From 2774eef72e6d9adbeb7ed4001cb8db9539a76bc1 Mon Sep 17 00:00:00 2001
From: dotSILENT <dot.silentium@gmail.com>
Date: Sun, 20 Jan 2019 20:49:18 +0100
Subject: [PATCH] Add compatibility version checking

---
 src/Actions.cpp    | 19 +++++++++++++++++--
 src/Actions.h      |  3 ++-
 src/chandlingsvr.h |  8 ++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/Actions.cpp b/src/Actions.cpp
index c84df37..4221f47 100644
--- a/src/Actions.cpp
+++ b/src/Actions.cpp
@@ -1,6 +1,8 @@
 #include "Actions.h"
+#include "sampgdk/sampgdk.h"
 #include "CPlayer.h"
 #include "HandlingManager.h"
+#include "chandlingsvr.h"
 
 bool Actions::Process(CHandlingAction id, RakNet::BitStream *bs, int playerid)
 {
@@ -9,8 +11,21 @@ bool Actions::Process(CHandlingAction id, RakNet::BitStream *bs, int playerid)
 	case ACTION_INIT:
 		if (IS_VALID_PLAYERID(playerid))
 		{
-			sampgdk::logprintf("[chandling] Player %d reports having chandling plugin", playerid);
-			gPlayers[playerid].setHasCHandling();
+			uint32_t compat_ver;
+			bs->Read(compat_ver);
+
+			CHandlingActionPacket pkt(ACTION_INIT_RESPONSE);
+			pkt.data.Write((uint32_t)CHANDLING_COMPAT_VERSION);
+			
+			if (compat_ver >= CHANDLING_COMPAT_VERSION)
+			{
+				pkt.data.Write(true);
+				gPlayers[playerid].setHasCHandling();
+				sampgdk::logprintf("[chandling] Player %d reports having chandling plugin", playerid);
+			}
+			else pkt.data.Write(false);
+			
+			pRakServer->Send(&pkt.data, HIGH_PRIORITY, RELIABLE_ORDERED, 0, pRakServer->GetPlayerIDFromIndex(playerid), false);
 		}
 
 		return true;
diff --git a/src/Actions.h b/src/Actions.h
index 0db0f0b..484f712 100644
--- a/src/Actions.h
+++ b/src/Actions.h
@@ -1,13 +1,14 @@
 #pragma once
 
 #include "raknet/BitStream.h"
-#include "sampgdk/sampgdk.h"
 #include "PacketEnum.h"
+#include <cstdint>
 
 // action identifier is sent as single byte
 enum CHandlingAction : unsigned char
 {
 	ACTION_INIT = 10, // This is the only packet that is sent  by the player, to indicate that we can speak to him
+	ACTION_INIT_RESPONSE,
 
 	ACTION_RESET_MODEL = 15,
 	ACTION_RESET_VEHICLE,
diff --git a/src/chandlingsvr.h b/src/chandlingsvr.h
index c1160eb..7104c8f 100644
--- a/src/chandlingsvr.h
+++ b/src/chandlingsvr.h
@@ -2,6 +2,14 @@
 
 #define CHANDLING_VERSION "v1.0-dev"
 
+/*
+ * The compaatibility version number decides if the client supports our CHandling version or not
+ * Clients with smaller compat version won't be able to use CHandling
+ * 
+ * Increase this number only if doing things that break the compatibility with older client
+*/
+#define CHANDLING_COMPAT_VERSION 0x1001D
+
 #define MAX_VEHICLE_MODELS (212)
 #ifndef MAX_VEHICLES
 #define MAX_VEHICLES (2000)