From a57b68891bdaf8d4db5d355fa0c165fd37aa37da Mon Sep 17 00:00:00 2001 From: Muhammad Nauman Raza Date: Sun, 20 Aug 2023 12:50:21 +0100 Subject: [PATCH] feat(backend): websockets with player co-ordination and JWT auto-generation --- backend/go.mod | 1 + backend/go.sum | 2 + backend/main.go | 146 +++++++++++++++++++++++++++++++++++++++++++++++- backend/user.go | 39 ++++++++++++- 4 files changed, 184 insertions(+), 4 deletions(-) diff --git a/backend/go.mod b/backend/go.mod index a1ba94d..0f44019 100644 --- a/backend/go.mod +++ b/backend/go.mod @@ -5,6 +5,7 @@ go 1.20 require ( github.com/charmbracelet/log v0.2.3 github.com/golang-jwt/jwt v3.2.2+incompatible + github.com/gorilla/websocket v1.5.0 github.com/joho/godotenv v1.5.1 github.com/mattn/go-sqlite3 v1.14.17 golang.org/x/crypto v0.11.0 diff --git a/backend/go.sum b/backend/go.sum index 04e0f7d..75723ea 100644 --- a/backend/go.sum +++ b/backend/go.sum @@ -9,6 +9,8 @@ github.com/go-logfmt/logfmt v0.6.0 h1:wGYYu3uicYdqXVgoYbvnkrPVXkuLM1p1ifugDMEdRi github.com/go-logfmt/logfmt v0.6.0/go.mod h1:WYhtIu8zTZfxdn5+rREduYbwxfcBr/Vr6KEVveWlfTs= github.com/golang-jwt/jwt v3.2.2+incompatible h1:IfV12K8xAKAnZqdXVzCZ+TOjboZ2keLg81eXfW3O+oY= github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I= +github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc= +github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE= github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0= github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4= github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY= diff --git a/backend/main.go b/backend/main.go index 847f068..023a221 100644 --- a/backend/main.go +++ b/backend/main.go @@ -1,6 +1,7 @@ package main import ( + "encoding/json" "fmt" _ "github.com/joho/godotenv/autoload" "net/http" @@ -8,20 +9,92 @@ import ( // Stylish stuff "github.com/charmbracelet/log" + + // Websockets + "github.com/gorilla/websocket" ) type App struct { UserHandler *UserHandler + clients map[*websocket.Conn]bool + broadcast chan []byte + upgrader websocket.Upgrader } +type Player struct { + X int `json:"x"` + Y int `json:"y"` +} + +type GameState struct { + Players []Player `json:"players"` +} + +func (s *App) handlePlayerMovement(conn *websocket.Conn) { + var player Player + player.X = 0 + player.Y = 0 + + for { + // Read the next message from the client + _, message, err := conn.ReadMessage() + if err != nil { + log.Error("Failed to read message:", err) + break + } + + // Update the player's position based on the received message + switch string(message) { + case "up": + player.Y-- + case "down": + player.Y++ + case "left": + player.X-- + case "right": + player.X++ + } + + // Create a JSON representation of the game state + gameState := GameState{ + Players: []Player{player}, + } + gameStateData, err := json.Marshal(gameState) + if err != nil { + log.Error("Failed to marshal game state:", err) + break + } + + // Broadcast the game state to all clients + s.broadcast <- gameStateData + } +} + +func (s *App) handleBroadcasts() { + for { + // Read the next message from the broadcast channel + message := <-s.broadcast + + // Broadcast the message to all clients + for client := range s.clients { + err := client.WriteMessage(websocket.TextMessage, message) + if err != nil { + log.Error("Failed to write message:", err) + } + } + } +} + +var upgrader = websocket.Upgrader{} + // Define the serve function -func (h *App) ServeHTTP(res http.ResponseWriter, req *http.Request) { +func (s *App) ServeHTTP(res http.ResponseWriter, req *http.Request) { var head string head, req.URL.Path = ShiftPath(req.URL.Path) switch head { // Start the user handler should the requested user be found case "user": - h.UserHandler.Handle(res, req) + s.UserHandler.Handle(res, req) // Return a `Not Found` if the user is not found default: http.Error(res, "Not Found", http.StatusNotFound) @@ -29,7 +102,75 @@ func (h *App) ServeHTTP(res http.ResponseWriter, req *http.Request) { } // Run the server +func (s *App) Run() { + http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) { + // Upgrade the connection to a WebSocket connection + conn, err := s.upgrader.Upgrade(w, r, nil) + if err != nil { + log.Error("Failed to upgrade connection:", err) + return + } + + // Add the client connection to the clients map + s.clients[conn] = true + + // Log when a client connects + log.Info("Client connected:", conn.RemoteAddr()) + + // Allow the server to handle player movement + go s.handlePlayerMovement(conn) + + // Close the connection and remove it from the clients map + defer func() { + // Log when a client disconnects + log.Info("Client disconnected:", conn.RemoteAddr()) + + conn.Close() + delete(s.clients, conn) + }() + + // Handle incoming messages + for { + _, message, err := conn.ReadMessage() + if err != nil { + log.Error("Failed to read message:", err) + break + } + + // Broadcast the received message to all clients + s.broadcast <- message + } + }) + + go s.handleBroadcasts() + + http.HandleFunc("/echo", func(w http.ResponseWriter, r *http.Request) { + conn, err := upgrader.Upgrade(w, r, nil) + + if err != nil { + log.Fatal(err) + } + + for { + + msgType, msg, err := conn.ReadMessage() + if err != nil { + return + } + + fmt.Printf("%s sent: %s\n", conn.RemoteAddr(), string(msg)) + + if err = conn.WriteMessage(msgType, msg); err != nil { + return + } + } + }) +} + func main() { + // Make the jwt_secret file within the server configuration directory + makeSecret() + // Initialise the user handler user_handler, err := NewUserHandler() @@ -49,4 +190,5 @@ func main() { // Log that the program has successfully started listening to the port log.Info(fmt.Sprintf("Ambition backend listening to port %v", port)) http.ListenAndServe(":"+port, a) + } diff --git a/backend/user.go b/backend/user.go index 95f1ef4..c6953dc 100644 --- a/backend/user.go +++ b/backend/user.go @@ -7,8 +7,13 @@ import ( "io" "os" + // A cute logging system + "github.com/charmbracelet/log" + // Encryption + "crypto/rand" "encoding/json" + "math/big" "net/http" "github.com/golang-jwt/jwt" @@ -19,6 +24,11 @@ import ( _ "github.com/mattn/go-sqlite3" ) +// Define the configuration directories +var userConfigDirectory, err = os.UserConfigDir() +var serverConfigDirectory = fmt.Sprintf("%v/ambition/server", userConfigDirectory) +var jwtPath = fmt.Sprintf("%v/jwt_secret", serverConfigDirectory) + // Define the user request struct type UserRequest struct { Name string `json:"name"` @@ -37,6 +47,30 @@ func (ur *UserRequest) Parse(req *http.Request) error { return nil } +// A function to write a randomly-generated cryptographically secure 24-character string to a file +func makeSecret() { + const characters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-" + ret := make([]byte, 24) + for i := 0; i < 24; i++ { + num, err := rand.Int(rand.Reader, big.NewInt(int64(len(characters)))) + if err != nil { + log.Fatal(err) + } + ret[i] = characters[num.Int64()] + } + + // Check if the Ambition server config folder exists, otherwise make it + _, err2 := os.Stat(serverConfigDirectory) + if os.IsNotExist(err2) { + log.Info("Ambition backend config folder does not exist, creating...") + os.MkdirAll(serverConfigDirectory, 0755) + log.Info("Made Ambition backend config folder!") + } + + // Write the secret to the file + os.WriteFile(jwtPath, ret, 0755) +} + // Define the user handler struct type UserHandler struct { db *sql.DB @@ -51,8 +85,9 @@ func NewUserHandler() (*UserHandler, error) { return nil, err } - // Define the JSON web token - jwt_secret_str := os.Getenv("JWT_SECRET") + // Get the JSON web token + jwt_secret_bytes, err := os.ReadFile(jwtPath) + jwt_secret_str := string(jwt_secret_bytes) // Return any errors if jwt_secret_str == "" { return nil, errors.New("no JWT_SECRET provided in .env")