From 9b950b4202fc2cf4487a69152f7150daf6d0262e Mon Sep 17 00:00:00 2001
From: Lemonymous <10490534+Lemonymous@users.noreply.github.com>
Date: Sun, 4 Sep 2022 00:04:00 +0200
Subject: [PATCH] Add event for when difficulty changes

Also nuke external library with the same event.
Add compatibility for event `onRealDifficultyChanged`, referencing `onDifficultyChanged`.
---
 scripts/mod_loader/bootstrap/modApi.lua  |  1 +
 scripts/mod_loader/compat/difficulty.lua | 17 +++++++++++++++++
 scripts/mod_loader/compat/nuke.lua       |  3 +++
 3 files changed, 21 insertions(+)

diff --git a/scripts/mod_loader/bootstrap/modApi.lua b/scripts/mod_loader/bootstrap/modApi.lua
index e05802ac..0f9968f3 100644
--- a/scripts/mod_loader/bootstrap/modApi.lua
+++ b/scripts/mod_loader/bootstrap/modApi.lua
@@ -54,6 +54,7 @@ t.onSettingsInitialized = Event()
 t.onProfileChanged = Event()
 t.onProfileCreated = Event()
 t.onProfileDeleted = Event()
+t.onDifficultyChanged = Event()
 
 t.onHangarUiShown = Event()
 t.onHangarUiHidden = Event()
diff --git a/scripts/mod_loader/compat/difficulty.lua b/scripts/mod_loader/compat/difficulty.lua
index 3584a477..512bd85f 100644
--- a/scripts/mod_loader/compat/difficulty.lua
+++ b/scripts/mod_loader/compat/difficulty.lua
@@ -1,3 +1,20 @@
+
+-- EVENTS
+---------
+
+local difficulty
+
+modApi.events.onFrameDrawStart:subscribe(function()
+	local prev_difficulty = difficulty
+
+	difficulty = GetDifficulty()
+
+	if difficulty ~= prev_difficulty then
+		modApi.events.onDifficultyChanged:dispatch(difficulty, prev_difficulty)
+	end
+end)
+
+
 -- Legacy: originally GetDifficulty() returned the custom difficulty while GetRealDifficulty() returned vanilla
 GetRealDifficulty = GetDifficulty
 
diff --git a/scripts/mod_loader/compat/nuke.lua b/scripts/mod_loader/compat/nuke.lua
index 46e35510..bee8ab49 100644
--- a/scripts/mod_loader/compat/nuke.lua
+++ b/scripts/mod_loader/compat/nuke.lua
@@ -2,3 +2,6 @@
 -- nuke libraries that have been migrated to the mod loader
 
 SquadEvents = { version = tostring(INT_MAX) }
+DifficultyEvents = { version = tostring(INT_MAX) }
+
+modApi.events.onRealDifficultyChanged = modApi.events.onDifficultyChanged