package eu.dnetlib.repo.manager.service;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import eu.dnetlib.repo.manager.domain.RepositorySnippet;
import eu.dnetlib.repo.manager.domain.Term;
import eu.dnetlib.repo.manager.domain.Tuple;
import eu.dnetlib.repo.manager.domain.broker.*;
import eu.dnetlib.repo.manager.exception.BrokerException;
import org.apache.commons.lang.NotImplementedException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.*;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestClientException;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponents;
import org.springframework.web.util.UriComponentsBuilder;

import javax.annotation.PostConstruct;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service("brokerService")
public class BrokerServiceImpl implements BrokerService {

    @Autowired
    private RepositoryServiceImpl repoAPI;
    @Value("${services.provide.broker.url}:${services.provide.broker.port}/${services.provide.broker.api}${services.provide.broker.openaire}")
    private String openairePath;
    @Value("${services.provide.broker.url}:${services.provide.broker.port}/${services.provide.broker.api}")
    private String apiPath;
    @Value("${services.provide.topic_types.url}")
    private String topicsURL;

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

    @Autowired
    RestTemplate restTemplate;

    private HttpHeaders httpHeaders;

    private final HashMap<String, Term> topics = new HashMap<>();

    @PostConstruct
    private void initDnetTopicsMap() {

        httpHeaders = new HttpHeaders();
        httpHeaders.set("Content-Type", "application/json");

        logger.debug("Init dnet topics!");
        try (InputStream is = new URL(topicsURL).openStream()) {
            ObjectMapper mapper = new ObjectMapper();
            JsonNode root = mapper.readTree(is);
            for (JsonNode term : root.path("terms"))
                topics.put(term.path("code").textValue(), parseTerm(term));
        } catch (IOException e) {
            logger.error("Exception on initDnetTopicsMap", e);
        }
    }

    private Term parseTerm(JsonNode term) {
        return new Term(term.path("englishName").textValue(), term.path("nativeName").textValue(),
                term.path("encoding").textValue(), term.path("code").textValue());
    }


    @Override
    public DatasourcesBroker getDatasourcesOfUser(String user, String includeShared, String includeByOthers) {
        long start = System.currentTimeMillis();
        DatasourcesBroker ret = new DatasourcesBroker();
        try {
            ret.setDatasourcesOfUser(getDatasourcesOfUserType(repoAPI.getRepositoriesSnippetsOfUser(user, "0", "100")));
            //TODO fix bug when values are true
//            if (Boolean.parseBoolean(includeShared)) {
//                List<String> sharedDatasourceIds = new ArrayList<String>();
//                ret.setSharedDatasources(getDatasourcesOfUserType(getRepositoriesByIds(sharedDatasourceIds)));
//            }

//            if (Boolean.parseBoolean(includeByOthers)) {
//                ret.setDatasourcesOfOthers(getDatasourcesOfUserType(getRepositoriesOfUser(user)));
//            }
        } catch (Exception e) {
            logger.error("Exception on getDatasourcesOfUser", e);
        }
        long end = System.currentTimeMillis();
        logger.debug("Getting datasources of user in " + (end - start) + "ms");
        return ret;
    }

    @Override
    public List<BrowseEntry> getTopicsForDatasource(String datasourceName) throws BrokerException {
        final String service = "/topicsForDatasource";

        UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(openairePath + service)
                .queryParam("ds", datasourceName);

        ResponseEntity<List<BrowseEntry>> resp;
        try {
            resp = restTemplate.exchange(
                    builder.build().encode().toUri(),
                    HttpMethod.GET,
                    null,
                    new ParameterizedTypeReference<List<BrowseEntry>>() {
                    });
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }

        return resp.getBody();
    }

    @Override
    public EventsPage advancedShowEvents(String page,
                                         String size,
                                         AdvQueryObject advQueryObject) throws BrokerException {

        final String service = "/events/{page}/{pageSize}";

        long pageNum = Long.parseLong(page);
        advQueryObject.setPage(pageNum);

        Map<String, Long> uriParams = new HashMap<>();
        uriParams.put("page", pageNum);
        uriParams.put("pageSize", Long.parseLong(size));

        UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(openairePath + service);

        HttpEntity<AdvQueryObject> entity = new HttpEntity<>(advQueryObject, httpHeaders);
        ResponseEntity<EventsPage> resp;
        try {
            resp = restTemplate.exchange(
                    builder.buildAndExpand(uriParams).encode().toUri(),
                    HttpMethod.POST,
                    entity,
                    new ParameterizedTypeReference<EventsPage>() {}
            );
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }
        return resp.getBody();
    }


    private List<Tuple<BrowseEntry, String>> getDatasourcesOfUserType(List<RepositorySnippet> repositories) throws BrokerException {
        long start = System.currentTimeMillis();
        List<Tuple<BrowseEntry, String>> entries = new ArrayList<>();
        for (RepositorySnippet repo : repositories) {
            BrowseEntry temp = new BrowseEntry();
            temp.setValue(repo.getOfficialname());
            temp.setSize(0L);
            for (BrowseEntry e : getTopicsForDatasource(repo.getOfficialname())) {
                temp.setSize(temp.getSize() + e.getSize());
            }
            Tuple<BrowseEntry, String> tup = new Tuple<>(temp, repo.getLogoUrl());
            entries.add(tup);
        }

        // sort the collection by the second field of the tuple which is size
        entries.sort((e1, e2) -> (int) (e2.getFirst().getSize() - e1.getFirst().getSize()));
        long stop = System.currentTimeMillis();
        logger.debug("getDatasourcesOfUserType returned in " + (stop - start) + "ms ");
        return entries;
    }

    @Override
    public EventsPage showEvents(String datasourceName,
                                 String topic,
                                 String page,
                                 String size) throws BrokerException {

        final String service = "/events";

        UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(openairePath + service)
                .queryParam("ds", datasourceName)
                .queryParam("topic", topic)
                .path("/{page}/{size}/");

        ResponseEntity<EventsPage> resp;
        try {
            resp = restTemplate.exchange(
                    builder.build().expand(page, size).encode().toUri(),
                    HttpMethod.GET,
                    null,
                    new ParameterizedTypeReference<EventsPage>() {
                    });
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }
        return resp.getBody();
    }

    @Override
    public Map<String, List<SimpleSubscriptionDesc>> getSimpleSubscriptionsOfUser(String userEmail)
            throws BrokerException {

        final String service = "/subscriptions";

        URI uri = UriComponentsBuilder.fromHttpUrl(openairePath + service)
                .queryParam("email", userEmail).build().encode().toUri();

        logger.debug("{}", uri);
        ResponseEntity<Map<String, List<SimpleSubscriptionDesc>>> resp;
        try {
            resp = restTemplate.exchange(
                    uri,
                    HttpMethod.GET,
                    null,
                    new ParameterizedTypeReference<Map<String, List<SimpleSubscriptionDesc>>>() {
                    });
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }
        return resp.getBody();
    }

    @Override
    public Map<String, List<SimpleSubscriptionDesc>> getSimpleSubscriptionsOfUserByRepoId(String userEmail, String repoId) {    //throws BrokerException {
        throw new NotImplementedException();
        //Map<String, List<SimpleSubscriptionDesc>> subscriptionsOfUser = getSimpleSubscriptionsOfUser(userEmail);
    }

    @Override
    public Subscription subscribe(OpenaireSubscription obj) throws BrokerException {
        final String service = "/subscribe";

        //build the uri params
        UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(openairePath + service);

        HttpEntity<OpenaireSubscription> entity = new HttpEntity<>(obj, httpHeaders);

        //create new template engine
        RestTemplate template = new RestTemplate();
        template.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
        ResponseEntity<Subscription> resp;
        try {
            //communicate with endpoint
            resp = restTemplate.exchange(
                    builder.build().encode().toUri(),
                    HttpMethod.POST,
                    entity,
                    new ParameterizedTypeReference<Subscription>() {
                    });
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }

        return resp.getBody();
    }

    @Override
    public ResponseEntity<Object> unsubscribe(String subscriptionId) throws BrokerException {
        final String service = "/subscriptions/" + subscriptionId;

        //build the uri params
        UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(apiPath + service);

        try {
            //communicate with endpoint
            restTemplate.exchange(
                    builder.build().encode().toUri(),
                    HttpMethod.DELETE,
                    null,
                    new ParameterizedTypeReference<Void>() {
                    });
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }
        return new ResponseEntity<>("OK", HttpStatus.OK);
    }

    @Override
    public Subscription getSubscription(String subscriptionId) throws BrokerException {
        final String service = "/subscriptions/" + subscriptionId;

        //build the uri params
        UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(apiPath + service);

        ResponseEntity<Subscription> resp;
        try {
            //communicate with endpoint
            resp = restTemplate.exchange(
                    builder.build().encode().toUri(),
                    HttpMethod.GET,
                    null,
                    new ParameterizedTypeReference<Subscription>() {
                    });
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }
        return resp.getBody();
    }

    @Override
    public Map<String, Term> getDnetTopics() throws BrokerException {
        return topics;
    }

    @Override
    public EventsPage getNotificationsBySubscriptionId(String subscriptionId,
                                                       String page,
                                                       String size) throws BrokerException {

        UriComponents uriComponents = UriComponentsBuilder
                .fromHttpUrl(openairePath + "/notifications/")
                .path("/{id}/{page}/{size}/")
                .build().expand(subscriptionId, page, size).encode();

        ResponseEntity<EventsPage> resp;
        try {
            resp = restTemplate.exchange(
                    uriComponents.toUri(),
                    HttpMethod.GET,
                    null,
                    new ParameterizedTypeReference<EventsPage>() {
                    });
        } catch (RestClientException e) {
            logger.error(e.getMessage());
            throw new BrokerException(e);
        }
        return resp.getBody();
    }

    //@Override
    public Map<String, List<Subscription>> getSubscriptionsOfUser(String userEmail)
            throws BrokerException {

        Map<String, List<SimpleSubscriptionDesc>> simpleSubs = getSimpleSubscriptionsOfUser(userEmail);
        Map<String, List<Subscription>> subs = new HashMap<>();
        List<Subscription> subscriptions = null;

        for (String s : simpleSubs.keySet()) {
            List<SimpleSubscriptionDesc> simpleSubscriptionDescs = simpleSubs.get(s);
            for (SimpleSubscriptionDesc simpleSubscriptionDesc : simpleSubscriptionDescs) {
                subscriptions = new ArrayList<>();
                subscriptions.add(getSubscription(simpleSubscriptionDesc.getId()));
            }
            subs.put(s, subscriptions);
        }
        return subs;
    }


}