/*
 *
 *  Copyright 2016 Netflix, Inc.
 *
 *     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.netflix.genie.web.configs.aws;

import com.amazonaws.ClientConfiguration;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.auth.ClasspathPropertiesFileCredentialsProvider;
import com.amazonaws.auth.STSAssumeRoleSessionCredentialsProvider;
import com.amazonaws.retry.PredefinedRetryPolicies;
import com.amazonaws.services.s3.AmazonS3Client;
import com.netflix.genie.common.exceptions.GenieException;
import com.netflix.genie.core.services.FileTransfer;
import com.netflix.genie.core.services.impl.S3FileTransferImpl;
import com.netflix.spectator.api.Registry;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;
import org.springframework.core.annotation.Order;

/**
 * Beans and configuration specifically for S3 connection on AWS.
 *
 * @author amsharma
 * @since 3.0.0
 */
@Profile("s3")
@Configuration
@Slf4j
public class AwsS3Config {

    /**
     * Create the credentials needed for the application to be able to connect to Aws. Only triggered if the
     * property cloud.aws.credentials.provided is set to true in the config.
     *
     * @param credentialsFilePath The path of the file containing aws credentials
     * @return AWS credentials object to use to connect to AWS
     */
    @Bean
    @ConditionalOnProperty(value = "genie.aws.credentials.file")
    public ClasspathPropertiesFileCredentialsProvider awsCredentialsFromFile(
        @Value("${genie.aws.credentials.file}")
        final String credentialsFilePath
    ) {
        log.info("Creating file credentials provider bean");
        return new ClasspathPropertiesFileCredentialsProvider(credentialsFilePath);
    }

    /**
     * Assume role credentials provider which will be used to fetch session credentials.
     *
     * @param roleArn Arn of the IAM role
     * @return Credentials provider to ask the credentials from
     */
    @Bean
    @ConditionalOnProperty(value = "genie.aws.credentials.role")
    public STSAssumeRoleSessionCredentialsProvider awsCredentialsProvider(
        @Value("${genie.aws.credentials.role}")
        final String roleArn
    ) {
        log.info("Creating STS Assume Role Session Credentials provider bean");
        return new STSAssumeRoleSessionCredentialsProvider(roleArn, "Genie");
    }

    /**
     * A bean providing a client to work with S3.
     *
     * @param noOfS3Retries          No. of S3 request retries
     * @param awsCredentialsProvider A credentials provider used to instantiate the client.
     * @return An amazon s3 client object
     */
    @Bean
    @ConditionalOnBean(AWSCredentialsProvider.class)
    public AmazonS3Client genieS3Client(
        @Value("${genie.retry.s3.noOfRetries:5}") final int noOfS3Retries,
        final AWSCredentialsProvider awsCredentialsProvider
    ) {
        final ClientConfiguration clientConfiguration = new ClientConfiguration()
            .withRetryPolicy(PredefinedRetryPolicies.getDefaultRetryPolicyWithCustomMaxRetries(noOfS3Retries));
        return new AmazonS3Client(awsCredentialsProvider, clientConfiguration);
    }

    /**
     * Returns a bean which has an s3 implementation of the File Transfer interface.
     *
     * @param s3Client S3 client to initialize the service
     * @param registry The metrics registry to use
     * @return An s3 implementation of the FileTransfer interface
     * @throws GenieException if there is any problem
     */
    @Bean(name = {"file.system.s3", "file.system.s3n", "file.system.s3a"})
    @Order(value = 1)
    @ConditionalOnBean(AmazonS3Client.class)
    public FileTransfer s3FileTransferImpl(
        final AmazonS3Client s3Client,
        final Registry registry
    ) throws GenieException {
        return new S3FileTransferImpl(s3Client, registry);
    }
}