package account

import "sync"

// Account just represents a user's account
type Account struct {
	sync.RWMutex
	balance int
	closed  bool
}

// Open returns a new account
func Open(amt int) *Account {
	a := new(Account)
	_, ok := a.Deposit(amt)
	if ok {
		return a
	}
	return nil
}

// Close returns the payout amount and an 'ok' flag
func (a *Account) Close() (int, bool) {
	a.Lock()
	ret := a.balance
	if a.closed {
		a.Unlock()
		return 0, false
	}
	a.closed = true
	a.balance = 0
	a.Unlock()
	return ret, true
}

// Balance returns the current account balance
// and an 'ok' flag
func (a *Account) Balance() (int, bool) {
	if a.closed {
		return 0, false
	}
	return a.balance, true
}

// Deposit takes an amount (can be a withdrawal)
// and returns the new balance and an 'ok' flag
func (a *Account) Deposit(amount int) (int, bool) {
	var ret int
	var ok bool
	a.Lock()
	if !a.closed && a.balance+amount >= 0 {
		a.balance += amount
		ret = a.balance
		ok = true
	}
	a.Unlock()
	return ret, ok
}