From 14f4c40404d4d3b1a4e9f739b156f8c8b2eeded6 Mon Sep 17 00:00:00 2001
From: Andrea Maria Piana <andrea.maria.piana@gmail.com>
Date: Thu, 3 Dec 2020 18:04:38 +0100
Subject: [PATCH] Split Merge into functions

---
 protocol/messenger_response.go | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/protocol/messenger_response.go b/protocol/messenger_response.go
index c22e89654..0280bd990 100644
--- a/protocol/messenger_response.go
+++ b/protocol/messenger_response.go
@@ -18,12 +18,22 @@ func (m *MessengerResponse) IsEmpty() bool {
 	return len(m.Chats) == 0 && len(m.Messages) == 0 && len(m.Contacts) == 0 && len(m.Installations) == 0 && len(m.Invitations) == 0
 }
 
+// Merge takes another response and appends the new Chats & new Messages and replaces
+// the existing Messages & Chats if they have the same ID
 func (m *MessengerResponse) Merge(response *MessengerResponse) error {
 	if len(response.Contacts)+len(response.Installations)+len(response.EmojiReactions)+len(response.Invitations) != 0 {
 		return ErrNotImplemented
 	}
 
-	for _, overrideChat := range response.Chats {
+	m.overrideChats(response.Chats)
+	m.overrideMessages(response.Messages)
+
+	return nil
+}
+
+// overrideChats append new chats and override existing ones in response.Chats
+func (m *MessengerResponse) overrideChats(chats []*Chat) {
+	for _, overrideChat := range chats {
 		var found = false
 		for idx, chat := range m.Chats {
 			if chat.ID == overrideChat.ID {
@@ -35,8 +45,11 @@ func (m *MessengerResponse) Merge(response *MessengerResponse) error {
 			m.Chats = append(m.Chats, overrideChat)
 		}
 	}
+}
 
-	for _, overrideMessage := range response.Messages {
+// overrideMessages append new messages and override existing ones in response.Messages
+func (m *MessengerResponse) overrideMessages(messages []*common.Message) {
+	for _, overrideMessage := range messages {
 		var found = false
 		for idx, chat := range m.Messages {
 			if chat.ID == overrideMessage.ID {
@@ -48,6 +61,4 @@ func (m *MessengerResponse) Merge(response *MessengerResponse) error {
 			m.Messages = append(m.Messages, overrideMessage)
 		}
 	}
-
-	return nil
 }