Fix conversions, enumerator and table

Author: bchapuis

baremaps-calcite/src/main/java/org/apache/baremaps/calcite/geoparquet/GeoParquetTable.java

@@ -101,11 +101,18 @@ private static class GeoParquetEnumerator implements Enumerator<Object[]> {
     private GeoParquetGroup currentRow;
     private boolean hasNext;
     private final Path path;
+    private java.util.Iterator<GeoParquetGroup> iterator;
 
     public GeoParquetEnumerator(GeoParquetReader reader, GeoParquetSchema schema) {
       this.reader = reader;
       this.schema = schema;
       this.path = new Path(reader.getGeoParquetSchema().name());
+      try {
+        // Initialize the iterator once from the stream
+        this.iterator = reader.read().iterator();
+      } catch (Exception e) {
+        throw new RuntimeException("Failed to initialize GeoParquet reader", e);
+      }
       this.hasNext = true;
       moveNext();
     }
@@ -124,12 +131,14 @@ public boolean moveNext() {
       if (!hasNext) {
         return false;
       }
-      try {
-        currentRow = reader.read().findFirst().orElse(null);
-        hasNext = currentRow != null;
-        return hasNext;
-      } catch (Exception e) {
-        throw new RuntimeException("Failed to read GeoParquet row", e);
+
+      if (iterator.hasNext()) {
+        currentRow = iterator.next();
+        return true;
+      } else {
+        currentRow = null;
+        hasNext = false;
+        return false;
       }
     }
 
@@ -138,6 +147,7 @@ public void reset() {
       try {
         reader.close();
         GeoParquetReader newReader = new GeoParquetReader(this.path);
+        this.iterator = newReader.read().iterator();
         currentRow = null;
         hasNext = true;
         moveNext();

baremaps-calcite/src/main/java/org/apache/baremaps/calcite/geoparquet/GeoParquetTypeConversion.java

@@ -244,35 +244,13 @@ public static List<Object> asPostgresRowValues(GeoParquetGroup group) {
 
     for (int i = 0; i < schema.fields().size(); i++) {
       Field field = schema.fields().get(i);
+      // Use convertValue to get values converted to Calcite types
       Object value = convertValue(field, group, i);
 
-      // Convert record types to JSON strings
-      if (field.type() == Type.GROUP || field.type() == Type.ENVELOPE) {
+      // Only handle GROUP types for PostgreSQL - other types pass through Calcite
+      if (field.type() == Type.GROUP) {
         try {
-          if (field.type() == Type.GROUP) {
-            value = MAPPER.writeValueAsString(value);
-          } else if (field.type() == Type.ENVELOPE) {
-            // Convert envelope to a map with minx, miny, maxx, maxy
-            Map<String, Object> envelopeMap = new HashMap<>();
-            if (value instanceof org.locationtech.jts.geom.Envelope) {
-              org.locationtech.jts.geom.Envelope envelope =
-                  (org.locationtech.jts.geom.Envelope) value;
-              envelopeMap.put("minx", envelope.getMinX());
-              envelopeMap.put("miny", envelope.getMinY());
-              envelopeMap.put("maxx", envelope.getMaxX());
-              envelopeMap.put("maxy", envelope.getMaxY());
-            } else if (value instanceof Object[]) {
-              Object[] envelope = (Object[]) value;
-              envelopeMap.put("minx", envelope[0]);
-              envelopeMap.put("miny", envelope[1]);
-              envelopeMap.put("maxx", envelope[2]);
-              envelopeMap.put("maxy", envelope[3]);
-            } else {
-              throw new IllegalArgumentException(
-                  "Unexpected envelope type: " + value.getClass().getName());
-            }
-            value = MAPPER.writeValueAsString(envelopeMap);
-          }
+          value = MAPPER.writeValueAsString(value);
         } catch (Exception e) {
           throw new RuntimeException("Error converting record type to JSON", e);
         }