//
// program to track bank balance and transactions
// prompts for initial balance, 
// then repeatedly for one of the following:
//   't' for transaction -- amount (positive for credit, negative for debit)
//     and description
//   'h' for transaction history
//   'q' to quit
//

println("initial balance (integer)?")
var balance = readInt
var history = List[(Int, String)]()

var choice = ' '

do {
  println("current balance $" + balance)
  println("what do you want to do?")
  println("(t for transaction, h for history, q for quit)")
  choice = readChar

  choice match {
    case 't' => 
      println("enter amount (integer, positive for credit, negative for debit)")
      val amt = readInt
      println("enter description (line of text)")
      val text = readLine
      history = (amt, text) :: history
      balance += amt
    case 'h' => 
      for (trans <- history) {
        println(trans) // FIXME format this better
      }
    case 'q' => 
      println("ending balance $" + balance)
    case _ => 
      println("invalid choice")
  }
} while (choice != 'q')