package securecookie

import (
	"bytes"
	"encoding/gob"
	"encoding/json"
)

// Serialize encodes a value using gob.
func (e GobEncoder) Serialize(src interface{}) ([]byte, error) {
	buf := new(bytes.Buffer)
	enc := gob.NewEncoder(buf)
	if err := enc.Encode(src); err != nil {
		return nil, cookieError{cause: err, typ: usageError}
	}
	return buf.Bytes(), nil
}

// Deserialize decodes a value using gob.
func (e GobEncoder) Deserialize(src []byte, dst interface{}) error {
	dec := gob.NewDecoder(bytes.NewBuffer(src))
	if err := dec.Decode(dst); err != nil {
		return cookieError{cause: err, typ: decodeError}
	}
	return nil
}

// Serialize encodes a value using encoding/json.
func (e JSONEncoder) Serialize(src interface{}) ([]byte, error) {
	buf := new(bytes.Buffer)
	enc := json.NewEncoder(buf)
	if err := enc.Encode(src); err != nil {
		return nil, cookieError{cause: err, typ: usageError}
	}
	return buf.Bytes(), nil
}

// Deserialize decodes a value using encoding/json.
func (e JSONEncoder) Deserialize(src []byte, dst interface{}) error {
	dec := json.NewDecoder(bytes.NewReader(src))
	if err := dec.Decode(dst); err != nil {
		return cookieError{cause: err, typ: decodeError}
	}
	return nil
}

// Serialize passes a []byte through as-is.
func (e NopEncoder) Serialize(src interface{}) ([]byte, error) {
	if b, ok := src.([]byte); ok {
		return b, nil
	}

	return nil, errValueNotByte
}

// Deserialize passes a []byte through as-is.
func (e NopEncoder) Deserialize(src []byte, dst interface{}) error {
	if _, ok := dst.([]byte); ok {
		dst = src
		return nil
	}

	return errValueNotByte
}