package ssob

import (
	"fmt"
	"io"
	"sync"
)

type Encoder struct {
	mutex sync.Mutex
	w     io.Writer
}

func NewEncoder(w io.Writer) *Encoder {
	enc := new(Encoder)
	enc.w = w
	return enc
}

func (enc *Encoder) Encode(e interface{}) (err error) {
	_, v, err := parseInterface(e)
	if err != nil {
		return err
	}

	var b []byte
	if b, err = marshalVal(v.Interface()); err != nil {
		return fmt.Errorf("ssob: Cannot encode value: %w", err)
	}

	wb := marshalUint32(uint32(len(b)))
	wb = append(wb, b...)

	enc.mutex.Lock()
	defer enc.mutex.Unlock()

	if _, err = enc.w.Write(wb); err != nil {
		return fmt.Errorf("ssob: Cannot encode value: %w", err)
	}

	return nil
}