gcp4zio.bq.Encoder.scala Maven / Gradle / Ivy

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package gcp4zio.bq

import com.google.cloud.bigquery.{Field, LegacySQLTypeName, Schema}
import java.util
import scala.jdk.CollectionConverters._
import scala.reflect.ClassTag
import scala.util.Try

object Encoder {

  private def getBQType(spType: String): LegacySQLTypeName = spType match {
    case "string"         => LegacySQLTypeName.STRING
    case "int"            => LegacySQLTypeName.INTEGER
    case "long"           => LegacySQLTypeName.INTEGER
    case "double"         => LegacySQLTypeName.FLOAT
    case "java.sql.Date"  => LegacySQLTypeName.DATE
    case "java.util.Date" => LegacySQLTypeName.DATE
    case "boolean"        => LegacySQLTypeName.BOOLEAN
    case _                => LegacySQLTypeName.STRING
  }

  private def getFields[T: ClassTag]: Array[(String, String)] =
    implicitly[ClassTag[T]].runtimeClass.getDeclaredFields.map(f => (f.getName, f.getType.getName))

  @SuppressWarnings(Array("org.wartremover.warts.Throw"))
  def apply[T: ClassTag]: Option[Schema] = Try {
    val fields   = new util.ArrayList[Field]
    val ccFields = getFields[T]
    if (ccFields.isEmpty)
      throw new RuntimeException("Schema not provided")
    ccFields.foreach(x => fields.add(Field.of(x._1, getBQType(x._2))))
    val s = Schema.of(fields)
    logger.info(s"Schema provided: ${s.getFields.asScala.map(x => (x.getName, x.getType))}")
    s
  }.toOption
}