package nomino

import (
	"time"

	"github.com/google/uuid"
)

type generator func() (string, error)

func setGenerator(c *config, g generator) {
	c.generator = g
}

func uuidGen() (string, error) {
	u, err := uuid.NewRandom()
	if err != nil {
		return "", err
	}
	return u.String(), nil
}

// WithUUID sets a generator that creates a UUIDv4
func WithUUID() Option {
	return func(c *config) {
		setGenerator(c, uuidGen)
	}
}

// FileTimestamp is the default format for WithTimestamp and WithTime
const FileTimestamp string = "2006-01-02_03-05-06-0700"

// WithTimestamp sets a generator that creates a date and time for the current time.
// The format is FileStamp
func WithTimestamp() Option {
	return WithTimestampFormat(FileTimestamp)
}

// WithTimestampFormat sets a generator the creates a date and time for the current time with the supplied format.
func WithTimestampFormat(f string) Option {
	return WithFormattedTime(time.Now(), f)
}

// WithTime sets a generator that creates a date and time for the supplied time.
// The format is FileStamp
func WithTime(t time.Time) Option {
	return WithFormattedTime(t, FileTimestamp)
}

// WithFormattedTime sets a generator that creates a date and time for the supplied time with the supplied format.
func WithFormattedTime(t time.Time, f string) Option {
	return func(c *config) {
		setGenerator(c, func() (string, error) {
			return t.Format(f), nil
		})
	}
}

// FileTimestamp is the default format for WithTimestampUTC and WithTimeUTC
const FileTimestampNoTZ string = "2006-01-02_03-05-06"

// WithTimestampUTC sets a generator the creates a date and time for the current time in UTC without a timezone in the format.
func WithTimestampUTC() Option {
	return WithTimeUTC(time.Now())
}

// WithTimeUTC sets a generate that creates a date and time for the supplied time in UTC without a timezone in the format.
func WithTimeUTC(t time.Time) Option {
	return WithFormattedTime(t.UTC(), FileTimestampNoTZ)
}