From 85dc0ec4816f50311433dde6cc9e3fb569d6448c Mon Sep 17 00:00:00 2001
From: "Mitten.O" <Mitten.O@gmail.com>
Date: Thu, 6 Apr 2023 22:08:16 +0300
Subject: [PATCH] Create a custom Lua usertype to expose a record store as a
 read-only array

---
 apps/openmw/mwlua/types/activator.cpp  |  2 +-
 apps/openmw/mwlua/types/apparatus.cpp  |  2 +-
 apps/openmw/mwlua/types/armor.cpp      |  2 +-
 apps/openmw/mwlua/types/book.cpp       |  2 +-
 apps/openmw/mwlua/types/clothing.cpp   |  2 +-
 apps/openmw/mwlua/types/container.cpp  |  2 +-
 apps/openmw/mwlua/types/creature.cpp   |  2 +-
 apps/openmw/mwlua/types/door.cpp       |  2 +-
 apps/openmw/mwlua/types/ingredient.cpp |  2 +-
 apps/openmw/mwlua/types/light.cpp      |  2 +-
 apps/openmw/mwlua/types/lockpick.cpp   |  2 +-
 apps/openmw/mwlua/types/misc.cpp       |  2 +-
 apps/openmw/mwlua/types/npc.cpp        |  2 +-
 apps/openmw/mwlua/types/potion.cpp     |  2 +-
 apps/openmw/mwlua/types/probe.cpp      |  2 +-
 apps/openmw/mwlua/types/repair.cpp     |  2 +-
 apps/openmw/mwlua/types/static.cpp     |  2 +-
 apps/openmw/mwlua/types/types.hpp      | 34 +++++++++++++++++++++++++-
 apps/openmw/mwlua/types/weapon.cpp     |  2 +-
 apps/openmw/mwworld/store.cpp          |  5 ++++
 apps/openmw/mwworld/store.hpp          |  1 +
 21 files changed, 57 insertions(+), 19 deletions(-)

diff --git a/apps/openmw/mwlua/types/activator.cpp b/apps/openmw/mwlua/types/activator.cpp
index 88cf4d0f29..72baeffac5 100644
--- a/apps/openmw/mwlua/types/activator.cpp
+++ b/apps/openmw/mwlua/types/activator.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Activator>(activator);
+        addRecordFunctionBinding<ESM::Activator>(activator, context);
 
         sol::usertype<ESM::Activator> record = context.mLua->sol().new_usertype<ESM::Activator>("ESM3_Activator");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/apparatus.cpp b/apps/openmw/mwlua/types/apparatus.cpp
index 0747d97d4c..10bdbcdd29 100644
--- a/apps/openmw/mwlua/types/apparatus.cpp
+++ b/apps/openmw/mwlua/types/apparatus.cpp
@@ -30,7 +30,7 @@ namespace MWLua
 
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Apparatus>(apparatus);
+        addRecordFunctionBinding<ESM::Apparatus>(apparatus, context);
 
         sol::usertype<ESM::Apparatus> record = context.mLua->sol().new_usertype<ESM::Apparatus>("ESM3_Apparatus");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/armor.cpp b/apps/openmw/mwlua/types/armor.cpp
index 7c5b477e10..0368a89b21 100644
--- a/apps/openmw/mwlua/types/armor.cpp
+++ b/apps/openmw/mwlua/types/armor.cpp
@@ -37,7 +37,7 @@ namespace MWLua
 
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Armor>(armor);
+        addRecordFunctionBinding<ESM::Armor>(armor, context);
 
         sol::usertype<ESM::Armor> record = context.mLua->sol().new_usertype<ESM::Armor>("ESM3_Armor");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/book.cpp b/apps/openmw/mwlua/types/book.cpp
index 02602bd6a7..651ba8fd4f 100644
--- a/apps/openmw/mwlua/types/book.cpp
+++ b/apps/openmw/mwlua/types/book.cpp
@@ -32,7 +32,7 @@ namespace MWLua
 
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Book>(book);
+        addRecordFunctionBinding<ESM::Book>(book, context);
 
         sol::usertype<ESM::Book> record = context.mLua->sol().new_usertype<ESM::Book>("ESM3_Book");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/clothing.cpp b/apps/openmw/mwlua/types/clothing.cpp
index 35634d5fc1..947b997f71 100644
--- a/apps/openmw/mwlua/types/clothing.cpp
+++ b/apps/openmw/mwlua/types/clothing.cpp
@@ -36,7 +36,7 @@ namespace MWLua
 
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Clothing>(clothing);
+        addRecordFunctionBinding<ESM::Clothing>(clothing, context);
 
         sol::usertype<ESM::Clothing> record = context.mLua->sol().new_usertype<ESM::Clothing>("ESM3_Clothing");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/container.cpp b/apps/openmw/mwlua/types/container.cpp
index cd6d2e3d24..21ec2f04dc 100644
--- a/apps/openmw/mwlua/types/container.cpp
+++ b/apps/openmw/mwlua/types/container.cpp
@@ -48,7 +48,7 @@ namespace MWLua
 
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Container>(container);
+        addRecordFunctionBinding<ESM::Container>(container, context);
 
         sol::usertype<ESM::Container> record = context.mLua->sol().new_usertype<ESM::Container>("ESM3_Container");
         record[sol::meta_function::to_string] = [](const ESM::Container& rec) -> std::string {
diff --git a/apps/openmw/mwlua/types/creature.cpp b/apps/openmw/mwlua/types/creature.cpp
index ecba2b7eba..be6786b4ca 100644
--- a/apps/openmw/mwlua/types/creature.cpp
+++ b/apps/openmw/mwlua/types/creature.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Creature>(creature);
+        addRecordFunctionBinding<ESM::Creature>(creature, context);
 
         sol::usertype<ESM::Creature> record = context.mLua->sol().new_usertype<ESM::Creature>("ESM3_Creature");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/door.cpp b/apps/openmw/mwlua/types/door.cpp
index db54a77277..7dee2d7af3 100644
--- a/apps/openmw/mwlua/types/door.cpp
+++ b/apps/openmw/mwlua/types/door.cpp
@@ -43,7 +43,7 @@ namespace MWLua
 
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Door>(door);
+        addRecordFunctionBinding<ESM::Door>(door, context);
 
         sol::usertype<ESM::Door> record = context.mLua->sol().new_usertype<ESM::Door>("ESM3_Door");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/ingredient.cpp b/apps/openmw/mwlua/types/ingredient.cpp
index ed66ec9a9b..69b4a670fb 100644
--- a/apps/openmw/mwlua/types/ingredient.cpp
+++ b/apps/openmw/mwlua/types/ingredient.cpp
@@ -24,7 +24,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Ingredient>(ingredient);
+        addRecordFunctionBinding<ESM::Ingredient>(ingredient, context);
 
         sol::usertype<ESM::Ingredient> record = context.mLua->sol().new_usertype<ESM::Ingredient>(("ESM3_Ingredient"));
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/light.cpp b/apps/openmw/mwlua/types/light.cpp
index bc9630289b..347bb61641 100644
--- a/apps/openmw/mwlua/types/light.cpp
+++ b/apps/openmw/mwlua/types/light.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Light>(light);
+        addRecordFunctionBinding<ESM::Light>(light, context);
 
         sol::usertype<ESM::Light> record = context.mLua->sol().new_usertype<ESM::Light>("ESM3_Light");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/lockpick.cpp b/apps/openmw/mwlua/types/lockpick.cpp
index c5d9c6983d..786471461a 100644
--- a/apps/openmw/mwlua/types/lockpick.cpp
+++ b/apps/openmw/mwlua/types/lockpick.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Lockpick>(lockpick);
+        addRecordFunctionBinding<ESM::Lockpick>(lockpick, context);
 
         sol::usertype<ESM::Lockpick> record = context.mLua->sol().new_usertype<ESM::Lockpick>("ESM3_Lockpick");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/misc.cpp b/apps/openmw/mwlua/types/misc.cpp
index 7b0b5934ec..c565094022 100644
--- a/apps/openmw/mwlua/types/misc.cpp
+++ b/apps/openmw/mwlua/types/misc.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Miscellaneous>(miscellaneous);
+        addRecordFunctionBinding<ESM::Miscellaneous>(miscellaneous, context);
 
         sol::usertype<ESM::Miscellaneous> record
             = context.mLua->sol().new_usertype<ESM::Miscellaneous>("ESM3_Miscellaneous");
diff --git a/apps/openmw/mwlua/types/npc.cpp b/apps/openmw/mwlua/types/npc.cpp
index 71d611f99c..31dc87095f 100644
--- a/apps/openmw/mwlua/types/npc.cpp
+++ b/apps/openmw/mwlua/types/npc.cpp
@@ -25,7 +25,7 @@ namespace MWLua
     {
         addNpcStatsBindings(npc, context);
 
-        addRecordFunctionBinding<ESM::NPC>(npc);
+        addRecordFunctionBinding<ESM::NPC>(npc, context);
 
         sol::usertype<ESM::NPC> record = context.mLua->sol().new_usertype<ESM::NPC>("ESM3_NPC");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/potion.cpp b/apps/openmw/mwlua/types/potion.cpp
index c14d84024c..3ab15f2691 100644
--- a/apps/openmw/mwlua/types/potion.cpp
+++ b/apps/openmw/mwlua/types/potion.cpp
@@ -41,7 +41,7 @@ namespace MWLua
 {
     void addPotionBindings(sol::table potion, const Context& context)
     {
-        addRecordFunctionBinding<ESM::Potion>(potion);
+        addRecordFunctionBinding<ESM::Potion>(potion, context);
 
         // Creates a new potion struct but does not store it in MWWorld::ESMStore.
         // Global scripts can use world.createRecord to add the potion to the world.
diff --git a/apps/openmw/mwlua/types/probe.cpp b/apps/openmw/mwlua/types/probe.cpp
index e042e4a0ab..668e58c98c 100644
--- a/apps/openmw/mwlua/types/probe.cpp
+++ b/apps/openmw/mwlua/types/probe.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Probe>(probe);
+        addRecordFunctionBinding<ESM::Probe>(probe, context);
 
         sol::usertype<ESM::Probe> record = context.mLua->sol().new_usertype<ESM::Probe>("ESM3_Probe");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/repair.cpp b/apps/openmw/mwlua/types/repair.cpp
index f38b7e2992..75d0a17c49 100644
--- a/apps/openmw/mwlua/types/repair.cpp
+++ b/apps/openmw/mwlua/types/repair.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Repair>(repair);
+        addRecordFunctionBinding<ESM::Repair>(repair, context);
 
         sol::usertype<ESM::Repair> record = context.mLua->sol().new_usertype<ESM::Repair>("ESM3_Repair");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/static.cpp b/apps/openmw/mwlua/types/static.cpp
index ad7ee6b640..76dac4fa00 100644
--- a/apps/openmw/mwlua/types/static.cpp
+++ b/apps/openmw/mwlua/types/static.cpp
@@ -23,7 +23,7 @@ namespace MWLua
     {
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Static>(stat);
+        addRecordFunctionBinding<ESM::Static>(stat, context);
 
         sol::usertype<ESM::Static> record = context.mLua->sol().new_usertype<ESM::Static>("ESM3_Static");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwlua/types/types.hpp b/apps/openmw/mwlua/types/types.hpp
index 284bc95d39..01d0766289 100644
--- a/apps/openmw/mwlua/types/types.hpp
+++ b/apps/openmw/mwlua/types/types.hpp
@@ -4,6 +4,7 @@
 #include <sol/sol.hpp>
 
 #include <components/esm/defs.hpp>
+#include <components/lua/luastate.hpp>
 
 #include "apps/openmw/mwbase/environment.hpp"
 #include "apps/openmw/mwbase/world.hpp"
@@ -13,6 +14,16 @@
 #include "../context.hpp"
 #include "../object.hpp"
 
+namespace sol
+{
+    // Ensure sol does not try to create the automatic Container or usertype bindings for Store.
+    // They include write operations and we want the store to be read-only.
+    template <typename T>
+    struct is_automagical<typename MWWorld::Store<T>> : std::false_type
+    {
+    };
+}
+
 namespace MWLua
 {
     // `getLiveCellRefType()` is not exactly what we usually mean by "type" because some refids have special meaning.
@@ -53,12 +64,33 @@ namespace MWLua
     void addLightBindings(sol::table light, const Context& context);
 
     template <class T>
-    void addRecordFunctionBinding(sol::table table)
+    void addRecordFunctionBinding(sol::table table, const Context& context)
     {
         const MWWorld::Store<T>& store = MWBase::Environment::get().getWorld()->getStore().get<T>();
 
         table["record"] = sol::overload([](const Object& obj) -> const T* { return obj.ptr().get<T>()->mBase; },
             [&store](std::string_view id) -> const T* { return store.find(ESM::RefId::deserializeText(id)); });
+
+        // Define a custom user type for the store.
+        // Provide the interface of a read-only array.
+        using StoreT = MWWorld::Store<T>;
+        sol::state_view& lua = context.mLua->sol();
+        sol::usertype<StoreT> storeT = lua.new_usertype<StoreT>(std::string(T::getRecordType()) + "WorldStore");
+        storeT[sol::meta_function::to_string] = [](const StoreT& store) {
+            return "{" + std::to_string(store.getSize()) + " " + std::string(T::getRecordType()) + " records}";
+        };
+        storeT[sol::meta_function::length] = [](const StoreT& store) { return store.getSize(); };
+        storeT[sol::meta_function::index] = [](const StoreT& store, size_t index) -> const T& {
+            if (index > 0 && index <= store.getSize())
+                return store.at(index - 1); // Translate from Lua's 1-based indexing.
+            else
+                throw std::runtime_error("Index out of range");
+        };
+        storeT[sol::meta_function::pairs] = lua["ipairsForArray"].template get<sol::function>();
+        storeT[sol::meta_function::ipairs] = lua["ipairsForArray"].template get<sol::function>();
+
+        // Provide access to the store.
+        table["records"] = [&store]() { return &store; };
     }
 }
 
diff --git a/apps/openmw/mwlua/types/weapon.cpp b/apps/openmw/mwlua/types/weapon.cpp
index b333f4ef57..aa781c58ea 100644
--- a/apps/openmw/mwlua/types/weapon.cpp
+++ b/apps/openmw/mwlua/types/weapon.cpp
@@ -40,7 +40,7 @@ namespace MWLua
 
         auto vfs = MWBase::Environment::get().getResourceSystem()->getVFS();
 
-        addRecordFunctionBinding<ESM::Weapon>(weapon);
+        addRecordFunctionBinding<ESM::Weapon>(weapon, context);
 
         sol::usertype<ESM::Weapon> record = context.mLua->sol().new_usertype<ESM::Weapon>("ESM3_Weapon");
         record[sol::meta_function::to_string]
diff --git a/apps/openmw/mwworld/store.cpp b/apps/openmw/mwworld/store.cpp
index 39d022a393..faa04ffba1 100644
--- a/apps/openmw/mwworld/store.cpp
+++ b/apps/openmw/mwworld/store.cpp
@@ -209,6 +209,11 @@ namespace MWWorld
     {
         return mShared.end();
     }
+    template <typename T>
+    const T& TypedDynamicStore<T>::at(size_t index) const
+    {
+        return *mShared.at(index);
+    }
 
     template <typename T>
     size_t TypedDynamicStore<T>::getSize() const
diff --git a/apps/openmw/mwworld/store.hpp b/apps/openmw/mwworld/store.hpp
index dbcf4c5a98..d6e713207e 100644
--- a/apps/openmw/mwworld/store.hpp
+++ b/apps/openmw/mwworld/store.hpp
@@ -209,6 +209,7 @@ namespace MWWorld
 
         iterator begin() const;
         iterator end() const;
+        const T& at(size_t index) const;
 
         size_t getSize() const override;
         int getDynamicSize() const override;