wechaty/go-wechaty

package filebox

import (
    "errors"
    "fmt"
    "io"
)

var _ fileImplInterface = fileBoxUuid{}

// UuidLoader uuid loader
type UuidLoader func(uuid string) (io.Reader, error)

// UuidSaver uuid saver
type UuidSaver func(reader io.Reader) (uuid string, err error)

var uuidToStream UuidLoader
var uuidFromStream UuidSaver

// SetUuidLoader set uuid loader
func SetUuidLoader(loader UuidLoader) {
    uuidToStream = loader
}

// SetUuidSaver set uuid saver
func SetUuidSaver(saver UuidSaver) {
    uuidFromStream = saver
}

type fileBoxUuid struct {
    uuid string
}

func (f fileBoxUuid) toJSONMap() (map[string]interface{}, error) {
    if f.uuid == "" {
        return nil, fmt.Errorf("fileBoxUuid.toJSONMap %w", ErrNoUuid)
    }
    return map[string]interface{}{
        "uuid": f.uuid,
    }, nil
}

func (f fileBoxUuid) toReader() (io.Reader, error) {
    if uuidToStream == nil {
        return nil, errors.New("need to call filebox.setUuidLoader() to set UUID loader first")
    }
    return uuidToStream(f.uuid)
}

func newFileBoxUuid(uuid string) *fileBoxUuid {
    return &fileBoxUuid{uuid: uuid}
}