/*
 * 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.flink.fs.s3.common.writer;

import org.apache.flink.annotation.Internal;

import com.amazonaws.services.s3.model.PartETag;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

import static org.apache.flink.util.Preconditions.checkArgument;
import static org.apache.flink.util.Preconditions.checkNotNull;

/**
 * A data structure containing information concerning the in-flight MPU.
 */
@Internal
final class MultiPartUploadInfo {

	private final String objectName;

	private final String uploadId;

	private final List<PartETag> completeParts;

	private final Optional<File> incompletePart;

	/**
	 * This contains both the parts that are already uploaded but also
	 * the ones that are queued to be uploaded at the {@link RecoverableMultiPartUpload}.
	 */
	private int numberOfRegisteredParts;

	/**
	 * This is the total size of the upload, i.e. also with the parts
	 * that are queued but not uploaded yet.
	 */
	private long expectedSizeInBytes;

	MultiPartUploadInfo(
			final String objectName,
			final String uploadId,
			final List<PartETag> completeParts,
			final long numBytes,
			final Optional<File> incompletePart) {

		checkArgument(numBytes >= 0L);

		this.objectName = checkNotNull(objectName);
		this.uploadId = checkNotNull(uploadId);
		this.completeParts = checkNotNull(completeParts);
		this.incompletePart = checkNotNull(incompletePart);

		this.numberOfRegisteredParts = completeParts.size();
		this.expectedSizeInBytes = numBytes;
	}

	String getObjectName() {
		return objectName;
	}

	String getUploadId() {
		return uploadId;
	}

	int getNumberOfRegisteredParts() {
		return numberOfRegisteredParts;
	}

	long getExpectedSizeInBytes() {
		return expectedSizeInBytes;
	}

	Optional<File> getIncompletePart() {
		return incompletePart;
	}

	List<PartETag> getCopyOfEtagsOfCompleteParts() {
		return new ArrayList<>(completeParts);
	}

	void registerNewPart(long length) {
		this.expectedSizeInBytes += length;
		this.numberOfRegisteredParts++;
	}

	void registerCompletePart(PartETag eTag) {
		completeParts.add(eTag);
	}

	int getRemainingParts() {
		return numberOfRegisteredParts - completeParts.size();
	}
}