server/control.go

package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"runtime/pprof"
	"strings"
)

type JsonHandler func(http.ResponseWriter, *http.Request)

func (h JsonHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	h(w, req)
}

func startGame(w http.ResponseWriter, req *http.Request) {
	log.Println("asked to create a game")

	requested_game_name := idg.Hash()
	width, height := float32(conf.Width), float32(conf.Height)
	obstacles := 0
	maxPoints := conf.MaxPoints
	mode := "deathmatch"

	// here we determine if we are going to run with defaults or pick them off
	// a posted json blob
	if req.Method == "POST" {
		body, err := ioutil.ReadAll(req.Body)
		if err != nil {
			log.Printf("unable to read request body:", err)
		}
		req.Body.Close()
		cfg := struct {
			Name string `json:"name"`
			Config
		}{}
		err = json.Unmarshal(body, &cfg)
		if err != nil {
			if err := json.NewEncoder(w).Encode(NewFailure(err.Error())); err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
			}
			return
		}
		requested_game_name = cfg.Name
		width = float32(cfg.Width)
		height = float32(cfg.Height)
		obstacles = cfg.Obstacles
		maxPoints = cfg.MaxPoints
		mode = cfg.Mode
	}

	g := games.get(requested_game_name)
	if g == nil {
		log.Printf("Game '%s' non-existant; making it now", requested_game_name)
		g, err := NewGame(requested_game_name, width, height, obstacles, conf.Tick, maxPoints, mode)
		if err != nil {
			log.Printf("problem creating game: %s: %s", requested_game_name, err)
			b, _ := json.Marshal(NewFailure("game creation failure"))
			http.Error(w, string(b), http.StatusConflict)
			return
		}
		go g.run()
		games.add(g)
	} else {
		log.Printf("Game '%s' already exists: %p", requested_game_name, g)
		b, _ := json.Marshal(NewFailure("game already exists"))
		http.Error(w, string(b), http.StatusConflict)
		return
	}

	game_json := struct {
		Id string `json:"id"`
	}{
		Id: g.id,
	}
	if err := json.NewEncoder(w).Encode(game_json); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func listGames(w http.ResponseWriter, req *http.Request) {
	log.Println("games list requested")
	games.RLock()
	defer games.RUnlock()
	type pout struct {
		Name string `json:"name"`
		Id   string `json:"id"`
	}
	type gl struct {
		Id      string `json:"id"`
		Players []pout `json:"players"`
	}
	ids := make([]gl, 0)
	for id, g := range games.m {
		players := make([]pout, 0)
		// TODO - players instead of robots?
		for p := range g.players {
			for _, r := range p.Robots {
				players = append(players, pout{
					Name: r.Name,
					Id:   r.Id,
				})
			}
		}
		ids = append(ids, gl{
			Id:      id,
			Players: players,
		})
	}
	if err := json.NewEncoder(w).Encode(ids); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func gameStats(w http.ResponseWriter, req *http.Request) {
	// TODO: wrap this up in something similar to the JsonHandler to verify the
	// url? Look at gorilla routing?
	key, err := getGameId(req.URL.Path)
	if err != nil {
		b, _ := json.Marshal(NewFailure(err.Error()))
		http.Error(w, string(b), http.StatusBadRequest)
		return
	}
	log.Printf("requested stats for game: %s", key)
	games.RLock()
	g, ok := games.m[key]
	games.RUnlock()
	if !ok {
		b, _ := json.Marshal(NewFailure("game not found"))
		http.Error(w, string(b), http.StatusNotFound)
		return
	}
	g.stats.RLock()
	defer g.stats.RUnlock()
	if err := json.NewEncoder(w).Encode(g.stats.PlayerStats); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func bw(w http.ResponseWriter, req *http.Request) {
	// TODO: wrap this up in something similar to the JsonHandler to verify the
	// url? Look at gorilla routing?
	key, err := getGameId(req.URL.Path)
	if err != nil {
		b, _ := json.Marshal(NewFailure(err.Error()))
		http.Error(w, string(b), http.StatusBadRequest)
		return
	}
	log.Printf("requested bandwidth for game: %s", key)
	games.RLock()
	g, ok := games.m[key]
	games.RUnlock()
	if !ok {
		b, _ := json.Marshal(NewFailure("game not found"))
		http.Error(w, string(b), http.StatusNotFound)
		return
	}
	s := map[string][]float64{
		"tx": <-g.bw.Tx,
		"rx": <-g.bw.Rx,
	}
	if err := json.NewEncoder(w).Encode(s); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func stopGame(w http.ResponseWriter, req *http.Request) {
	key, err := getGameId(req.URL.Path)
	if err != nil {
		b, _ := json.Marshal(NewFailure(err.Error()))
		http.Error(w, string(b), http.StatusBadRequest)
		return
	}
	games.Lock()
	g, ok := games.m[key]
	defer games.Unlock()
	if !ok {
		http.NotFound(w, req)
		return
	}
	g.kill <- true
	message := struct {
		Ok      bool   `json:"ok"`
		Message string `json:"message"`
	}{
		Ok:      true,
		Message: fmt.Sprintf("Successfully stopped game: %s", key),
	}
	if err := json.NewEncoder(w).Encode(message); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func killServer(w http.ResponseWriter, req *http.Request) {
	if *profile != "" {
		log.Print("trying to stop cpu profile")
		pprof.StopCPUProfile()
		log.Print("stopped cpu profile")
	}
	log.Fatal("shit got fucked up")
}

func index(w http.ResponseWriter, req *http.Request) {
	log.Println("version requested")
	version := struct {
		Version string `json:"version"`
		Name    string `json:"name"`
	}{
		Version: "0.1.2",
		Name:    "Hackerbots",
	}
	if err := json.NewEncoder(w).Encode(version); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

func getGameId(path string) (string, error) {
	var err error
	trimmed := strings.Trim(path, "/")
	fullPath := strings.Split(trimmed, "/")
	if len(fullPath) != 3 {
		return "", errors.New("improperly formed url")
	}
	key := fullPath[2]
	return key, err
}