package helpers

import (
	"encoding/json"
	"fmt"
	"time"
)

type DateOnly struct {
	time.Time
}

func (d DateOnly) MarshalJSON() ([]byte, error) {
	if d.IsZero() {
		return []byte("null"), nil
	}
	return json.Marshal(d.Format("2006-01-02"))
}

func (d *DateOnly) UnmarshalJSON(b []byte) error {
	var s string
	if err := json.Unmarshal(b, &s); err != nil {
		return err
	}
	if s == "" {
		return nil
	}
	t, err := time.Parse("2006-01-02", s)
	if err != nil {
		return err
	}
	d.Time = t
	return nil
}

type KontorTime struct {
	time.Time
}

var layouts = []string{
	"2006-01-02 15:04:05.000000",
	"2006-01-02T15:04:05.999Z",
	"2006-01-02",
}

func (kt KontorTime) MarshalJSON() ([]byte, error) {
	if kt.IsZero() {
		return []byte("null"), nil
	}
	return json.Marshal(kt.Format(layouts[0]))
}

func (kt *KontorTime) UnmarshalJSON(b []byte) error {
	var s string
	if err := json.Unmarshal(b, &s); err != nil {
		return err
	}
	if s == "" {
		return nil
	}
	for _, layout := range layouts {
		t, err := time.Parse(layout, s)
		if err == nil {
			kt.Time = t
			return nil
		}
	}
	return fmt.Errorf("failed to parse time from %s", s)
}