package org.gcube.data.access.storagehub.storage.backend.impl;

import java.io.InputStream;
import java.util.Map;
import java.util.function.Function;

import org.gcube.common.authorization.library.provider.AuthorizationProvider;
import org.gcube.common.storagehub.model.items.nodes.Content;
import org.gcube.common.storagehub.model.storages.MetaInfo;
import org.gcube.common.storagehub.model.storages.StorageBackend;

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.CopyObjectRequest;
import com.amazonaws.services.s3.model.ObjectMetadata;
import com.amazonaws.services.s3.model.PutObjectResult;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectInputStream;

public class S3Backend implements StorageBackend{

	Map<String, Object> parameters;
	Function<Void, String> keyGenerator; 
	AWSCredentials credentials = new BasicAWSCredentials("user", "password");
	final static Regions clientRegion = Regions.DEFAULT_REGION;
	String bucketName;


	public S3Backend(Map<String, Object> parameters, Function<Void, String> keyGenerator) {
		super();
		this.parameters = parameters;
		this.keyGenerator = keyGenerator;
		this.bucketName = (String)parameters.get("bucketName");
	}

	@Override
	public String getName() {
		return "s3";
	}

	@Override
	public MetaInfo onCopy(Content content, String newParentPath, String newName) {


		String sourceKey = content.getStorageId();
		String destinationKey = keyGenerator.apply(null);

		try {
			AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
					.withCredentials(new AWSStaticCredentialsProvider(credentials))
					.withRegion(clientRegion)
					.build();

			// Copy the object into a new object in the same bucket.
			CopyObjectRequest copyObjRequest = new CopyObjectRequest(bucketName, sourceKey, bucketName, destinationKey);
			s3Client.copyObject(copyObjRequest);
		} catch (Exception e) {
			throw new RuntimeException("error copying file on s3");
		} 
		return new MetaInfo(content.getSize(), destinationKey, null, getName());
	}

	@Override
	public MetaInfo onMove(Content content, String newParentPath) {
		//new contentPath can be set as remotePath to the storage backend ?
		return new MetaInfo(content.getSize(),content.getStorageId(), content.getRemotePath(), getName());
	}

	@Override
	public void onDelete(Content content) {
		// TODO Auto-generated method stub

	}

	@Override
	public MetaInfo upload(InputStream stream, String relativePath, String name) {
		try {
			AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
					.withCredentials(new AWSStaticCredentialsProvider(credentials))
					.withRegion(clientRegion)
					.build();
			
			String storageId = keyGenerator.apply(null);
			
			ObjectMetadata metadata = new ObjectMetadata();
			metadata.addUserMetadata("user", AuthorizationProvider.instance.get().getClient().getId());
			
			PutObjectResult result = s3Client.putObject(
					  bucketName, 
					  keyGenerator.apply(null), 
					  stream, 
					  metadata
					);
			
			long size = result.getMetadata().getContentLength();
			
			
			s3Client.getObjectMetadata(bucketName,   );
			
			
			return new MetaInfo(content.getSize(),storageId, null, getName());
		} catch (Exception e) {
			throw new RuntimeException("error copying file on s3");
		} 
		
	}

	@Override
	public InputStream download(Content item) {
		try {
			AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
					.withCredentials(new AWSStaticCredentialsProvider(credentials))
					.withRegion(clientRegion)
					.build();
			S3Object s3object = s3Client.getObject(bucketName, item.getStorageId());
			S3ObjectInputStream inputStream = s3object.getObjectContent();
			return inputStream;
		} catch (Exception e) {
			throw new RuntimeException("error copying file on s3");
		} 
	}

	@Override
	public String getTotalSizeStored() {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public String getTotalItemsCount() {
		// TODO Auto-generated method stub
		return null;
	}

}