Fix NameMapping loss in ParquetUtil.footerMetrics (#14617)

* Fix NameMapping loss in ParquetUtil.footerMetrics

When footerMetrics was called with a NameMapping, it correctly applied
the mapping to get field IDs but then passed the wrong MessageType to
ParquetMetrics.metrics, causing the IDs to be lost. This resulted in
empty metrics for Parquet files without embedded field IDs.

Fixed by passing parquetTypeWithIds instead of the original messageType.

* Addressed review comments

Author: tmater

parquet/src/main/java/org/apache/iceberg/parquet/ParquetUtil.java

@@ -79,10 +79,10 @@ public static Metrics footerMetrics(
       MetricsConfig metricsConfig,
       NameMapping nameMapping) {
     Preconditions.checkNotNull(fieldMetrics, "fieldMetrics should not be null");
-    MessageType messageType = metadata.getFileMetaData().getSchema();
     MessageType parquetTypeWithIds = getParquetTypeWithIds(metadata, nameMapping);
     Schema fileSchema = ParquetSchemaUtil.convertAndPrune(parquetTypeWithIds);
-    return ParquetMetrics.metrics(fileSchema, messageType, metricsConfig, metadata, fieldMetrics);
+    return ParquetMetrics.metrics(
+        fileSchema, parquetTypeWithIds, metricsConfig, metadata, fieldMetrics);
   }
 
   private static MessageType getParquetTypeWithIds(

parquet/src/test/java/org/apache/iceberg/parquet/TestParquet.java

@@ -28,6 +28,7 @@
 import static org.apache.iceberg.parquet.ParquetWritingTestUtils.write;
 import static org.apache.iceberg.relocated.com.google.common.collect.Iterables.getOnlyElement;
 import static org.apache.iceberg.types.Types.NestedField.optional;
+import static org.apache.iceberg.types.Types.NestedField.required;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.io.File;
@@ -37,6 +38,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.function.Function;
+import java.util.stream.Stream;
 import org.apache.avro.generic.GenericData;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.generic.GenericRecordBuilder;
@@ -46,6 +48,8 @@
 import org.apache.iceberg.Schema;
 import org.apache.iceberg.avro.AvroSchemaUtil;
 import org.apache.iceberg.io.InputFile;
+import org.apache.iceberg.mapping.MappingUtil;
+import org.apache.iceberg.mapping.NameMapping;
 import org.apache.iceberg.relocated.com.google.common.base.Strings;
 import org.apache.iceberg.relocated.com.google.common.collect.ImmutableMap;
 import org.apache.iceberg.relocated.com.google.common.collect.Iterables;
@@ -265,6 +269,51 @@ public void testColumnStatisticsEnabled() throws Exception {
     }
   }
 
+  @Test
+  public void testFooterMetricsWithNameMappingForFileWithoutIds() throws IOException {
+    Schema schemaWithIds =
+        new Schema(
+            required(1, "id", Types.LongType.get()), optional(2, "data", Types.StringType.get()));
+
+    NameMapping nameMapping = MappingUtil.create(schemaWithIds);
+
+    File file = createTempFile(temp);
+
+    // Write a Parquet file WITHOUT field IDs using plain Avro schema
+    org.apache.avro.Schema avroSchemaWithoutIds =
+        org.apache.avro.SchemaBuilder.record("test")
+            .fields()
+            .requiredLong("id")
+            .optionalString("data")
+            .endRecord();
+
+    try (ParquetWriter<GenericData.Record> writer =
+        AvroParquetWriter.<GenericData.Record>builder(ParquetIO.file(Files.localOutput(file)))
+            .withDataModel(GenericData.get())
+            .withSchema(avroSchemaWithoutIds)
+            .build()) {
+
+      GenericData.Record record = new GenericData.Record(avroSchemaWithoutIds);
+      record.put("id", 1L);
+      record.put("data", "a");
+      writer.write(record);
+    }
+
+    InputFile inputFile = Files.localInput(file);
+
+    try (ParquetFileReader reader = ParquetFileReader.open(ParquetIO.file(inputFile))) {
+      MessageType parquetSchema = reader.getFooter().getFileMetaData().getSchema();
+      assertThat(ParquetSchemaUtil.hasIds(parquetSchema)).isFalse();
+
+      Metrics metrics =
+          ParquetUtil.footerMetrics(
+              reader.getFooter(), Stream.empty(), MetricsConfig.getDefault(), nameMapping);
+
+      // The key assertion: column sizes should be keyed by field IDs from NameMapping
+      assertThat(metrics.columnSizes()).containsOnlyKeys(1, 2);
+    }
+  }
+
   private Pair<File, Long> generateFile(
       Function<MessageType, ParquetValueWriter<?>> createWriterFunc,
       int desiredRecordCount,