server/protocol.go

package main

import (
	"bitbucket.org/hackerbots/bot"
	"code.google.com/p/go.net/websocket"
	"errors"
)

type Failure struct {
	Reason string `json:"reason"`
	Type   string `json:"type"`
}

func NewFailure(reason string) *Failure {
	return &Failure{
		Reason: reason,
		Type:   "failure",
	}
}

func Negociate(ws *websocket.Conn, id string, width, height float64) (*bot.Config, error) {
	var err error

	err = websocket.JSON.Send(ws, bot.NewIdRequest(id))
	if err != nil {
		return nil, errors.New("generic servr error")
	}

	var clientid bot.ClientID
	err = websocket.JSON.Receive(ws, &clientid)
	if err != nil {
		return nil, errors.New("could not parse id")
	}
	if v, msg := clientid.Valid(); !v {
		websocket.JSON.Send(
			ws,
			NewFailure(msg),
		)
		return nil, errors.New(msg)
	}

	gameParam := bot.NewGameParam(width, height)
	err = websocket.JSON.Send(ws, gameParam)
	if err != nil {
		websocket.JSON.Send(ws, NewFailure("generic server error"))
		return nil, err
	}
	switch clientid.Type {
	case "robot":
		var conf bot.Config
		for {
			err = websocket.JSON.Receive(ws, &conf)
			if err != nil {
				return nil, err
			}
			// TODO: verify conf's type
			if conf.Stats.Valid() {
				_ = websocket.JSON.Send(ws, bot.NewHandshake(id, true))
				break
			} else {
				_ = websocket.JSON.Send(ws, bot.NewHandshake(id, false))
			}
		}
		return &conf, nil
	case "spectator":
		return nil, nil
	}
	return nil, nil
}