D-Net

package eu.dnetlib.wds.resolver;

import com.google.gson.JsonArray;

import com.google.gson.JsonObject;

import eu.dnetlib.miscutils.collections.Pair;

import eu.dnetlib.pid.resolver.AbstractPIDResolver;

import eu.dnetlib.pid.resolver.model.ObjectType;

import eu.dnetlib.pid.resolver.model.PID;

import eu.dnetlib.pid.resolver.model.SubjectType;

import org.apache.commons.lang3.StringUtils;

import org.springframework.http.ResponseEntity;

import org.springframework.web.client.RestTemplate;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

public class DLIResolver extends AbstractPIDResolver {

    private static String INDEX_URL = "http://ip-90-147-167-27.ct1.garrservices.it:9200/dli_shadow/object/_search?pretty";

    @Override

    protected boolean canResolvePid(String pidType) {

        return StringUtils.isNotEmpty(pidType);

    }

    public WDSResolvedObject resolve(final String pid, final String pidType) {

        final RestTemplate restTemplate = new RestTemplate();

        final ResponseEntity<JsonObject> jsonObjectResponseEntity = restTemplate.postForEntity(INDEX_URL, createJson(pid, pidType), JsonObject.class);

        final JsonObject hits = jsonObjectResponseEntity.getBody().getAsJsonObject("hits");

        final int total = hits.get("total").getAsInt();

        if (total > 0) {

            final JsonArray results = hits.getAsJsonArray("hits");

            return parseDLIResponse(results.get(0).getAsJsonObject());

        }

        return null;

    }

    private WDSResolvedObject parseDLIResponse(final JsonObject input) {

        final WDSResolvedObject result = new WDSResolvedObject();

        final JsonObject source = input.getAsJsonObject("_source");

        if (source == null || source.isJsonNull())

            return null;

        final JsonArray localIdentifiers = source.getAsJsonArray("localIdentifier");

        if (localIdentifiers == null || localIdentifiers.isJsonNull())

            return null;

        localIdentifiers.forEach(it -> result.addPid(new PID(it.getAsJsonObject().get("id").getAsString(), it.getAsJsonObject().get("type").getAsString())));

        final String typology = source.get("typology").getAsString();

        if (typology.equals("publication") || typology.equals("dataset")) {

            result.setType(ObjectType.valueOf(typology));

        } else {

            return null;

        }

        result.setTitles(getArrayFromJson("title", source));

        result.setAuthors(getArrayFromJson("author", source));

        final List<String> date = getArrayFromJson("date", source);

        Map<String, String> d = new HashMap<>();

        if (date != null && date.size() > 0) {

            d.put("unknown", date.get(0));

        }

        result.setDates(d);

        final String description = source.get("abstract") != null ? source.get("abstract").getAsString() : null;

        if (description != null && StringUtils.isNotEmpty(description))

            result.addDescription(new Pair<>("unknown", description));

        final JsonArray subjectArray = source.getAsJsonArray("subject");

        if (subjectArray != null && !subjectArray.isJsonNull()) {

            subjectArray.forEach(it -> result.addSubject(new SubjectType(it.getAsJsonObject().get("scheme").getAsString(), it.getAsJsonObject().get("value").getAsString())));

        }

        final JsonArray publisherArray = source.getAsJsonArray("publisher");

        if (publisherArray != null && !publisherArray.isJsonNull()) {

            publisherArray.forEach(it -> result.setPublisher(it.getAsString()));

        }

        return result;

    }

    private List<String> getArrayFromJson(final String key, final JsonObject source) {

        final List<String> result = new ArrayList<>();

        final JsonArray inputArray = source.getAsJsonArray(key);

        if (inputArray != null && !inputArray.isJsonNull()) {

            inputArray.forEach(it -> {

                if (StringUtils.isNotEmpty(it.getAsString())) result.add(it.getAsString());

            });

        }

        return result;

    }

    private JsonObject createJson(final String pid, final String pidType) {

        final JsonObject root = new JsonObject();

        final JsonObject nested = new JsonObject();

        final JsonObject n1 = new JsonObject();

        final JsonObject nestedQuery = new JsonObject();

        final JsonObject boolQuery = new JsonObject();

        final JsonArray mustArray = new JsonArray();

        final JsonObject firstMatch = new JsonObject();

        final JsonObject firstMatchId = new JsonObject();

        final JsonObject secondMatch = new JsonObject();

        final JsonObject secondMatchType = new JsonObject();

        root.add("query", n1);

        n1.add("nested", nested);

        nested.addProperty("path", "localIdentifier");

        nested.add("query", nestedQuery);

        nestedQuery.add("bool", boolQuery);

        boolQuery.add("must", mustArray);

        mustArray.add(firstMatch);

        mustArray.add(secondMatch);

        firstMatch.add("match", firstMatchId);

        secondMatch.add("match", secondMatchType);

        firstMatchId.addProperty("localIdentifier.id", pid.toLowerCase().trim());

        secondMatchType.addProperty("localIdentifier.type", pidType.toLowerCase().trim());

        return root;

    }

}