mchess-server/main.go

package main

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"log"
	"mchess_server/api"
	"mchess_server/chess"
	lobbies "mchess_server/lobby_registry"
	"mchess_server/usher"
	"mchess_server/utils"
	"net/http"
	"sync"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
	"nhooyr.io/websocket"
)

var cert_path = "/etc/letsencrypt/live/chess.sw-gross.de/"
var cert_file = cert_path + "fullchain.pem"
var key_file = cert_path + "privkey.pem"
var mut sync.Mutex

func main() {
	var debugMode bool

	debugModeLong := flag.Bool("debug", false, "activates debug mode")
	debugModeShort := flag.Bool("d", false, "activates debug mode")
	flag.Parse()
	if *debugModeShort || *debugModeLong {
		debugMode = true
	}

	router := gin.Default()
	router.GET("/api/random", registerForRandomGame)
	router.GET("/api/hostPrivate", hostPrivateGame)
	router.POST("/api/joinPrivate", joinPrivateGame)
	router.GET("/api/ws", registerWebSocketConnection)

	if debugMode {
		log.Println("Starting service WITHOUT TLS")
		log.Fatal(router.Run(":8080"))
	} else {
		gin.SetMode(gin.ReleaseMode)
		log.Println("Starting in release mode")
		log.Println("Starting service with TLS")
		log.Fatal(router.RunTLS("chess.sw-gross.de:9999", cert_file, key_file))
	}
}

func registerForRandomGame(c *gin.Context) {
	player := chess.NewPlayer(uuid.New())
	usher := usher.GetUsher()

	mut.Lock()
	defer mut.Unlock()
	lobby := usher.WelcomeNewPlayer(player)
	usher.AddPlayerToLobbyAndStartGameIfFull(player, lobby)

	info := api.PlayerInfo{
		PlayerID: &player.Uuid,
		LobbyID:  &lobby.Uuid,
	}
	log.Println("responding with info ", info)

	c.Header("Access-Control-Allow-Origin", "*")
	c.IndentedJSON(http.StatusOK, info)
}

func hostPrivateGame(c *gin.Context) {
	player := chess.NewPlayer(uuid.New())
	u := usher.GetUsher()

	mut.Lock()
	defer mut.Unlock()
	lobby := u.CreateNewPrivateLobby(player)
	u.AddPlayerToLobbyAndStartGameIfFull(player, lobby)

	passphrase := lobby.Passphrase.String()
	info := api.PlayerInfo{
		PlayerID:   &player.Uuid,
		LobbyID:    &lobby.Uuid,
		Passphrase: &passphrase,
	}
	c.Header("Access-Control-Allow-Origin", "*")
	c.IndentedJSON(http.StatusOK, info)
}

func joinPrivateGame(c *gin.Context) {
	req := api.PlayerInfo{}
	log.Println(c.Request.Body)
	err := c.ShouldBindJSON(&req)
	if err != nil {
		c.IndentedJSON(http.StatusBadRequest, req)
	}

	connectingPlayer := chess.NewPlayer(*req.PlayerID)
	player := chess.NewPlayer(uuid.New())
	u := usher.GetUsher()

	if req.Passphrase != nil &&
		*req.Passphrase != "" &&
		req.PlayerID != nil &&
		req.LobbyID != nil { //is reconnect
		lobby := u.FindExistingPrivateLobbyByID(utils.Passphrase(*req.Passphrase))
		_, found := lobby.GetPlayerByUUID(connectingPlayer.Uuid)
		if found {
			c.IndentedJSON(
				http.StatusOK,
				api.PlayerInfo{
					PlayerID:   req.PlayerID,
					LobbyID:    req.LobbyID,
					Passphrase: req.Passphrase,
				})
			return
		} else {
			c.IndentedJSON(http.StatusNotFound, req)
		}
	}

	mut.Lock()
	defer mut.Unlock()
	lobby := u.FindExistingPrivateLobbyByID(utils.Passphrase(*req.Passphrase))
	if lobby != nil {
		u.AddPlayerToLobbyAndStartGameIfFull(player, lobby)
	} else {
		c.IndentedJSON(http.StatusNotFound, req)
		return
	}

	info := api.PlayerInfo{
		PlayerID:   &player.Uuid,
		LobbyID:    &lobby.Uuid,
		Passphrase: req.Passphrase,
	}
	c.Header("Access-Control-Allow-Origin", "*")
	c.IndentedJSON(http.StatusOK, info)
}

func registerWebSocketConnection(c *gin.Context) {
	webSocketConn, err := websocket.Accept(c.Writer, c.Request, &websocket.AcceptOptions{OriginPatterns: []string{"chess.sw-gross.de", "localhost:*"}})
	if err != nil {
		log.Println(err)
		return
	}
	go waitForAndHandlePlayerID(c, webSocketConn)
}

func waitForAndHandlePlayerID(ctx context.Context, conn *websocket.Conn) {
	msgType, msg, err := conn.Read(ctx)
	if err != nil {
		errorMessage := fmt.Sprintf("Reading from websocket connection did not work: %s", err)
		log.Println(errorMessage)
		conn.Close(websocket.StatusCode(400), errorMessage)
		return
	}

	log.Println("read from websocket endpoint: ", msgType, string(msg), err)

	var info api.PlayerInfo
	err = json.Unmarshal(msg, &info)
	if err != nil {
		errorMessage := fmt.Sprintf("Unmarshaling message did not work: %s", err)
		log.Println(errorMessage)
		conn.Close(websocket.StatusCode(400), errorMessage)
		return
	}

	lobby := lobbies.GetLobbyRegistry().GetLobbyByUUID(*info.LobbyID)
	if lobby == nil {
		conn.Close(websocket.StatusCode(400), "lobby not found")
		return
	}

	player, found := lobby.GetPlayerByUUID(*info.PlayerID)
	if !found {
		conn.Close(websocket.StatusCode(400), "player not found")
		return
	}
	if player.Conn.HasWebsocketConnection() {
		player.Conn.Close("closing existing connection")
	}
	lobby.Game.SetWebsocketConnectionFor(ctx, player, conn)
	log.Println("player after setting connection: ", player)
}