Add spark value writers for Date/Timestamp/TimestampNTZ and Struct types

java/vortex-jni/src/main/java/dev/vortex/api/expressions/IsNull.java

@@ -35,8 +35,7 @@ public static IsNull parse(byte[] metadata, List<Expression> children) {
                     "IsNull expression must have exactly one child, found: " + children.size());
         }
         if (metadata.length > 0) {
-            throw new IllegalArgumentException(
-                    "IsNull expression must not have metadata, found: " + metadata.length);
+            throw new IllegalArgumentException("IsNull expression must not have metadata, found: " + metadata.length);
         }
         return new IsNull(children.get(0));
     }

java/vortex-spark/src/main/java/dev/vortex/spark/write/SparkToArrowSchema.java

@@ -100,6 +100,8 @@ private static ArrowType convertType(DataType sparkType) {
             return new ArrowType.Date(DateUnit.DAY);
         } else if (sparkType instanceof TimestampType) {
             return new ArrowType.Timestamp(TimeUnit.MICROSECOND, "UTC");
+        } else if (sparkType instanceof TimestampNTZType) {
+            return new ArrowType.Timestamp(TimeUnit.MICROSECOND, null);
         } else if (sparkType instanceof DecimalType) {
             DecimalType decimal = (DecimalType) sparkType;
             return new ArrowType.Decimal(decimal.precision(), decimal.scale(), 128);

java/vortex-spark/src/main/java/dev/vortex/spark/write/VortexDataWriter.java

@@ -10,8 +10,10 @@
 import dev.vortex.relocated.org.apache.arrow.memory.BufferAllocator;
 import dev.vortex.relocated.org.apache.arrow.memory.RootAllocator;
 import dev.vortex.relocated.org.apache.arrow.vector.*;
+import dev.vortex.relocated.org.apache.arrow.vector.FieldVector;
 import dev.vortex.relocated.org.apache.arrow.vector.VectorSchemaRoot;
 import dev.vortex.relocated.org.apache.arrow.vector.complex.ListVector;
+import dev.vortex.relocated.org.apache.arrow.vector.complex.StructVector;
 import dev.vortex.spark.SparkTypes;
 import java.io.IOException;
 import java.nio.file.Files;
@@ -205,16 +207,23 @@ private void populateVector(
             if (bytes != null) {
                 ((VarBinaryVector) vector).setSafe(rowIndex, bytes);
             }
-        } else if (dataType instanceof DecimalType) {
-            DecimalType decType = (DecimalType) dataType;
+        } else if (dataType instanceof DateType) {
+            ((DateDayVector) vector).setSafe(rowIndex, row.getInt(fieldIndex));
+        } else if (dataType instanceof TimestampType) {
+            ((TimeStampMicroTZVector) vector).setSafe(rowIndex, row.getLong(fieldIndex));
+        } else if (dataType instanceof TimestampNTZType) {
+            ((TimeStampMicroVector) vector).setSafe(rowIndex, row.getLong(fieldIndex));
+        } else if (dataType instanceof DecimalType decType) {
             if (decType.precision() <= 38) {
                 // Use Decimal type from InternalRow
                 java.math.BigDecimal decimal = row.getDecimal(fieldIndex, decType.precision(), decType.scale())
                         .toJavaBigDecimal();
                 ((DecimalVector) vector).setSafe(rowIndex, decimal);
             }
-        } else if (dataType instanceof ArrayType) {
-            ArrayType arrayType = (ArrayType) dataType;
+        } else if (dataType instanceof StructType structType) {
+            populateStructVector(
+                    (StructVector) vector, structType, row.getStruct(fieldIndex, structType.fields().length), rowIndex);
+        } else if (dataType instanceof ArrayType arrayType) {
             ArrayData data = row.getArray(fieldIndex);
             ListVector listVector = ((ListVector) vector);
             int writtenElements = listVector.getElementEndIndex(listVector.getLastSet());
@@ -229,6 +238,20 @@ private void populateVector(
         }
     }
 
+    private void populateStructVector(StructVector vector, StructType dataType, InternalRow row, int rowIndex) {
+        vector.setIndexDefined(rowIndex);
+
+        StructField[] fields = dataType.fields();
+        for (int fieldIndex = 0; fieldIndex < fields.length; fieldIndex++) {
+            FieldVector childVector = (FieldVector) vector.getVectorById(fieldIndex);
+            if (row.isNullAt(fieldIndex)) {
+                childVector.setNull(rowIndex);
+                continue;
+            }
+            populateVector(childVector, fields[fieldIndex].dataType(), row, fieldIndex, rowIndex);
+        }
+    }
+
     /**
      * Commits the write operation and returns a commit message.
      * <p>

java/vortex-spark/src/test/java/dev/vortex/spark/VortexDataSourceWriteTest.java

@@ -3,6 +3,7 @@
 
 package dev.vortex.spark;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -324,6 +325,73 @@ public void testSpecialCharactersAndNulls() throws IOException {
         assertEquals("special!@#$%^&*()", specialRows.first().getString(1));
     }
 
+    @Test
+    @DisplayName("Write and read date, timestamp, and nested struct columns")
+    public void testWriteAndReadTemporalAndStructColumns() throws IOException {
+        Dataset<Row> originalDf = spark.range(0, 2)
+                .selectExpr(
+                        "cast(id as int) as id",
+                        "CASE WHEN id = 0 THEN CAST('2024-01-02' AS DATE) ELSE CAST('2024-02-03' AS DATE) END AS event_date",
+                        "CASE WHEN id = 0 THEN CAST('2024-01-02 03:04:05.123456' AS TIMESTAMP) "
+                                + "ELSE CAST('2024-02-03 04:05:06.654321' AS TIMESTAMP) END AS event_ts",
+                        "named_struct("
+                                + "'event_date', CASE WHEN id = 0 THEN CAST('2024-01-02' AS DATE) ELSE CAST('2024-02-03' AS DATE) END, "
+                                + "'event_ts', CASE WHEN id = 0 THEN CAST('2024-01-02 03:04:05.123456' AS TIMESTAMP) "
+                                + "ELSE CAST('2024-02-03 04:05:06.654321' AS TIMESTAMP) END, "
+                                + "'label', CASE WHEN id = 0 THEN 'alpha' ELSE 'beta' END"
+                                + ") AS payload");
+
+        Path outputPath = tempDir.resolve("temporal_struct_output");
+        originalDf
+                .write()
+                .format("vortex")
+                .option("path", outputPath.toUri().toString())
+                .mode(SaveMode.Overwrite)
+                .save();
+
+        Dataset<Row> readDf = spark.read()
+                .format("vortex")
+                .option("path", outputPath.toUri().toString())
+                .load();
+
+        List<String> expectedRows = List.of(
+                "{\"id\":0,\"event_date\":\"2024-01-02\",\"event_ts\":\"2024-01-02 03:04:05.123456\","
+                        + "\"payload_event_date\":\"2024-01-02\",\"payload_event_ts\":\"2024-01-02 03:04:05.123456\","
+                        + "\"payload_label\":\"alpha\"}",
+                "{\"id\":1,\"event_date\":\"2024-02-03\",\"event_ts\":\"2024-02-03 04:05:06.654321\","
+                        + "\"payload_event_date\":\"2024-02-03\",\"payload_event_ts\":\"2024-02-03 04:05:06.654321\","
+                        + "\"payload_label\":\"beta\"}");
+
+        assertEquals(DataTypes.DateType, readDf.schema().fields()[1].dataType());
+        assertEquals(DataTypes.TimestampType, readDf.schema().fields()[2].dataType());
+        assertTrue(readDf.schema().fields()[3].dataType() instanceof StructType);
+        assertEquals(expectedRows, projectTemporalAndStructRows(readDf));
+    }
+
+    @Test
+    @DisplayName("Write TimestampNTZ columns and nested structs")
+    public void testWriteTimestampNtzColumns() throws IOException {
+        Dataset<Row> timestampNtzDf = spark.range(0, 2)
+                .selectExpr(
+                        "cast(id as int) as id",
+                        "CASE WHEN id = 0 THEN CAST('2024-01-02 03:04:05.123456' AS TIMESTAMP_NTZ) "
+                                + "ELSE CAST(NULL AS TIMESTAMP_NTZ) END AS event_ntz",
+                        "named_struct("
+                                + "'event_ntz', CASE WHEN id = 0 THEN CAST('2024-01-02 03:04:05.123456' AS TIMESTAMP_NTZ) "
+                                + "ELSE CAST('2024-02-03 04:05:06.654321' AS TIMESTAMP_NTZ) END"
+                                + ") AS payload");
+
+        Path outputPath = tempDir.resolve("timestamp_ntz_output");
+        assertDoesNotThrow(() -> timestampNtzDf
+                .write()
+                .format("vortex")
+                .option("path", outputPath.toUri().toString())
+                .mode(SaveMode.Overwrite)
+                .save());
+
+        assertTrue(!findVortexFiles(outputPath).isEmpty(), "TimestampNTZ write should create Vortex files");
+    }
+
     /**
      * Creates a test DataFrame with monotonically increasing integers
      * and their string representations.
@@ -337,6 +405,23 @@ private Dataset<Row> createTestDataFrame(int numRows) {
                         "array('Alpha', 'Bravo', 'Charlie') AS elements");
     }
 
+    private List<String> projectTemporalAndStructRows(Dataset<Row> df) {
+        return df
+                .orderBy("id")
+                .selectExpr("to_json(named_struct("
+                        + "'id', id, "
+                        + "'event_date', cast(event_date as string), "
+                        + "'event_ts', date_format(event_ts, 'yyyy-MM-dd HH:mm:ss.SSSSSS'), "
+                        + "'payload_event_date', cast(payload.event_date as string), "
+                        + "'payload_event_ts', date_format(payload.event_ts, 'yyyy-MM-dd HH:mm:ss.SSSSSS'), "
+                        + "'payload_label', payload.label"
+                        + ")) as json")
+                .collectAsList()
+                .stream()
+                .map(row -> row.getString(0))
+                .collect(Collectors.toList());
+    }
+
     /**
      * Finds all Vortex files in the given directory.
      */