firebase via REST (less dependencies)

server/firebase/firebase.go

@@ -1,40 +1,44 @@
 package firebase
 
 import (
+	scn "blackforestbytes.com/simplecloudnotifier"
 	"blackforestbytes.com/simplecloudnotifier/models"
+	"bytes"
 	"context"
 	_ "embed"
-	fb "firebase.google.com/go"
-	"firebase.google.com/go/messaging"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/gin-gonic/gin"
 	"github.com/rs/zerolog/log"
 	"gogs.mikescher.com/BlackForestBytes/goext/langext"
-	"google.golang.org/api/option"
+	"io"
+	"net/http"
 	"strconv"
+	"time"
 )
 
-//go:embed scnserviceaccountkey.json
-var scnserviceaccountkey []byte
+// https://firebase.google.com/docs/cloud-messaging/send-message#rest
+// https://firebase.google.com/docs/cloud-messaging/auth-server
 
-type App struct {
-	app       *fb.App
-	messaging *messaging.Client
+type FBConnector struct {
+	fbProject string
+	client    http.Client
+	auth      *FBOAuth2
 }
 
-func NewFirebaseApp() App {
-	opt := option.WithCredentialsJSON(scnserviceaccountkey)
-	app, err := fb.NewApp(context.Background(), nil, opt)
+func NewFirebase(conf scn.Config) (*FBConnector, error) {
+
+	fbauth, err := NewAuth(conf.FirebaseTokenURI, conf.FirebaseProjectID, conf.FirebaseClientMail, conf.FirebasePrivateKey)
 	if err != nil {
-		log.Error().Err(err).Msg("failed to init firebase app")
-	}
-	msg, err := app.Messaging(context.Background())
-	if err != nil {
-		log.Error().Err(err).Msg("failed to init messaging client")
-	}
-	log.Info().Msg("Initialized Firebase")
-	return App{
-		app:       app,
-		messaging: msg,
+		return nil, err
 	}
+
+	return &FBConnector{
+		fbProject: conf.FirebaseProjectID,
+		client:    http.Client{Timeout: 5 * time.Second},
+		auth:      fbauth,
+	}, nil
 }
 
 type Notification struct {
@@ -46,10 +50,12 @@ type Notification struct {
 	Priority int
 }
 
-func (fb App) SendNotification(ctx context.Context, client models.Client, msg models.Message) (string, error) {
+func (fb FBConnector) SendNotification(ctx context.Context, client models.Client, msg models.Message) (string, error) {
 
-	n := messaging.Message{
-		Data: map[string]string{
+	uri := "https://fcm.googleapis.com/v1/projects/" + fb.fbProject + "/messages:send"
+
+	jsonBody := gin.H{
+		"data": gin.H{
 			"scn_msg_id": strconv.FormatInt(msg.SCNMessageID, 10),
 			"usr_msg_id": langext.Coalesce(msg.UserMessageID, ""),
 			"client_id":  strconv.FormatInt(client.ClientID, 10),
@@ -59,29 +65,64 @@ func (fb App) SendNotification(ctx context.Context, client models.Client, msg mo
 			"title":      msg.Title,
 			"body":       langext.Coalesce(msg.TrimmedContent(), ""),
 		},
-		Notification: &messaging.Notification{
-			Title: msg.Title,
-			Body:  msg.ShortContent(),
+		"token": *client.FCMToken,
+		"android": gin.H{
+			"priority": "high",
 		},
-		Android:    nil,
-		APNS:       nil,
-		Webpush:    nil,
-		FCMOptions: nil,
-		Token:      *client.FCMToken,
-		Topic:      "",
-		Condition:  "",
+		"apns": gin.H{},
 	}
-
 	if client.Type == models.ClientTypeIOS {
-		n.APNS = nil
-	} else if client.Type == models.ClientTypeAndroid {
-		n.Notification = nil
-		n.Android = &messaging.AndroidConfig{Priority: "high"}
+		jsonBody["notification"] = gin.H{
+			"title": msg.Title,
+			"body":  msg.ShortContent(),
+		}
 	}
 
-	res, err := fb.messaging.Send(ctx, &n)
+	bytesBody, err := json.Marshal(gin.H{"message": jsonBody})
 	if err != nil {
-		log.Error().Err(err).Msg("failed to send push")
+		return "", err
 	}
-	return res, err
+
+	request, err := http.NewRequestWithContext(ctx, "POST", uri, bytes.NewBuffer(bytesBody))
+	if err != nil {
+		return "", err
+	}
+
+	tok, err := fb.auth.Token(ctx)
+	if err != nil {
+		log.Err(err).Msg("Refreshing FB token failed")
+		return "", err
+	}
+
+	request.Header.Set("Authorization", "Bearer "+tok)
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Accept", "application/json")
+
+	response, err := fb.client.Do(request)
+	if err != nil {
+		return "", err
+	}
+	defer func() { _ = response.Body.Close() }()
+
+	if response.StatusCode < 200 || response.StatusCode >= 300 {
+		if bstr, err := io.ReadAll(response.Body); err == nil {
+			return "", errors.New(fmt.Sprintf("FCM-Request returned %d: %s", response.StatusCode, string(bstr)))
+		} else {
+			return "", errors.New(fmt.Sprintf("FCM-Request returned %d", response.StatusCode))
+		}
+	}
+
+	respBodyBin, err := io.ReadAll(response.Body)
+	if err != nil {
+		return "", err
+	}
+
+	var respBody struct {
+		Name string `json:"name"`
+	}
+	if err := json.Unmarshal(respBodyBin, &respBody); err != nil {
+		return "", err
+	}
+
+	return respBody.Name, nil
 }