/*
 * Copyright (C) 2010 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 com.android.ddmlib;

import static java.nio.charset.StandardCharsets.UTF_8;

import com.android.annotations.NonNull;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

/** A {@link IShellOutputReceiver} which collects the whole shell output into one {@link String}. */
public class CollectingOutputReceiver implements IShellOutputReceiver {
    @NonNull private final CountDownLatch mCompletionLatch;
    @NonNull private final StringBuffer mOutputBuffer = new StringBuffer();
    @NonNull private final AtomicBoolean mIsCanceled = new AtomicBoolean(false);

    public CollectingOutputReceiver() {
        mCompletionLatch = new CountDownLatch(1);
    }

    public CollectingOutputReceiver(@NonNull CountDownLatch commandCompleteLatch) {
        mCompletionLatch = commandCompleteLatch;
    }

    @NonNull
    public String getOutput() {
        return mOutputBuffer.toString();
    }

    @Override
    public boolean isCancelled() {
        return mIsCanceled.get();
    }

    /** Cancels the output collection. */
    public void cancel() {
        mIsCanceled.set(true);
    }

    @Override
    public void addOutput(byte[] data, int offset, int length) {
        if (!isCancelled()) {
            String s = new String(data, offset, length, UTF_8);
            mOutputBuffer.append(s);
        }
    }

    @Override
    public void flush() {
        mCompletionLatch.countDown();
    }

    public boolean isComplete() {
        return mCompletionLatch.getCount() == 0;
    }

    public boolean awaitCompletion(long timeout, TimeUnit unit) throws InterruptedException {
        return mCompletionLatch.await(timeout, unit);
    }
}