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package org.hsqldb.types;

import org.hsqldb.Error;
import org.hsqldb.ErrorCode;
import org.hsqldb.Types;

/**
 * Implementation of data item for INTERVAL MONTH.<p>
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 1.9.0
 * @since 1.9.0
 */
public class IntervalMonthData {

    public final long units;

    public static IntervalMonthData newIntervalYear(long years,
            IntervalType type) {
        return new IntervalMonthData(years * 12, type);
    }

    public static IntervalMonthData newIntervalMonth(long months,
            IntervalType type) {
        return new IntervalMonthData(months, type);
    }

    public IntervalMonthData(long months, IntervalType type) {

        if (months >= type.getIntervalValueLimit()) {
            throw Error.error(ErrorCode.X_22006);
        }

        if (type.typeCode == Types.SQL_INTERVAL_YEAR) {
            months -= (months % 12);
        }

        this.units = months;
    }

    public IntervalMonthData(long months) {
        this.units = months;
    }

    public boolean equals(Object other) {

        if (other instanceof IntervalMonthData) {
            return units == ((IntervalMonthData) other).units;
        }

        return false;
    }

    public int hashCode() {
        return (int) units;
    }

    public int compareTo(IntervalMonthData b) {

        long diff = units - b.units;

        if (diff == 0) {
            return 0;
        } else {
            return diff > 0 ? 1
                            : -1;
        }
    }

    public String toString() {
        throw Error.runtimeError(ErrorCode.U_S0500, "IntervalMonthData");
    }
}