package dagcbor

import (
	"io"

	"github.com/polydawn/refmt/cbor"

	"gitlab.dms3.io/ld/go-ld-prime"
	"gitlab.dms3.io/ld/go-ld-prime/multicodec"
)

var (
	_ ld.Decoder = Decode
	_ ld.Encoder = Encode
)

func init() {
	multicodec.RegisterEncoder(0x71, Encode)
	multicodec.RegisterDecoder(0x71, Decode)
}

func Decode(na ld.NodeAssembler, r io.Reader) error {
	// Probe for a builtin fast path.  Shortcut to that if possible.
	type detectFastPath interface {
		DecodeDagCbor(io.Reader) error
	}
	if na2, ok := na.(detectFastPath); ok {
		return na2.DecodeDagCbor(r)
	}
	// Okay, generic builder path.
	return Unmarshal(na, cbor.NewDecoder(cbor.DecodeOptions{}, r), true)
}

func Encode(n ld.Node, w io.Writer) error {
	// Probe for a builtin fast path.  Shortcut to that if possible.
	type detectFastPath interface {
		EncodeDagCbor(io.Writer) error
	}
	if n2, ok := n.(detectFastPath); ok {
		return n2.EncodeDagCbor(w)
	}
	// Okay, generic inspection path.
	return Marshal(n, cbor.NewEncoder(w), true)
}