nucleus/businessobjects/src/main/java/org/eclipse/mdm/nodeprovider/entity/ValuePrecision.java

/********************************************************************************
 * Copyright (c) 2015-2020 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 ********************************************************************************/

package org.eclipse.mdm.nodeprovider.entity;

import java.time.LocalDateTime;
import java.time.temporal.TemporalAdjusters;

import org.eclipse.mdm.api.base.adapter.Attribute;
import org.eclipse.mdm.api.base.model.Value;
import org.eclipse.mdm.api.base.model.ValueType;
import org.eclipse.mdm.api.base.query.ComparisonOperator;
import org.eclipse.mdm.api.base.query.Condition;
import org.eclipse.mdm.api.base.search.ContextState;

public enum ValuePrecision {

	EXACT {
		@Override
		public void applyOn(Value value) {
			// Intentionally empty
		}

		@Override
		public Condition getCondition(ContextState contextState, Attribute attribute, Object value) {
			return ComparisonOperator.EQUAL.create(contextState, attribute, value);
		}
	},
	YEAR {
		@Override
		public void applyOn(Value value) {
			ValuePrecision.applyDate(value, YEAR);
		}

		@Override
		public Condition getCondition(ContextState contextState, Attribute attribute, Object value) {
			return getDateCondition(contextState, attribute, value, YEAR);
		}
	},
	MONTH {
		@Override
		public void applyOn(Value value) {
			ValuePrecision.applyDate(value, MONTH);
		}

		@Override
		public Condition getCondition(ContextState contextState, Attribute attribute, Object value) {
			return getDateCondition(contextState, attribute, value, MONTH);
		}
	},
	DAY {
		@Override
		public void applyOn(Value value) {
			ValuePrecision.applyDate(value, DAY);
		}

		@Override
		public Condition getCondition(ContextState contextState, Attribute attribute, Object value) {
			return getDateCondition(contextState, attribute, value, DAY);
		}
	},
	HOUR {
		@Override
		public void applyOn(Value value) {
			ValuePrecision.applyDate(value, HOUR);
		}

		@Override
		public Condition getCondition(ContextState contextState, Attribute attribute, Object value) {
			return getDateCondition(contextState, attribute, value, HOUR);
		}
	},
	MINUTE {
		@Override
		public void applyOn(Value value) {
			ValuePrecision.applyDate(value, MINUTE);
		}

		@Override
		public Condition getCondition(ContextState contextState, Attribute attribute, Object value) {
			return getDateCondition(contextState, attribute, value, MINUTE);
		}
	};

	/**
	 * Applies this {@link ValuePrecision} to given {@link Value}s value, if
	 * acceptable for related {@link ValueType}.
	 * 
	 * @param value the value
	 */
	abstract public void applyOn(Value value);

	abstract public Condition getCondition(ContextState contextState, Attribute attribute, Object value);

	/**
	 * Applies this {@link ValuePrecision} to given {@link Value}s value, for
	 * {@link ValueType.DATE}.
	 *
	 * @param value the value
	 */
	private static void applyDate(Value value, ValuePrecision precision) {
		if (value.getValueType() == ValueType.DATE) {
			LocalDateTime dateTime = value.extract();
			if (dateTime != null) {
				switch (precision) {
				case YEAR:
					dateTime = dateTime.with(TemporalAdjusters.firstDayOfYear());
					// no break intentionally;
				case MONTH:
					dateTime = dateTime.with(TemporalAdjusters.firstDayOfMonth());
					// no break intentionally;
				case DAY:
					dateTime = dateTime.withHour(0);
					// no break intentionally;
				case HOUR:
					dateTime = dateTime.withMinute(0);
					// no break intentionally;
				case MINUTE:
					dateTime = dateTime.withSecond(0);
					break;
				default:
					// Intentionally empty.
				}
				value.set(dateTime);
			}
		}
	}

	private static Condition getDateCondition(ContextState contextState, Attribute attribute, Object value,
			ValuePrecision precision) {
		if (attribute.getValueType() == ValueType.DATE) {
			LocalDateTime start = (LocalDateTime) value;
			LocalDateTime end;
			switch (precision) {
			case YEAR:
				end = start.plusYears(1);
				break;
			case MONTH:
				end = start.plusMonths(1);
				break;
			case DAY:
				end = start.plusDays(1);
				break;
			case HOUR:
				end = start.plusHours(1);
				break;
			case MINUTE:
				end = start.plusMinutes(1);
				break;
			default:
				end = start.plusNanos(1);
			}
			return ComparisonOperator.BETWEEN.create(contextState, attribute,
					new LocalDateTime[] { start, end.minusNanos(1) });
		} else {
			return ComparisonOperator.EQUAL.create(contextState, attribute, value);
		}
	}
}