// Package datetime centralizes the application's Beijing time policy.
package datetime

import "time"

const Zone = "Asia/Shanghai"

var Location = func() *time.Location {
	location, err := time.LoadLocation(Zone)
	if err != nil {
		return time.FixedZone("CST", 8*60*60)
	}
	return location
}()

func Now() time.Time { return time.Now().In(Location) }

// Normalize converts any source instant (including COS metadata) to Beijing time.
func Normalize(value time.Time) time.Time {
	if value.IsZero() { return value }
	return value.In(Location)
}

func Parse(value string) (time.Time, error) {
	parsed, err := time.Parse(time.RFC3339Nano, value)
	if err != nil { return time.Time{}, err }
	return Normalize(parsed), nil
}

func Format(value time.Time) string { return Normalize(value).Format(time.RFC3339Nano) }