feat: implemented handling webhooks

main.go

@@ -28,17 +28,34 @@ type server struct {
 	database       *database.Queries
 	platform       string
 	jwtSecret      []byte
+	polkaKey       string
 }
 
 func writeJsonResponse(w http.ResponseWriter, statusCode int, response any) {
-	w.WriteHeader(statusCode)
-	w.Header().Add("Content-Type", "application/json")
-
-	encoder := json.NewEncoder(w)
-
-	if err := encoder.Encode(response); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+	if response == nil {
+		w.WriteHeader(statusCode)
+		return
 	}
+
+	data, err := json.Marshal(response)
+
+	if err != nil {
+		w.Header().Add("Content-Type", "application/json")
+		w.WriteHeader(http.StatusInternalServerError)
+
+		err := apiError{
+			Err: "Failed to encode JSON response",
+		}
+
+		errData, _ := json.Marshal(err)
+
+		w.Write(errData)
+		return
+	}
+
+	w.Header().Add("Content-Type", "application/json")
+	w.WriteHeader(statusCode)
+	w.Write(data)
 }
 
 func decodeJsonRequest[T any](r *http.Request) (*T, error) {
@@ -207,10 +224,11 @@ type createUserRequest struct {
 }
 
 type createUserResponse struct {
-	Id        string `json:"id"`
-	CreatedAt string `json:"created_at"`
-	UpdatedAt string `json:"updated_at"`
-	Email     string `json:"email"`
+	Id          string `json:"id"`
+	CreatedAt   string `json:"created_at"`
+	UpdatedAt   string `json:"updated_at"`
+	Email       string `json:"email"`
+	IsChirpyRed bool   `json:"is_chirpy_red"`
 }
 
 func (s *server) HandleCreateUser(w http.ResponseWriter, r *http.Request) {
@@ -263,10 +281,11 @@ func (s *server) HandleCreateUser(w http.ResponseWriter, r *http.Request) {
 	}
 
 	writeJsonResponse(w, http.StatusCreated, createUserResponse{
-		Id:        createdUser.ID.String(),
-		CreatedAt: createdUser.CreatedAt.Format(time.RFC3339),
-		UpdatedAt: createdUser.UpdatedAt.Format(time.RFC3339),
-		Email:     createdUser.Email,
+		Id:          createdUser.ID.String(),
+		CreatedAt:   createdUser.CreatedAt.Format(time.RFC3339),
+		UpdatedAt:   createdUser.UpdatedAt.Format(time.RFC3339),
+		Email:       createdUser.Email,
+		IsChirpyRed: createdUser.IsChirpyRed,
 	})
 }
 
@@ -344,6 +363,7 @@ type loginResponse struct {
 	CreatedAt    string `json:"created_at"`
 	UpdatedAt    string `json:"updated_at"`
 	Email        string `json:"email"`
+	IsChirpyRed  bool   `json:"is_chirpy_red"`
 	Token        string `json:"token"`
 	RefreshToken string `json:"refresh_token"`
 }
@@ -411,6 +431,7 @@ func (s *server) HandleLogin(w http.ResponseWriter, r *http.Request) {
 		CreatedAt:    existingUser.CreatedAt.Format(time.RFC3339),
 		UpdatedAt:    existingUser.UpdatedAt.Format(time.RFC3339),
 		Email:        existingUser.Email,
+		IsChirpyRed:  existingUser.IsChirpyRed,
 		Token:        accessToken,
 		RefreshToken: createdRefreshToken.Token,
 	})
@@ -500,10 +521,11 @@ type updateUserRequest struct {
 }
 
 type updateUserResponse struct {
-	Id        string `json:"id"`
-	CreatedAt string `json:"created_at"`
-	UpdatedAt string `json:"updated_at"`
-	Email     string `json:"email"`
+	Id          string `json:"id"`
+	CreatedAt   string `json:"created_at"`
+	UpdatedAt   string `json:"updated_at"`
+	Email       string `json:"email"`
+	IsChirpyRed bool   `json:"is_chirpy_red"`
 }
 
 func (r *updateUserRequest) Validate() error {
@@ -574,10 +596,11 @@ func (s *server) HandleUpdateUser(w http.ResponseWriter, r *http.Request) {
 	}
 
 	writeJsonResponse(w, http.StatusOK, updateUserResponse{
-		Id:        updatedUser.ID.String(),
-		CreatedAt: updatedUser.CreatedAt.Format(time.RFC3339),
-		UpdatedAt: updatedUser.UpdatedAt.Format(time.RFC3339),
-		Email:     updatedUser.Email,
+		Id:          updatedUser.ID.String(),
+		CreatedAt:   updatedUser.CreatedAt.Format(time.RFC3339),
+		UpdatedAt:   updatedUser.UpdatedAt.Format(time.RFC3339),
+		Email:       updatedUser.Email,
+		IsChirpyRed: updatedUser.IsChirpyRed,
 	})
 }
 
@@ -638,6 +661,91 @@ func (s *server) HandleDeleteChirp(w http.ResponseWriter, r *http.Request) {
 	writeJsonResponse(w, http.StatusNoContent, nil)
 }
 
+type userUpgradeData struct {
+	UserId string `json:"user_id"`
+}
+
+type webhookEvent struct {
+	Event string `json:"event"`
+	Data  any    `json:"-"`
+}
+
+func (p *webhookEvent) UnmarshalJSON(b []byte) error {
+	type Alias webhookEvent
+
+	aux := &struct {
+		*Alias
+		RawData json.RawMessage `json:"data"`
+	}{
+		Alias: (*Alias)(p),
+	}
+
+	if err := json.Unmarshal(b, aux); err != nil {
+		return err
+	}
+
+	switch p.Event {
+	case "user.upgraded":
+		var data userUpgradeData
+
+		if err := json.Unmarshal(aux.RawData, &data); err != nil {
+			return err
+		}
+
+		p.Data = data
+	default:
+	}
+
+	return nil
+}
+
+func (s *server) HandleWebhooks(w http.ResponseWriter, r *http.Request) {
+	apiKey, err := auth.GetAPIKey(r.Header)
+
+	unauthorizedError := apiError{
+		Err: "You are not authorized to perform this action",
+	}
+
+	if err != nil || apiKey != s.polkaKey {
+		writeJsonResponse(w, http.StatusUnauthorized, unauthorizedError)
+		return
+	}
+
+	event, err := decodeJsonRequest[webhookEvent](r)
+
+	if err != nil {
+		writeJsonResponse(w, http.StatusInternalServerError, apiError{
+			Err: "Unable to deserialize webhook event",
+		})
+		return
+	}
+
+	switch v := event.Data.(type) {
+	case userUpgradeData:
+		validUserId, err := uuid.Parse(v.UserId)
+
+		userNotFoundError := apiError{
+			Err: "Unable to upgrade user",
+		}
+
+		if err != nil {
+			writeJsonResponse(w, http.StatusNotFound, userNotFoundError)
+			return
+		}
+
+		_, err = s.database.UpgradeUser(r.Context(), validUserId)
+
+		if err != nil {
+			writeJsonResponse(w, http.StatusNotFound, userNotFoundError)
+			return
+		}
+
+		writeJsonResponse(w, http.StatusNoContent, nil)
+	default:
+		writeJsonResponse(w, http.StatusNoContent, nil)
+	}
+}
+
 func main() {
 	err := godotenv.Load()
 
@@ -649,12 +757,18 @@ func main() {
 	dbURL := os.Getenv("DB_URL")
 	platform := os.Getenv("PLATFORM")
 	jwtSecret := os.Getenv("JWT_SECRET")
+	polkaKey := os.Getenv("POLKA_KEY")
 
 	if strings.TrimSpace(jwtSecret) == "" {
 		log.Fatalf("Failed to retrieve JWT_SECRET")
 		os.Exit(1)
 	}
 
+	if strings.TrimSpace(polkaKey) == "" {
+		log.Fatalf("Failed to retrieve POLKA_KEY")
+		os.Exit(1)
+	}
+
 	db, err := sql.Open("postgres", dbURL)
 
 	if err != nil {
@@ -666,6 +780,7 @@ func main() {
 		database:  database.New(db),
 		platform:  platform,
 		jwtSecret: []byte(jwtSecret),
+		polkaKey:  polkaKey,
 	}
 
 	mux := http.NewServeMux()
@@ -683,6 +798,7 @@ func main() {
 	mux.HandleFunc("POST /api/revoke", server.HandleRevoke)
 	mux.HandleFunc("POST /api/users", server.HandleCreateUser)
 	mux.HandleFunc("PUT /api/users", server.HandleUpdateUser)
+	mux.HandleFunc("POST /api/polka/webhooks", server.HandleWebhooks)
 
 	mux.HandleFunc("GET /api/chirps", server.HandleGetAllChirps)
 	mux.HandleFunc("GET /api/chirps/{id}", server.HandleGetChirp)