package o1.time

class Interval (val start: Moment, val end: Moment)   {
  def length: Int = start.distance(end)

  override def toString = {
    if(length == 0) "" + start
    else if(length <= 50) "" + start +  ("-" * length) + end
    else "" + start + "..." + end
  }

  def isLaterThan(another: Moment): Boolean = {
    start.isLaterThan(another)
  }

  def isLaterThan(another: Interval) = {
    start.isLaterThan(another.end)
  }

  def contains(another: Interval): Boolean = {
    !this.start.isLaterThan(another.start) && !another.end.isLaterThan(this.end)
  }

  def contains(another: Moment): Boolean = {
    !start.isLaterThan(another) && !another.isLaterThan(end)
  }

  def overlaps(another: Interval): Boolean = {
    !this.start.isLaterThan(another.end) && !another.start.isLaterThan(this.end)
  }

  def union(another: Interval): Interval = {
    new Interval(if (this.start.isLaterThan(another.start)) another.start else this.start, if(this.end.isLaterThan(another.end)) this.end else another.end)
  }

  def intersection(another: Interval): Option[Interval] = {
    if(this.overlaps(another)) Some( new Interval(this.start.later(another.start), this.end.earlier(another.end)) )

    else None
  }
}