package week5

import swing._
import javax.swing._
import java.awt.BorderLayout
import scala.swing.event._

object Calculator extends SimpleSwingApplication {
  final val INFO_FIELD_TEXT_DEFAULT = "------------------------------"
  def numberField = new TextField {
    text = "0"
    columns = 5
  }

  val a = numberField
  val b = numberField
  val plusButton = new Button("+")
  val minusButton = new Button("-")
  val timesButton = new Button("*")
  val divisionButton = new Button("/")
  val info = new TextField(INFO_FIELD_TEXT_DEFAULT)

  def top = new MainFrame {
    title = "Kuljulator"
    contents = new FlowPanel(
        new FlowPanel(a, b),
        new FlowPanel(plusButton, minusButton, timesButton, divisionButton),
        new FlowPanel(info))
  }

  listenTo(plusButton, minusButton, timesButton, divisionButton)
  reactions += {
    case ButtonClicked(x) => x.text match {
      case "+" => plus
      case "-" => minus
      case "*" => times
      case "/" => divide
    }
  }

  def getXY(a : TextField, b : TextField) : Tuple2[Double, Double] = {
    val x = a.text.replace(',', '.').toDouble
    val y = b.text.replace(',', '.').toDouble

    new Tuple2(x, y)
  }

  def setValuesToButtons(result : Double) {
    a.text = result+""
    b.text = "0"
    info.text = INFO_FIELD_TEXT_DEFAULT
  }

  def plus {
    val xy = getXY(a, b)
    setValuesToButtons(xy._1 + xy._2)
  }

  def minus {
    val xy = getXY(a, b)
    setValuesToButtons(xy._1-xy._2)
  }

  def times {
    val xy = getXY(a, b)
    setValuesToButtons(xy._1*xy._2)
  }

  def divide {
    val xy = getXY(a, b)
    if (xy._2 != 0) {
      setValuesToButtons(xy._1/xy._2)
    } else {
      info.text = "Division by zero"
    }
  }
}