Added local datetime formatter

Signed-off-by: Prabhat Sharma <[email protected]>

server/src/main/java/org/opensearch/common/time/DateFormatters.java

@@ -1334,6 +1334,38 @@ public class DateFormatters {
         )
     );
 
+    public static final DateFormatter LOCAL_DATETIME_FORMATTER = new JavaDateFormatter(
+        "local_datetime",
+        new OpenSearchDateTimeFormatter(STRICT_DATE_OPTIONAL_TIME_PRINTER),
+        new LocalDateTimeFormatter(
+            new DateTimeFormatterBuilder().append(DATE_FORMATTER)
+                .optionalStart()
+                .optionalStart()
+                .appendLiteral(' ')
+                .optionalEnd()
+                .optionalStart()
+                .appendLiteral('T')
+                .optionalEnd()
+                .appendValue(HOUR_OF_DAY, 1, 2, SignStyle.NOT_NEGATIVE)
+                .appendLiteral(':')
+                .appendValue(MINUTE_OF_HOUR, 1, 2, SignStyle.NOT_NEGATIVE)
+                .optionalStart()
+                .appendLiteral(':')
+                .appendValue(SECOND_OF_MINUTE, 1, 2, SignStyle.NOT_NEGATIVE)
+                .optionalStart()
+                .appendFraction(NANO_OF_SECOND, 1, 9, true)
+                .optionalEnd()
+                .optionalStart()
+                .appendLiteral(',')
+                .appendFraction(NANO_OF_SECOND, 1, 9, false)
+                .optionalEnd()
+                .optionalEnd()
+                .optionalEnd()
+                .toFormatter(Locale.ROOT)
+                .withResolverStyle(ResolverStyle.STRICT)
+        )
+    );
+
     private static final DateTimeFormatter HOUR_MINUTE_SECOND_FORMATTER = new DateTimeFormatterBuilder().append(HOUR_MINUTE_FORMATTER)
         .appendLiteral(":")
         .appendValue(SECOND_OF_MINUTE, 1, 2, SignStyle.NOT_NEGATIVE)
@@ -2189,6 +2221,8 @@ static DateFormatter forPattern(String input) {
             return STRICT_YEAR_MONTH_DAY;
         } else if (FormatNames.RFC3339.matches(input)) {
             return RFC3339_DATE_FORMATTER;
+        } else if (FormatNames.LOCAL_DATE_TIME.matches(input)) {
+            return LOCAL_DATETIME_FORMATTER;
         } else {
             try {
                 return new JavaDateFormatter(

server/src/main/java/org/opensearch/common/time/DateTime.java

@@ -9,6 +9,7 @@
 package org.opensearch.common.time;
 
 import java.time.DateTimeException;
+import java.time.LocalDateTime;
 import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
 import java.time.temporal.ChronoField;
@@ -159,6 +160,15 @@ public OffsetDateTime toOffsetDatetime() {
         throw new DateTimeException("No zone offset information found");
     }
 
+    /**
+     * Creates an {@link java.time.LocalDateTime}
+     *
+     * return the {@link java.time.LocalDateTime}
+     */
+    public LocalDateTime toLocalDatetime() {
+        return LocalDateTime.of(year, month, day, hour, minute, second, nano);
+    }
+
     /**
      * * @hidden
      */

server/src/main/java/org/opensearch/common/time/DateUtils.java

@@ -35,12 +35,15 @@
 import org.opensearch.common.logging.DeprecationLogger;
 import org.joda.time.DateTimeZone;
 
+import java.text.ParsePosition;
 import java.time.Clock;
 import java.time.Duration;
 import java.time.Instant;
 import java.time.ZoneId;
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
+import java.time.format.DateTimeParseException;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -57,6 +60,18 @@
  * @opensearch.internal
  */
 public class DateUtils {
+    public static final char DATE_SEPARATOR = '-';
+    public static final char TIME_SEPARATOR = ':';
+    public static final char SEPARATOR_UPPER = 'T';
+    static final char PLUS = '+';
+    static final char MINUS = '-';
+    static final char SEPARATOR_LOWER = 't';
+    static final char SEPARATOR_SPACE = ' ';
+    static final char FRACTION_SEPARATOR_1 = '.';
+    static final char FRACTION_SEPARATOR_2 = ',';
+    static final char ZULU_UPPER = 'Z';
+    static final char ZULU_LOWER = 'z';
+
     public static DateTimeZone zoneIdToDateTimeZone(ZoneId zoneId) {
         if (zoneId == null) {
             return null;
@@ -430,4 +445,135 @@ public static ZonedDateTime nowWithMillisResolution(Clock clock) {
         Clock millisResolutionClock = Clock.tick(clock, Duration.ofMillis(1));
         return ZonedDateTime.now(millisResolutionClock);
     }
+
+    private static boolean isDigit(char c) {
+        return (c >= '0' && c <= '9');
+    }
+
+    private static int digit(char c) {
+        return c - '0';
+    }
+
+    static int readInt(final char[] strNum, ParsePosition pos, int n) {
+        int start = pos.getIndex(), end = start + n;
+        if (end > strNum.length) {
+            pos.setErrorIndex(end);
+            throw new DateTimeParseException("Unexpected end of expression at position " + strNum.length, new String(strNum), end);
+        }
+
+        int result = 0;
+        for (int i = start; i < end; i++) {
+            final char c = strNum[i];
+            if (isDigit(c) == false) {
+                pos.setErrorIndex(i);
+                throw new DateTimeParseException("Character " + c + " is not a digit", new String(strNum), i);
+            }
+            int digit = digit(c);
+            result = result * 10 + digit;
+        }
+        pos.setIndex(end);
+        return result;
+    }
+
+    static int readIntUnchecked(final char[] strNum, ParsePosition pos, int n) {
+        int start = pos.getIndex(), end = start + n;
+        int result = 0;
+        for (int i = start; i < end; i++) {
+            final char c = strNum[i];
+            int digit = digit(c);
+            result = result * 10 + digit;
+        }
+        pos.setIndex(end);
+        return result;
+    }
+
+    private static boolean isValidOffset(char[] chars, int offset) {
+        if (offset >= chars.length) {
+            return false;
+        }
+        return true;
+    }
+
+    static void consumeChar(char[] chars, ParsePosition pos, char expected) {
+        int offset = pos.getIndex();
+        if (isValidOffset(chars, offset) == false) {
+            throw new DateTimeParseException("Unexpected end of input", new String(chars), offset);
+        }
+
+        if (chars[offset] != expected) {
+            throw new DateTimeParseException("Expected character " + expected + " at position " + offset, new String(chars), offset);
+        }
+        pos.setIndex(offset + 1);
+    }
+
+    static void consumeNextChar(char[] chars, ParsePosition pos) {
+        int offset = pos.getIndex();
+        if (isValidOffset(chars, offset) == false) {
+            throw new DateTimeParseException("Unexpected end of input", new String(chars), offset);
+        }
+        pos.setIndex(offset + 1);
+    }
+
+    static boolean checkPositionContains(char[] chars, ParsePosition pos, char... expected) {
+        int offset = pos.getIndex();
+        if (offset >= chars.length) {
+            throw new DateTimeParseException("Unexpected end of input", new String(chars), offset);
+        }
+
+        boolean found = false;
+        for (char e : expected) {
+            if (chars[offset] == e) {
+                found = true;
+                break;
+            }
+        }
+        return found;
+    }
+
+    static void consumeChar(char[] chars, ParsePosition pos, char... expected) {
+        int offset = pos.getIndex();
+        if (offset >= chars.length) {
+            throw new DateTimeParseException("Unexpected end of input", new String(chars), offset);
+        }
+
+        boolean found = false;
+        for (char e : expected) {
+            if (chars[offset] == e) {
+                found = true;
+                pos.setIndex(offset + 1);
+                break;
+            }
+        }
+        if (!found) {
+            throw new DateTimeParseException(
+                "Expected character " + Arrays.toString(expected) + " at position " + offset,
+                new String(chars),
+                offset
+            );
+        }
+    }
+
+    static void assertNoMoreChars(char[] chars, ParsePosition pos) {
+        if (chars.length > pos.getIndex()) {
+            throw new DateTimeParseException("Trailing junk data after position " + pos.getIndex(), new String(chars), pos.getIndex());
+        }
+    }
+
+    public static int indexOfNonDigit(final char[] text, int offset) {
+        for (int i = offset; i < text.length; i++) {
+            if (isDigit(text[i]) == false) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    public static void consumeDigits(final char[] text, ParsePosition pos) {
+        final int idx = indexOfNonDigit(text, pos.getIndex());
+        if (idx == -1) {
+            pos.setErrorIndex(text.length);
+        } else {
+            pos.setIndex(idx);
+        }
+    }
 }

server/src/main/java/org/opensearch/common/time/FormatNames.java

@@ -45,6 +45,7 @@
 public enum FormatNames {
     ISO8601(null, "iso8601"),
     RFC3339(null, "rfc3339"),
+    LOCAL_DATE_TIME("localDateTime", "local_date_time"),
     BASIC_DATE("basicDate", "basic_date"),
     BASIC_DATE_TIME("basicDateTime", "basic_date_time"),
     BASIC_DATE_TIME_NO_MILLIS("basicDateTimeNoMillis", "basic_date_time_no_millis"),