[SEDONA-429][SEDONA-430] Support specifying GeoParquet spec version number and CRS

docs/tutorial/sql.md

@@ -656,6 +656,37 @@ Since v`1.3.0`, Sedona natively supports writing GeoParquet file. GeoParquet can
 df.write.format("geoparquet").save(geoparquetoutputlocation + "/GeoParquet_File_Name.parquet")
 ```
 
+Since v`1.5.1`, Sedona supports writing GeoParquet files with custom GeoParquet spec version and crs.
+The default GeoParquet spec version is `1.0.0` and the default crs is `null`. You can specify the GeoParquet spec version and crs as follows:
+
+```scala
+val projjson = "{...}" // PROJJSON string for all geometry columns
+df.write.format("geoparquet")
+		.option("geoparquet.version", "1.0.0")
+		.option("geoparquet.crs", projjson)
+		.save(geoparquetoutputlocation + "/GeoParquet_File_Name.parquet")
+```
+
+If you have multiple geometry columns written to the GeoParquet file, you can specify the CRS for each column.
+For example, `g0` and `g1` are two geometry columns in the DataFrame `df`, and you want to specify the CRS for each column as follows:
+
+```scala
+val projjson_g0 = "{...}" // PROJJSON string for g0
+val projjson_g1 = "{...}" // PROJJSON string for g1
+df.write.format("geoparquet")
+		.option("geoparquet.version", "1.0.0")
+		.option("geoparquet.crs.g0", projjson_g0)
+		.option("geoparquet.crs.g1", projjson_g1)
+		.save(geoparquetoutputlocation + "/GeoParquet_File_Name.parquet")
+```
+
+You can find the projjson string of a specific CRS from here: https://epsg.io/ (click the JSON option at the bottom of the page). You can also customize your projjson string as needed.
+
+Please note that Sedona currently cannot set/get a projjson string to/from a CRS. Its geoparquet reader will ignore the projjson metadata and you will have to set your CRS via [`ST_SetSRID`](../api/sql/Function.md#st_setsrid) after reading the file.
+Its geoparquet writer will not leverage the SRID field of a geometry so you will have to always set the `geoparquet.crs` option manually when writing the file, if you want to write a meaningful CRS field.
+
+Due to the same reason, Sedona geoparquet reader and writer do NOT check the axis order (lon/lat or lat/lon) and assume they are handled by the users themselves when writing / reading the files. You can always use [`ST_FlipCoordinates`](../api/sql/Function.md#st_flipcoordinates) to swap the axis order of your geometries.
+
 ## Sort then Save GeoParquet
 
 To maximize the performance of Sedona GeoParquet filter pushdown, we suggest that you sort the data by their geohash values (see [ST_GeoHash](../../api/sql/Function/#st_geohash)) and then save as a GeoParquet file. An example is as follows:

spark/common/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/GeoParquetMetaData.scala

@@ -14,12 +14,7 @@
 package org.apache.spark.sql.execution.datasources.parquet
 
 import org.json4s.jackson.JsonMethods.parse
-
-/**
- * A case class that holds CRS metadata for geometry columns. This class is left empty since CRS
- * metadata was not implemented yet.
- */
-case class CRSMetaData()
+import org.json4s.JValue
 
 /**
  * A case class that holds the metadata of geometry column in GeoParquet metadata
@@ -31,7 +26,7 @@ case class GeometryFieldMetaData(
   encoding: String,
   geometryTypes: Seq[String],
   bbox: Seq[Double],
-  crs: Option[CRSMetaData] = None)
+  crs: Option[JValue] = None)
 
 /**
  * A case class that holds the metadata of GeoParquet file
@@ -45,10 +40,20 @@ case class GeoParquetMetaData(
   columns: Map[String, GeometryFieldMetaData])
 
 object GeoParquetMetaData {
-  // We're conforming to version 1.0.0-beta.1 of the GeoParquet specification, please refer to
-  // https://github.com/opengeospatial/geoparquet/blob/v1.0.0-beta.1/format-specs/geoparquet.md
-  // for more details.
-  val VERSION = "1.0.0-beta.1"
+  // We're conforming to version 1.0.0 of the GeoParquet specification, please refer to
+  // https://geoparquet.org/releases/v1.0.0/ for more details.
+  val VERSION = "1.0.0"
+
+  /**
+   * Configuration key for overriding the version field in GeoParquet file metadata.
+   */
+  val GEOPARQUET_VERSION_KEY = "geoparquet.version"
+
+  /**
+   * Configuration key for setting the CRS of the geometries in GeoParquet column metadata. This is applied to
+   * all geometry columns in the file.
+   */
+  val GEOPARQUET_CRS_KEY = "geoparquet.crs"
 
   def parseKeyValueMetaData(keyValueMetaData: java.util.Map[String, String]): Option[GeoParquetMetaData] = {
     Option(keyValueMetaData.get("geo")).map { geo =>

spark/spark-3.0/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/GeoParquetWriteSupport.scala

@@ -30,14 +30,15 @@ import org.apache.spark.sql.SPARK_VERSION_METADATA_KEY
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions.SpecializedGetters
 import org.apache.spark.sql.catalyst.util.DateTimeUtils
+import org.apache.spark.sql.execution.datasources.parquet.GeoParquetMetaData.{GEOPARQUET_CRS_KEY, GEOPARQUET_VERSION_KEY, VERSION}
 import org.apache.spark.sql.execution.datasources.parquet.GeoParquetWriteSupport.GeometryColumnInfo
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.internal.SQLConf.LegacyBehaviorPolicy
 import org.apache.spark.sql.sedona_sql.UDT.GeometryUDT
 import org.apache.spark.sql.types._
-import org.json4s.DefaultFormats
-import org.json4s.Extraction
+import org.json4s.{DefaultFormats, Extraction, JValue}
 import org.json4s.jackson.compactJson
+import org.json4s.jackson.JsonMethods.parse
 import org.locationtech.jts.geom.Geometry
 import org.locationtech.jts.io.WKBWriter
 
@@ -106,6 +107,10 @@ class GeoParquetWriteSupport extends WriteSupport[InternalRow] with Logging {
   // fields in nested structures.
   private val geometryColumnInfoMap: mutable.Map[Int, GeometryColumnInfo] = mutable.Map.empty
 
+  private var geoParquetVersion: Option[String] = None
+  private var defaultGeoParquetCrs: Option[JValue] = None
+  private val geoParquetColumnCrsMap: mutable.Map[String, Option[JValue]] = mutable.Map.empty
+
   override def init(configuration: Configuration): WriteContext = {
     val schemaString = configuration.get(ParquetWriteSupport.SPARK_ROW_SCHEMA)
     this.schema = StructType.fromString(schemaString)
@@ -129,6 +134,25 @@ class GeoParquetWriteSupport extends WriteSupport[InternalRow] with Logging {
       throw new RuntimeException("No geometry column found in the schema")
     }
 
+    geoParquetVersion = configuration.get(GEOPARQUET_VERSION_KEY) match {
+      case null => Some(VERSION)
+      case version: String => Some(version)
+    }
+    defaultGeoParquetCrs = configuration.get(GEOPARQUET_CRS_KEY) match {
+      case null =>
+        // If no CRS is specified, we write null to the crs metadata field. This is for compatibility with
+        // geopandas 0.10.0 and earlier versions, which requires crs field to be present.
+        Some(org.json4s.JNull)
+      case "" => None
+      case crs: String => Some(parse(crs))
+    }
+    geometryColumnInfoMap.keys.map(schema(_).name).foreach { name =>
+      Option(configuration.get(GEOPARQUET_CRS_KEY + "." + name)).foreach {
+        case "" => geoParquetColumnCrsMap.put(name, None)
+        case crs: String => geoParquetColumnCrsMap.put(name, Some(parse(crs)))
+      }
+    }
+
     val messageType = new SparkToParquetSchemaConverter(configuration).convert(schema)
     val sparkSqlParquetRowMetadata = GeoParquetWriteSupport.getSparkSqlParquetRowMetadata(schema)
     val metadata = Map(
@@ -173,10 +197,11 @@ class GeoParquetWriteSupport extends WriteSupport[InternalRow] with Logging {
         val bbox = if (geometryTypes.nonEmpty) {
           Seq(columnInfo.bbox.minX, columnInfo.bbox.minY, columnInfo.bbox.maxX, columnInfo.bbox.maxY)
         } else Seq(0.0, 0.0, 0.0, 0.0)
-        columnName -> GeometryFieldMetaData("WKB", geometryTypes, bbox)
+        val crs = geoParquetColumnCrsMap.getOrElse(columnName, defaultGeoParquetCrs)
+        columnName -> GeometryFieldMetaData("WKB", geometryTypes, bbox, crs)
       }.toMap
-      val geoParquetMetadata = GeoParquetMetaData(Some(GeoParquetMetaData.VERSION), primaryColumn, columns)
-      implicit val formats: org.json4s.Formats = DefaultFormats.preservingEmptyValues
+      val geoParquetMetadata = GeoParquetMetaData(geoParquetVersion, primaryColumn, columns)
+      implicit val formats: org.json4s.Formats = DefaultFormats
       val geoParquetMetadataJson = compactJson(Extraction.decompose(geoParquetMetadata).underscoreKeys)
       metadata.put("geo", geoParquetMetadataJson)
     }