package main

import "fmt"
import "os"
import "strconv"

const accountBalanceFile = "balance.txt"

func getBalanceFromFile() float64 {
	data, err := os.ReadFile(accountBalanceFile, )

	if err != nil {

	}
	
	balanceText := string(data)
	balance, _ :=strconv.ParseFloat(balanceText, 64)
	return balance
}

func writeBalanceToFile(balance float64) {
	balanceText := fmt.Sprint(balance)
	os.WriteFile(accountBalanceFile, []byte(balanceText), 0644)
}

func main() {
	var accountBalance = getBalanceFromFile()

	fmt.Println("Welcome to Go Bank!")

	for {
		fmt.Println("What do you want to do?")
		fmt.Println("1. Check balance")
		fmt.Println("2. Deposit money")
		fmt.Println("3. Withdraw money")
		fmt.Println("4. Exit")

		var choice int
		fmt.Print("Your choice: ")
		fmt.Scan(&choice)

		switch choice {
		case 1:
			fmt.Println("Your balance is: ", accountBalance)
		case 2:
			fmt.Print("Your deposit: ")
			var depositAmount float64
			fmt.Scan(&depositAmount)

			if depositAmount <= 0 {
				fmt.Println("Invalid amount. Must be greater than 0.")
				continue
			}

			accountBalance += accountBalance
			fmt.Println("Balance updated! New amount:", accountBalance)
			writeBalanceToFile(accountBalance)
		case 3:
			fmt.Print("Your withdrawal")
			var withdrawalAmount float64
			fmt.Scan(&withdrawalAmount)

			if withdrawalAmount <= 0 {
				fmt.Println("Invalid amount. Must be greater than 0.")
				continue
			}

			if withdrawalAmount > accountBalance {
				fmt.Println("Invalid amount. You can't withdraw more than you have.")
				continue
			}

			accountBalance -= withdrawalAmount
			fmt.Println("Balance updated! New amount:", accountBalance)
			writeBalanceToFile(accountBalance)
		default:
			fmt.Println("Goodbye!")
			fmt.Println("Thanks for choosing our bank")
			return
		}
	}
}