package net.tz.spss

import java.io.File

import com.bedatadriven.spss.SpssDataFileReader

import scala.collection.JavaConverters._

import scala.language.postfixOps

class SpssReader(private val r: SpssDataFileReader)

  extends Iterator[Map[SpssVariable, SpssValue]] {

  lazy val variables: List[SpssVariable] =

    r.getVariables.asScala.toList map spssVarJtoS

  override def hasNext: Boolean = r.readNextCase()

  override def next(): Map[SpssVariable, SpssValue] =

    variables map(v => (v, asValue(v))) toMap

  private def asValue(variable: SpssVariable): SpssValue = {

    val i = variable.index

      SystemMissing

      Option(r.getDoubleValue(i)) map(x =>

        if (r.isValueMissing(i, x)) MissingDouble(x) else DoubleValue(x)

        ) getOrElse SystemMissing

  }

}

object SpssReader {

  def apply(f: File): SpssReader = new SpssReader(new SpssDataFileReader(f))

}