package main

import (
	"encoding/json"
	"fmt"
	"net"
)

const (
	MESSAGE      = "message"
	AUTHENTICATE = "authenticate"
	EXIT         = "exit"
	REGISTER     = "register"
)

const (
	SUCCESS = "success"
	FAILURE = "failure"
	PING    = "ping"
)

type Request struct {
	Type string
	Data string
	User string
}

func (req *Request) serialize() string {
	data, _ := json.Marshal(req)
	return string(data)
}

func (req *Request) toString() string {
	return fmt.Sprintf("%s: %s", req.User, req.Data)
}

type Response struct {
	Status string
	Data   string
}

func toBytes(num uint32) []byte {
	buf := make([]byte, 4)
	var mask uint32 = 0x00FF
	for i := 0; i < 4; i += 1 {
		buf[4-i-1] = byte(num & mask)
		num >>= 8
	}
	return buf
}

func fromBytes(data []byte) uint32 {
	var num uint32
	for i := 0; i < 4; i += 1 {
		num += uint32(data[i] << ((4 - i - 1) * 8))
	}
	return num
}

func sendMessage(conn net.Conn, message []byte) error {
	size := uint32(len(message))

	data := append(toBytes(size), message...)
	_, err := conn.Write(data)
	if err != nil {
		return err
	}

	return nil
}

func parseRequest(data []byte) (Request, error) {
	var m Request
	err := json.Unmarshal(data, &m)
	return m, err
}

func parseResponse(data []byte) (Response, error) {
	var r Response
	err := json.Unmarshal(data, &r)
	return r, err
}