package nomino

import "time"

// FileTimestamp is the default format for WithTimestamp and WithTime
const FileTimestamp string = "2006-01-02T15-04-05-0700"

// FileTimestampNoTZ is the default format for WithTimestampUTC and WithTimeUTC
const FileTimestampNoTZ string = "2006-01-02T15-04-05"

type timestampConf struct {
	format string
	ts     time.Time
	utc    bool
}

// TimestampOption provides options for the Timestamp Generator
type TimestampOption func(c *timestampConf)

// Timestamp generates a a date and time. By default, it uses the current time, and will.
// be formatted accourding to FileTimestamp
func Timestamp(opts ...TimestampOption) Generator {
	c := timestampConf{format: FileTimestamp, ts: time.Now()}
	for _, opt := range opts {
		opt(&c)
	}

	if c.utc {
		c.ts = c.ts.UTC()
	}

	return func(*Config) (string, error) {
		return c.ts.Format(c.format), nil
	}
}

// TimestampFormat sets the format for the generated name.
// Consult time.Time.Format for details on the format.
func TimestampFormat(format string) TimestampOption {
	return func(c *timestampConf) {
		c.format = format
	}
}

// TimestampTime sets the time for the generated name.
// By default, it uses the current time.
func TimestampTime(t time.Time) TimestampOption {
	return func(c *timestampConf) {
		c.ts = t
	}
}

// TimestampUTC uses the time in UTC, while also stripping the timezone from the format.
func TimestampUTC() TimestampOption {
	return func(c *timestampConf) {
		c.utc = true
		c.format = FileTimestampNoTZ
	}
}