package org.simantics.district.network.techtype.requests;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.procedure.adapter.TransientCacheListener;
import org.simantics.db.common.request.BinaryRead;
import org.simantics.db.exception.DatabaseException;
import org.simantics.district.network.ontology.DistrictNetworkResource;
import org.simantics.district.network.techtype.TechTypeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Get a map of tech type table records, indexed by the key column.
 *
 * The query result value is list of records in the form of a map from property name
 * to string value.
 * 
 * The second constructor argument allows selection of enabled records only.
 *
 * @author Reino Ruusu
 */
public class TechTypeTableData extends BinaryRead<Resource, Boolean, Map<String, Map<String, String>>> {

	final static Logger LOGGER = LoggerFactory.getLogger(TechTypeTableData.class);
	
	public TechTypeTableData(Resource table) {
		super(table, Boolean.FALSE);
	}
	
	public TechTypeTableData(Resource table, boolean enabledOnly) {
		super(table, enabledOnly);
	}

	@Override
	public Map<String, Map<String, String>> perform(ReadGraph graph) throws DatabaseException {
		Resource table = this.parameter;
		boolean enabledOnly = this.parameter2;

		String keyName = getKeyName(graph, table);
		
		List<Map<String, String>> records = graph.syncRequest(new TechTypeTableRecords(table), TransientCacheListener.instance());
		if (records == null || records.size() < 2)
			return Collections.emptyMap();
		
		Stream<Map<String, String>> enabled;
		if (enabledOnly) {
			int[] enabledKeys = graph.getRelatedValue2(table, DistrictNetworkResource.getInstance(graph).TechType_TechTypeTable_HasEnabledItems, Bindings.INT_ARRAY);
			enabled = Arrays.stream(enabledKeys)
					.filter(i -> i >= 0 && i < records.size())
					.mapToObj(i -> records.get(i));
		} else {
			enabled = records.stream();
		}
		
		return enabled
				.filter(r -> r.containsKey(keyName))
				.collect(Collectors.toMap(r -> r.get(keyName), r -> r, (p, q) -> p));
	}

	private String getKeyName(ReadGraph graph, Resource table) throws DatabaseException {
		String keyName = TechTypeUtils.getKeyPropertyName(graph, table);
		if (keyName.startsWith("_"))
			keyName = keyName.substring(1);
		return keyName;
	}
}