Interval conversion from/to Duration

The conversion algorithm assumes a year last 12 months and a month lasts 30 days, as Postgres does and ISO 8601 suggests.

See https://github.com/postgres/postgres/blob/5bbdfa8a18dc56d3e64aa723a68e02e897cb5ec3/src/include/datatype/timestamp.h#L116

Signed-off-by: Thomas Segismont <tsegismont@gmail.com>

vertx-pg-client/src/main/java/io/vertx/pgclient/data/Interval.java

@@ -1,7 +1,6 @@
 package io.vertx.pgclient.data;
 
-import io.vertx.codegen.annotations.DataObject;
-import io.vertx.core.json.JsonObject;
+import java.time.Duration;
 
 /**
  * Postgres Interval is date and time based
@@ -84,6 +83,35 @@ public static Interval of(int years) {
     return new Interval(years);
   }
 
+  /**
+   * Creates an instance from the given {@link Duration}.
+   * <p>
+   * The conversion algorithm assumes a year last 12 months and a month lasts 30 days, as <a href="https://github.com/postgres/postgres/blob/5bbdfa8a18dc56d3e64aa723a68e02e897cb5ec3/src/include/datatype/timestamp.h#L116">Postgres does</a> and ISO 8601 suggests.
+   *
+   * @param duration the value to convert
+   * @return a new instance of {@link Interval}
+   */
+  public static Interval of(Duration duration) {
+    long totalSeconds = duration.getSeconds();
+
+    int years = (int) (totalSeconds / 31104000);
+    long remainder = totalSeconds % 31104000;
+
+    int months = (int) (remainder / 2592000);
+    remainder = totalSeconds % 2592000;
+
+    int days = (int) (remainder / 86400);
+    remainder = remainder % 86400;
+
+    int hours = (int) (remainder / 3600);
+    remainder = remainder % 3600;
+
+    int minutes = (int) (remainder / 60);
+    remainder = remainder % 60;
+
+    return new Interval(years, months, days, hours, minutes, (int) remainder, duration.getNano() / 1000);
+  }
+
   public Interval years(int years)  {
     this.years = years;
     return this;
@@ -203,7 +231,25 @@ public int hashCode() {
 
   @Override
   public String toString() {
-    return "Interval( " + years + " years " + months + " months " + days + " days " + hours + " hours " +
-      minutes + " minutes " + seconds + (microseconds == 0 ? "" : "." + Math.abs(microseconds)) + " seconds )";
+    return "Interval( "
+           + years + " years "
+           + months + " months "
+           + days + " days "
+           + hours + " hours "
+           + minutes + " minutes "
+           + seconds + " seconds "
+           + microseconds + " microseconds )";
+  }
+
+  /**
+   * Convert this interval to an instance of {@link Duration}.
+   * <p>
+   * The conversion algorithm assumes a year last 12 months and a month lasts 30 days, as <a href="https://github.com/postgres/postgres/blob/5bbdfa8a18dc56d3e64aa723a68e02e897cb5ec3/src/include/datatype/timestamp.h#L116">Postgres does</a> and ISO 8601 suggests.
+   *
+   * @return an instance of {@link Duration} representing the same amount of time as this interval
+   */
+  public Duration toDuration() {
+    return Duration.ofSeconds(((((years * 12L + months) * 30L + days) * 24L + hours) * 60 + minutes) * 60 + seconds)
+      .plusNanos(microseconds * 1000L);
   }
 }

vertx-pg-client/src/test/java/io/vertx/pgclient/data/IntervalTest.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2011-2024 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+ * which is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+ */
+
+package io.vertx.pgclient.data;
+
+import org.junit.Test;
+
+import java.time.Duration;
+import java.time.LocalDateTime;
+
+import static java.time.temporal.ChronoUnit.MICROS;
+import static org.junit.Assert.assertEquals;
+
+public class IntervalTest {
+
+  @Test
+  public void testFromDuration() {
+    assertEquals(Interval.of(), Interval.of(Duration.ZERO));
+
+    assertEquals(
+      Interval.of(0, 0, 0, 0, 0, -1, 999999),
+      Interval.of(Duration.ZERO.minus(1, MICROS)));
+
+    assertEquals(
+      Interval.of(0, 0, -15, 0, -12, -3),
+      Interval.of(Duration.ofDays(-15)
+        .minusMinutes(12)
+        .minusSeconds(3)));
+
+    assertEquals(
+      Interval.of(1, 3, 14, 3, 55, 5, 463123),
+      Interval.of(Duration.ofDays(12 * 30 + 3 * 30 + 14)
+        .plusHours(3)
+        .plusMinutes(55)
+        .plusSeconds(5)
+        .plusNanos(463123 * 1000)));
+  }
+
+  @Test
+  public void testToDuration() {
+    assertEquals(Duration.ZERO, Interval.of().toDuration());
+
+    assertEquals(
+      Duration.ZERO.minus(1, MICROS),
+      Interval.of(0, 0, 0, 0, 0, 0, -1).toDuration());
+
+    assertEquals(
+      Duration.ofDays(-15)
+        .minusMinutes(12)
+        .minusSeconds(3),
+      Interval.of(0, 0, -15, 0, -12, -3).toDuration());
+
+    assertEquals(
+      Duration.between(
+        LocalDateTime.of(2024, 2, 1, 13, 30),
+        LocalDateTime.of(2024, 3, 1, 12, 0)),
+      Interval.of(0, 0, 29, -1, -30, 0, 0).toDuration());
+  }
+}