package rpc

import "bytes"

type Vars map[string]string

func NewVars() Vars {
	return make(Vars)
}

func (vs Vars) MarshalBinary() ([]byte, error) {
	var buf bytes.Buffer
	for k, v := range vs {
		buf.WriteString(k)
		buf.WriteByte(byte(0))
		buf.Write(varLen(v))
		buf.WriteString(v)
		buf.WriteByte(byte(0))
	}
	return buf.Bytes(), nil
}

func (vs *Vars) UnmarshalBinary(data []byte) error {
	return nil
}

func varLen(v string) (l []byte) {
	/* Using a slice instead of [4]byte the wasted 2 bytes are better than the
	   more difficult to read read/write calls, and the extra copy operations
	   that would be needed anyway, which waste 6 bytes at a time */
	sl := len(v)
	l = make([]byte, 4)
	l[0] = byte((sl / 0x1) % 0x100)
	l[1] = byte((sl / 0x100) % 0x100)
	l[2] = byte((sl / 0x10000) % 0x100)
	l[3] = byte((sl / 0x1000000) % 0x100)

	return l
}