package cobol

import (
	"errors"
	"time"

	"google.golang.org/protobuf/types/known/durationpb"
	"google.golang.org/protobuf/types/known/timestamppb"
)

func Duration(howLongWasThis any) string {
	d, err := DurationCheck(howLongWasThis)
	if errors.Is(err, Broken) {
		return "bad"
	}
	if errors.Is(err, NoTime) {
		return "nope"
	}
	return FormatDuration(d)
}

func GetDuration(tookForever any) (time.Duration, error) {
	d, err := DurationCheck(tookForever)
	return d, err
}

func DurationCheck(maybeTime any) (time.Duration, error) {
	var d time.Duration
	var err error

	switch v := maybeTime.(type) {
	case time.Time:
		// If the type is time.Time, 'v' is now a time.Time variable.
		d = time.Since(v)
	case time.Duration:
		// If the type is time.Time, 'v' is now a time.Time variable.
		d = v
	case *time.Duration:
		// If the type is time.Time, 'v' is now a time.Time variable.
		d = *v
	case string:
		// The type is string, so 'v' is a string variable.
		// t, err = doTimeString(v)
		err = NewFeature
	case *timestamppb.Timestamp:
		// If it's a protobuf Timestamp pointer (most common case),
		// 'v' is a *timestamppb.Timestamp. We must convert it.
		// It's also good to check if it's a valid timestamp.
		if v.IsValid() {
			d = time.Since(v.AsTime())
		} else {
			err = errors.New("pb time invalid")
		}
	case *durationpb.Duration:
		d = v.AsDuration()
	case durationpb.Duration:
		d = v.AsDuration()
	case timestamppb.Timestamp:
		// Handle the less common case of a value type instead of a pointer.
		if v.IsValid() {
			d = time.Since(v.AsTime())
		}
	default:
		err = errors.Join(err, NoTime)
	}
	return d, err
}