//
// program to simulate checkbook, sort of -- maintain list of transactions
// (checks and deposits) and current balance, allow some simple queries of
// transactions
//
// each transaction will consist of an amount, "check" or "deposit",
// and a line of text to identify it (e.g., "paycheck" or "rent")
//

var balance = 0
var transactions = List[(Int, String, String)]()

val Prompt = """enter one of:
    c for check
    d for deposit
    h for transaction history
    s to search transactions
    q to quit"""

println("starting balance (integer):")
balance = readInt

var choice = ' '

do {
  println("current balance $" + balance)
  println(Prompt)
  choice = readChar

  choice match {
    case 'c' => {
      getTransaction('c')
    }
    case 'd' => {
      getTransaction('d')
    }
    case 'h' => {
      // FIXME improve this
      transactions.foreach(elem => println(elem))
    }
    case 's' => {
      println("text to search for:")
      val s = readLine
      transactions.filter(trans => descrMatch(trans, s)).
      foreach(elem => println(elem))
    }
    case 'q' => { }
    case _ => {
      println("invalid choice")
    }
  }
} while (choice != 'q')

def descrMatch(trans : (Int, String, String), searchText : String) : Boolean = {
  val (a, c, d) = trans
  d.contains(searchText)
}

def getTransaction(choice : Char) {
  println("enter amount")
  val amount = readInt
  println("enter description")
  val d = readLine
  choice match {
    case 'c' => { 
      balance -= amount 
      transactions = (amount, "check", d) :: transactions
    }
    case 'd' => { 
      balance += amount 
      transactions = (amount, "deposit", d) :: transactions
    }
    case _ => { } // FIXME should this be an error?
  }
}