/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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 android.os;

import android.annotation.NonNull;
import android.annotation.Nullable;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

Extends ResultReceiver to allow the server end of the ResultReceiver to synchronously wait
on the response from the client. This enables an RPC like system but with the ability to
timeout and discard late results.
NOTE: Can only be used for one response. Subsequent responses on the same instance are ignored.
{@hide}
/**
 * Extends ResultReceiver to allow the server end of the ResultReceiver to synchronously wait
 * on the response from the client. This enables an RPC like system but with the ability to
 * timeout and discard late results.
 *
 * NOTE: Can only be used for one response. Subsequent responses on the same instance are ignored.
 * {@hide}
 */
public class SynchronousResultReceiver extends ResultReceiver {
    public static class Result {
        public int resultCode;
        @Nullable public Bundle bundle;

        public Result(int resultCode, @Nullable Bundle bundle) {
            this.resultCode = resultCode;
            this.bundle = bundle;
        }
    }

    private final CompletableFuture<Result> mFuture = new CompletableFuture<>();
    private final String mName;

    public SynchronousResultReceiver() {
        super((Handler) null);
        mName = null;
    }

    
Params:
name – Name for logging purposes/**
     * @param name Name for logging purposes
     */
    public SynchronousResultReceiver(String name) {
        super((Handler) null);
        mName = name;
    }

    @Override
    final protected void onReceiveResult(int resultCode, Bundle resultData) {
        super.onReceiveResult(resultCode, resultData);
        mFuture.complete(new Result(resultCode, resultData));
    }

    public String getName() {
        return mName;
    }

    
Blocks waiting for the result from the remote client.
Throws:
TimeoutException – if the timeout in milliseconds expired.
Returns:
the Result/**
     * Blocks waiting for the result from the remote client.
     *
     * @return the Result
     * @throws TimeoutException if the timeout in milliseconds expired.
     */
    public @NonNull Result awaitResult(long timeoutMillis) throws TimeoutException {
        final long deadline = System.currentTimeMillis() + timeoutMillis;
        while (timeoutMillis >= 0) {
            try {
                return mFuture.get(timeoutMillis, TimeUnit.MILLISECONDS);
            } catch (ExecutionException e) {
                // This will NEVER happen.
                throw new AssertionError("Error receiving response", e);
            } catch (InterruptedException e) {
                // The thread was interrupted, try and get the value again, this time
                // with the remaining time until the deadline.
                timeoutMillis -= deadline - System.currentTimeMillis();
            }
        }
        throw new TimeoutException();
    }

}