/*
 * 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.gcp;

import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.InputStreamContent;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.services.storage.Storage;
import com.google.api.services.storage.Storage.Objects.Insert;
import com.google.api.services.storage.StorageScopes;
import com.google.api.services.storage.model.ObjectAccessControl;
import com.google.api.services.storage.model.StorageObject;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import org.apache.airavata.mft.core.ConnectorContext;
import org.apache.airavata.mft.core.api.Connector;
import org.apache.airavata.mft.credential.stubs.gcs.GCSSecret;
import org.apache.airavata.mft.credential.stubs.gcs.GCSSecretGetRequest;
import org.apache.airavata.mft.resource.client.ResourceServiceClient;
import org.apache.airavata.mft.resource.client.ResourceServiceClientBuilder;
import org.apache.airavata.mft.resource.stubs.gcs.resource.GCSResource;
import org.apache.airavata.mft.resource.stubs.gcs.resource.GCSResourceGetRequest;
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.ByteArrayInputStream;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Collection;


public class GCSSender implements Connector {

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

    private GCSResource gcsResource;
    private Storage storage;
    private JsonObject jsonObject;

    @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.gcsResource = resourceClient.gcs().getGCSResource(GCSResourceGetRequest.newBuilder().setResourceId(resourceId).build());

        SecretServiceClient secretClient = SecretServiceClientBuilder.buildClient(secretServiceHost, secretServicePort);
        GCSSecret gcsSecret = secretClient.gcs().getGCSSecret(GCSSecretGetRequest.newBuilder().setSecretId(credentialToken).build());

        HttpTransport transport = GoogleNetHttpTransport.newTrustedTransport();
        JsonFactory jsonFactory = new JacksonFactory();
        String jsonString = gcsSecret.getCredentialsJson();
        jsonObject = new JsonParser().parse(jsonString).getAsJsonObject();
        GoogleCredential credential = GoogleCredential.fromStream(new ByteArrayInputStream(jsonString.getBytes(StandardCharsets.UTF_8)));
        if (credential.createScopedRequired()) {
            Collection<String> scopes = StorageScopes.all();
            credential = credential.createScoped(scopes);
        }

        storage = new Storage.Builder(transport, jsonFactory, credential).build();
    }

    @Override
    public void destroy() {

    }

    @Override
    public void startStream(ConnectorContext context) throws Exception {
        logger.info("Starting GCS Sender stream for transfer {}", context.getTransferId());
        logger.info("Content length for transfer {} {}", context.getTransferId(), context.getMetadata().getResourceSize());

        InputStreamContent contentStream = new InputStreamContent(
                null, context.getStreamBuffer().getInputStream());
        String entityUser = jsonObject.get("client_email").getAsString();
        StorageObject objectMetadata = new StorageObject()
                // Set the destination object name
                .setName(this.gcsResource.getResourcePath())
                // Set the access control list to publicly read-only
                .setAcl(Arrays.asList(new ObjectAccessControl().setEntity("user-" + entityUser).setRole("OWNER")));

        Insert insertRequest = storage.objects().insert(
                this.gcsResource.getBucketName(), objectMetadata, contentStream);

        insertRequest.execute();

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