crossover

backend-go/internal/firebase/admin.go

@@ -0,0 +1,49 @@
+package firebase
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	fb "firebase.google.com/go/v4"
+	"firebase.google.com/go/v4/auth"
+	"google.golang.org/api/option"
+)
+
+var (
+	authClient *auth.Client
+	once       sync.Once
+	initErr    error
+)
+
+func Init(projectID string) error {
+	once.Do(func() {
+		ctx := context.Background()
+
+		var app *fb.App
+		var err error
+
+		if projectID != "" {
+			cfg := &fb.Config{ProjectID: projectID}
+			app, err = fb.NewApp(ctx, cfg, option.WithoutAuthentication())
+		} else {
+			app, err = fb.NewApp(ctx, nil)
+		}
+		if err != nil {
+			initErr = fmt.Errorf("initialize firebase app: %w", err)
+			return
+		}
+
+		authClient, err = app.Auth(ctx)
+		if err != nil {
+			initErr = fmt.Errorf("initialize firebase auth: %w", err)
+			return
+		}
+	})
+
+	return initErr
+}
+
+func Auth() *auth.Client {
+	return authClient
+}