/*
 * 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.apache.airavata.mft.transport.s3;

import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectInputStream;
import org.apache.airavata.mft.core.ConnectorContext;
import org.apache.airavata.mft.core.ResourceTypes;
import org.apache.airavata.mft.core.api.Connector;
import org.apache.airavata.mft.credential.stubs.s3.S3Secret;
import org.apache.airavata.mft.credential.stubs.s3.S3SecretGetRequest;
import org.apache.airavata.mft.resource.client.ResourceServiceClient;
import org.apache.airavata.mft.resource.client.ResourceServiceClientBuilder;
import org.apache.airavata.mft.resource.stubs.s3.resource.S3Resource;
import org.apache.airavata.mft.resource.stubs.s3.resource.S3ResourceGetRequest;
import org.apache.airavata.mft.secret.client.SecretServiceClient;
import org.apache.airavata.mft.secret.client.SecretServiceClientBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;

public class S3Receiver implements Connector {

    private static final Logger logger = LoggerFactory.getLogger(S3Receiver.class);

    private S3Resource s3Resource;
    private AmazonS3 s3Client;

    @Override
    public void init(String resourceId, String credentialToken, String resourceServiceHost, int resourceServicePort,
                                                    String secretServiceHost, int secretServicePort) throws Exception {

        ResourceServiceClient resourceClient = ResourceServiceClientBuilder.buildClient(resourceServiceHost, resourceServicePort);
        this.s3Resource = resourceClient.s3().getS3Resource(S3ResourceGetRequest.newBuilder().setResourceId(resourceId).build());

        SecretServiceClient secretClient = SecretServiceClientBuilder.buildClient(secretServiceHost, secretServicePort);
        S3Secret s3Secret = secretClient.s3().getS3Secret(S3SecretGetRequest.newBuilder().setSecretId(credentialToken).build());
        BasicAWSCredentials awsCreds = new BasicAWSCredentials(s3Secret.getAccessKey(), s3Secret.getSecretKey());

        s3Client = AmazonS3ClientBuilder.standard()
                .withCredentials(new AWSStaticCredentialsProvider(awsCreds))
                .withRegion(s3Resource.getS3Storage().getRegion())
                .build();
    }

    @Override
    public void destroy() {

    }

    @Override
    public void startStream(ConnectorContext context) throws Exception {

        if (ResourceTypes.FILE.equals(this.s3Resource.getResourceCase().name())) {
            logger.info("Starting S3 Receiver stream for transfer {}", context.getTransferId());

            S3Object s3object = s3Client.getObject(s3Resource.getS3Storage().getBucketName(), s3Resource.getFile().getResourcePath());
            S3ObjectInputStream inputStream = s3object.getObjectContent();

            OutputStream os = context.getStreamBuffer().getOutputStream();
            int read;
            long bytes = 0;
            while ((read = inputStream.read()) != -1) {
                bytes++;
                os.write(read);
            }
            os.flush();
            os.close();

            logger.info("Completed S3 Receiver stream for transfer {}", context.getTransferId());

        } else {
            logger.error("Resource {} should be a FILE type. Found a {}",
                    this.s3Resource.getResourceId(), this.s3Resource.getResourceCase().name());
            throw new Exception("Resource " + this.s3Resource.getResourceId() + " should be a FILE type. Found a " +
                    this.s3Resource.getResourceCase().name());
        }
    }
}