package org.gcube.gcat.moderation.thread.zulip;

import java.util.Set;

import javax.ws.rs.InternalServerErrorException;

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;
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.gcat.api.moderation.CMItemStatus;
import org.gcube.gcat.api.moderation.Moderated;
import org.gcube.gcat.moderation.thread.ModerationThread;
import org.gcube.gcat.moderation.thread.zulip.ZulipResponse.Result;
import org.gcube.gcat.social.SocialUsers;
import org.gcube.gcat.utils.Constants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.taliox.zulip.ZulipRestExecutor;
import io.taliox.zulip.calls.ZulipRestAPICall;
import io.taliox.zulip.calls.messages.PostMessage;
import io.taliox.zulip.calls.streams.GetStreamID;
import io.taliox.zulip.calls.streams.PostCreateStream;

/**
 * @author Luca Frosini (ISTI - CNR)
 */
public class ZulipStream extends ModerationThread {
	
	private static final Logger logger = LoggerFactory.getLogger(ZulipStream.class);
	
	public static final String TOPICS_KEY = "topics";
	public static final String NAME_KEY = "name";
	public static final String MAX_ID_KEY = "max_id";
	public static final String INITIAL_TOPIC_NAME = "hello";
	
	protected ZulipRestExecutor gCatZulipRestExecutor;
	protected ZulipRestExecutor userZulipRestExecutor;
	
	protected String streamName;
	protected String streamDescription;
	
	public ZulipStream() {
		super();
	}
	
	protected ZulipRestExecutor getZulipRestExecutor() {
		ZulipAuth zulipAuth = new ZulipAuth(SecretManagerProvider.instance.get().getUser().getUsername());
		return new ZulipRestExecutor(zulipAuth.getEmail(), zulipAuth.getAPIKey(), zulipAuth.getSite());
	}
	
	public ZulipRestExecutor getGCatZulipRestExecutor() throws Exception {
		if(gCatZulipRestExecutor==null) {
			SecretManager secretManager = SecretManagerProvider.instance.get();
			Secret secret = Constants.getCatalogueSecret();
			secretManager.startSession(secret);
			gCatZulipRestExecutor = getZulipRestExecutor();
			secretManager.endSession();
		}
		return gCatZulipRestExecutor;
	}
	
	public ZulipRestExecutor getUserZulipRestExecutor() {
		if(userZulipRestExecutor==null) {
			userZulipRestExecutor = getZulipRestExecutor();
		}
		return userZulipRestExecutor;
	}
	
	protected String getStreamName() {
		if(streamName==null) {
			streamName = String.format("Item '%s' moderation", itemID);
		}
		return streamName;
	}
	
	protected Integer getStreamID() throws Exception {
		GetStreamID getStreamID = new GetStreamID(getStreamName());
		ZulipResponse zulipResponse = executeZulipCall(gCatZulipRestExecutor, getStreamID);
		JsonNode response = zulipResponse.getResponse();
		return response.get("stream_id").asInt();
	}
	
	protected String getStreamDescription() {
		if(streamDescription==null) {
			streamDescription = String.format("This stream is used to discuss about the moderation of the item '%s' with id '%s'", itemName, itemID);
		}
		return streamDescription;
	}
	
	protected ZulipResponse executeZulipCall(ZulipRestExecutor zulipRestExecutor, ZulipRestAPICall call) throws Exception {
		logger.trace("Going to execute {}", call);
		String responseString = zulipRestExecutor.executeCall(call);
		logger.trace("Response from {} is {}", call.getClass().getSimpleName(), responseString);
		ZulipResponse zulipResponse = new ZulipResponse(responseString);
		if(zulipResponse.getResponseResult()==Result.error) {
			throw new InternalServerErrorException(zulipResponse.getResponseMessage());
		}
		return zulipResponse;
	}

	@Override
	protected void createModerationThread() throws Exception {
		ArrayNode streamsArrayNode = objectMapper.createArrayNode();
		ObjectNode streamobjectNode = objectMapper.createObjectNode();
		streamobjectNode.put("name", getStreamName());
		streamobjectNode.put("description", getStreamDescription());
		streamsArrayNode.add(streamobjectNode);
		
		ArrayNode principalsArrayNode = objectMapper.createArrayNode();
		// Going to add the item creator
		String itemCreatorEmail = ckanUser.getEMail();
		principalsArrayNode.add(itemCreatorEmail);
		
		getGCatZulipRestExecutor();
		
		principalsArrayNode.add(gCatZulipRestExecutor.httpController.getUserName());
		
		// Going to add the catalogue moderators
		Set<String> moderators = SocialUsers.getUsernamesByRole(Moderated.CATALOGUE_MODERATOR);
		for(String moderator : moderators) {
			principalsArrayNode.add(moderator);
		}
		
		PostCreateStream postCreateStream = new PostCreateStream(streamsArrayNode.toString());
		postCreateStream.setPrincipals(principalsArrayNode.toString());
		postCreateStream.setInvite_only(true);
		postCreateStream.setAnnounce(false);
		
		executeZulipCall(gCatZulipRestExecutor, postCreateStream);
	}
	
	protected void postMessageToStream(ZulipRestExecutor zulipRestExecutor, String message) throws Exception {
		PostMessage postMessage = new PostMessage(getStreamName(), cmItemStatus.getFancyValue(), message);
		logger.debug("Going to send the following message: {}", message);
		executeZulipCall(zulipRestExecutor, postMessage);
	}
	
	@Override
	protected void postMessage(String message) throws Exception {
		postMessageToStream(getGCatZulipRestExecutor(), message);
	}
	
	@Override
	public void postUserMessage(CMItemStatus cmItemStatus, String message) throws Exception {
		this.cmItemStatus = cmItemStatus;
		postMessageToStream(getUserZulipRestExecutor(), message);
	}
	
}