/*
 * Copyright 2002-2004 The Apache Software Foundation.
 * 
 * Licensed 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.axis.types;

import org.apache.axis.utils.Messages;

import java.text.NumberFormat;

/**
 * Implementation of the XML Schema type gYearMonth
 *
 * @author Tom Jordahl <tomj@macromedia.com>
 * @see <a href="http://www.w3.org/TR/xmlschema-2/#gYearMonth">XML Schema 3.2.10</a>
 */
public class YearMonth implements java.io.Serializable {
    int year;
    int month;
    String timezone = null;

    /**
     * Constructs a YearMonth with the given values
     * No timezone is specified
     */
    public YearMonth(int year, int month) throws NumberFormatException {
        setValue(year, month);
    }

    /**
     * Constructs a YearMonth with the given values, including a timezone string
     * The timezone is validated but not used.
     */
    public YearMonth(int year, int month, String timezone) throws NumberFormatException {
        setValue(year, month, timezone);
    }

    /**
     * Construct a YearMonth from a String in the format [-]CCYY-MM
     */
    public YearMonth(String source) throws NumberFormatException {
        int negative = 0;

        if (source.charAt(0) == '-') {
            negative = 1;
        }
        if (source.length() < (7 + negative)) {
            throw new NumberFormatException(
                    Messages.getMessage("badYearMonth00"));
        }

        // look for first '-'
        int pos = source.substring(negative).indexOf('-');
        if (pos < 0) {
            throw new NumberFormatException(
                    Messages.getMessage("badYearMonth00"));
        }
        if (negative > 0) pos++;    //adjust index for orginal string

        setValue(Integer.parseInt(source.substring(0,pos)),
                 Integer.parseInt(source.substring(pos+1,pos+3)),
                 source.substring(pos+3));
    }

    public int getYear() {
        return year;
    }

    public void setYear(int year) {
        // validate year, more than 4 digits are allowed!
        if (year == 0) {
            throw new NumberFormatException(
                    Messages.getMessage("badYearMonth00"));
        }

        this.year = year;
    }

    public int getMonth() {
        return month;
    }

    public void setMonth(int month) {
        // validate month
        if (month < 1 || month > 12) {
            throw new NumberFormatException(
                    Messages.getMessage("badYearMonth00"));
        }
        this.month = month;
    }

    public String getTimezone() {
        return timezone;
    }

    public void setTimezone(String timezone) {
        // validate timezone
        if (timezone != null && timezone.length() > 0) {
            // Format [+/-]HH:MM
            if (timezone.charAt(0)=='+' || (timezone.charAt(0)=='-')) {
                    if (timezone.length() != 6 ||
                        !Character.isDigit(timezone.charAt(1)) ||
                        !Character.isDigit(timezone.charAt(2)) ||
                        timezone.charAt(3) != ':'              ||
                        !Character.isDigit(timezone.charAt(4)) ||
                        !Character.isDigit(timezone.charAt(5)))
                        throw new NumberFormatException(
                                Messages.getMessage("badTimezone00"));

            } else if (!timezone.equals("Z")) {
                throw new NumberFormatException(
                        Messages.getMessage("badTimezone00"));
            }
            // if we got this far, its good
            this.timezone = timezone;
        }
    }

    public void setValue(int year, int month, String timezone) throws NumberFormatException {
        setYear(year);
        setMonth(month);
        setTimezone(timezone);
    }

    public void setValue(int year, int month) throws NumberFormatException {
        setYear(year);
        setMonth(month);
    }

    public String toString() {
        // use NumberFormat to ensure leading zeros
        NumberFormat nf = NumberFormat.getInstance();
        nf.setGroupingUsed(false);

        // year
        nf.setMinimumIntegerDigits(4);
        String s = nf.format(year) + "-";

        // month
        nf.setMinimumIntegerDigits(2);
        s += nf.format(month);

        // timezone
        if (timezone != null) {
            s = s + timezone;
        }
        return s;
    }

    public boolean equals(Object obj) {
        if (!(obj instanceof YearMonth)) return false;
        YearMonth other = (YearMonth) obj;
        if (obj == null) return false;
        if (this == obj) return true;

        boolean equals = (this.year == other.year && this.month == other.month);
        if (timezone != null) {
            equals = equals && timezone.equals(other.timezone);
        }
        return equals;
    }

    /**
     * Return the value of (month + year) XORed with the hashCode of
     * timezone iff one is defined.
     *
     * @return an <code>int</code> value
     */
    public int hashCode() {
        return null == timezone
            ? (month + year)
            : (month + year) ^ timezone.hashCode();
    }
}