Scala Script to print Git PunchCard

GitPunchCard.scala

/**
  * Quick and dirty Scala app to print git commit punch-card e.g.
  *
  *    ┃08┃09┃10┃11┃12┃13┃14┃15┃16┃17┃18┃19┃20┃21┃22┃23┃00┃01┃02┃03┃04┃05┃06┃07┃
  * Sun┃▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
  * Mon┃▁▁▁▄▄▄▅▅▅▅▅▅▄▄▄▆▆▆▇▇▇▇▇▇███▆▆▆▅▅▅▄▄▄▃▃▃▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
  * Tue┃▁▁▁▃▃▃▆▆▆▅▅▅▅▅▅▅▅▅▆▆▆▇▇▇▆▆▆▆▆▆▅▅▅▅▅▅▄▄▄▃▃▃▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
  * Wed┃▁▁▁▄▄▄▅▅▅▇▇▇▅▅▅▅▅▅███▇▇▇▅▅▅▆▆▆▇▇▇▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
  * Thu┃▁▁▁▂▂▂▄▄▄▆▆▆▅▅▅▆▆▆▇▇▇▇▇▇▆▆▆▇▇▇▅▅▅▄▄▄▃▃▃▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
  * Fri┃▁▁▁▂▂▂▄▄▄▅▅▅▅▅▅▄▄▄▄▄▄▅▅▅▅▅▅▃▃▃▃▃▃▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
  * Sat┃▁▁▁▁▁▁▁▁▁▃▃▃▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁
  */
object GitPunchCard extends App {
  import java.time._
  /********************************[Config]*************************************/
  val startHour = 8                                        // Starting hour [0,23]
  val startDay = DayOfWeek.SUNDAY                          // Starting week day
  val gitLogFilter = ""                                    // Specify author or date filter for git log
  val dir = Option.empty[String]                           // If specified run in particular git directory
  val locale = java.util.Locale.getDefault
  /******************************************************************************/

  val commits = {
    import scala.sys.process._
    val cmd = s"git ${dir.map("-C " + _).getOrElse("")} log --format=%cI $gitLogFilter"
    cmd.!!.split("\n").map(ZonedDateTime.parse)
  }

  val table = commits.groupBy(t => (t.getDayOfWeek, t.getHour)).mapValues(_.length).withDefaultValue(0)

  val bars = "▁▂▃▄▅▆▇█"

  def sparkLine(x: Int, max: Int = table.values.max) = bars(((bars.length*(x-1))/max) max 0)

  def makeLine(prefix: String, f: Int => String) = s"$prefix┃" + (0 until 24).map(h => f((h + startHour)%24)).mkString

  def shortDay(d: DayOfWeek) = d.getDisplayName(format.TextStyle.SHORT, locale)

  val lines = makeLine(" " * shortDay(startDay).length, h => f"$h%02d┃") +:
    DayOfWeek.values()
      .map(_.plus(startDay.getValue.toLong - 1))
      .map(day => makeLine(shortDay(day), h => sparkLine(table(day -> h)).toString * 3))

  lines.foreach(println)
}