package sandcrawler

import scala.math
import scala.util.parsing.json.JSON
import scala.util.parsing.json.JSONObject

import cascading.flow.FlowDef
import cascading.tuple.Fields
import com.twitter.scalding._
import com.twitter.scalding.typed.TDsl._
import parallelai.spyglass.hbase.HBasePipeConversions

class CrossrefScorable extends Scorable with HBasePipeConversions {
  // TODO: Generalize args so there can be multiple Crossref pipes in one job.
  def getSource(args : Args) : Source = {
    TextLine(args("crossref-input"))
  }

  def getFeaturesPipe(args : Args)(implicit mode : Mode, flowDef : FlowDef) : TypedPipe[MapFeatures] = {
    getSource(args).read
      .toTypedPipe[String](new Fields("line"))
      .filter { CrossrefScorable.keepRecord(_) }
      .map { CrossrefScorable.jsonToMapFeatures(_) }
  }
}

object CrossrefScorable {
  def keepRecord(json : String) : Boolean = {
    Scorable.jsonToMap(json) match {
      case None => false
      case Some(map) => {
        mapToTitle(map) match {
          case None => false
          case Some(title) => title.length <= Scorable.MaxTitleLength
        }
      }
    }
  }

  // Returns None if title is null, empty, or too long.
  def mapToTitle(map : Map[String, Any]) : Option[String] = {
    if (map contains "title") {
      val titles = map("title").asInstanceOf[List[String]]
      if (titles.isEmpty || titles == null) {
        None
      } else {
        val title = titles(0)
        if (title == null || title.isEmpty || title.length > Scorable.MaxTitleLength) None else Some(title)
      }
    } else None
  }

  def jsonToMapFeatures(json : String) : MapFeatures = {
    Scorable.jsonToMap(json) match {
      case None => MapFeatures(Scorable.NoSlug, json)
      case Some(map) => 
        mapToTitle(map) match {
          case None => MapFeatures(Scorable.NoSlug, json)
          case Some(title) => {
            val doi = Scorable.getString(map, "DOI")
            if (doi.isEmpty || doi == null) {
              MapFeatures(Scorable.NoSlug, json)
            } else {
              val sf : ScorableFeatures = ScorableFeatures.create(title=title, doi=doi)
              MapFeatures(sf.toSlug, sf.toString)
            }
          }
        }
    }
  }
}