package week5

import swing._
import javax.swing._
import scala.swing.event._

object SuperCalculator extends SimpleSwingApplication {
  val numberField = new TextField() { columns = 10 }
  val numbers = new GridPanel(4, 3) {
    contents ++= (1 to 9).map(x => new Button(x.toString))
    contents ++= Array(new Button("0"), new Button("C"))
  }

  val operations = new GridPanel(5,1) {
    contents ++= Array("/", "*", "-", "+", "=").map(x => new Button(x))
  }

  def top = new MainFrame {
    title = "Neliölaskin"
    contents = new BorderPanel {
      layout(numberField) = BorderPanel.Position.North
      layout(numbers) = BorderPanel.Position.West
      layout(operations) = BorderPanel.Position.East
    }
  }

  var currentOperation : (Double, Double) => Double = null
  var currentNumber : Double = 0

  numbers.contents.foreach(listenTo(_))
  operations.contents.foreach(listenTo(_))
  reactions += {
    case ButtonClicked(x) => x.text match {
      case "+" => setCurrentOperation((x, y) => x+y)
      case "-" => setCurrentOperation((x, y) => x-y)
      case "*" => setCurrentOperation((x, y) => x*y)
      case "/" => setCurrentOperation((x, y) => x/y)
      case "C" => {
        numberField.text = ""
        currentOperation = null
        currentNumber = 0
      }
      case "=" => calculate(currentOperation)
      case _   => numberField.text += x.text.toInt
    }
  }

  def setCurrentOperation(function : (Double, Double) => Double) = {
    currentOperation = function
    currentNumber = numberField.text.replace(',', '.').toDouble
    numberField.text = ""
  }

  def calculate(operation : (Double, Double) => Double) {
    numberField.text = (operation(currentNumber, numberField.text.replace(',', '.').toDouble)).toString
  }
}