package vote

import (
	"fmt"
	"strings"
)

// Choice defines a custom int8 type for use as choice in a vote.
type Choice int8

// String implements fmt.Stringer
func (choice Choice) String() string {
	switch choice {
	case Yes:
		return "YIP"
	case No:
		return "NOPE"
	case Abstain:
		return "DUNNO"
	default:
		panic("this code should never be reached")
	}
}

// Available choices are:
const (
	Abstain Choice = 0
	Yes     Choice = 1
	No      Choice = -1
)

// ValidChoices returns a []Choice with all available choices.
func ValidChoices() []Choice {
	return []Choice{Yes, No, Abstain}
}

// ChoiceFromString takes a string and returns an initialized Choice or an
// error if the string couldn't be parsed.
func ChoiceFromString(s string) (Choice, error) {
	for _, c := range ValidChoices() {
		if strings.ToUpper(c.String()) == strings.ToUpper(s) {
			return c, nil
		}
	}
	return Abstain, fmt.Errorf("invalid choice: %s", s)
}