From a8516edb98436ff22f376211407723b8cfca9d69 Mon Sep 17 00:00:00 2001
From: c9s <yoan@maicoin.com>
Date: Sun, 21 Feb 2021 16:55:45 +0800
Subject: [PATCH] add Get method to the persistence service facade

---
 pkg/bbgo/environment.go           |  7 +------
 pkg/service/persistence_facade.go | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/pkg/bbgo/environment.go b/pkg/bbgo/environment.go
index 7ab10b72f..28b7df21f 100644
--- a/pkg/bbgo/environment.go
+++ b/pkg/bbgo/environment.go
@@ -536,12 +536,6 @@ func getSessionSymbols(session *ExchangeSession, defaultSymbols ...string) ([]st
 }
 
 func (environ *Environment) ConfigureNotificationSystem(userConfig *Config) error {
-	// Configure persistence service, by default we will use memory service
-	var persistence service.PersistenceService = environ.PersistenceServiceFacade.Memory
-	if environ.PersistenceServiceFacade.Redis != nil {
-		persistence = environ.PersistenceServiceFacade.Redis
-	}
-
 	environ.Notifiability = Notifiability{
 		SymbolChannelRouter:  NewPatternChannelRouter(nil),
 		SessionChannelRouter: NewPatternChannelRouter(nil),
@@ -562,6 +556,7 @@ func (environ *Environment) ConfigureNotificationSystem(userConfig *Config) erro
 		}
 	}
 
+	persistence := environ.PersistenceServiceFacade.Get()
 	telegramBotToken := viper.GetString("telegram-bot-token")
 	if len(telegramBotToken) > 0 {
 		tt := strings.Split(telegramBotToken, ":")
diff --git a/pkg/service/persistence_facade.go b/pkg/service/persistence_facade.go
index cc8f8b2f1..2adce0eb2 100644
--- a/pkg/service/persistence_facade.go
+++ b/pkg/service/persistence_facade.go
@@ -5,3 +5,17 @@ type PersistenceServiceFacade struct {
 	Json   *JsonPersistenceService
 	Memory *MemoryService
 }
+
+// Get returns the preferred persistence service by fallbacks
+// Redis will be preferred at the first position.
+func (facade *PersistenceServiceFacade) Get() PersistenceService {
+	if facade.Redis != nil {
+		return facade.Redis
+	}
+
+	if facade.Json != nil {
+		return facade.Json
+	}
+
+	return facade.Memory
+}