/*
 * Copyright 2016 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.store.primitives;

import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Consumer;

import org.onosproject.cluster.Leadership;
import org.onosproject.cluster.NodeId;
import org.onosproject.event.Change;
import org.onosproject.store.service.AsyncLeaderElector;
import org.onosproject.store.service.LeaderElector;
import org.onosproject.store.service.StorageException;
import org.onosproject.store.service.Synchronous;

/**
 * Default implementation for a {@code LeaderElector} backed by a {@link AsyncLeaderElector}.
 */
public class DefaultLeaderElector extends Synchronous<AsyncLeaderElector> implements LeaderElector {

    private final AsyncLeaderElector asyncElector;
    private final long operationTimeoutMillis;

    public DefaultLeaderElector(AsyncLeaderElector asyncElector, long operationTimeoutMillis) {
        super(asyncElector);
        this.asyncElector = asyncElector;
        this.operationTimeoutMillis = operationTimeoutMillis;
    }

    @Override
    public Leadership run(String topic, NodeId nodeId) {
        return complete(asyncElector.run(topic, nodeId));
    }

    @Override
    public void withdraw(String topic) {
        complete(asyncElector.withdraw(topic));
    }

    @Override
    public boolean anoint(String topic, NodeId nodeId) {
        return complete(asyncElector.anoint(topic, nodeId));
    }

    @Override
    public Leadership getLeadership(String topic) {
        return complete(asyncElector.getLeadership(topic));
    }

    @Override
    public Map<String, Leadership> getLeaderships() {
        return complete(asyncElector.getLeaderships());
    }

    @Override
    public void addChangeListener(Consumer<Change<Leadership>> consumer) {
        complete(asyncElector.addChangeListener(consumer));
    }

    @Override
    public void removeChangeListener(Consumer<Change<Leadership>> consumer) {
        complete(asyncElector.removeChangeListener(consumer));
    }

    private <T> T complete(CompletableFuture<T> future) {
        try {
            return future.get(operationTimeoutMillis, TimeUnit.MILLISECONDS);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new StorageException.Interrupted();
        } catch (TimeoutException e) {
            throw new StorageException.Timeout();
        } catch (ExecutionException e) {
            throw new StorageException(e.getCause());
        }
    }
}