/*
 * 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.api.common.typeutils.base;

import java.io.IOException;
import java.sql.Timestamp;
import org.apache.flink.annotation.Internal;
import org.apache.flink.core.memory.DataInputView;
import org.apache.flink.core.memory.MemorySegment;

/**
 * Comparator for comparing Java SQL Timestamps.
 */
@Internal
public final class SqlTimestampComparator extends BasicTypeComparator<java.util.Date> {

	private static final long serialVersionUID = 1L;

	public SqlTimestampComparator(boolean ascending) {
		super(ascending);
	}

	@Override
	public int compareSerialized(DataInputView firstSource, DataInputView secondSource) throws IOException {
		// compare Date part
		final int comp = DateComparator.compareSerializedDate(firstSource, secondSource, ascendingComparison);
		// compare nanos
		if (comp == 0) {
			final int i1 = firstSource.readInt();
			final int i2 = secondSource.readInt();
			final int comp2 = (i1 < i2 ? -1 : (i1 == i2 ? 0 : 1));
			return ascendingComparison ? comp2 : -comp2;
		}
		return comp;
	}

	@Override
	public boolean supportsNormalizedKey() {
		return true;
	}

	@Override
	public int getNormalizeKeyLen() {
		return 12;
	}

	@Override
	public boolean isNormalizedKeyPrefixOnly(int keyBytes) {
		return keyBytes < 12;
	}

	@Override
	public void putNormalizedKey(java.util.Date record, MemorySegment target, int offset, int numBytes) {
		// put Date key
		DateComparator.putNormalizedKeyDate(record, target, offset, numBytes > 8 ? 8 : numBytes);
		numBytes -= 8;
		offset += 8;
		if (numBytes <= 0) {
			// nothing to do
		}
		// put nanos
		else if (numBytes < 4) {
			final int nanos = ((Timestamp) record).getNanos();
			for (int i = 0; numBytes > 0; numBytes--, i++) {
				target.put(offset + i, (byte) (nanos >>> ((3-i)<<3)));
			}
		}
		// put nanos with padding
		else {
			final int nanos = ((Timestamp) record).getNanos();
			target.putIntBigEndian(offset, nanos);
			for (int i = 4; i < numBytes; i++) {
				target.put(offset + i, (byte) 0);
			}
		}
	}

	@Override
	public SqlTimestampComparator duplicate() {
		return new SqlTimestampComparator(ascendingComparison);
	}
}