Extended list viewer now has an edit button (#19706)

Extended list viewer now has an edit button, and the ability to edit the
extended list it's seeing; it's also (opinionately) better formatted.

code/modules/admin/verbs/viewlist.dm

@@ -1,18 +1,32 @@
-/client/proc/view_extended_list(var/list/L)
-	if(!check_rights(R_VAREDIT|R_DEV))	return
+/**
+ * Used to create a tgui Extended List Viewer
+ *
+ * Accepts either an associative list or a flat list
+ *
+ * If an associative list is passed, the key is a string and the value the datum
+ */
+/client/proc/view_extended_list(list/L, datum/original_datum)
+	if(!check_rights(R_VAREDIT|R_DEV))
+		return
 
 	if(istype(L))
-		new /datum/tgui_module/list_viewer(L, usr)
+		new /datum/tgui_module/list_viewer(L, usr, original_datum = original_datum)
 
 /datum/tgui_module/list_viewer
 	var/list/viewed_list
+	var/datum/weakref/original_datum_ref
 
-/datum/tgui_module/list_viewer/New(var/list/L, mob/user)
+/datum/tgui_module/list_viewer/New(list/L, mob/user, datum/original_datum)
 	if(istype(L))
 		viewed_list = L
+	if(istype(original_datum))
+		original_datum_ref = WEAKREF(original_datum)
+		if(!original_datum_ref)
+			stack_trace("Unable to create a weakref to the original datum, please report this to a developer")
+
 	ui_interact(user)
 
-/datum/tgui_module/list_viewer/ui_interact(mob/user, var/datum/tgui/ui)
+/datum/tgui_module/list_viewer/ui_interact(mob/user, datum/tgui/ui)
 	if(!check_rights(R_VAREDIT|R_DEV|R_MOD))
 		return
 
@@ -41,3 +55,48 @@
 			index++
 
 	return data
+
+/datum/tgui_module/list_viewer/ui_act(action, list/params, datum/tgui/ui, datum/ui_state/state)
+	. = ..()
+	if(.)
+		return
+
+	if(!check_rights(R_VAREDIT|R_DEV))
+		return
+
+	var/client/user_client = ui.user?.client
+	if(!user_client)
+		stack_trace("No client found to open entry in, despite having received a request to edit a list, uh oh!")
+		return
+
+	switch(action)
+
+		if("open_entry")
+
+			var/datum/entry_to_open = null
+
+			if(isnum(text2num(params["open_entry_key"])))
+				entry_to_open = viewed_list[text2num(params["open_entry_key"])]
+			else
+				entry_to_open = viewed_list[params["open_entry_key"]]
+
+			if(!entry_to_open)
+				to_chat(usr, "No entry found to open!")
+				return FALSE
+
+			user_client.debug_variables_open(entry_to_open)
+
+			return TRUE
+
+		if("open_whole_list")
+			if(tgui_alert(usr, "Opening the whole list in VV might take a long time or cause issues, are you sure?", "Confirm", list("Yes", "No")) != "Yes")
+				return FALSE
+
+			var/datum/original_datum = original_datum_ref.resolve()
+			if(!original_datum)
+				tgui_alert(usr, "Unable to open the list, the original datum has been deleted or has never been set.")
+				return FALSE
+
+			user_client.mod_list(viewed_list, original_datum)
+
+			return TRUE