/*
 * 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.graph.drivers.parameter;

import org.apache.flink.api.java.utils.ParameterTool;

/**
 * A {@link Parameter} storing a {@link Long}.
 */
public class LongParameter
extends SimpleParameter<Long> {

	private boolean hasMinimumValue = false;
	private long minimumValue;

	private boolean hasMaximumValue = false;
	private long maximumValue;

	/**
	 * Set the parameter name and add this parameter to the list of parameters
	 * stored by owner.
	 *
	 * @param owner the {@link Parameterized} using this {@link Parameter}
	 * @param name the parameter name
	 */
	public LongParameter(ParameterizedBase owner, String name) {
		super(owner, name);
	}

	/**
	 * Set the default value.
	 *
	 * @param defaultValue the default value.
	 * @return this
	 */
	public LongParameter setDefaultValue(long defaultValue) {
		super.setDefaultValue(defaultValue);

		if (hasMinimumValue) {
			Util.checkParameter(defaultValue >= minimumValue,
				"Default value (" + defaultValue + ") must be greater than or equal to minimum (" + minimumValue + ")");
		}

		if (hasMaximumValue) {
			Util.checkParameter(defaultValue <= maximumValue,
				"Default value (" + defaultValue + ") must be less than or equal to maximum (" + maximumValue + ")");
		}

		return this;
	}

	/**
	 * Set the minimum value.
	 *
	 * @param minimumValue the minimum value
	 * @return this
	 */
	public LongParameter setMinimumValue(long minimumValue) {
		if (hasDefaultValue) {
			Util.checkParameter(minimumValue <= defaultValue,
				"Minimum value (" + minimumValue + ") must be less than or equal to default (" + defaultValue + ")");
		} else if (hasMaximumValue) {
			Util.checkParameter(minimumValue <= maximumValue,
				"Minimum value (" + minimumValue + ") must be less than or equal to maximum (" + maximumValue + ")");
		}

		this.hasMinimumValue = true;
		this.minimumValue = minimumValue;

		return this;
	}

	/**
	 * Set the maximum value.
	 *
	 * @param maximumValue the maximum value
	 * @return this
	 */
	public LongParameter setMaximumValue(long maximumValue) {
		if (hasDefaultValue) {
			Util.checkParameter(maximumValue >= defaultValue,
				"Maximum value (" + maximumValue + ") must be greater than or equal to default (" + defaultValue + ")");
		} else if (hasMinimumValue) {
			Util.checkParameter(maximumValue >= minimumValue,
				"Maximum value (" + maximumValue + ") must be greater than or equal to minimum (" + minimumValue + ")");
		}

		this.hasMaximumValue = true;
		this.maximumValue = maximumValue;

		return this;
	}

	@Override
	public void configure(ParameterTool parameterTool) {
		value = hasDefaultValue ? parameterTool.getLong(name, defaultValue) : parameterTool.getLong(name);

		if (hasMinimumValue) {
			Util.checkParameter(value >= minimumValue,
				name + " must be greater than or equal to " + minimumValue);
		}

		if (hasMaximumValue) {
			Util.checkParameter(value <= maximumValue,
				name + " must be less than or equal to " + maximumValue);
		}
	}

	@Override
	public String toString() {
		return Long.toString(value);
	}
}