SpotifyBox.scala

package spotifybox

import java.net.HttpURLConnection
import java.net.URI
import java.net.URL
import scala.io.Source
import scala.xml.XML
import java.net.URLEncoder

object SpotifyBox extends App {

  val songs = getSongs("love").sortBy((x) => -x.length)
  println(songs)
  val answer = boxPack2(songs, 1500)

  def sumTracks(tracks: Seq[Track]): Float = {
	  tracks.foldLeft(0f)((acc, track) => acc + track.length)
  }
  
  var runningTotal = 0f;
  answer.foreach(track => {
    runningTotal += track.length
    println(s"${track.artist} ${track.title} ${timeFormat(track.length)} ${timeFormat(runningTotal)}")
  })

  def timeFormat(timef : Float) : String = {
    def timePad(s: Int): String = {
      if (s < 10) {
        "0" + s
      } else {
        s.toString
      }
    }
    val time = timef.toInt
    s"${time / 60}:${timePad(time % 60)}"
  }
  
  def getSongs(query: String): Seq[Track] = {
    val url = new URL("http://ws.spotify.com/search/1/track?q=" + URLEncoder.encode(query, "utf-8"));

    val xml = XML.load(url.openConnection().getInputStream())

    (xml \ "track").map(track => (
      Track((track \ "name").text, (track \ "artist" \ "name").text, (track \ "length").text.toFloat)))
  }

  def boxPack2(list: Seq[Track], len: Float): Seq[Track] = {
    def boxPack2(list: Seq[Track], len: Float, box: Seq[Track]): Seq[Track] = {
      list match {
        case Nil => box
        case h :: t if h.length < len => boxPack2(t, len-h.length, h +: box)
        case h :: t => boxPack2(t, len, box)
      }
    }
 
    var bestFit = boxPack2(list, len, Seq())
    var ewHax = list.tail
    while (sumTracks(ewHax) > len) {
      val fit = boxPack2(ewHax, len, Seq())
      ewHax = ewHax.tail
      if (sumTracks(fit) > sumTracks(bestFit)) {
        bestFit = fit
      }
    }
    bestFit
  }
}
case class Track(title: String, artist: String, length: Float)