package eu.dnetlib.dhp.provision.update;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import org.apache.commons.lang3.StringUtils;

import com.jayway.jsonpath.JsonPath;

import eu.dnetlib.dhp.provision.scholix.*;
import eu.dnetlib.dhp.utils.DHPUtils;
import eu.dnetlib.scholexplorer.relation.RelInfo;
import eu.dnetlib.scholexplorer.relation.RelationMapper;

public class Datacite2Scholix {

	private String rootPath = "$.attributes";
	final RelationMapper relationMapper;

	public Datacite2Scholix(RelationMapper relationMapper) {
		this.relationMapper = relationMapper;
	}

	public List<Scholix> generateScholixFromJson(final String dJson) {
		List<Map<String, String>> relIds = getRelatedIendtifiers(dJson);
		relIds = relIds != null
			? relIds
				.stream()
				.filter(
					m -> m.containsKey("relatedIdentifierType")
						&& m.containsKey("relationType")
						&& m.containsKey("relatedIdentifier"))
				.collect(Collectors.toList())
			: null;
		if (relIds == null || relIds.size() == 0)
			return null;

		final String updated = JsonPath.read(dJson, rootPath + ".updated");
		ScholixResource resource = generateDataciteScholixResource(dJson);

		return relIds
			.stream()
			.flatMap(
				s -> {
					try {
						final List<Scholix> result = generateScholix(
							resource,
							"" + s.get("relatedIdentifier"),
							s.get("relatedIdentifierType"),
							s.get("relationType"),
							updated);
						return result.stream();
					} catch (Throwable e) {
						return new ArrayList<Scholix>().stream();
					}
				})
			.collect(Collectors.toList());
	}

	public String getRootPath() {
		return rootPath;
	}

	public void setRootPath(String rootPath) {
		this.rootPath = rootPath;
	}

	private List<Scholix> generateScholix(
		ScholixResource source,
		final String pid,
		final String pidtype,
		final String relType,
		final String updated) {

		if ("doi".equalsIgnoreCase(pidtype)) {
			ScholixResource target = new ScholixResource();
			target.setIdentifier(Collections.singletonList(new ScholixIdentifier(pid, pidtype)));
			final RelInfo relInfo = relationMapper.get(relType.toLowerCase());
			final ScholixRelationship rel = new ScholixRelationship(relInfo.getOriginal(), "datacite",
				relInfo.getInverse());
			final ScholixEntityId provider = source.getCollectedFrom().get(0).getProvider();
			final Scholix s = new Scholix();
			s.setSource(source);
			s.setTarget(target);
			s.setLinkprovider(Collections.singletonList(provider));
			s.setPublisher(source.getPublisher());
			s.setRelationship(rel);
			s.setPublicationDate(updated);
			return Collections.singletonList(s);
		} else {
			final List<Scholix> result = new ArrayList<>();
			ScholixResource target = new ScholixResource();
			target.setIdentifier(Collections.singletonList(new ScholixIdentifier(pid, pidtype)));
			target.setDnetIdentifier(generateId(pid, pidtype, "unknown"));
			target.setObjectType("unknown");
			target.setCollectedFrom(generateDataciteCollectedFrom("incomplete"));
			final RelInfo relInfo = relationMapper.get(relType.toLowerCase());
			final ScholixRelationship rel = new ScholixRelationship(relInfo.getOriginal(), "datacite",
				relInfo.getInverse());
			final ScholixEntityId provider = source.getCollectedFrom().get(0).getProvider();
			final Scholix s = new Scholix();
			s.setSource(source);
			s.setTarget(target);
			s.setLinkprovider(Collections.singletonList(provider));
			s.setPublisher(source.getPublisher());
			s.setRelationship(rel);
			s.setPublicationDate(updated);
			s.generateIdentifier();
			result.add(s);
			final Scholix s2 = new Scholix();
			s2.setSource(target);
			s2.setTarget(source);
			s2.setLinkprovider(Collections.singletonList(provider));
			s2.setPublisher(source.getPublisher());
			s2
				.setRelationship(
					new ScholixRelationship(relInfo.getInverse(), "datacite", relInfo.getOriginal()));
			s2.setPublicationDate(updated);
			s2.generateIdentifier();
			result.add(s2);
			return result;
		}
	}

	public ScholixResource generateDataciteScholixResource(String dJson) {
		ScholixResource resource = new ScholixResource();
		String DOI_PATH = rootPath + ".doi";
		final String doi = JsonPath.read(dJson, DOI_PATH);
		resource.setIdentifier(Collections.singletonList(new ScholixIdentifier(doi, "doi")));
		resource.setObjectType(getType(dJson));
		resource.setDnetIdentifier(generateId(doi, "doi", resource.getObjectType()));
		resource.setCollectedFrom(generateDataciteCollectedFrom("complete"));
		final String publisher = JsonPath.read(dJson, rootPath + ".publisher");
		if (StringUtils.isNotBlank(publisher))
			resource.setPublisher(Collections.singletonList(new ScholixEntityId(publisher, null)));
		final String date = getDate(dJson);
		if (StringUtils.isNotBlank(date))
			resource.setPublicationDate(date);
		final String title = getTitle(dJson);
		if (StringUtils.isNotBlank(title))
			resource.setTitle(title);
		resource.setCreator(getCreators(dJson));
		return resource;
	}

	private List<ScholixEntityId> getCreators(final String json) {
		final List<String> creatorName = JsonPath.read(json, rootPath + ".creators[*].name");
		if (creatorName != null && creatorName.size() > 0) {
			return creatorName
				.stream()
				.map(s -> new ScholixEntityId(s, null))
				.collect(Collectors.toList());
		}
		return null;
	}

	private String getTitle(final String json) {
		final List<String> titles = JsonPath.read(json, rootPath + ".titles[*].title");
		return titles != null && titles.size() > 0 ? titles.get(0) : null;
	}

	private String getDate(final String json) {
		final List<Map<String, String>> dates = JsonPath.read(json, rootPath + ".dates");
		if (dates != null && dates.size() > 0) {

			List<Map<String, String>> issued = dates
				.stream()
				.filter(s -> "issued".equalsIgnoreCase(s.get("dateType")))
				.collect(Collectors.toList());
			if (issued.size() > 0)
				return issued.get(0).get("date");
		}
		return null;
	}

	private List<ScholixCollectedFrom> generateDataciteCollectedFrom(final String completionStatus) {
		final ScholixEntityId scholixEntityId = new ScholixEntityId(
			"Datasets in Datacite",
			Collections
				.singletonList(
					new ScholixIdentifier("dli_________::datacite", "dnet_identifier")));
		return Collections
			.singletonList(
				new ScholixCollectedFrom(scholixEntityId, "collected", completionStatus));
	}

	private String getType(final String json) {
		try {
			final String bibtext = JsonPath.read(json, rootPath + ".types.bibtex");
			if ("article".equalsIgnoreCase(bibtext)) {
				return "publication";
			}
			return "dataset";
		} catch (Throwable e) {
			return "dataset";
		}
	}

	private List<Map<String, String>> getRelatedIendtifiers(final String json) {
		String REL_IDENTIFIER_PATH = rootPath + ".relatedIdentifiers[*]";
		List<Map<String, String>> res = JsonPath.read(json, REL_IDENTIFIER_PATH);
		return res;
	}

	public static String generateId(final String pid, final String pidType, final String entityType) {
		String type;
		switch (entityType) {
			case "publication":
				type = "50|";
				break;
			case "dataset":
				type = "60|";
				break;
			case "unknown":
				type = "70|";
				break;
			default:
				throw new IllegalArgumentException("unexpected value " + entityType);
		}
		return type
			+ DHPUtils
				.md5(
					String.format("%s::%s", pid.toLowerCase().trim(), pidType.toLowerCase().trim()));
	}
}