should be it

external/duckdb/extension/parquet/include/geo_parquet.hpp

@@ -0,0 +1,102 @@
+//===----------------------------------------------------------------------===//
+//                         DuckDB
+//
+// geo_parquet.hpp
+//
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include "column_writer.hpp"
+#include "duckdb/common/string.hpp"
+#include "duckdb/common/types/data_chunk.hpp"
+#include "duckdb/common/unordered_map.hpp"
+#include "duckdb/common/unordered_set.hpp"
+#include "parquet_types.h"
+
+namespace duckdb {
+
+struct ParquetColumnSchema;
+class ParquetReader;
+class ColumnReader;
+class ClientContext;
+class ExpressionExecutor;
+
+enum class GeoParquetColumnEncoding : uint8_t {
+	WKB = 1,
+	POINT,
+	LINESTRING,
+	POLYGON,
+	MULTIPOINT,
+	MULTILINESTRING,
+	MULTIPOLYGON,
+};
+
+enum class GeoParquetVersion : uint8_t {
+	// Write GeoParquet 1.0 metadata
+	// GeoParquet 1.0 has the widest support among readers and writers
+	V1,
+
+	// Write GeoParquet 2.0
+	// The GeoParquet 2.0 options is identical to GeoParquet 1.0 except the underlying storage
+	// of spatial columns is Parquet native geometry, where the Parquet writer will include
+	// native statistics according to the underlying Parquet options. Compared to 'BOTH', this will
+	// actually write the metadata as containing GeoParquet version 2.0.0
+	// However, V2 isnt standardized yet, so this option is still a bit experimental
+	V2,
+
+	// Write GeoParquet 1.0 metadata, with native Parquet geometry types
+	// This is a bit of a hold-over option for compatibility with systems that
+	// reject GeoParquet 2.0 metadata, but can read Parquet native geometry types as they simply ignore the extra
+	// logical type. DuckDB v1.4.0 falls into this category.
+	BOTH,
+
+	// Do not write GeoParquet metadata
+	// This option suppresses GeoParquet metadata; however, spatial types will be written as
+	// Parquet native Geometry/Geography.
+	NONE,
+};
+
+struct GeoParquetColumnMetadata {
+	// The encoding of the geometry column
+	GeoParquetColumnEncoding geometry_encoding;
+
+	// The statistics of the geometry column
+	GeometryStatsData stats;
+
+	// The crs of the geometry column (if any) in PROJJSON format
+	string projjson;
+
+	// Used to track the "primary" geometry column (if any)
+	idx_t insertion_index = 0;
+};
+
+class GeoParquetFileMetadata {
+public:
+	explicit GeoParquetFileMetadata(GeoParquetVersion geo_parquet_version) : version(geo_parquet_version) {
+	}
+	void AddGeoParquetStats(const string &column_name, const LogicalType &type, const GeometryStatsData &stats);
+	void Write(duckdb_parquet::FileMetaData &file_meta_data);
+
+	// Try to read GeoParquet metadata. Returns nullptr if not found, invalid or the required spatial extension is not
+	// available.
+	static unique_ptr<GeoParquetFileMetadata> TryRead(const duckdb_parquet::FileMetaData &file_meta_data,
+	                                                  const ClientContext &context);
+	const unordered_map<string, GeoParquetColumnMetadata> &GetColumnMeta() const;
+
+	static unique_ptr<ColumnReader> CreateColumnReader(ParquetReader &reader, const ParquetColumnSchema &schema,
+	                                                   ClientContext &context);
+
+	bool IsGeometryColumn(const string &column_name) const;
+
+	static bool IsGeoParquetConversionEnabled(const ClientContext &context);
+	static LogicalType GeometryType();
+
+private:
+	mutex write_lock;
+	unordered_map<string, GeoParquetColumnMetadata> geometry_columns;
+	GeoParquetVersion version;
+};
+
+} // namespace duckdb