package rest

import (
	"fmt"
	"time"
)

var (
	fieldConverters = make(map[string]*FieldConverter)
)

type FieldConverter struct {
	Pack   func(any) any
	Unpack func(any) (any, error)
}

func RegisterFieldConverter(name string, converter *FieldConverter) {
	fieldConverters[name] = converter
}

func init() {
	RegisterFieldConverter(
		"time.Time",
		&FieldConverter{
			Pack: func(v any) any {
				t := v.(time.Time)
				return t.Format("02.01.2006 15:04")
			},
			Unpack: func(val any) (any, error) {
				ts, check := val.(string)
				if !check {
					return nil, fmt.Errorf("expected string")
				}
				layout := "02.01.2006 15:04"
				parsedTime, err := time.Parse(layout, ts)
				if err != nil {
					return nil, err
				}
				return parsedTime, nil
			},
		},
	)
}