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package com.sun.org.apache.xerces.internal.jaxp.datatype;

import java.math.BigInteger;

import javax.xml.datatype.DatatypeConstants;

/**

 * <p>Represent a subtype <code>xdt:yearMonthDuration</code> of a <code>Duration</code>

 * as specified in <a href="http://www.w3.org/TR/xpath-datamodel#yearMonthDuration">

 *   XQuery 1.0 and XPath 2.0 Data Model, xdt:yearMonthDuration</a>.</p>

 *

 *

 * <p>The DurationYearMonth object represents a period of Gregorian time,

 * with a lexical representation, "<em>PnYnM</em>" that contains only year and month components.

 * </p>

 *

 *

 * @author <a href="mailto:Vikram.Aroskar@Sun.COM">Vikram Aroskar</a>

 * @author <a href="mailto:Huizhe.wang@oracle.com">Joe Wang</a>

 * @see XMLGregorianCalendar#add(Duration)

 */

class DurationYearMonthImpl

        extends DurationImpl {

    /**

     * <p>Constructs a new Duration object by specifying each field individually.</p>

     *

     * <p>All the parameters are optional as long as at least one field is present.

     * If specified, parameters have to be zero or positive.</p>

     *

     * @param isPositive Set to <code>false</code> to create a negative duration. When the length

     *   of the duration is zero, this parameter will be ignored.

     * @param years of this <code>Duration</code>

     * @param months of this <code>Duration</code>

     *

     * @throws IllegalArgumentException

     *    If years, months parameters are all <code>null</code>. Or if any

     *    of those parameters are negative.

     */

    public DurationYearMonthImpl(

        boolean isPositive,

        BigInteger years,

        BigInteger months) {

        super(isPositive, years, months, null, null, null, null);

        convertToCanonicalYearMonth();

    }

        /**

         * <p>Construct a <code>Duration</code> of type <code>xdt:yearMonthDuration</code> using the specified

         * <code>year</code> and <code>month</code> as defined in

         * <a href="http://www.w3.org/TR/xpath-datamodel#yearMonthDuration">

         *   XQuery 1.0 and XPath 2.0 Data Model, xdt:yearMonthDuration</a>.</p>

         *

     * <p>A {@link DatatypeConstants#FIELD_UNDEFINED} value indicates that field is not set.</p>

     *

     * @param isPositive Set to <code>false</code> to create a negative duration. When the length

     *   of the duration is zero, this parameter will be ignored.

         * @param year Year of <code>Duration</code>.

         * @param month Month of <code>Duration</code>.

         *

         * @throws IllegalArgumentException If the values are not a valid representation of a

         * <code>Duration</code>: if any of the fields (year, month) is negative.

         */

    protected DurationYearMonthImpl(

        final boolean isPositive,

        final int years,

        final int months) {

        this(isPositive,

            wrap(years),

            wrap(months));

    }

        /**

         * <p>Construct a <code>Duration</code> of type <code>xdt:yearMonthDuration</code> using the specified milliseconds as defined in

         * <a href="http://www.w3.org/TR/xpath-datamodel#yearMonthDuration">

         *   XQuery 1.0 and XPath 2.0 Data Model, xdt:yearMonthDuration</a>.</p>

         *

         * <p>The datatype <code>xdt:yearMonthDuration</code> is a subtype of <code>xs:duration</code>

         * whose lexical representation contains only year and month components.

         * This datatype resides in the namespace {@link javax.xml.XMLConstants#W3C_XPATH_DATATYPE_NS_URI}.</p>

         *

     * <p>Both values are set by computing their values from the specified milliseconds

     * and are availabe using the <code>get</code> methods of  the created {@link Duration}.

     * The values conform to and are defined by:</p>

     * <ul>

     *   <li>ISO 8601:2000(E) Section 5.5.3.2 Alternative format</li>

     *   <li><a href="http://www.w3.org/TR/xmlschema-2/#isoformats">

     *     W3C XML Schema 1.0 Part 2, Appendix D, ISO 8601 Date and Time Formats</a>

     *   </li>

     *   <li>{@link XMLGregorianCalendar}  Date/Time Datatype Field Mapping Between XML Schema 1.0 and Java Representation</li>

     * </ul>

     *

         * <p>The default start instance is defined by {@link GregorianCalendar}'s use of the start of the epoch: i.e.,

         * {@link java.util.Calendar#YEAR} = 1970,

         * {@link java.util.Calendar#MONTH} = {@link java.util.Calendar#JANUARY},

         * {@link java.util.Calendar#DATE} = 1, etc.

         * This is important as there are variations in the Gregorian Calendar,

         * e.g. leap years have different days in the month = {@link java.util.Calendar#FEBRUARY}

         * so the result of {@link Duration#getMonths()} can be influenced.</p>

         *

     * <p>Any remaining milliseconds after determining the year and month are discarded.</p>

         *

         * @param durationInMilliseconds Milliseconds of <code>Duration</code> to create.

         */

    protected DurationYearMonthImpl(long durationInMilliseconds) {

        super(durationInMilliseconds);

        convertToCanonicalYearMonth();

        //Any remaining milliseconds after determining the year and month are discarded.

        days = null;

        hours = null;

        minutes = null;

        seconds = null;

        signum = calcSignum((signum<0)?false:true);

    }

        /**

         * <p>Construct a <code>Duration</code> of type <code>xdt:yearMonthDuration</code> by parsing its <code>String</code> representation,

         * "<em>PnYnM</em>", <a href="http://www.w3.org/TR/xpath-datamodel#yearMonthDuration">

         *   XQuery 1.0 and XPath 2.0 Data Model, xdt:yearMonthDuration</a>.</p>

         *

         * <p>The datatype <code>xdt:yearMonthDuration</code> is a subtype of <code>xs:duration</code>

         * whose lexical representation contains only year and month components.

         * This datatype resides in the namespace {@link javax.xml.XMLConstants#W3C_XPATH_DATATYPE_NS_URI}.</p>

         *

     * <p>Both values are set and availabe from the created {@link Duration}</p>

         *

     * <p>The XML Schema specification states that values can be of an arbitrary size.

     * Implementations may chose not to or be incapable of supporting arbitrarily large and/or small values.

     * An {@link UnsupportedOperationException} will be thrown with a message indicating implementation limits

     * if implementation capacities are exceeded.</p>

     *

         * @param lexicalRepresentation Lexical representation of a duration.

         *

         * @throws IllegalArgumentException If <code>lexicalRepresentation</code> is not a valid representation of a <code>Duration</code> expressed only in terms of years and months.

         * @throws UnsupportedOperationException If implementation cannot support requested values.

         * @throws NullPointerException If <code>lexicalRepresentation</code> is <code>null</code>.

         */

    protected DurationYearMonthImpl(String lexicalRepresentation) {

        super(lexicalRepresentation);

        if (getDays() > 0 || getHours() > 0

                || getMinutes() > 0 || getSeconds() > 0) {

            throw new IllegalArgumentException(

                    "Trying to create an xdt:yearMonthDuration with an invalid"

                    + " lexical representation of \"" + lexicalRepresentation

                    + "\", data model requires PnYnM.");

        }

        convertToCanonicalYearMonth();

    }

    /**

     * The value space of xs:yearMonthDuration is the set of xs:integer month values.

     * @return the value of yearMonthDuration

     */

    public int getValue() {

        return getYears() * 12 + getMonths();

    }

    private void convertToCanonicalYearMonth() {

        while (getMonths() >= 12)

        {

            months = months.subtract(BigInteger.valueOf(12));

            years = BigInteger.valueOf((long) getYears()).add(BigInteger.ONE);

        }

    }

}