/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.eclipse.aether.connector.basic;

import java.nio.ByteBuffer;
import java.util.Collections;
import java.util.Map;

import org.eclipse.aether.spi.connector.Transfer;
import org.eclipse.aether.spi.connector.transport.TransportListener;
import org.eclipse.aether.transfer.TransferCancelledException;
import org.eclipse.aether.transfer.TransferEvent;
import org.eclipse.aether.transfer.TransferEvent.EventType;
import org.eclipse.aether.transfer.TransferListener;

class TransferTransportListener<T extends Transfer> extends TransportListener {

    private final T transfer;

    private final TransferListener listener;

    private final TransferEvent.Builder eventBuilder;

    private ChecksumCalculator checksumCalculator;

    protected TransferTransportListener(T transfer, TransferEvent.Builder eventBuilder) {
        this.transfer = transfer;
        this.listener = transfer.getListener();
        this.eventBuilder = eventBuilder;
    }

    protected T getTransfer() {
        return transfer;
    }

    public void transferInitiated() throws TransferCancelledException {
        if (listener != null) {
            eventBuilder.resetType(EventType.INITIATED);
            listener.transferInitiated(eventBuilder.build());
        }
    }

    @Override
    public void transportStarted(long dataOffset, long dataLength) throws TransferCancelledException {
        if (checksumCalculator != null) {
            checksumCalculator.init(dataOffset);
        }
        if (listener != null) {
            eventBuilder.resetType(EventType.STARTED).setTransferredBytes(dataOffset);
            TransferEvent event = eventBuilder.build();
            event.getResource().setContentLength(dataLength).setResumeOffset(dataOffset);
            listener.transferStarted(event);
        }
    }

    @Override
    public void transportProgressed(ByteBuffer data) throws TransferCancelledException {
        if (checksumCalculator != null) {
            checksumCalculator.update(data);
        }
        if (listener != null) {
            eventBuilder
                    .resetType(EventType.PROGRESSED)
                    .addTransferredBytes(data.remaining())
                    .setDataBuffer(data);
            listener.transferProgressed(eventBuilder.build());
        }
    }

    public void transferCorrupted(Exception exception) throws TransferCancelledException {
        if (listener != null) {
            eventBuilder.resetType(EventType.CORRUPTED).setException(exception);
            listener.transferCorrupted(eventBuilder.build());
        }
    }

    public void transferFailed(Exception exception, int classification) {
        if (listener != null) {
            eventBuilder.resetType(EventType.FAILED).setException(exception);
            listener.transferFailed(eventBuilder.build());
        }
    }

    public void transferSucceeded() {
        if (listener != null) {
            eventBuilder.resetType(EventType.SUCCEEDED);
            listener.transferSucceeded(eventBuilder.build());
        }
    }

    public Map<String, Object> getChecksums() {
        if (checksumCalculator == null) {
            return Collections.emptyMap();
        }
        return checksumCalculator.get();
    }

    public void setChecksumCalculator(ChecksumCalculator checksumCalculator) {
        this.checksumCalculator = checksumCalculator;
    }
}
