From 9ce2bdae8caf2e65800dc34505dfeec6977189bf Mon Sep 17 00:00:00 2001
From: spookydonut <github@spooksoftware.com>
Date: Thu, 26 Dec 2019 14:02:27 +0800
Subject: [PATCH] COMPONENT_DUPE_SELECTIVE (#48021)

* COMPONENT_DUPE_SELECTIVE

* a

* changes per review

* webedit
---
 code/__DEFINES/components.dm         |  2 ++
 code/datums/components/_component.dm | 27 +++++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/code/__DEFINES/components.dm b/code/__DEFINES/components.dm
index 6d9cbf639d3..f4060495d61 100644
--- a/code/__DEFINES/components.dm
+++ b/code/__DEFINES/components.dm
@@ -34,6 +34,8 @@
 #define COMPONENT_DUPE_UNIQUE			2
 /// old component is given the initialization args of the new
 #define COMPONENT_DUPE_UNIQUE_PASSARGS	4
+/// each component of the same type is consulted as to whether the duplicate should be allowed
+#define COMPONENT_DUPE_SELECTIVE		5
 
 // All signals. Format:
 // When the signal is called: (signal arguments)
diff --git a/code/datums/components/_component.dm b/code/datums/components/_component.dm
index 13c8a733c28..88e13ae5ffe 100644
--- a/code/datums/components/_component.dm
+++ b/code/datums/components/_component.dm
@@ -233,6 +233,17 @@
 /datum/component/proc/InheritComponent(datum/component/C, i_am_original)
 	return
 
+
+/**
+  * Called on a component when a component of the same type was added to the same parent with COMPONENT_DUPE_SELECTIVE
+  * See `/datum/component/var/dupe_mode`
+  * `C`'s type will always be the same of the called component
+  * return TRUE if you are absorbing the component, otherwise FALSE if you are fine having it exist as a duplicate component
+  */
+/datum/component/proc/CheckDupeComponent(datum/component/C, ...)
+	return
+
+
 /**
   * Callback Just before this component is transferred
   *
@@ -295,7 +306,7 @@
   */
 /datum/proc/GetComponent(datum/component/c_type)
 	RETURN_TYPE(c_type)
-	if(initial(c_type.dupe_mode) == COMPONENT_DUPE_ALLOWED)
+	if(initial(c_type.dupe_mode) == COMPONENT_DUPE_ALLOWED || initial(c_type.dupe_mode) == COMPONENT_DUPE_SELECTIVE)
 		stack_trace("GetComponent was called to get a component of which multiple copies could be on an object. This can easily break and should be changed. Type: \[[c_type]\]")
 	var/list/dc = datum_components
 	if(!dc)
@@ -314,7 +325,7 @@
   */
 /datum/proc/GetExactComponent(datum/component/c_type)
 	RETURN_TYPE(c_type)
-	if(initial(c_type.dupe_mode) == COMPONENT_DUPE_ALLOWED)
+	if(initial(c_type.dupe_mode) == COMPONENT_DUPE_ALLOWED || initial(c_type.dupe_mode) == COMPONENT_DUPE_SELECTIVE)
 		stack_trace("GetComponent was called to get a component of which multiple copies could be on an object. This can easily break and should be changed. Type: \[[c_type]\]")
 	var/list/dc = datum_components
 	if(!dc)
@@ -390,6 +401,18 @@
 						old_comp.InheritComponent(null, TRUE, arguments)
 					else
 						old_comp.InheritComponent(new_comp, TRUE)
+				if(COMPONENT_DUPE_SELECTIVE)
+					var/list/arguments = args.Copy()
+					arguments[1] = new_comp
+					var/make_new_component = TRUE
+					for(var/i in GetComponents(new_type))
+						var/datum/component/C = i
+						if(C.CheckDupeComponent(arglist(arguments)))
+							make_new_component = FALSE
+							QDEL_NULL(new_comp)
+							break
+					if(!new_comp && make_new_component)
+						new_comp = new nt(arglist(args))
 		else if(!new_comp)
 			new_comp = new nt(arglist(args)) // There's a valid dupe mode but there's no old component, act like normal
 	else if(!new_comp)