From 711b77b7e25c2d94c0dc1611801210b5179b696b Mon Sep 17 00:00:00 2001
From: Celtic Minstrel <celtic.minstrel.ca@some.place>
Date: Sat, 14 Sep 2024 18:10:47 -0400
Subject: [PATCH] Lua API: Add __dir metamethod to wesnoth.terrain_types

---
 src/scripting/game_lua_kernel.cpp | 18 ++++++++++++++++++
 src/scripting/game_lua_kernel.hpp |  1 +
 2 files changed, 19 insertions(+)

diff --git a/src/scripting/game_lua_kernel.cpp b/src/scripting/game_lua_kernel.cpp
index 99fdf45c0e4..5ceda504110 100644
--- a/src/scripting/game_lua_kernel.cpp
+++ b/src/scripting/game_lua_kernel.cpp
@@ -1124,6 +1124,22 @@ int game_lua_kernel::impl_get_terrain_info(lua_State *L)
 	return 1;
 }
 
+/**
+ * Gets a list of known terrain codes.
+ * - Ret 1: array of terrain codes
+ */
+int game_lua_kernel::impl_get_terrain_list(lua_State *L)
+{
+	auto codes = board().map().tdata()->list();
+	std::vector<std::string> terrains;
+	terrains.reserve(codes.size());
+	for(auto code : codes) {
+		terrains.push_back(t_translation::write_terrain_code(code));
+	}
+	lua_push(L, terrains);
+	return 1;
+}
+
 /**
  * Gets time of day information.
  * - Arg 1: schedule object, location, time area ID, or nil
@@ -5267,6 +5283,8 @@ game_lua_kernel::game_lua_kernel(game_state & gs, play_controller & pc, reports
 	lua_createtable(L, 0, 2);
 	lua_pushcfunction(L, &dispatch<&game_lua_kernel::impl_get_terrain_info>);
 	lua_setfield(L, -2, "__index");
+	lua_pushcfunction(L, &dispatch<&game_lua_kernel::impl_get_terrain_list>);
+	lua_setfield(L, -2, "__dir");
 	lua_pushstring(L, "terrain types");
 	lua_setfield(L, -2, "__metatable");
 	lua_setmetatable(L, -2);
diff --git a/src/scripting/game_lua_kernel.hpp b/src/scripting/game_lua_kernel.hpp
index 5d8c3098483..b56d994ffe1 100644
--- a/src/scripting/game_lua_kernel.hpp
+++ b/src/scripting/game_lua_kernel.hpp
@@ -97,6 +97,7 @@ class game_lua_kernel : public lua_kernel_base
 	int intf_view_locked(lua_State *L);
 	int intf_lock_view(lua_State *L);
 	int impl_get_terrain_info(lua_State *L);
+	int impl_get_terrain_list(lua_State *L);
 	template<bool consider_illuminates>
 	int intf_get_time_of_day(lua_State *L);
 	int impl_schedule_get(lua_State *L);