/*
 * 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.core.fs.RecoverableWriter;

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

import javax.annotation.Nullable;

import java.util.List;

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

/**
 * Data object to recover an S3 MultiPartUpload for a recoverable output stream.
 */
public final class S3Recoverable implements RecoverableWriter.ResumeRecoverable {

	private final String uploadId;

	private final String objectName;

	private final List<PartETag> parts;

	@Nullable
	private final String lastPartObject;

	private long numBytesInParts;

	private long lastPartObjectLength;

	S3Recoverable(
			String objectName,
			String uploadId,
			List<PartETag> parts,
			long numBytesInParts
	) {
		this(objectName, uploadId, parts, numBytesInParts, null, -1L);
	}

	S3Recoverable(
			String objectName,
			String uploadId,
			List<PartETag> parts,
			long numBytesInParts,
			@Nullable String lastPartObject,
			long lastPartObjectLength
	) {
		checkArgument(numBytesInParts >= 0L);
		checkArgument(lastPartObject == null || lastPartObjectLength > 0L);

		this.objectName = checkNotNull(objectName);
		this.uploadId = checkNotNull(uploadId);
		this.parts = checkNotNull(parts);
		this.numBytesInParts = numBytesInParts;

		this.lastPartObject = lastPartObject;
		this.lastPartObjectLength = lastPartObjectLength;
	}

	// ------------------------------------------------------------------------

	public String uploadId() {
		return uploadId;
	}

	public String getObjectName() {
		return objectName;
	}

	public List<PartETag> parts() {
		return parts;
	}

	public long numBytesInParts() {
		return numBytesInParts;
	}

	@Nullable
	public String incompleteObjectName() {
		return lastPartObject;
	}

	public long incompleteObjectLength() {
		return lastPartObjectLength;
	}

	// ------------------------------------------------------------------------

	@Override
	public String toString() {
		StringBuilder buf = new StringBuilder(128);
		buf.append("S3Recoverable: ");
		buf.append("key=").append(objectName);
		buf.append(", uploadId=").append(uploadId);
		buf.append(", bytesInParts=").append(numBytesInParts);
		buf.append(", parts=[");
		int num = 0;
		for (PartETag part : parts) {
			if (0 != num++) {
				buf.append(", ");
			}
			buf.append(part.getPartNumber()).append('=').append(part.getETag());
		}
		buf.append("], trailingPart=").append(lastPartObject);
		buf.append("trailingPartLen=").append(lastPartObjectLength);

		return buf.toString();
	}
}