package eu.dnetlib.ariadneplus.workflows.nodes;

import java.io.IOException;
import java.net.ConnectException;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.gson.Gson;
import eu.dnetlib.enabling.resultset.client.ResultSetClient;
import eu.dnetlib.msro.workflows.graph.Arc;
import eu.dnetlib.msro.workflows.nodes.AsyncJobNode;
import eu.dnetlib.msro.workflows.procs.Env;
import eu.dnetlib.msro.workflows.util.WorkflowsConstants;
import eu.dnetlib.rmi.common.ResultSet;
import eu.dnetlib.rmi.manager.MSROException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.springframework.beans.factory.annotation.Autowired;


public class PublishGraphDBJobNode extends AsyncJobNode {

	private static final Log log = LogFactory.getLog(PublishGraphDBJobNode.class);

	private String eprParam;

	@Autowired
	private ResultSetClient resultSetClient;

	private String publisherEndpoint;

	//for parallel requests to the publisher endpoint
	private int nThreads = 5;
	private ExecutorService executorService = Executors.newFixedThreadPool(nThreads);
	private List<Future<Integer>> resList = Lists.newArrayList();

	@Override
	protected String execute(final Env env) throws Exception {

		final ResultSet<?> rsIn = env.getAttribute(getEprParam(), ResultSet.class);
		if ((rsIn == null)) { throw new MSROException("EprParam (" + getEprParam() + ") not found in ENV"); }

		int countAll = 0;
		int countOk = 0;
		Map<Integer, Integer> errors = Maps.newHashMap();
		log.info("Publisher endpoint: " + getPublisherEndpoint());

		for (String record : getResultSetClient().iter(rsIn, String.class)) {
			countAll++;
			Future<Integer> res = executorService.submit( () -> {
				try {
					HttpPost post = new HttpPost(getPublisherEndpoint());
					List<NameValuePair> params = Lists.newArrayList();
					params.add(new BasicNameValuePair("record", record));
					UrlEncodedFormEntity ent =  new UrlEncodedFormEntity(params, "UTF-8");
					post.setEntity(ent);
					HttpClient client = HttpClients.createDefault();
					HttpResponse responsePOST = client.execute(post);
					int statusCode = responsePOST.getStatusLine().getStatusCode();
					switch (statusCode) {
					case 200:
						return statusCode;
					default:
						log.error(responsePOST.getStatusLine().getStatusCode() + ": " + responsePOST.getStatusLine().getReasonPhrase());
						log.error("Source record causing error: " + record);
						errors.merge(statusCode, 1, Integer::sum);
						return statusCode;
					}
				} catch (ConnectException ce) {
					throw new MSROException("unable to connect to Publisher endpoint" + getPublisherEndpoint());
				}
				catch (IOException e) {
					e.printStackTrace();
					errors.merge(-1, 1, Integer::sum);
				}
				return -1;
			});
			resList.add(res);
		}
		executorService.shutdown();

		//now let's wait for the results. We can block ourselves here: we have nothing else to do
		log.info("Waiting for responses");
		for(Future<Integer> res : resList){
			if(res.get() == 200) countOk++;
		}
		log.info(String.format("Got all responses. Ok %s/%s", countOk, countAll));

		env.setAttribute(WorkflowsConstants.MAIN_LOG_PREFIX + "countOk", countOk);
		env.setAttribute(WorkflowsConstants.MAIN_LOG_PREFIX + "countAll", countAll);
		env.setAttribute(WorkflowsConstants.MAIN_LOG_PREFIX + "errorsMap", new Gson().toJson(errors));

		log.info("publishing completed");
		if (!errors.isEmpty()) {
			log.warn("Problems in publishing: "+countOk+"/"+countAll+" see error maps for details");
		}
		if(countAll == 0) log.warn("0 resources to publish");
		return Arc.DEFAULT_ARC;
	}

	public String getPublisherEndpoint() {
		return publisherEndpoint;
	}

	public void setPublisherEndpoint(final String publisherEndpoint) {
		this.publisherEndpoint = publisherEndpoint;
	}

	public ResultSetClient getResultSetClient() {
		return resultSetClient;
	}

	public void setResultSetClient(final ResultSetClient resultSetClient) {
		this.resultSetClient = resultSetClient;
	}

	public String getEprParam() {
		return eprParam;
	}

	public void setEprParam(String eprParam) {
		this.eprParam = eprParam;
	}

}