package registry

import (
	"fmt"
	"reflect"

	"git.maximhutz.com/max/lambda/pkg/codec"
)

type Codec interface {
	codec.Codec[Expr]

	InType() string
}

type convertedCodec[T any] struct {
	codec  codec.Codec[T]
	inType string
}

func (c convertedCodec[T]) Decode(s string) (Expr, error) {
	t, err := c.codec.Decode(s)
	if err != nil {
		return nil, err
	}

	return NewExpr(c.inType, t), nil
}

func (c convertedCodec[T]) Encode(r Expr) (string, error) {
	t, ok := r.Data().(T)
	if !ok {
		dataType := reflect.TypeOf(r.Data())
		allowedType := reflect.TypeFor[T]()
		return "", fmt.Errorf("Codec for '%s' cannot parse '%s'", allowedType, dataType)
	}

	return c.codec.Encode(t)
}

func (c convertedCodec[T]) InType() string { return c.inType }

func RegisterCodec[T any](registry *Registry, m codec.Codec[T], inType string) error {
	if _, ok := registry.codecs[inType]; ok {
		return fmt.Errorf("Codec for '%s' already registered", inType)
	}

	registry.codecs[inType] = convertedCodec[T]{m, inType}
	return nil
}