// Chapter 30 example: a small command loop that uses package bank.
//
// Run from this folder:
//   cd exercises/30/02-account-package
//   go run .

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"

	"accountpackage/bank"
)

var reader = bufio.NewReader(os.Stdin)

// readLine prints the prompt and gives back one trimmed line. The error is
// not nil when there is no more input.
func readLine(prompt string) (string, error) {
	fmt.Print(prompt)
	text, err := reader.ReadString('\n')
	line := strings.TrimSpace(text)
	if err != nil && line == "" {
		return "", err
	}
	return line, nil
}

// doAmount runs "deposit" or "withdraw" with the amount the user typed.
func doAmount(acc *bank.Account, verb string, amountText string) {
	amount, err := strconv.Atoi(amountText)
	if err != nil {
		fmt.Println("That is not a whole number.")
		return
	}

	if verb == "deposit" {
		err = acc.Deposit(amount)
	} else {
		err = acc.Withdraw(amount)
	}
	if err != nil {
		fmt.Println("Error:", err)
		return
	}
	fmt.Println("Balance:", acc.Balance())
}

func main() {
	acc, err := bank.NewAccount("Keiko")
	if err != nil {
		fmt.Println("Error:", err)
		return
	}
	fmt.Println("Account for", acc.Owner())

	for {
		line, err := readLine("> ")
		if err != nil {
			fmt.Println()
			fmt.Println("No more input.")
			return
		}

		words := strings.Fields(line)
		if len(words) == 1 && words[0] == "quit" {
			fmt.Println("Goodbye.")
			return
		}
		if len(words) == 1 && words[0] == "balance" {
			fmt.Println("Balance:", acc.Balance())
			continue
		}
		if len(words) == 2 && (words[0] == "deposit" || words[0] == "withdraw") {
			doAmount(acc, words[0], words[1])
			continue
		}
		fmt.Println("Commands: deposit <amount>, withdraw <amount>, balance, quit")
	}
}