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 * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package java.sql;

import java.time.Instant;
import java.time.LocalDateTime;
import java.util.StringTokenizer;

/**
 * <P>A thin wrapper around <code>java.util.Date</code> that allows
 * the JDBC API to identify this as an SQL <code>TIMESTAMP</code> value.
 * It adds the ability
 * to hold the SQL <code>TIMESTAMP</code> fractional seconds value, by allowing
 * the specification of fractional seconds to a precision of nanoseconds.
 * A Timestamp also provides formatting and
 * parsing operations to support the JDBC escape syntax for timestamp values.
 *
 * <p>The precision of a Timestamp object is calculated to be either:
 * <ul>
 * <li><code>19 </code>, which is the number of characters in yyyy-mm-dd hh:mm:ss
 * <li> <code> 20 + s </code>, which is the number
 * of characters in the yyyy-mm-dd hh:mm:ss.[fff...] and <code>s</code> represents the scale of the given Timestamp,
 * its fractional seconds precision.
 *</ul>
 *
 * <P><B>Note:</B> This type is a composite of a <code>java.util.Date</code> and a
 * separate nanoseconds value. Only integral seconds are stored in the
 * <code>java.util.Date</code> component. The fractional seconds - the nanos - are
 * separate. The <code>Timestamp.equals(Object)</code> method never returns
 * <code>true</code> when passed an object
 * that isn't an instance of <code>java.sql.Timestamp</code>,
 * because the nanos component of a date is unknown.
 * As a result, the <code>Timestamp.equals(Object)</code>
 * method is not symmetric with respect to the
 * <code>java.util.Date.equals(Object)</code>
 * method. Also, the <code>hashCode</code> method uses the underlying
 * <code>java.util.Date</code>
 * implementation and therefore does not include nanos in its computation.
 * <P>
 * Due to the differences between the <code>Timestamp</code> class
 * and the <code>java.util.Date</code>
 * class mentioned above, it is recommended that code not view
 * <code>Timestamp</code> values generically as an instance of
 * <code>java.util.Date</code>. The
 * inheritance relationship between <code>Timestamp</code>
 * and <code>java.util.Date</code> really
 * denotes implementation inheritance, and not type inheritance.
 */
public class Timestamp extends java.util.Date {

 /**
 * Constructs a <code>Timestamp</code> object initialized
 * with the given values.
 *
 * @param year the year minus 1900
 * @param month 0 to 11
 * @param date 1 to 31
 * @param hour 0 to 23
 * @param minute 0 to 59
 * @param second 0 to 59
 * @param nano 0 to 999,999,999
 * @deprecated instead use the constructor <code>Timestamp(long millis)</code>
 * @exception IllegalArgumentException if the nano argument is out of bounds
 */
 @Deprecated
 public Timestamp(int year, int month, int date,
 int hour, int minute, int second, int nano) {
 super(year, month, date, hour, minute, second);
 if (nano > 999999999 || nano < 0) {
 throw new IllegalArgumentException("nanos > 999999999 or < 0");
 }
 nanos = nano;
 }

 /**
 * Constructs a <code>Timestamp</code> object
 * using a milliseconds time value. The
 * integral seconds are stored in the underlying date value; the
 * fractional seconds are stored in the <code>nanos</code> field of
 * the <code>Timestamp</code> object.
 *
 * @param time milliseconds since January 1, 1970, 00:00:00 GMT.
 * A negative number is the number of milliseconds before
 * January 1, 1970, 00:00:00 GMT.
 * @see java.util.Calendar
 */
 public Timestamp(long time) {
 super((time/1000)*1000);
 nanos = (int)((time%1000) * 1000000);
 if (nanos < 0) {
 nanos = 1000000000 + nanos;
 super.setTime(((time/1000)-1)*1000);
 }
 }

 /**
 * Sets this <code>Timestamp</code> object to represent a point in time that is
 * <tt>time</tt> milliseconds after January 1, 1970 00:00:00 GMT.
 *
 * @param time the number of milliseconds.
 * @see #getTime
 * @see #Timestamp(long time)
 * @see java.util.Calendar
 */
 public void setTime(long time) {
 super.setTime((time/1000)*1000);
 nanos = (int)((time%1000) * 1000000);
 if (nanos < 0) {
 nanos = 1000000000 + nanos;
 super.setTime(((time/1000)-1)*1000);
 }
 }

 /**
 * Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT
 * represented by this <code>Timestamp</code> object.
 *
 * @return the number of milliseconds since January 1, 1970, 00:00:00 GMT
 * represented by this date.
 * @see #setTime
 */
 public long getTime() {
 long time = super.getTime();
 return (time + (nanos / 1000000));
 }


 /**
 * @serial
 */
 private int nanos;

 /**
 * Converts a <code>String</code> object in JDBC timestamp escape format to a
 * <code>Timestamp</code> value.
 *
 * @param s timestamp in format <code>yyyy-[m]m-[d]d hh:mm:ss[.f...]</code>. The
 * fractional seconds may be omitted. The leading zero for <code>mm</code>
 * and <code>dd</code> may also be omitted.
 *
 * @return corresponding <code>Timestamp</code> value
 * @exception java.lang.IllegalArgumentException if the given argument
 * does not have the format <code>yyyy-[m]m-[d]d hh:mm:ss[.f...]</code>
 */
 public static Timestamp valueOf(String s) {
 final int YEAR_LENGTH = 4;
 final int MONTH_LENGTH = 2;
 final int DAY_LENGTH = 2;
 final int MAX_MONTH = 12;
 final int MAX_DAY = 31;
 String date_s;
 String time_s;
 String nanos_s;
 int year = 0;
 int month = 0;
 int day = 0;
 int hour;
 int minute;
 int second;
 int a_nanos = 0;
 int firstDash;
 int secondDash;
 int dividingSpace;
 int firstColon = 0;
 int secondColon = 0;
 int period = 0;
 String formatError = "Timestamp format must be yyyy-mm-dd hh:mm:ss[.fffffffff]";
 String zeros = "000000000";
 String delimiterDate = "-";
 String delimiterTime = ":";

 if (s == null) throw new java.lang.IllegalArgumentException("null string");

 // Split the string into date and time components
 s = s.trim();
 dividingSpace = s.indexOf(' ');
 if (dividingSpace > 0) {
 date_s = s.substring(0,dividingSpace);
 time_s = s.substring(dividingSpace+1);
 } else {
 throw new java.lang.IllegalArgumentException(formatError);
 }

 // Parse the date
 firstDash = date_s.indexOf('-');
 secondDash = date_s.indexOf('-', firstDash+1);

 // Parse the time
 if (time_s == null)
 throw new java.lang.IllegalArgumentException(formatError);
 firstColon = time_s.indexOf(':');
 secondColon = time_s.indexOf(':', firstColon+1);
 period = time_s.indexOf('.', secondColon+1);

 // Convert the date
 boolean parsedDate = false;
 if ((firstDash > 0) && (secondDash > 0) && (secondDash < date_s.length() - 1)) {
 String yyyy = date_s.substring(0, firstDash);
 String mm = date_s.substring(firstDash + 1, secondDash);
 String dd = date_s.substring(secondDash + 1);
 if (yyyy.length() == YEAR_LENGTH &&
 (mm.length() >= 1 && mm.length() <= MONTH_LENGTH) &&
 (dd.length() >= 1 && dd.length() <= DAY_LENGTH)) {
 year = Integer.parseInt(yyyy);
 month = Integer.parseInt(mm);
 day = Integer.parseInt(dd);

 if ((month >= 1 && month <= MAX_MONTH) && (day >= 1 && day <= MAX_DAY)) {
 parsedDate = true;
 }
 }
 }
 if (! parsedDate) {
 throw new java.lang.IllegalArgumentException(formatError);
 }

 // Convert the time; default missing nanos
 if ((firstColon > 0) & (secondColon > 0) &
 (secondColon < time_s.length()-1)) {
 hour = Integer.parseInt(time_s.substring(0, firstColon));
 minute =
 Integer.parseInt(time_s.substring(firstColon+1, secondColon));
 if ((period > 0) & (period < time_s.length()-1)) {
 second =
 Integer.parseInt(time_s.substring(secondColon+1, period));
 nanos_s = time_s.substring(period+1);
 if (nanos_s.length() > 9)
 throw new java.lang.IllegalArgumentException(formatError);
 if (!Character.isDigit(nanos_s.charAt(0)))
 throw new java.lang.IllegalArgumentException(formatError);
 nanos_s = nanos_s + zeros.substring(0,9-nanos_s.length());
 a_nanos = Integer.parseInt(nanos_s);
 } else if (period > 0) {
 throw new java.lang.IllegalArgumentException(formatError);
 } else {
 second = Integer.parseInt(time_s.substring(secondColon+1));
 }
 } else {
 throw new java.lang.IllegalArgumentException(formatError);
 }

 return new Timestamp(year - 1900, month - 1, day, hour, minute, second, a_nanos);
 }

 /**
 * Formats a timestamp in JDBC timestamp escape format.
 * <code>yyyy-mm-dd hh:mm:ss.fffffffff</code>,
 * where <code>ffffffffff</code> indicates nanoseconds.
 * <P>
 * @return a <code>String</code> object in
 * <code>yyyy-mm-dd hh:mm:ss.fffffffff</code> format
 */
 @SuppressWarnings("deprecation")
 public String toString () {

 int year = super.getYear() + 1900;
 int month = super.getMonth() + 1;
 int day = super.getDate();
 int hour = super.getHours();
 int minute = super.getMinutes();
 int second = super.getSeconds();
 String yearString;
 String monthString;
 String dayString;
 String hourString;
 String minuteString;
 String secondString;
 String nanosString;
 String zeros = "000000000";
 String yearZeros = "0000";
 StringBuffer timestampBuf;

 if (year < 1000) {
 // Add leading zeros
 yearString = "" + year;
 yearString = yearZeros.substring(0, (4-yearString.length())) +
 yearString;
 } else {
 yearString = "" + year;
 }
 if (month < 10) {
 monthString = "0" + month;
 } else {
 monthString = Integer.toString(month);
 }
 if (day < 10) {
 dayString = "0" + day;
 } else {
 dayString = Integer.toString(day);
 }
 if (hour < 10) {
 hourString = "0" + hour;
 } else {
 hourString = Integer.toString(hour);
 }
 if (minute < 10) {
 minuteString = "0" + minute;
 } else {
 minuteString = Integer.toString(minute);
 }
 if (second < 10) {
 secondString = "0" + second;
 } else {
 secondString = Integer.toString(second);
 }
 if (nanos == 0) {
 nanosString = "0";
 } else {
 nanosString = Integer.toString(nanos);

 // Add leading zeros
 nanosString = zeros.substring(0, (9-nanosString.length())) +
 nanosString;

 // Truncate trailing zeros
 char[] nanosChar = new char[nanosString.length()];
 nanosString.getChars(0, nanosString.length(), nanosChar, 0);
 int truncIndex = 8;
 while (nanosChar[truncIndex] == '0') {
 truncIndex--;
 }

 nanosString = new String(nanosChar, 0, truncIndex + 1);
 }

 // do a string buffer here instead.
 timestampBuf = new StringBuffer(20+nanosString.length());
 timestampBuf.append(yearString);
 timestampBuf.append("-");
 timestampBuf.append(monthString);
 timestampBuf.append("-");
 timestampBuf.append(dayString);
 timestampBuf.append(" ");
 timestampBuf.append(hourString);
 timestampBuf.append(":");
 timestampBuf.append(minuteString);
 timestampBuf.append(":");
 timestampBuf.append(secondString);
 timestampBuf.append(".");
 timestampBuf.append(nanosString);

 return (timestampBuf.toString());
 }

 /**
 * Gets this <code>Timestamp</code> object's <code>nanos</code> value.
 *
 * @return this <code>Timestamp</code> object's fractional seconds component
 * @see #setNanos
 */
 public int getNanos() {
 return nanos;
 }

 /**
 * Sets this <code>Timestamp</code> object's <code>nanos</code> field
 * to the given value.
 *
 * @param n the new fractional seconds component
 * @exception java.lang.IllegalArgumentException if the given argument
 * is greater than 999999999 or less than 0
 * @see #getNanos
 */
 public void setNanos(int n) {
 if (n > 999999999 || n < 0) {
 throw new IllegalArgumentException("nanos > 999999999 or < 0");
 }
 nanos = n;
 }

 /**
 * Tests to see if this <code>Timestamp</code> object is
 * equal to the given <code>Timestamp</code> object.
 *
 * @param ts the <code>Timestamp</code> value to compare with
 * @return <code>true</code> if the given <code>Timestamp</code>
 * object is equal to this <code>Timestamp</code> object;
 * <code>false</code> otherwise
 */
 public boolean equals(Timestamp ts) {
 if (super.equals(ts)) {
 if (nanos == ts.nanos) {
 return true;
 } else {
 return false;
 }
 } else {
 return false;
 }
 }

 /**
 * Tests to see if this <code>Timestamp</code> object is
 * equal to the given object.
 *
 * This version of the method <code>equals</code> has been added
 * to fix the incorrect
 * signature of <code>Timestamp.equals(Timestamp)</code> and to preserve backward
 * compatibility with existing class files.
 *
 * Note: This method is not symmetric with respect to the
 * <code>equals(Object)</code> method in the base class.
 *
 * @param ts the <code>Object</code> value to compare with
 * @return <code>true</code> if the given <code>Object</code> is an instance
 * of a <code>Timestamp</code> that
 * is equal to this <code>Timestamp</code> object;
 * <code>false</code> otherwise
 */
 public boolean equals(java.lang.Object ts) {
 if (ts instanceof Timestamp) {
 return this.equals((Timestamp)ts);
 } else {
 return false;
 }
 }

 /**
 * Indicates whether this <code>Timestamp</code> object is
 * earlier than the given <code>Timestamp</code> object.
 *
 * @param ts the <code>Timestamp</code> value to compare with
 * @return <code>true</code> if this <code>Timestamp</code> object is earlier;
 * <code>false</code> otherwise
 */
 public boolean before(Timestamp ts) {
 return compareTo(ts) < 0;
 }

 /**
 * Indicates whether this <code>Timestamp</code> object is
 * later than the given <code>Timestamp</code> object.
 *
 * @param ts the <code>Timestamp</code> value to compare with
 * @return <code>true</code> if this <code>Timestamp</code> object is later;
 * <code>false</code> otherwise
 */
 public boolean after(Timestamp ts) {
 return compareTo(ts) > 0;
 }

 /**
 * Compares this <code>Timestamp</code> object to the given
 * <code>Timestamp</code> object.
 *
 * @param ts the <code>Timestamp</code> object to be compared to
 * this <code>Timestamp</code> object
 * @return the value <code>0</code> if the two <code>Timestamp</code>
 * objects are equal; a value less than <code>0</code> if this
 * <code>Timestamp</code> object is before the given argument;
 * and a value greater than <code>0</code> if this
 * <code>Timestamp</code> object is after the given argument.
 * @since 1.4
 */
 public int compareTo(Timestamp ts) {
 long thisTime = this.getTime();
 long anotherTime = ts.getTime();
 int i = (thisTime<anotherTime ? -1 :(thisTime==anotherTime?0 :1));
 if (i == 0) {
 if (nanos > ts.nanos) {
 return 1;
 } else if (nanos < ts.nanos) {
 return -1;
 }
 }
 return i;
 }

 /**
 * Compares this <code>Timestamp</code> object to the given
 * <code>Date</code> object.
 *
 * @param o the <code>Date</code> to be compared to
 * this <code>Timestamp</code> object
 * @return the value <code>0</code> if this <code>Timestamp</code> object
 * and the given object are equal; a value less than <code>0</code>
 * if this <code>Timestamp</code> object is before the given argument;
 * and a value greater than <code>0</code> if this
 * <code>Timestamp</code> object is after the given argument.
 *
 * @since 1.5
 */
 public int compareTo(java.util.Date o) {
 if(o instanceof Timestamp) {
 // When Timestamp instance compare it with a Timestamp
 // Hence it is basically calling this.compareTo((Timestamp))o);
 // Note typecasting is safe because o is instance of Timestamp
 return compareTo((Timestamp)o);
 } else {
 // When Date doing a o.compareTo(this)
 // will give wrong results.
 Timestamp ts = new Timestamp(o.getTime());
 return this.compareTo(ts);
 }
 }

 /**
 * {@inheritDoc}
 *
 * The {@code hashCode} method uses the underlying {@code java.util.Date}
 * implementation and therefore does not include nanos in its computation.
 *
 */
 @Override
 public int hashCode() {
 return super.hashCode();
 }

 static final long serialVersionUID = 2745179027874758501L;

 private static final int MILLIS_PER_SECOND = 1000;

 /**
 * Obtains an instance of {@code Timestamp} from a {@code LocalDateTime}
 * object, with the same year, month, day of month, hours, minutes,
 * seconds and nanos date-time value as the provided {@code LocalDateTime}.
 * <p>
 * The provided {@code LocalDateTime} is interpreted as the local
 * date-time in the local time zone.
 *
 * @param dateTime a {@code LocalDateTime} to convert
 * @return a {@code Timestamp} object
 * @exception NullPointerException if {@code dateTime} is null.
 * @since 1.8
 */
 @SuppressWarnings("deprecation")
 public static Timestamp valueOf(LocalDateTime dateTime) {
 return new Timestamp(dateTime.getYear() - 1900,
 dateTime.getMonthValue() - 1,
 dateTime.getDayOfMonth(),
 dateTime.getHour(),
 dateTime.getMinute(),
 dateTime.getSecond(),
 dateTime.getNano());
 }

 /**
 * Converts this {@code Timestamp} object to a {@code LocalDateTime}.
 * <p>
 * The conversion creates a {@code LocalDateTime} that represents the
 * same year, month, day of month, hours, minutes, seconds and nanos
 * date-time value as this {@code Timestamp} in the local time zone.
 *
 * @return a {@code LocalDateTime} object representing the same date-time value
 * @since 1.8
 */
 @SuppressWarnings("deprecation")
 public LocalDateTime toLocalDateTime() {
 return LocalDateTime.of(getYear() + 1900,
 getMonth() + 1,
 getDate(),
 getHours(),
 getMinutes(),
 getSeconds(),
 getNanos());
 }

 /**
 * Obtains an instance of {@code Timestamp} from an {@link Instant} object.
 * <p>
 * {@code Instant} can store points on the time-line further in the future
 * and further in the past than {@code Date}. In this scenario, this method
 * will throw an exception.
 *
 * @param instant the instant to convert
 * @return an {@code Timestamp} representing the same point on the time-line as
 * the provided instant
 * @exception NullPointerException if {@code instant} is null.
 * @exception IllegalArgumentException if the instant is too large to
 * represent as a {@code Timesamp}
 * @since 1.8
 */
 public static Timestamp from(Instant instant) {
 try {
 Timestamp stamp = new Timestamp(instant.getEpochSecond() * MILLIS_PER_SECOND);
 stamp.nanos = instant.getNano();
 return stamp;
 } catch (ArithmeticException ex) {
 throw new IllegalArgumentException(ex);
 }
 }

 /**
 * Converts this {@code Timestamp} object to an {@code Instant}.
 * <p>
 * The conversion creates an {@code Instant} that represents the same
 * point on the time-line as this {@code Timestamp}.
 *
 * @return an instant representing the same point on the time-line
 * @since 1.8
 */
 @Override
 public Instant toInstant() {
 return Instant.ofEpochSecond(super.getTime() / MILLIS_PER_SECOND, nanos);
 }
}