Make web app work for updated notifications

server/errors.go

@@ -40,14 +40,16 @@ var (
 	errHTTPBadRequestAttachmentsExpiryBeforeDelivery = &errHTTP{40015, http.StatusBadRequest, "invalid request: attachment expiry before delayed delivery date", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
 	errHTTPBadRequestWebSocketsUpgradeHeaderMissing  = &errHTTP{40016, http.StatusBadRequest, "invalid request: client not using the websocket protocol", "https://ntfy.sh/docs/subscribe/api/#websockets"}
 	errHTTPBadRequestJSONInvalid                     = &errHTTP{40017, http.StatusBadRequest, "invalid request: request body must be message JSON", "https://ntfy.sh/docs/publish/#publish-as-json"}
-	errHTTPNotFound                                  = &errHTTP{40401, http.StatusNotFound, "page not found", ""}
+	errHTTPNotFound                                  = &errHTTP{40401, http.StatusNotFound, "not found", ""}
+	errHTTPNotFoundMessageID                         = &errHTTP{40402, http.StatusNotFound, "not found: unable to find message with this ID", "https://ntfy.sh/docs/publish/#updating-messages"} // FIXME LINK
 	errHTTPUnauthorized                              = &errHTTP{40101, http.StatusUnauthorized, "unauthorized", "https://ntfy.sh/docs/publish/#authentication"}
 	errHTTPForbidden                                 = &errHTTP{40301, http.StatusForbidden, "forbidden", "https://ntfy.sh/docs/publish/#authentication"}
 	errHTTPTooManyRequestsLimitRequests              = &errHTTP{42901, http.StatusTooManyRequests, "limit reached: too many requests, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
 	errHTTPTooManyRequestsLimitEmails                = &errHTTP{42902, http.StatusTooManyRequests, "limit reached: too many emails, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
 	errHTTPTooManyRequestsLimitSubscriptions         = &errHTTP{42903, http.StatusTooManyRequests, "limit reached: too many active subscriptions, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
 	errHTTPTooManyRequestsLimitTotalTopics           = &errHTTP{42904, http.StatusTooManyRequests, "limit reached: the total number of topics on the server has been reached, please contact the admin", "https://ntfy.sh/docs/publish/#limitations"}
-	errHTTPTooManyRequestsAttachmentBandwidthLimit   = &errHTTP{42905, http.StatusTooManyRequests, "too many requests: daily bandwidth limit reached", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPTooManyRequestsAttachmentBandwidthLimit   = &errHTTP{42905, http.StatusTooManyRequests, "limit reached: daily bandwidth limit reached, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPTooManyRequestsUpdatingTooQuickly         = &errHTTP{42906, http.StatusTooManyRequests, "limit reached: too many consecutive message updates", "https://ntfy.sh/docs/publish/#updating-messages"} // FIXME LINK
 	errHTTPInternalError                             = &errHTTP{50001, http.StatusInternalServerError, "internal server error", ""}
 	errHTTPInternalErrorInvalidFilePath              = &errHTTP{50002, http.StatusInternalServerError, "internal server error: invalid file path", ""}
 )

server/message_cache.go

@@ -23,6 +23,7 @@ const (
 			id INTEGER PRIMARY KEY AUTOINCREMENT,
 			mid TEXT NOT NULL,
 			time INT NOT NULL,
+			updated INT NOT NULL,
 			topic TEXT NOT NULL,
 			message TEXT NOT NULL,
 			title TEXT NOT NULL,
@@ -43,41 +44,47 @@ const (
 		COMMIT;
 	`
 	insertMessageQuery = `
-		INSERT INTO messages (mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding, published) 
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+		INSERT INTO messages (mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding, published) 
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
 	`
+	updateMessageQuery           = `UPDATE messages SET updated = ?, message = ?, title = ?, priority = ?, tags = ?, click = ? WHERE topic = ? AND mid = ?`
 	pruneMessagesQuery           = `DELETE FROM messages WHERE time < ? AND published = 1`
 	selectRowIDFromMessageID     = `SELECT id FROM messages WHERE topic = ? AND mid = ?`
 	selectMessagesSinceTimeQuery = `
-		SELECT mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
+		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
 		FROM messages 
 		WHERE topic = ? AND time >= ? AND published = 1
 		ORDER BY time, id
 	`
 	selectMessagesSinceTimeIncludeScheduledQuery = `
-		SELECT mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
+		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
 		FROM messages 
 		WHERE topic = ? AND time >= ?
 		ORDER BY time, id
 	`
 	selectMessagesSinceIDQuery = `
-		SELECT mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
+		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
 		FROM messages 
-		WHERE topic = ? AND id > ? AND published = 1 
+		WHERE topic = ? AND id >= ? AND published = 1 
 		ORDER BY time, id
 	`
 	selectMessagesSinceIDIncludeScheduledQuery = `
-		SELECT mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
+		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
 		FROM messages 
-		WHERE topic = ? AND (id > ? OR published = 0)
+		WHERE topic = ? AND (id >= ? OR published = 0)
 		ORDER BY time, id
 	`
 	selectMessagesDueQuery = `
-		SELECT mid, time, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
+		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
 		FROM messages 
 		WHERE time <= ? AND published = 0
 		ORDER BY time, id
 	`
+	selectMessageByIDQuery = `
+		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
+		FROM messages 
+		WHERE topic = ? AND mid = ?
+	`
 	updateMessagePublishedQuery     = `UPDATE messages SET published = 1 WHERE mid = ?`
 	selectMessagesCountQuery        = `SELECT COUNT(*) FROM messages`
 	selectMessageCountForTopicQuery = `SELECT COUNT(*) FROM messages WHERE topic = ?`
@@ -88,7 +95,7 @@ const (
 
 // Schema management queries
 const (
-	currentSchemaVersion          = 5
+	currentSchemaVersion          = 6
 	createSchemaVersionTableQuery = `
 		CREATE TABLE IF NOT EXISTS schemaVersion (
 			id INT PRIMARY KEY,
@@ -166,6 +173,11 @@ const (
 		ALTER TABLE messages_new RENAME TO messages;
 		COMMIT;
 	`
+
+	// 5 -> 6
+	migrate5To6AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN updated INT NOT NULL DEFAULT (0);
+	`
 )
 
 type messageCache struct {
@@ -232,6 +244,7 @@ func (c *messageCache) AddMessage(m *message) error {
 		insertMessageQuery,
 		m.ID,
 		m.Time,
+		m.Updated,
 		m.Topic,
 		m.Message,
 		m.Title,
@@ -250,6 +263,28 @@ func (c *messageCache) AddMessage(m *message) error {
 	return err
 }
 
+func (c *messageCache) UpdateMessage(m *message) error {
+	if m.Event != messageEvent {
+		return errUnexpectedMessageType
+	}
+	if c.nop {
+		return nil
+	}
+	tags := strings.Join(m.Tags, ",")
+	_, err := c.db.Exec(
+		updateMessageQuery,
+		m.Updated,
+		m.Message,
+		m.Title,
+		m.Priority,
+		tags,
+		m.Click,
+		m.Topic,
+		m.ID,
+	)
+	return err
+}
+
 func (c *messageCache) Messages(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
 	if since.IsNone() {
 		return make([]*message, 0), nil
@@ -296,7 +331,15 @@ func (c *messageCache) messagesSinceID(topic string, since sinceMarker, schedule
 	if err != nil {
 		return nil, err
 	}
-	return readMessages(rows)
+	messages, err := readMessages(rows)
+	if err != nil {
+		return nil, err
+	} else if len(messages) == 0 {
+		return messages, nil
+	} else if since.IsTime() && messages[0].Updated > since.Time().Unix() {
+		return messages, nil
+	}
+	return messages[1:], nil // Do not include row with ID itself
 }
 
 func (c *messageCache) MessagesDue() ([]*message, error) {
@@ -393,16 +436,31 @@ func (c *messageCache) AttachmentsExpired() ([]string, error) {
 	return ids, nil
 }
 
+func (c *messageCache) Message(topic, id string) (*message, error) {
+	rows, err := c.db.Query(selectMessageByIDQuery, topic, id)
+	if err != nil {
+		return nil, err
+	}
+	messages, err := readMessages(rows)
+	if err != nil {
+		return nil, err
+	} else if len(messages) == 0 {
+		return nil, errors.New("not found")
+	}
+	return messages[0], nil
+}
+
 func readMessages(rows *sql.Rows) ([]*message, error) {
 	defer rows.Close()
 	messages := make([]*message, 0)
 	for rows.Next() {
-		var timestamp, attachmentSize, attachmentExpires int64
+		var timestamp, updated, attachmentSize, attachmentExpires int64
 		var priority int
 		var id, topic, msg, title, tagsStr, click, attachmentName, attachmentType, attachmentURL, attachmentOwner, encoding string
 		err := rows.Scan(
 			&id,
 			&timestamp,
+			&updated,
 			&topic,
 			&msg,
 			&title,
@@ -438,6 +496,7 @@ func readMessages(rows *sql.Rows) ([]*message, error) {
 		messages = append(messages, &message{
 			ID:         id,
 			Time:       timestamp,
+			Updated:    updated,
 			Event:      messageEvent,
 			Topic:      topic,
 			Message:    msg,
@@ -490,6 +549,8 @@ func setupCacheDB(db *sql.DB) error {
 		return migrateFrom3(db)
 	} else if schemaVersion == 4 {
 		return migrateFrom4(db)
+	} else if schemaVersion == 5 {
+		return migrateFrom5(db)
 	}
 	return fmt.Errorf("unexpected schema version found: %d", schemaVersion)
 }
@@ -562,5 +623,16 @@ func migrateFrom4(db *sql.DB) error {
 	if _, err := db.Exec(updateSchemaVersion, 5); err != nil {
 		return err
 	}
+	return migrateFrom5(db)
+}
+
+func migrateFrom5(db *sql.DB) error {
+	log.Print("Migrating cache database schema: from 5 to 6")
+	if _, err := db.Exec(migrate5To6AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 6); err != nil {
+		return err
+	}
 	return nil // Update this when a new version is added
 }

server/server.go

@@ -55,9 +55,10 @@ type handleFunc func(http.ResponseWriter, *http.Request, *visitor) error
 
 var (
 	// If changed, don't forget to update Android App and auth_sqlite.go
-	topicRegex             = regexp.MustCompile(`^[-_A-Za-z0-9]{1,64}$`)               // No /!
-	topicPathRegex         = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`)              // Regex must match JS & Android app!
-	externalTopicPathRegex = regexp.MustCompile(`^/[^/]+\.[^/]+/[-_A-Za-z0-9]{1,64}$`) // Extended topic path, for web-app, e.g. /example.com/mytopic
+	topicRegex             = regexp.MustCompile(`^[-_A-Za-z0-9]{1,64}$`)                  // No /!
+	topicPathRegex         = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`)                 // Regex must match JS & Android app!
+	updateTopicPathRegex   = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}/[A-Za-z0-9]{12}$`) // ID length must match messageIDLength & util.randomStringCharset
+	externalTopicPathRegex = regexp.MustCompile(`^/[^/]+\.[^/]+/[-_A-Za-z0-9]{1,64}$`)    // Extended topic path, for web-app, e.g. /example.com/mytopic
 	jsonPathRegex          = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`)
 	ssePathRegex           = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/sse$`)
 	rawPathRegex           = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/raw$`)
@@ -279,7 +280,7 @@ func (s *Server) handleInternal(w http.ResponseWriter, r *http.Request, v *visit
 		return s.handleOptions(w, r)
 	} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && r.URL.Path == "/" {
 		return s.limitRequests(s.transformBodyJSON(s.authWrite(s.handlePublish)))(w, r, v)
-	} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicPathRegex.MatchString(r.URL.Path) {
+	} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && (topicPathRegex.MatchString(r.URL.Path) || updateTopicPathRegex.MatchString(r.URL.Path)) {
 		return s.limitRequests(s.authWrite(s.handlePublish))(w, r, v)
 	} else if r.Method == http.MethodGet && publishPathRegex.MatchString(r.URL.Path) {
 		return s.limitRequests(s.authWrite(s.handlePublish))(w, r, v)
@@ -390,7 +391,26 @@ func (s *Server) handleFile(w http.ResponseWriter, r *http.Request, v *visitor)
 }
 
 func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visitor) error {
-	t, err := s.topicFromPath(r.URL.Path)
+	t, messageID, err := s.topicAndMessageIDFromPath(r.URL.Path)
+	if err != nil {
+		return err
+	}
+	var m *message
+	update := messageID != ""
+	if update {
+		m, err = s.messageCache.Message(t.ID, messageID)
+		if err != nil {
+			return errHTTPNotFoundMessageID
+		}
+		newUpdated := time.Now().Unix()
+		if newUpdated <= m.Updated {
+			return errHTTPTooManyRequestsUpdatingTooQuickly
+		}
+		m.Updated = newUpdated
+	} else {
+		m = newDefaultMessage(t.ID, "")
+	}
+	cache, firebase, email, unifiedpush, err := s.parsePublishParams(r, v, m)
 	if err != nil {
 		return err
 	}
@@ -398,11 +418,6 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 	if err != nil {
 		return err
 	}
-	m := newDefaultMessage(t.ID, "")
-	cache, firebase, email, unifiedpush, err := s.parsePublishParams(r, v, m)
-	if err != nil {
-		return err
-	}
 	if err := s.handlePublishBody(r, v, m, body, unifiedpush); err != nil {
 		return err
 	}
@@ -430,8 +445,14 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 		}()
 	}
 	if cache {
-		if err := s.messageCache.AddMessage(m); err != nil {
-			return err
+		if update {
+			if err := s.messageCache.UpdateMessage(m); err != nil {
+				return err
+			}
+		} else {
+			if err := s.messageCache.AddMessage(m); err != nil {
+				return err
+			}
 		}
 	}
 	w.Header().Set("Content-Type", "application/json")
@@ -447,9 +468,19 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 
 func (s *Server) parsePublishParams(r *http.Request, v *visitor, m *message) (cache bool, firebase bool, email string, unifiedpush bool, err error) {
 	cache = readBoolParam(r, true, "x-cache", "cache")
+	if !cache && m.Updated != 0 {
+		return false, false, "", false, errors.New("message updates must be cached")
+	}
+	// TODO more restrictions
 	firebase = readBoolParam(r, true, "x-firebase", "firebase")
-	m.Title = readParam(r, "x-title", "title", "t")
-	m.Click = readParam(r, "x-click", "click")
+	title := readParam(r, "x-title", "title", "t")
+	if title != "" {
+		m.Title = title
+	}
+	click := readParam(r, "x-click", "click")
+	if click != "" {
+		m.Click = click
+	}
 	filename := readParam(r, "x-filename", "filename", "file", "f")
 	attach := readParam(r, "x-attach", "attach", "a")
 	if attach != "" || filename != "" {
@@ -489,9 +520,11 @@ func (s *Server) parsePublishParams(r *http.Request, v *visitor, m *message) (ca
 	if messageStr != "" {
 		m.Message = messageStr
 	}
-	m.Priority, err = util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p"))
+	priority, err := util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p"))
 	if err != nil {
 		return false, false, "", false, errHTTPBadRequestPriorityInvalid
+	} else if priority > 0 {
+		m.Priority = priority
 	}
 	tagsStr := readParam(r, "x-tags", "tags", "tag", "ta")
 	if tagsStr != "" {
@@ -870,6 +903,13 @@ func parseSince(r *http.Request, poll bool) (sinceMarker, error) {
 		return sinceNoMessages, nil
 	}
 
+	// ID/timestamp
+	parts := strings.Split(since, "/")
+	if len(parts) == 2 && validMessageID(parts[0]) && validUnixTimestamp(parts[1]) {
+		t, _ := toUnixTimestamp(parts[1])
+		return newSince(parts[0], t), nil
+	}
+
 	// ID, timestamp, duration
 	if validMessageID(since) {
 		return newSinceID(since), nil
@@ -888,16 +928,20 @@ func (s *Server) handleOptions(w http.ResponseWriter, _ *http.Request) error {
 	return nil
 }
 
-func (s *Server) topicFromPath(path string) (*topic, error) {
+func (s *Server) topicAndMessageIDFromPath(path string) (*topic, string, error) {
 	parts := strings.Split(path, "/")
-	if len(parts) < 2 {
-		return nil, errHTTPBadRequestTopicInvalid
+	if len(parts) != 2 && len(parts) != 3 {
+		return nil, "", errHTTPBadRequestTopicInvalid
 	}
 	topics, err := s.topicsFromIDs(parts[1])
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
-	return topics[0], nil
+	messageID := ""
+	if len(parts) == 3 && len(parts[2]) == messageIDLength {
+		messageID = parts[2]
+	}
+	return topics[0], messageID, nil
 }
 
 func (s *Server) topicsFromPath(path string) ([]*topic, string, error) {

server/server_firebase.go

@@ -72,6 +72,7 @@ func toFirebaseMessage(m *message, auther auth.Auther) (*messaging.Message, erro
 			data = map[string]string{
 				"id":       m.ID,
 				"time":     fmt.Sprintf("%d", m.Time),
+				"updated":  fmt.Sprintf("%d", m.Updated),
 				"event":    m.Event,
 				"topic":    m.Topic,
 				"priority": fmt.Sprintf("%d", m.Priority),

server/server_firebase_test.go

@@ -77,6 +77,7 @@ func TestToFirebaseMessage_Message_Normal_Allowed(t *testing.T) {
 	require.Equal(t, map[string]string{
 		"id":                 m.ID,
 		"time":               fmt.Sprintf("%d", m.Time),
+		"updated":            "0",
 		"event":              "message",
 		"topic":              "mytopic",
 		"priority":           "4",

server/server_test.go

@@ -390,6 +390,69 @@ func TestServer_PublishAndPollSince(t *testing.T) {
 	require.Equal(t, 40008, toHTTPError(t, response.Body.String()).Code)
 }
 
+func TestServer_PublishUpdateAndPollSince(t *testing.T) {
+	s := newTestServer(t, newTestConfig(t))
+
+	// Initial PUT
+	response := request(t, s, "PUT", "/mytopic?t=atitle&tags=tag1,tag2&prio=high&click=https://google.com&attach=https://heckel.io", "test 1", nil)
+	message1 := toMessage(t, response.Body.String())
+	require.Equal(t, int64(0), message1.Updated)
+	require.Equal(t, "test 1", message1.Message)
+	require.Equal(t, "atitle", message1.Title)
+	require.Equal(t, 4, message1.Priority)
+	require.Equal(t, []string{"tag1", "tag2"}, message1.Tags)
+	require.Equal(t, "https://google.com", message1.Click)
+	require.Equal(t, "https://heckel.io", message1.Attachment.URL)
+
+	// Update
+	response = request(t, s, "PUT", "/mytopic/"+message1.ID+"?prio=low", "test 2", nil)
+	message2 := toMessage(t, response.Body.String())
+	require.Equal(t, message1.ID, message2.ID)
+	require.True(t, message2.Updated > message1.Updated)
+	require.Equal(t, "test 2", message2.Message) // Updated
+	require.Equal(t, "atitle", message2.Title)
+	require.Equal(t, 2, message2.Priority) // Updated
+	require.Equal(t, []string{"tag1", "tag2"}, message2.Tags)
+	require.Equal(t, "https://google.com", message2.Click)
+	require.Equal(t, "https://heckel.io", message2.Attachment.URL)
+
+	time.Sleep(1100 * time.Millisecond)
+
+	// Another update
+	response = request(t, s, "PUT", "/mytopic/"+message1.ID+"?title=new+title", "test 3", nil)
+	message3 := toMessage(t, response.Body.String())
+	require.True(t, message3.Updated > message2.Updated)
+	require.Equal(t, "test 3", message3.Message)  // Updated
+	require.Equal(t, "new title", message3.Title) // Updated
+
+	// Get all messages: Should be only one that was updated
+	since := "all"
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages := toMessages(t, response.Body.String())
+	require.Equal(t, 1, len(messages))
+	require.Equal(t, message1.ID, messages[0].ID)
+	require.Equal(t, "test 3", messages[0].Message)
+
+	// Get all messages since "message ID": Should be zero, since we know this message
+	since = message1.ID
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages = toMessages(t, response.Body.String())
+	require.Equal(t, 0, len(messages))
+
+	// Get all messages since "message ID" but with an older timestamp: Should be the latest updated message
+	since = fmt.Sprintf("%s/%d", message1.ID, message2.Updated) // We're missing an update
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages = toMessages(t, response.Body.String())
+	require.Equal(t, 1, len(messages))
+	require.Equal(t, "test 3", messages[0].Message)
+
+	// Get all messages since "message ID" with the current timestamp: No messages expected
+	since = fmt.Sprintf("%s/%d", message3.ID, message3.Updated) // We are up-to-date
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages = toMessages(t, response.Body.String())
+	require.Equal(t, 0, len(messages))
+}
+
 func TestServer_PublishViaGET(t *testing.T) {
 	s := newTestServer(t, newTestConfig(t))
 

server/types.go

@@ -1,8 +1,10 @@
 package server
 
 import (
+	"errors"
 	"heckel.io/ntfy/util"
 	"net/http"
+	"strconv"
 	"time"
 )
 
@@ -20,9 +22,11 @@ const (
 
 // message represents a message published to a topic
 type message struct {
-	ID         string      `json:"id"`    // Random message ID
-	Time       int64       `json:"time"`  // Unix time in seconds
-	Event      string      `json:"event"` // One of the above
+	ID         string      `json:"id"`                // Random message ID
+	Time       int64       `json:"time"`              // Unix time in seconds
+	Updated    int64       `json:"updated,omitempty"` // Set if updated, unix time in seconds
+	Deleted    int64       `json:"deleted,omitempty"` // Set if deleted, unix time in seconds
+	Event      string      `json:"event"`             // One of the above
 	Topic      string      `json:"topic"`
 	Priority   int         `json:"priority,omitempty"`
 	Tags       []string    `json:"tags,omitempty"`
@@ -30,7 +34,7 @@ type message struct {
 	Attachment *attachment `json:"attachment,omitempty"`
 	Title      string      `json:"title,omitempty"`
 	Message    string      `json:"message,omitempty"`
-	Encoding   string      `json:"encoding,omitempty"` // empty for raw UTF-8, or "base64" for encoded bytes
+	Encoding   string      `json:"encoding,omitempty"` // Empty for raw UTF-8, or "base64" for encoded bytes
 }
 
 type attachment struct {
@@ -90,11 +94,31 @@ func validMessageID(s string) bool {
 	return util.ValidRandomString(s, messageIDLength)
 }
 
+func validUnixTimestamp(s string) bool {
+	_, err := toUnixTimestamp(s)
+	return err == nil
+}
+
+func toUnixTimestamp(s string) (int64, error) {
+	u, err := strconv.ParseInt(s, 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	if u < 1000000000 || u > 3000000000 { // I know. It's practical. So relax ...
+		return 0, errors.New("invalid unix date")
+	}
+	return u, nil
+}
+
 type sinceMarker struct {
 	time time.Time
 	id   string
 }
 
+func newSince(id string, timestamp int64) sinceMarker {
+	return sinceMarker{time.Unix(timestamp, 0), id}
+}
+
 func newSinceTime(timestamp int64) sinceMarker {
 	return sinceMarker{time.Unix(timestamp, 0), ""}
 }
@@ -115,6 +139,10 @@ func (t sinceMarker) IsID() bool {
 	return t.id != ""
 }
 
+func (t sinceMarker) IsTime() bool {
+	return t.time.Unix() > 0
+}
+
 func (t sinceMarker) Time() time.Time {
 	return t.time
 }

util/util.go

@@ -17,7 +17,7 @@ import (
 )
 
 const (
-	randomStringCharset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	randomStringCharset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" // Update updateTopicPathRegex if changed
 )
 
 var (

web/src/app/SubscriptionManager.js

@@ -65,13 +65,17 @@ class SubscriptionManager {
 
     /** Adds notification, or returns false if it already exists */
     async addNotification(subscriptionId, notification) {
-        const exists = await db.notifications.get(notification.id);
-        if (exists) {
-            return false;
+        const existingNotification = await db.notifications.get(notification.id);
+        if (existingNotification) {
+            const upToDate = (existingNotification?.updated ?? 0) >= (notification.updated ?? 0);
+            if (upToDate) {
+                console.error(`[SubscriptionManager] up to date`, existingNotification, notification);
+                return false;
+            }
         }
         try {
             notification.new = 1; // New marker (used for bubble indicator); cannot be boolean; Dexie index limitation
-            await db.notifications.add({ ...notification, subscriptionId }); // FIXME consider put() for double tab
+            await db.notifications.put({ ...notification, subscriptionId });
             await db.subscriptions.update(subscriptionId, {
                 last: notification.id
             });