import Element.elem

abstract class Element{

  def contents: Array[String]

  def height: Int = contents.length

  def width: Int = contents(0).length

  def above(that: Element): Element = {

    //new ArrayElement(this.contents ++ that.contents)

    val this1 = this widen that.width

    val that1 = that widen this.width

    elem(this1.contents ++ that1.contents)

  }

  def left_align(that: Element): Element = {

    if (this.width == that.width){

      this above that

    }

    else if (this.width < that.width) {

      (this beside elem(' ', that.width - this.width, this.height)) above that

    }

    else {

      this above (that beside elem(' ', this.width - that.width, that.height))

    }

  }

  def up_align(that: Element): Element = {

    if (this.height == that.height){

      this beside that

    }

    else if (this.height < that.height) {

      (this above elem(' ', this.width, that.height - this.height)) beside that

    }

    else {

      this beside (that above elem(' ', that.width, this.height - that.height))

    }  

  }

  def beside(that: Element): Element = {

    val this1 = this heighten that.height

    val that1 = that heighten this.height

    elem(

      for ((line1, line2) <- this1.contents zip that1.contents)

      yield line1 + line2)

  }

  def widen(w: Int): Element = 

    if(w <= width) this

    else {

      val left = Element.elem(' ', (w - width) / 2, height)

      var right = Element.elem(' ', w - width - left.width, height)

      left beside this beside right

    }

  def heighten(h: Int): Element = 

    if (h <= height) this

    else {

      val top = Element.elem(' ', width, (h - height) / 2)

      val bot = Element.elem(' ', width, h - height - top.height)

      top above this above bot

    }

  override def toString = contents mkString "\n"

}

object Element {

  private class ArrayElement(

    val contents: Array[String]

  ) extends Element

  private class LineElement(s: String) extends Element {

    val contents = Array(s)

    override def width = s.length

    override def height = 1

  }

  private class UniformElement(

    ch: Char,

    override val width: Int,

    override val height: Int

  ) extends Element {

    private val line = ch.toString * width

    def contents = Array.fill(height)(line)

  }

  def elem(contents: Array[String]): Element =

    new ArrayElement(contents)

  def elem(chr: Char, width: Int, height: Int): Element =

    new UniformElement(chr, width, height)

  def elem(line: String): Element =

      new LineElement(line)

}