A way to get OHLC data from Cryptowatch API in scala

CryptowatchData.scala

import org.json4s._
import org.json4s.native.JsonMethods._

case class MarketCandle(
    unixCloseTime: Int, 
    openPrice: Double,
    highPrice: Double,
    lowPrice: Double,
    closePrice: Double,
    change: Double,
    volume: Double
)

object CryptowatchData{

    implicit val formats = DefaultFormats

    def main(args: Array[String]): Unit = {
        if (args.length != 3) {
            println("Usage:\n\tCryptowatchData <exchange> <market> <period>")
            System.exit(1)
        }
        val exchange = args(0)
        val market = args(1)
        val period = args(2)
        println(s"CryptowatchData started with parameters [$exchange] [$market] [$period]")
        var data = getApiData(s"https://api.cryptowat.ch/markets/$exchange/$market/ohlc?periods=$period")
        data = data.slice(data.indexOf("[["), data.indexOf("]]") + 2) //remove whatever crap cryptowatch put in front and after value arrays
        var candles = List[MarketCandle]()
        parse(data).asInstanceOf[JArray].arr.foreach(a => {
            candles = MarketCandle(
                a(0).extract[Int], 
                a(1).extract[Double], 
                a(2).extract[Double], 
                a(3).extract[Double], 
                a(4).extract[Double], 
                a(5).extract[Double], 
                a(6).extract[Double]) :: candles
        })
        println(candles)
    }

    @throws(classOf[java.io.IOException])
    def getApiData(url: String) = scala.io.Source.fromURL(url).mkString
}