ntfy/server/server_firebase.go
2022-04-19 19:22:19 -04:00

120 lines
3.3 KiB
Go

package server
import (
"context"
"encoding/json"
firebase "firebase.google.com/go"
"firebase.google.com/go/messaging"
"fmt"
"google.golang.org/api/option"
"heckel.io/ntfy/auth"
"strings"
)
const (
fcmMessageLimit = 4000
)
// maybeTruncateFCMMessage performs best-effort truncation of FCM messages.
// The docs say the limit is 4000 characters, but during testing it wasn't quite clear
// what fields matter; so we're just capping the serialized JSON to 4000 bytes.
func maybeTruncateFCMMessage(m *messaging.Message) *messaging.Message {
s, err := json.Marshal(m)
if err != nil {
return m
}
if len(s) > fcmMessageLimit {
over := len(s) - fcmMessageLimit + 16 // = len("truncated":"1",), sigh ...
message, ok := m.Data["message"]
if ok && len(message) > over {
m.Data["truncated"] = "1"
m.Data["message"] = message[:len(message)-over]
}
}
return m
}
func createFirebaseSubscriber(credentialsFile string, auther auth.Auther) (subscriber, error) {
fb, err := firebase.NewApp(context.Background(), nil, option.WithCredentialsFile(credentialsFile))
if err != nil {
return nil, err
}
msg, err := fb.Messaging(context.Background())
if err != nil {
return nil, err
}
return func(m *message) error {
fbm, err := toFirebaseMessage(m, auther)
if err != nil {
return err
}
_, err = msg.Send(context.Background(), fbm)
return err
}, nil
}
func toFirebaseMessage(m *message, auther auth.Auther) (*messaging.Message, error) {
var data map[string]string // Mostly matches https://ntfy.sh/docs/subscribe/api/#json-message-format
switch m.Event {
case keepaliveEvent, openEvent:
data = map[string]string{
"id": m.ID,
"time": fmt.Sprintf("%d", m.Time),
"event": m.Event,
"topic": m.Topic,
}
case messageEvent:
allowForward := true
if auther != nil {
allowForward = auther.Authorize(nil, m.Topic, auth.PermissionRead) == nil
}
if allowForward {
data = map[string]string{
"id": m.ID,
"time": fmt.Sprintf("%d", m.Time),
"event": m.Event,
"topic": m.Topic,
"priority": fmt.Sprintf("%d", m.Priority),
"tags": strings.Join(m.Tags, ","),
"click": m.Click,
"title": m.Title,
"message": m.Message,
"encoding": m.Encoding,
}
if len(m.Actions) > 0 {
actions, err := json.Marshal(m.Actions)
if err != nil {
return nil, err
}
data["actions"] = string(actions)
}
if m.Attachment != nil {
data["attachment_name"] = m.Attachment.Name
data["attachment_type"] = m.Attachment.Type
data["attachment_size"] = fmt.Sprintf("%d", m.Attachment.Size)
data["attachment_expires"] = fmt.Sprintf("%d", m.Attachment.Expires)
data["attachment_url"] = m.Attachment.URL
}
} else {
// If anonymous read for a topic is not allowed, we cannot send the message along
// via Firebase. Instead, we send a "poll_request" message, asking the client to poll.
data = map[string]string{
"id": m.ID,
"time": fmt.Sprintf("%d", m.Time),
"event": pollRequestEvent,
"topic": m.Topic,
}
}
}
var androidConfig *messaging.AndroidConfig
if m.Priority >= 4 {
androidConfig = &messaging.AndroidConfig{
Priority: "high",
}
}
return maybeTruncateFCMMessage(&messaging.Message{
Topic: m.Topic,
Data: data,
Android: androidConfig,
}), nil
}