From 444a4f67440706ec1c01323f8cbb430a46ad1695 Mon Sep 17 00:00:00 2001
From: hg <4683435+hgtw@users.noreply.github.com>
Date: Sat, 29 Oct 2022 20:46:08 -0400
Subject: [PATCH] [Tasks] Add pre-task update event (#2512)

This adds the player EVENT_TASK_BEFORE_UPDATE event which will allow
quests to prevent a source controlled task update by returning non-zero.
---
 zone/embparser.cpp         | 2 ++
 zone/event_codes.h         | 1 +
 zone/lua_general.cpp       | 3 ++-
 zone/lua_parser.cpp        | 2 ++
 zone/task_client_state.cpp | 9 +++++++++
 5 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/zone/embparser.cpp b/zone/embparser.cpp
index 14c0c7dc4..c866e47ca 100644
--- a/zone/embparser.cpp
+++ b/zone/embparser.cpp
@@ -160,6 +160,7 @@ const char *QuestEventSubroutines[_LargestEventID] = {
 	"EVENT_MERCHANT_BUY",
 	"EVENT_MERCHANT_SELL",
 	"EVENT_INSPECT",
+	"EVENT_TASK_BEFORE_UPDATE",
 };
 
 PerlembParser::PerlembParser() : perl(nullptr)
@@ -1465,6 +1466,7 @@ void PerlembParser::ExportEventVariables(
 		}
 
 		case EVENT_TASK_COMPLETE:
+		case EVENT_TASK_BEFORE_UPDATE:
 		case EVENT_TASK_UPDATE: {
 			Seperator sep(data);
 			ExportVar(package_name.c_str(), "donecount", sep.arg[0]);
diff --git a/zone/event_codes.h b/zone/event_codes.h
index 9230f9fa4..7c469527e 100644
--- a/zone/event_codes.h
+++ b/zone/event_codes.h
@@ -103,6 +103,7 @@ typedef enum {
 	EVENT_MERCHANT_BUY,
 	EVENT_MERCHANT_SELL,
 	EVENT_INSPECT,
+	EVENT_TASK_BEFORE_UPDATE,
 	_LargestEventID
 } QuestEventID;
 
diff --git a/zone/lua_general.cpp b/zone/lua_general.cpp
index a705f245e..24012687e 100644
--- a/zone/lua_general.cpp
+++ b/zone/lua_general.cpp
@@ -4307,7 +4307,8 @@ luabind::scope lua_register_events() {
 			luabind::value("alt_currency_merchant_sell", static_cast<int>(EVENT_ALT_CURRENCY_MERCHANT_SELL)),
 			luabind::value("merchant_buy", static_cast<int>(EVENT_MERCHANT_BUY)),
 			luabind::value("merchant_sell", static_cast<int>(EVENT_MERCHANT_SELL)),
-			luabind::value("inspect", static_cast<int>(EVENT_INSPECT))
+			luabind::value("inspect", static_cast<int>(EVENT_INSPECT)),
+			luabind::value("task_before_update", static_cast<int>(EVENT_TASK_BEFORE_UPDATE))
 		];
 }
 
diff --git a/zone/lua_parser.cpp b/zone/lua_parser.cpp
index 91aaad096..42f62c967 100644
--- a/zone/lua_parser.cpp
+++ b/zone/lua_parser.cpp
@@ -147,6 +147,7 @@ const char *LuaEvents[_LargestEventID] = {
 	"event_merchant_buy",
 	"event_merchant_sell",
 	"event_inspect",
+	"event_task_before_update",
 };
 
 extern Zone *zone;
@@ -222,6 +223,7 @@ LuaParser::LuaParser() {
 	PlayerArgumentDispatch[EVENT_TASK_STAGE_COMPLETE] = handle_player_task_stage_complete;
 	PlayerArgumentDispatch[EVENT_TASK_COMPLETE] = handle_player_task_update;
 	PlayerArgumentDispatch[EVENT_TASK_UPDATE] = handle_player_task_update;
+	PlayerArgumentDispatch[EVENT_TASK_BEFORE_UPDATE] = handle_player_task_update;
 	PlayerArgumentDispatch[EVENT_COMMAND] = handle_player_command;
 	PlayerArgumentDispatch[EVENT_COMBINE_SUCCESS] = handle_player_combine;
 	PlayerArgumentDispatch[EVENT_COMBINE_FAILURE] = handle_player_combine;
diff --git a/zone/task_client_state.cpp b/zone/task_client_state.cpp
index 9f9c06bf5..7923af74b 100644
--- a/zone/task_client_state.cpp
+++ b/zone/task_client_state.cpp
@@ -564,6 +564,15 @@ int ClientTaskState::UpdateTasks(Client* client, const TaskUpdateFilter& filter,
 
 			if (CanUpdate(client, filter, client_task.task_id, activity, client_activity))
 			{
+				auto args = fmt::format("{} {} {}", count, client_activity.activity_id, client_task.task_id);
+				if (parse->EventPlayer(EVENT_TASK_BEFORE_UPDATE, client, args, 0) != 0)
+				{
+					LogTasks("[UpdateTasks] client [{}] task [{}]-[{}] update prevented by quest",
+						client->GetName(), client_task.task_id, client_activity.activity_id);
+
+					continue;
+				}
+
 				LogTasks("[UpdateTasks] client [{}] task [{}] activity [{}] increment [{}]",
 					client->GetName(), client_task.task_id, client_activity.activity_id, count);