/*
 * 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.typeinfo;

import java.lang.reflect.Constructor;
import java.sql.Date;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.Objects;
import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.typeutils.TypeComparator;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.api.common.typeutils.base.DateComparator;
import org.apache.flink.api.common.typeutils.base.SqlDateSerializer;
import org.apache.flink.api.common.typeutils.base.SqlTimeSerializer;
import org.apache.flink.api.common.typeutils.base.SqlTimestampComparator;
import org.apache.flink.api.common.typeutils.base.SqlTimestampSerializer;
import static org.apache.flink.util.Preconditions.checkNotNull;

/**
 * Type information for Java SQL Date/Time/Timestamp.
 */
@PublicEvolving
public class SqlTimeTypeInfo<T> extends TypeInformation<T> implements AtomicType<T> {

	private static final long serialVersionUID = -132955295409131880L;

	@SuppressWarnings({ "rawtypes", "unchecked" })
	public static final SqlTimeTypeInfo<Date> DATE = new SqlTimeTypeInfo<>(Date.class, SqlDateSerializer.INSTANCE, (Class) DateComparator.class);

	@SuppressWarnings({ "rawtypes", "unchecked" })
	public static final SqlTimeTypeInfo<Time> TIME = new SqlTimeTypeInfo<>(Time.class, SqlTimeSerializer.INSTANCE, (Class) DateComparator.class);

	@SuppressWarnings({ "rawtypes", "unchecked" })
	public static final SqlTimeTypeInfo<Timestamp> TIMESTAMP = new SqlTimeTypeInfo<>(Timestamp.class, SqlTimestampSerializer.INSTANCE, (Class) SqlTimestampComparator.class);

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

	private final Class<T> clazz;

	private final TypeSerializer<T> serializer;

	private final Class<? extends TypeComparator<T>> comparatorClass;

	protected SqlTimeTypeInfo(Class<T> clazz, TypeSerializer<T> serializer, Class<? extends TypeComparator<T>> comparatorClass) {
		this.clazz = checkNotNull(clazz);
		this.serializer = checkNotNull(serializer);
		this.comparatorClass = checkNotNull(comparatorClass);
	}

	@Override
	public boolean isBasicType() {
		return false;
	}

	@Override
	public boolean isTupleType() {
		return false;
	}

	@Override
	public int getArity() {
		return 1;
	}

	@Override
	public int getTotalFields() {
		return 1;
	}

	@Override
	public Class<T> getTypeClass() {
		return clazz;
	}

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

	@Override
	public TypeSerializer<T> createSerializer(ExecutionConfig executionConfig) {
		return serializer;
	}

	@Override
	public TypeComparator<T> createComparator(boolean sortOrderAscending, ExecutionConfig executionConfig) {
		return instantiateComparator(comparatorClass, sortOrderAscending);
	}

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

	@Override
	public int hashCode() {
		return Objects.hash(clazz, serializer, comparatorClass);
	}

	@Override
	public boolean canEqual(Object obj) {
		return obj instanceof SqlTimeTypeInfo;
	}

	@Override
	public boolean equals(Object obj) {
		if (obj instanceof SqlTimeTypeInfo) {
			@SuppressWarnings("unchecked")
			SqlTimeTypeInfo<T> other = (SqlTimeTypeInfo<T>) obj;

			return other.canEqual(this) &&
				this.clazz == other.clazz &&
				serializer.equals(other.serializer) &&
				this.comparatorClass == other.comparatorClass;
		} else {
			return false;
		}
	}

	@Override
	public String toString() {
		return clazz.getSimpleName();
	}

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

	private static <X> TypeComparator<X> instantiateComparator(Class<? extends TypeComparator<X>> comparatorClass, boolean ascendingOrder) {
		try {
			Constructor<? extends TypeComparator<X>> constructor = comparatorClass.getConstructor(boolean.class);
			return constructor.newInstance(ascendingOrder);
		}
		catch (Exception e) {
			throw new RuntimeException("Could not initialize comparator " + comparatorClass.getName(), e);
		}
	}

	@SuppressWarnings("unchecked")
	public static <X> SqlTimeTypeInfo<X> getInfoFor(Class<X> type) {
		checkNotNull(type);

		if (type == Date.class) {
			return (SqlTimeTypeInfo<X>) DATE;
		}
		else if (type == Time.class) {
			return (SqlTimeTypeInfo<X>) TIME;
		}
		else if (type == Timestamp.class) {
			return (SqlTimeTypeInfo<X>) TIMESTAMP;
		}
		return null;
	}

}