chore:less boilerplate heavy ios notifications (#272)

* removed a bit of ios boilerplate

* removed even more boilerplate

* removed another instance of boilerplate

* more refactoring

* more simplification work

* refactored the enum mirator to also be simpler to maintain

server/api/tumdev/campus_backend.proto

@@ -174,7 +174,7 @@ enum DeviceType {
 
 message CreateDeviceRequest {
   string device_id = 1;
-  optional string public_key = 2;
+  string public_key = 2;
   DeviceType device_type = 3;
 }
 

server/backend/cafeteria.go

@@ -301,7 +301,7 @@ func queryTags(cafeteriaID int32, dishID int32, ratingType ModelType, tx *gorm.D
 	}
 
 	if err != nil {
-		log.WithError(err).Error("while querying the tags for the request.")
+		log.WithError(err).Error("while querying the tags for the request")
 	}
 
 	//needed since the gRPC element does not specify column names - cannot be directly queried into the grpc message object.
@@ -672,25 +672,25 @@ func (s *CampusServer) GetCafeterias(ctx context.Context, _ *pb.ListCanteensRequ
 	}, requestStatus
 }
 
-func (s *CampusServer) ListDishes(ctx context.Context, request *pb.ListDishesRequest) (*pb.ListDishesReply, error) {
-	if request.Year < 2022 {
+func (s *CampusServer) ListDishes(ctx context.Context, req *pb.ListDishesRequest) (*pb.ListDishesReply, error) {
+	if req.Year < 2022 {
 		return &pb.ListDishesReply{}, status.Error(codes.Internal, "Years must be larger or equal to 2022 ") // currently, no previous values have been added
 	}
-	if request.Week < 1 || request.Week > 53 {
+	if req.Week < 1 || req.Week > 53 {
 		return &pb.ListDishesReply{}, status.Error(codes.Internal, "Weeks must be in the range 1 - 53")
 	}
-	if request.Day < 0 || request.Day > 4 {
+	if req.Day < 0 || req.Day > 4 {
 		return &pb.ListDishesReply{}, status.Error(codes.Internal, "Days must be in the range 1 (Monday) - 4 (Friday)")
 	}
 
 	var requestStatus error = nil
 	var results []string
 	err := s.db.WithContext(ctx).Table("dishes_of_the_week weekly").
-		Where("weekly.day = ? AND weekly.week = ? and weekly.year = ?", request.Day, request.Week, request.Year).
+		Where("weekly.day = ? AND weekly.week = ? and weekly.year = ?", req.Day, req.Week, req.Year).
 		Select("weekly.dishID").
 		Joins("JOIN dish d ON d.dish = weekly.dishID").
 		Joins("JOIN cafeteria c ON c.cafeteria = d.cafeteriaID").
-		Where("c.name LIKE ?", request.CanteenId).
+		Where("c.name LIKE ?", req.CanteenId).
 		Select("d.name").
 		Find(&results).Error
 

server/backend/campus_api/campus_api.go

@@ -7,13 +7,16 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"os"
 
 	"github.com/TUM-Dev/Campus-Backend/server/model"
 	log "github.com/sirupsen/logrus"
 )
 
-func FetchExamResultsPublished(token string) (*model.TUMAPIPublishedExamResults, error) {
+// FetchExamResultsPublished fetches all published exam results from the TUM Campus API using CAMPUS_API_TOKEN.
+func FetchExamResultsPublished() (*model.TUMAPIPublishedExamResults, error) {
 	var examResultsPublished model.TUMAPIPublishedExamResults
+	token := os.Getenv("CAMPUS_API_TOKEN")
 	err := RequestCampusApi("/wbservicesbasic.pruefungenErgebnisse", token, &examResultsPublished)
 	if err != nil {
 		return nil, err

server/backend/device.go

@@ -128,7 +128,7 @@ func (s *CampusServer) CreateDevice(_ context.Context, req *pb.CreateDeviceReque
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 
-	switch req.GetDeviceType() {
+	switch req.DeviceType {
 	case pb.DeviceType_ANDROID:
 		return nil, status.Error(codes.Unimplemented, "android device creation not implemented")
 	case pb.DeviceType_IOS:
@@ -146,7 +146,7 @@ func (s *CampusServer) DeleteDevice(_ context.Context, req *pb.DeleteDeviceReque
 		return nil, status.Error(codes.InvalidArgument, err.Error())
 	}
 
-	switch req.GetDeviceType() {
+	switch req.DeviceType {
 	case pb.DeviceType_ANDROID:
 		return nil, status.Error(codes.Unimplemented, "android device remove not implemented")
 	case pb.DeviceType_IOS:

server/backend/ios_notifications/apns/jwt_token.go

@@ -15,20 +15,6 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-const (
-	// TokenTimeout for the token in seconds
-	TokenTimeout = 3000
-)
-
-var (
-	ErrorAuthKeyNotPem   = errors.New("failed to parse token: AuthKey must be a valid .p8 PEM file")
-	ErrorAuthKeyNotEcdsa = errors.New("failed to parse token: AuthKey must be of type ecdsa.PrivateKey")
-	ErrorAuthKeyNil      = errors.New("failed to parse token: AuthKey was nil")
-	ApnsKeyId            = os.Getenv("APNS_KEY_ID")
-	ApnsTeamId           = os.Getenv("APNS_TEAM_ID")
-	ApnsP8FilePath       = os.Getenv("APNS_P8_FILE_PATH")
-)
-
 type JWTToken struct {
 	sync.Mutex
 	EncryptionKey *ecdsa.PrivateKey
@@ -39,15 +25,15 @@ type JWTToken struct {
 }
 
 func NewToken() (*JWTToken, error) {
-	encryptionKey, err := APNsEncryptionKeyFromFile()
+	encryptionKey, err := EncryptionKeyFromFile()
 	if err != nil {
 		return nil, err
 	}
 
 	token := JWTToken{
 		EncryptionKey: encryptionKey,
-		KeyId:         ApnsKeyId,
-		TeamId:        ApnsTeamId,
+		KeyId:         os.Getenv("APNS_KEY_ID"),
+		TeamId:        os.Getenv("APNS_TEAM_ID"),
 	}
 
 	if err = token.Generate(); err != nil {
@@ -57,11 +43,11 @@ func NewToken() (*JWTToken, error) {
 	return &token, nil
 }
 
-// APNsEncryptionKeyFromFile reads the APNs encryption key from the file system
+// EncryptionKeyFromFile reads the APNs encryption key from the file system
 // and returns it as an ecdsa.PrivateKey
 // The file location is defined by the APNS_P8_FILE_PATH environment variable
-func APNsEncryptionKeyFromFile() (*ecdsa.PrivateKey, error) {
-	path, err := filepath.Abs(ApnsP8FilePath)
+func EncryptionKeyFromFile() (*ecdsa.PrivateKey, error) {
+	path, err := filepath.Abs(os.Getenv("APNS_P8_FILE_PATH"))
 
 	if err != nil {
 		log.Error("No valid path to AuthKey")
@@ -81,7 +67,7 @@ func APNsEncryptionKeyFromFile() (*ecdsa.PrivateKey, error) {
 	if block == nil {
 		log.Error("Could not decode APNs encryption key from file")
 
-		return nil, ErrorAuthKeyNotPem
+		return nil, errors.New("failed to parse token: AuthKey must be a valid .p8 PEM file")
 	}
 
 	key, err := x509.ParsePKCS8PrivateKey(block.Bytes)
@@ -96,7 +82,7 @@ func APNsEncryptionKeyFromFile() (*ecdsa.PrivateKey, error) {
 		return ecdsaKey, nil
 	}
 
-	return nil, ErrorAuthKeyNotEcdsa
+	return nil, errors.New("failed to parse token: AuthKey must be of type ecdsa.PrivateKey")
 }
 
 func (t *JWTToken) GenerateNewTokenIfExpired() (bearer string) {
@@ -114,12 +100,12 @@ func (t *JWTToken) GenerateNewTokenIfExpired() (bearer string) {
 }
 
 func (t *JWTToken) IsExpired() bool {
-	return currentTimestamp() >= (t.IssuedAt + TokenTimeout)
+	return currentTimestamp() >= (t.IssuedAt + 3000)
 }
 
 func (t *JWTToken) Generate() error {
 	if t.EncryptionKey == nil {
-		return ErrorAuthKeyNil
+		return errors.New("failed to parse token: AuthKey was nil")
 	}
 
 	issuedAt := currentTimestamp()

server/backend/ios_notifications/apns/repository.go

@@ -16,25 +16,6 @@ import (
 	"gorm.io/gorm"
 )
 
-const (
-	// BundleId from the Apple Developer Portal
-	BundleId = "de.tum.tca"
-	// ReadIdleTimeout is the idle time after which the http2 transport will do a health check
-	ReadIdleTimeout = 15 * time.Second
-	// HTTPClientTimeout is the timeout for the http client used to send notifications
-	HTTPClientTimeout = 60 * time.Second
-)
-
-const (
-	ApnsDevelopmentURL = "https://api.sandbox.push.apple.com:443"
-	ApnsProductionURL  = "https://api.push.apple.com:443"
-)
-
-var (
-	ErrCouldNotSendNotification   = errors.New("could not send notification")
-	ErrCouldNotDecodeAPNsResponse = errors.New("could not decode apns response")
-)
-
 type Repository struct {
 	DB         gorm.DB
 	Token      *JWTToken
@@ -43,11 +24,11 @@ type Repository struct {
 
 // ApnsUrl uses the environment variable ENVIRONMENT to determine whether
 // to use the production or development APNs URL.
-func (r *Repository) ApnsUrl() string {
+func (r *Repository) ApnsUrl(DeviceId string) string {
 	if env.IsProd() {
-		return ApnsProductionURL
+		return "https://api.push.apple.com:443/3/device/" + DeviceId
 	}
-	return ApnsDevelopmentURL
+	return "https://api.sandbox.push.apple.com:443/3/device/" + DeviceId
 }
 
 // CreateCampusTokenRequest creates a request log in the database that can be referred to
@@ -72,34 +53,24 @@ func (r *Repository) CreateRequest(deviceId string, requestType model.IOSBackgro
 	return &request, nil
 }
 
-func (r *Repository) SendAlertNotification(payload *model.IOSNotificationPayload) (*model.IOSRemoteNotificationResponse, error) {
-	return r.SendNotification(payload, model.IOSAPNSPushTypeAlert, 10)
-}
-
-func (r *Repository) SendBackgroundNotification(payload *model.IOSNotificationPayload) (*model.IOSRemoteNotificationResponse, error) {
-	return r.SendNotification(payload, model.IOSAPNSPushTypeBackground, 10)
-}
-
-func (r *Repository) SendNotification(notification *model.IOSNotificationPayload, apnsPushType model.IOSAPNSPushType, priority int) (*model.IOSRemoteNotificationResponse, error) {
-
-	url := r.ApnsUrl() + "/3/device/" + notification.DeviceId
+func (r *Repository) SendNotification(notification *model.IOSNotificationPayload, apnsPushType model.IOSAPNSPushType) (*model.IOSRemoteNotificationResponse, error) {
 	body, _ := notification.MarshalJSON()
 
-	req, _ := http.NewRequest(http.MethodPost, url, bytes.NewBuffer(body))
+	req, _ := http.NewRequest(http.MethodPost, r.ApnsUrl(notification.DeviceId), bytes.NewBuffer(body))
 
 	// can be e.g. alert or background
 	req.Header.Set("apns-push-type", apnsPushType.String())
-	req.Header.Set("apns-topic", BundleId)
+	req.Header.Set("apns-topic", "de.tum.tca")
 	// can be a value between 1 and 10
-	req.Header.Set("apns-priority", strconv.Itoa(priority))
+	req.Header.Set("apns-priority", strconv.Itoa(10))
 
 	bearer := r.Token.GenerateNewTokenIfExpired()
 	req.Header.Set("authorization", "bearer "+bearer)
 
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		log.WithError(err).Error("Could not send notification")
-		return nil, ErrCouldNotSendNotification
+		return nil, errors.New("could not send notification")
 	}
 	defer func(Body io.ReadCloser) {
 		if err := Body.Close(); err != nil {
@@ -108,25 +79,25 @@ func (r *Repository) SendNotification(notification *model.IOSNotificationPayload
 	}(resp.Body)
 
 	var response model.IOSRemoteNotificationResponse
-	if err = json.NewDecoder(resp.Body).Decode(&response); err != nil && err != io.EOF {
+	if err := json.NewDecoder(resp.Body).Decode(&response); err != nil && err != io.EOF {
 		log.WithError(err).Error("Could not decode APNs response")
-		return nil, ErrCouldNotDecodeAPNsResponse
+		return nil, errors.New("could not decode apns response")
 	}
 
 	return &response, nil
 }
 
 func NewRepository(db *gorm.DB, token *JWTToken) *Repository {
 	transport := &http2.Transport{
-		ReadIdleTimeout: ReadIdleTimeout,
+		ReadIdleTimeout: 15 * time.Second,
 	}
 
 	return &Repository{
 		DB:    *db,
 		Token: token,
 		httpClient: &http.Client{
 			Transport: transport,
-			Timeout:   HTTPClientTimeout,
+			Timeout:   60 * time.Second,
 		},
 	}
 }

server/backend/ios_notifications/apns/service.go

@@ -4,6 +4,7 @@ package apns
 
 import (
 	"errors"
+	"os"
 
 	"github.com/TUM-Dev/Campus-Backend/server/model"
 	log "github.com/sirupsen/logrus"
@@ -32,30 +33,23 @@ func (s *Service) RequestGradeUpdateForDevice(deviceID string) error {
 
 	notification := model.NewIOSNotificationPayload(deviceID).Background(campusRequestToken.RequestID, model.IOSBackgroundCampusTokenRequest)
 
-	if _, err := s.Repository.SendBackgroundNotification(notification); err != nil {
+	if _, err := s.Repository.SendNotification(notification, model.IOSAPNSPushTypeBackground); err != nil {
 		log.WithError(err).Error("Could not send background notification")
-		return ErrCouldNotSendNotification
+		return errors.New("could not send notification")
 	}
 	return nil
 }
 
 func ValidateRequirementsForIOSNotificationsService() error {
-	if ApnsKeyId == "" {
-		return errors.New("APNS_KEY_ID env variable is not set")
+	for _, envVar := range []string{"APNS_KEY_ID", "APNS_TEAM_ID", "APNS_P8_FILE_PATH"} {
+		if os.Getenv(envVar) == "" {
+			return errors.New(envVar + " env variable is not set")
+		}
 	}
 
-	if ApnsTeamId == "" {
-		return errors.New("APNS_TEAM_ID env variable is not set")
-	}
-
-	if ApnsP8FilePath == "" {
-		return errors.New("APNS_P8_FILE_PATH env variable is not set")
-	}
-
-	if _, err := APNsEncryptionKeyFromFile(); err != nil {
+	if _, err := EncryptionKeyFromFile(); err != nil {
 		return errors.New("APNS P8 token is not valid or not set")
 	}
-
 	return nil
 }
 

server/backend/ios_notifications/crypto/encrypted_string.go

@@ -47,21 +47,19 @@ func AsymmetricEncrypt(plaintext string, publicKey string) (*EncryptedString, er
 
 func StringToPublicKey(pub string) (*rsa.PublicKey, error) {
 	block, _ := pem.Decode([]byte(pub))
-
 	if block == nil {
 		return nil, errors.New("failed to parse PEM block containing the public key")
 	}
 
 	key, err := x509.ParsePKIXPublicKey(block.Bytes)
-
 	if err != nil {
 		return nil, errors.New("failed to parse DER encoded public key: " + err.Error())
 	}
 
-	if pubKey, ok := key.(*rsa.PublicKey); ok {
-		return pubKey, nil
-	} else {
+	if pubKey, ok := key.(*rsa.PublicKey); !ok {
 		return nil, errors.New("failed to parse DER encoded public key: " + err.Error())
+	} else {
+		return pubKey, nil
 	}
 }