From 6a9488b9c4d2bdf52e7f79cd358e127bf9443650 Mon Sep 17 00:00:00 2001
From: Kangping Dong <wgtdkp@google.com>
Date: Mon, 4 Sep 2023 20:32:47 +0800
Subject: [PATCH] [utils] make generic VendorServer (#1995)

This commit changes VendorServer to an abstract class so that it
can be extended to have different implementations.

Fulfills request from https://github.com/openthread/ot-br-posix/pull/1967#issuecomment-1702407419

Change-Id: Ic322efbee9b58d7a2743c72a511572ec7ebfb262
---
 src/agent/application.cpp |  4 ++--
 src/agent/application.hpp |  2 +-
 src/agent/vendor.hpp      | 25 +++++++++++++------------
 3 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/agent/application.cpp b/src/agent/application.cpp
index 6d7499676bc..c9a5598f2ff 100644
--- a/src/agent/application.cpp
+++ b/src/agent/application.cpp
@@ -77,7 +77,7 @@ Application::Application(const std::string               &aInterfaceName,
     , mDBusAgent(mNcp, mBorderAgent.GetPublisher())
 #endif
 #if OTBR_ENABLE_VENDOR_SERVER
-    , mVendorServer(mNcp)
+    , mVendorServer(vendor::VendorServer::newInstance(mNcp))
 #endif
 {
     OTBR_UNUSED_VARIABLE(aRestListenAddress);
@@ -104,7 +104,7 @@ void Application::Init(void)
     mDBusAgent.Init();
 #endif
 #if OTBR_ENABLE_VENDOR_SERVER
-    mVendorServer.Init();
+    mVendorServer->Init();
 #endif
 }
 
diff --git a/src/agent/application.hpp b/src/agent/application.hpp
index 9bfeee33e66..4d392c33063 100644
--- a/src/agent/application.hpp
+++ b/src/agent/application.hpp
@@ -147,7 +147,7 @@ class Application : private NonCopyable
     DBus::DBusAgent mDBusAgent;
 #endif
 #if OTBR_ENABLE_VENDOR_SERVER
-    vendor::VendorServer mVendorServer;
+    std::shared_ptr<vendor::VendorServer> mVendorServer;
 #endif
 
     static std::atomic_bool sShouldTerminate;
diff --git a/src/agent/vendor.hpp b/src/agent/vendor.hpp
index 833072225ed..61be192522d 100644
--- a/src/agent/vendor.hpp
+++ b/src/agent/vendor.hpp
@@ -41,29 +41,30 @@
 namespace otbr {
 namespace vendor {
 
+/**
+ * An interface for customized behavior depending on Openthread API and state.
+ */
 class VendorServer
 {
 public:
+    ~VendorServer(void) = default;
+
     /**
-     * The constructor of vendor server.
-     *
-     * @param[in] aNcp  A reference to the NCP controller.
+     * Creates a new instance of VendorServer.
      *
+     * Custom vendor servers should implement this method to return an object of the derived class.
      */
-    VendorServer(otbr::Ncp::ControllerOpenThread &aNcp)
-        : mNcp(aNcp)
-    {
-    }
+    static std::shared_ptr<VendorServer> newInstance(otbr::Ncp::ControllerOpenThread &aNcp);
 
     /**
-     * This method initializes the vendor server.
+     * Initializes the vendor server.
      *
+     * This will be called by `Application::Init()` after OpenThread instance and other built-in
+     * servers have been created and initialized.
      */
-    void Init(void);
-
-private:
-    otbr::Ncp::ControllerOpenThread &mNcp;
+    virtual void Init(void) = 0;
 };
+
 } // namespace vendor
 } // namespace otbr
 #endif // OTBR_AGENT_VENDOR_HPP_