result.go

package main

import (
	"bytes"
	"fmt"
	"strconv"
)

type resultTypeCode int

const (
	NO_TYPE resultTypeCode = iota
	SIMPLE_STRING
	ERROR_STRING
	BINARY_STRING
	MULTIPLE
)

type Result struct {
	resultType resultTypeCode
	data       []byte
}

func NewResult() *Result {
	r := new(Result)
	return r
}

func (r *Result) SetSimpleString(value string) bool {
	r.resultType = SIMPLE_STRING
	r.data = []byte(fmt.Sprintf("+%v\r\n", value))
	return true
}

func (r *Result) SetErrorString(value string) bool {
	r.resultType = ERROR_STRING
	r.data = []byte(fmt.Sprintf("-%v\r\n", value))
	return true
}

func (r *Result) SetBinaryString(element *Element) bool {
	r.resultType = BINARY_STRING
	buffer := bytes.NewBuffer(make([]byte, 0))
	r.writeBinaryString(buffer, element)
	r.data = buffer.Bytes()
	return true
}

func (r *Result) SetMultiple(elements []*Element) bool {
	r.resultType = MULTIPLE
	length := len(elements)
	buffer := bytes.NewBuffer(make([]byte, 0))
	buffer.Write([]byte("*"))
	buffer.Write([]byte(strconv.Itoa(length)))
	buffer.Write([]byte("\r\n"))
	for i := 0; i < length; i++ {
		element := elements[i]
		r.writeBinaryString(buffer, element)
	}
	r.data = buffer.Bytes()
	return true
}

func (r *Result) writeBinaryString(buffer *bytes.Buffer, element *Element) {
	if element == nil {
		buffer.Write([]byte("$-1\r\n"))
	} else {
		buffer.Write([]byte("$"))
		buffer.Write([]byte(strconv.Itoa(element.size)))
		buffer.Write([]byte("\r\n"))
		buffer.Write(element.data)
		buffer.Write([]byte("\r\n"))
	}
}