error code : "
							+ response.getStatusLine().getStatusCode());
				}else{

					Map<String, Object> mapResponseGeneratedToken = getResponseEntityAsJSON(response);
					boolean successGeneratedToken = (boolean)mapResponseGeneratedToken.get("success");
					if(!successGeneratedToken){

						throw new RuntimeException("Failed to generate the token for the application!"
								+ " Error message is " + mapResponseGeneratedToken.get("message"));

					}else{

						String applicationToken = (String)mapResponseGeneratedToken.get("result");

						// replace
						String message  = POST_MESSAGE.replace("PRODUCT_TITLE", bean.getGrsfName()).replace("PRODUCT_URL", bean.getRecordUrl()).replace("USER_FULLNAME", fullName);

						if(hashtags != null && !hashtags.isEmpty())
							for (String hashtag : hashtags) {
								String modifiedHashtag = hashtag.replaceAll(" ", "_").replace("_+", "_"); // no empty spaces allowed
								if(modifiedHashtag.endsWith("_"))
									modifiedHashtag = modifiedHashtag.substring(0, modifiedHashtag.length() - 1);
								message += " #" + modifiedHashtag;
							}

						logger.info("The post that is going to be written is -> " + message);
						postRequest = new HttpPost(basePath + SOCIAL_SERVICE_WRITE_APPLICATION_POST + "?gcube-token=" + applicationToken);
						JSONObject object = new JSONObject();
						object.put("text", message);
						object.put("enable_notification", enablePostNotification);
						input = new StringEntity(object.toJSONString());
						input.setContentType(MEDIATYPE_JSON);
						postRequest.setEntity(input);
						response = client.execute(postRequest);

						Map<String, Object> mapResponseWritePost = getResponseEntityAsJSON(response);

						if (response.getStatusLine().getStatusCode() != 201)
							throw new RuntimeException("Failed to write application post : HTTP error code : "
									+ response.getStatusLine().getStatusCode() + mapResponseWritePost.get("message"));
					}

				}

			}catch(Exception e){
				logger.error("Failed to create a post", e);
			}
		}
	}

	/**
	 * Send an email to the administrator as well as the 
	 * @param bean
	 * @param catalogue
	 * @param username
	 * @param fullName
	 * @param isMergeInvolved 
	 * @param httpSession 
	 * @throws Exceptio 
	 */
	@SuppressWarnings("unchecked")
	public static void sendEmailAdministrators(
			ManageProductBean bean,
			DataCatalogue catalogue, 
			String username, 
			String fullName, 
			long groupId, 
			HttpServletRequest httpServletRequest, 
			boolean isMergeInvolved) throws Exception {

		// get the list of GRSF Reviewers to alert them as well
		RoleManager roleManager = new LiferayRoleManager();
		List<GCubeTeam> teamRoles = roleManager.listTeamsByGroup(groupId);
		List<String> reviewers = new ArrayList<>();
		UserManager um = new LiferayUserManager();

		for(GCubeTeam tr: teamRoles){
			if(tr.getTeamName().equals(Constants.GRSF_CATALOGUE_REVIEWER_ROLE))
				reviewers.add(um.getUserById(tr.getUserId()).getUsername());
		}

		// if the user is a reviewer, then send the email just once
		reviewers.remove(username);

		logger.info("List of " + Constants.GRSF_CATALOGUE_REVIEWER_ROLE + " is " + reviewers);

		// build the url that allows to revert the operation 
		Operation operation = Operation.MERGE;

		// discover service endpoint for the social networking library
		String currentScope = ScopeProvider.instance.get();
		String tokenUser = SecurityTokenProvider.instance.get();

		logger.info("Current scope for writeProductPost is " + currentScope + " and token is " + tokenUser.substring(0, 10) + "***************");
		String basePath = getBaseUrlSocialService(currentScope);

		if(basePath == null){

			logger.error("Unable to write a post because there is no social networking service available");

		}else{

			basePath = basePath.endsWith("/") ? basePath : basePath + "/";

			try(CloseableHttpClient client = HttpClientBuilder.create().setRedirectStrategy(new LaxRedirectStrategy()).build();){

				// ask token application
				HttpPost postRequest = new HttpPost(basePath + SOCIAL_SERVICE_APPLICATION_TOKEN + "?gcube-token=" + tokenUser);
				StringEntity input = new StringEntity("{\"app_id\":\"" + APPLICATION_ID_CATALOGUE_MANAGER + "\"}");
				input.setContentType(MEDIATYPE_JSON);
				postRequest.setEntity(input);
				HttpResponse response = client.execute(postRequest);

				logger.debug("Url is " + basePath + SOCIAL_SERVICE_APPLICATION_TOKEN + "?gcube-token=" + tokenUser);

				if (response.getStatusLine().getStatusCode() != 201) {
					throw new RuntimeException("Failed to retrieve application token : HTTP error code : "
							+ response.getStatusLine().getStatusCode());
				}else{

					Map<String, Object> mapResponseGeneratedToken = getResponseEntityAsJSON(response);
					boolean successGeneratedToken = (boolean)mapResponseGeneratedToken.get("success");
					if(!successGeneratedToken){

						throw new RuntimeException("Failed to generate the token for the application!"
								+ " Error message is " + mapResponseGeneratedToken.get("message"));

					}else{

						String applicationToken = (String)mapResponseGeneratedToken.get("result");

						String revertUrl = getEncodedUrlManage(operation, username, System.currentTimeMillis(), bean.getKnowledgeBaseIdentifier(), httpServletRequest);

						String messageToEditor = (EMAIL_MESSAGE_EDITOR +
								(isMergeInvolved? REVERT_LINK_PIECE : "")).replace("USER_FULLNAME", fullName).replace("PRODUCT_TITLE", bean.getGrsfName()).replace("LINK_RECORD", bean.getRecordUrl()).replace("LINK", revertUrl);
						String messageToReviewer = (EMAIL_MESSAGE_REVIEWER+
								(isMergeInvolved? REVERT_LINK_PIECE : "")).replace("USER_FULLNAME", fullName).replace("PRODUCT_TITLE", bean.getGrsfName()).replace("LINK_RECORD", bean.getRecordUrl()).replace("LINK", revertUrl);
						String subject = "Update request on GRSF Record";

						// send email to the editor
						logger.info("The message that is going to be send to the editor is\n" + messageToEditor);
						postRequest = new HttpPost(basePath + SOCIAL_SEND_EMAIL + "?gcube-token=" + applicationToken);
						JSONObject reqMessage = new JSONObject();
						reqMessage.put("subject", subject);
						reqMessage.put("body", messageToEditor);
						JSONArray recipients = new JSONArray();
						JSONObject recipient = new JSONObject();
						recipient.put("id", username);
						recipients.add(recipient);
						reqMessage.put("recipients", recipients);
						input = new StringEntity(reqMessage.toJSONString());
						input.setContentType(MEDIATYPE_JSON);
						postRequest.setEntity(input);
						response = client.execute(postRequest);

						Map<String, Object> mapResponseWritePost = getResponseEntityAsJSON(response);

						if (response.getStatusLine().getStatusCode() != 201){
							logger.error("Failed to send message to editor : HTTP error code : "
									+ response.getStatusLine().getStatusCode() + mapResponseWritePost.get("message"));
						}

						// send email to the reviewers
						logger.info("The message that is going to be send to the reviewers is\n" + messageToReviewer);
						postRequest = new HttpPost(basePath + SOCIAL_SEND_EMAIL + "?gcube-token=" + applicationToken);
						reqMessage = new JSONObject();
						reqMessage.put("subject", subject);
						reqMessage.put("body", messageToReviewer);
						recipients = new JSONArray();
						for(String reviewer: reviewers){
							JSONObject recip = new JSONObject();
							recip.put("id", reviewer);
							recipients.add(recip);
						}
						reqMessage.put("recipients", recipients);
						input = new StringEntity(reqMessage.toJSONString());
						input.setContentType(MEDIATYPE_JSON);
						postRequest.setEntity(input);
						response = client.execute(postRequest);
						mapResponseWritePost = getResponseEntityAsJSON(response);

						if (response.getStatusLine().getStatusCode() != 201){
							logger.error("Failed to send message to editor : HTTP error code : "
									+ response.getStatusLine().getStatusCode() + mapResponseWritePost.get("message"));
						}

					}

				}

			}catch(Exception e){
				logger.error("Failed to create a post", e);
			}
		}

	}

	/**
	 * Create the url to be send for reverting the operation
	 * @param httpSession 
	 * @return
	 * @throws Exception 
	 */
	public static String getEncodedUrlManage(Operation operation, String administrator, long timestamp, String uuid, HttpServletRequest httpServletRequest) throws Exception{
		String clientUrl = Utils.getCurrentClientUrl(httpServletRequest).split("\\?")[0]; // ignore other parameters		
		RevertOperationUrl operationUrl = new RevertOperationUrl(clientUrl, administrator, timestamp, uuid, operation);
		String shortUrl = operationUrl.getShortUrl();
		return shortUrl;
	}

	/**
	 * Convert the json response to a map
	 * @param response
	 * @return
	 */
	@SuppressWarnings("unchecked")
	private static Map<String, Object> getResponseEntityAsJSON(HttpResponse response){

		Map<String, Object> toReturn = null;
		HttpEntity entity = response.getEntity();

		if (entity != null) {
			try {
				toReturn = new HashMap<String, Object>();
				String jsonString = EntityUtils.toString(response.getEntity());
				logger.debug("Response as string is " + jsonString);
				ObjectMapper objectMapper = new ObjectMapper();
				toReturn = objectMapper.readValue(jsonString, HashMap.class);
				logger.debug("Map is " + toReturn);
			}catch(Exception e){
				logger.error("Failed to read json object", e);
			}
		}

		return toReturn;
	}

}