;; Benchmark: 1.9us
;; Benchmark-Repeat: 1072
;; Output: [150 130 "Insufficient funds" 130]

; ---------------------------------------------------------
; Object-Oriented Records Example
; ---------------------------------------------------------
; This showcase treats a record as an object by storing 
; closures that capture private state.

(do
  ; A factory function (Constructor) for a BankAccount object
  (def make-account (fn [initial-balance]
    (do
      ; 'balance' is a captured parameter, acting as private state
      (def balance initial-balance)
      
      {
        ; Method: Get current balance
        :balance (fn [] balance)
        
        ; Method: Deposit money
        :deposit (fn [amount] 
          (assign balance (+ balance amount)))
        
        ; Method: Withdraw money with validation
        :withdraw (fn [amount]
          (if (>= balance amount)
            (assign balance (- balance amount))
            "Insufficient funds"))
      }
    )))

  ; 1. Create an instance
  (def my-acc (make-account 100))

  ; 2. Call 'deposit' method
  ; Note the double parens: (.deposit my-acc) gets the function, then we call it
  (def b1 ((.deposit my-acc) 50)) ; balance is now 150

  ; 3. Call 'withdraw' method
  (def b2 ((.withdraw my-acc) 20)) ; balance is now 130

  ; 4. Call 'withdraw' with invalid amount
  (def error-msg ((.withdraw my-acc) 1000))

  ; 5. Call 'balance' getter
  (def final-balance ((.balance my-acc)))

  ; Return summary of operations
  [b1 b2 error-msg final-balance]
)