/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.streampipes.connect.container.master.management;

import com.github.jqudt.Unit;
import com.google.gson.Gson;
import org.apache.streampipes.connect.api.exception.AdapterException;
import org.apache.streampipes.model.connect.unit.UnitDescription;
import org.apache.streampipes.units.UnitProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

public class UnitMasterManagement {

    private static final Logger logger = LoggerFactory.getLogger(UnitMasterManagement.class);
    private Gson gson;

    public UnitMasterManagement() {
        gson = new Gson();
    }

    public String getFittingUnits(UnitDescription unitDescription) throws AdapterException {
        List<UnitDescription> unitDescriptionList = new LinkedList<>();
        Unit unit;

        if(unitDescription.getResource() == null) throw new AdapterException("The resource cannot be null");
        try {
           unit = UnitProvider.INSTANCE.getUnit(unitDescription.getResource());
        } catch (IllegalStateException e) {
            throw new AdapterException("Invalid URI: " + unitDescription.getResource());
        }
        List<Unit> units = UnitProvider.INSTANCE.getUnitsByType(unit.getType());


        for ( Iterator iter = units.iterator(); iter.hasNext(); ) {
            Unit unitTmp = (Unit) iter.next();
            try {
                UnitDescription unitDescriptionTmp = new UnitDescription(unitTmp.getResource().toString(), unitTmp.getLabel());
                unitDescriptionList.add(unitDescriptionTmp);
            } catch (NullPointerException e) {
                logger.error("Unit has no resource and/or Label");
            }
        }

        return gson.toJson(unitDescriptionList);
    }

}
