/*-
 * ============LICENSE_START=======================================================
 * ONAP : APPC
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Copyright (C) 2017 Amdocs
 * =============================================================================
 * Licensed 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.
 * 
 * ECOMP is a trademark and service mark of AT&T Intellectual Property.
 * ============LICENSE_END=========================================================
 */

package org.onap.appc.adapter.iaas.provider.operation.api;

import org.onap.appc.adapter.iaas.provider.operation.impl.*;
import org.onap.appc.adapter.iaas.provider.operation.common.enums.Operation;
import org.onap.appc.exceptions.APPCException;
import java.util.HashMap;
import java.util.Map;

/**
 * Singleton factory of provider operations objects with cache
 * 
 * @since September 26, 2016
 */
public class ProviderOperationFactory {

    /**
     * holds instance of the class
     */
    private static ProviderOperationFactory instance;

    /**
     * holds concrete operations objects
     */
    private Map<Operation, IProviderOperation> operations;

    /**
     * private constructor
     */
    private ProviderOperationFactory() {
        this.operations = new HashMap<>();
    }

    /**
     * @return instance of the factory
     */
    public static ProviderOperationFactory getInstance() {
        if (instance == null) {
            instance = new ProviderOperationFactory();
        }
        return instance;
    }

    /**
     * @param op
     * @return concrete operation impl
     */
    public IProviderOperation getOperationObject(Operation op) throws APPCException {

        IProviderOperation opObject = operations.get(op);
        if (opObject == null) {
            switch (op) {
                case EVACUATE_SERVICE:
                    opObject = new EvacuateServer();
                    break;
                case MIGRATE_SERVICE:
                    opObject = new MigrateServer();
                    break;
                case REBUILD_SERVICE:
                    opObject = new RebuildServer();
                    break;
                case RESTART_SERVICE:
                    opObject = new RestartServer();
                    break;
                case VMSTATUSCHECK_SERVICE:
                    opObject = new VmStatuschecker();
                    break;
                case SNAPSHOT_SERVICE:
                    opObject = new CreateSnapshot();
                    break;
                case TERMINATE_STACK:
                    opObject = new TerminateStack();
                    break;
                case SNAPSHOT_STACK:
                    opObject = new SnapshotStack();
                    break;
                case RESTORE_STACK:
                    opObject = new RestoreStack();
                    break;
                case START_SERVICE:
                    opObject = new StartServer();
                    break;
                case STOP_SERVICE:
                    opObject = new StopServer();
                    break;
                case TERMINATE_SERVICE:
                    opObject = new TerminateServer();
                    break;
                case LOOKUP_SERVICE:
                    opObject = new LookupServer();
                    break;
                default:
                    throw new APPCException("Unsupported provider operation.");
            }
            operations.put(op, opObject);
        }
        return opObject;
    }
}