/*
// Copyright 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT-0
*/

package cwecc;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;

import org.eclipse.jgit.api.ArchiveCommand;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.archive.ZipFormat;
import org.eclipse.jgit.lib.ObjectId;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;

public class ArchiveRepositoryHandler
        implements RequestHandler<CodeCommitEvent, HandlerResponse> {

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

    private final String ZIP_FORMAT = "zip";
    private final String targetS3Bucket;
    private final AmazonS3 s3Client;

    public ArchiveRepositoryHandler() {
        targetS3Bucket = System.getenv("TARGET_S3_BUCKET");
        s3Client = AmazonS3ClientBuilder.defaultClient();
        ArchiveCommand.registerFormat(ZIP_FORMAT, new ZipFormat());
    }

    @Override
    public HandlerResponse handleRequest(CodeCommitEvent event, Context context) {
        String sourceName = event.getDetail().getRepositoryName();
        String sourceRegion = event.getRegion();
        String commitId = event.getDetail().getCommitId();

        try {
            // clone source repository
            CodeCommitMetadata source = new CodeCommitMetadata(sourceName, sourceRegion);
            String sourceUrl = source.getCloneUrlHttp();
            Git git = new CloneCommandBuilder().buildCloneCommand(sourceUrl).call();

            // create and upload archive for commitId
            File file = Files.createTempFile(null, null).toFile();
            try (OutputStream out = new FileOutputStream(file)) {
                ObjectId objectId = git.getRepository().resolve(commitId);
                git.archive().setTree(objectId)
                             .setFormat(ZIP_FORMAT)
                             .setOutputStream(out)
                             .call();

                String key = sourceName + "." + commitId + "." + ZIP_FORMAT;
                s3Client.putObject(targetS3Bucket, key, file);
            }

            return HandlerResponse.success();
        } catch (IllegalStateException | GitAPIException | IOException e) {
            logger.error(e.getMessage());
            return HandlerResponse.failure(e.getMessage());
        }
    }
}