core/net/src/main/java/org/onosproject/net/intent/impl/WithdrawCoordinating.java

/*
 * Copyright 2015 Open Networking Laboratory
 *
 * 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.
 */
package org.onosproject.net.intent.impl;

import org.onosproject.net.flow.FlowRuleOperations;
import org.onosproject.net.intent.IntentData;
import org.onosproject.net.intent.IntentState;

import java.util.Optional;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Represents a phase to create a {@link FlowRuleOperations} instance
 * with using registered intent installers.
 */
class WithdrawCoordinating implements IntentUpdate {

    // TODO: define an interface and use it, instead of IntentManager
    private final IntentManager intentManager;
    private final IntentData pending;
    private final IntentData current;

    WithdrawCoordinating(IntentManager intentManager, IntentData pending, IntentData current) {
        this.intentManager = checkNotNull(intentManager);
        this.pending = checkNotNull(pending);
        this.current = current;
    }

    @Override
    public Optional<IntentUpdate> execute() {
        if (current == null) { // there's nothing in the store with this key
            return Optional.of(new Withdrawn(pending, IntentState.WITHDRAWN));
        }
        FlowRuleOperations flowRules = intentManager.uninstallCoordinate(current, pending);
        pending.setInstallables(current.installables());
        return Optional.of(new Withdrawing(intentManager, pending, flowRules));
    }
}