feat(skymp5-server): add onEatItem, onDropItem gamemode events & impl…

…ement Potion.IsFood (#2085)

libespm/include/libespm/ALCH.h

@@ -14,7 +14,9 @@ class ALCH final : public RecordHeader
   struct Data
   {
     std::vector<Effects::Effect> effects;
-    float weight;
+    float weight = 0.f;
+    bool isFood = false;
+    bool isPoison = false;
   };
 
   Data GetData(CompressedFieldsCache& compressedFieldsCache) const noexcept;

libespm/src/ALCH.cpp

@@ -15,6 +15,12 @@ ALCH::Data ALCH::GetData(
       if (!std::memcmp(type, "DATA", 4)) {
         result.weight = *reinterpret_cast<const float*>(data);
       }
+      if (!std::memcmp(type, "ENIT", 4)) {
+        const auto flags = *reinterpret_cast<const uint32_t*>(data + 0x4);
+        // Other flags are not used in Skyrim
+        result.isFood = flags & 0x00002;
+        result.isPoison = flags & 0x20000;
+      }
     },
     compressedFieldsCache);
   return result;

skymp5-server/cpp/server_guest_lib/MpActor.cpp

@@ -850,8 +850,56 @@ bool MpActor::MpApiCraft(uint32_t craftedItemBaseId, uint32_t count,
   return !isCraftBlocked;
 }
 
+bool MpActor::MpApiDropItem(uint32_t baseId, uint32_t count)
+{
+  simdjson::dom::parser parser;
+  bool isDropItemBlocked = false;
+
+  std::string s =
+    "[" + std::to_string(baseId) + "," + std::to_string(count) + "]";
+  auto args = parser.parse(s).value();
+
+  if (auto wst = GetParent()) {
+    const auto id = GetFormId();
+    for (auto& listener : wst->listeners) {
+      if (listener->OnMpApiEvent("onDropItem", args, id) == false) {
+        isDropItemBlocked = true;
+      };
+    }
+  }
+
+  return !isDropItemBlocked;
+}
+
+bool MpActor::MpApiEatItem(uint32_t baseId)
+{
+  simdjson::dom::parser parser;
+  bool isEatItemBlocked = false;
+
+  std::string s = "[" + std::to_string(baseId) + "]";
+  auto args = parser.parse(s).value();
+
+  if (auto wst = GetParent()) {
+    const auto id = GetFormId();
+    for (auto& listener : wst->listeners) {
+      if (listener->OnMpApiEvent("onEatItem", args, id) == false) {
+        isEatItemBlocked = true;
+      };
+    }
+  }
+
+  return !isEatItemBlocked;
+}
+
 void MpActor::EatItem(uint32_t baseId, espm::Type t)
 {
+  if (!MpApiEatItem(baseId)) {
+    spdlog::info(
+      "MpActor::DropItem {:x} - blocked by MpApiEatItem (baseId={:x})",
+      GetFormId(), baseId);
+    return;
+  }
+
   auto espmProvider = GetParent();
   std::vector<espm::Effects::Effect> effects;
   if (t == "ALCH") {
@@ -902,16 +950,6 @@ bool MpActor::ReadBook(const uint32_t baseId)
   return false;
 }
 
-bool MpActor::CanActorValueBeRestored(espm::ActorValue av)
-{
-  if (std::chrono::steady_clock::now() - GetLastRestorationTime(av) <
-      std::chrono::minutes(1)) {
-    return false;
-  }
-  SetLastRestorationTime(av, std::chrono::steady_clock::now());
-  return true;
-}
-
 void MpActor::EnsureTemplateChainEvaluated(espm::Loader& loader,
                                            ChangeFormGuard::Mode mode)
 {
@@ -1039,18 +1077,6 @@ std::map<uint32_t, uint32_t> MpActor::EvaluateDeathItem()
   return map;
 }
 
-std::chrono::steady_clock::time_point MpActor::GetLastRestorationTime(
-  espm::ActorValue av) const noexcept
-{
-  return pImpl->restorationTimePoints[av];
-}
-
-void MpActor::SetLastRestorationTime(
-  espm::ActorValue av, std::chrono::steady_clock::time_point timePoint)
-{
-  pImpl->restorationTimePoints[av] = timePoint;
-}
-
 void MpActor::ModifyActorValuePercentage(espm::ActorValue av,
                                          float percentageDelta)
 {
@@ -1367,12 +1393,19 @@ void MpActor::DropItem(const uint32_t baseId, const Inventory::Entry& entry)
 
   constexpr uint32_t kGold001 = 0x0000000f;
   if (baseId == kGold001) {
-    spdlog::warn("MpActor::DropItem - Attempt to drop Gold001 by actor {:x}",
+    spdlog::warn("MpActor::DropItem {:x} - Attempt to drop Gold001 by actor",
                  GetFormId());
     return;
   }
 
-  int count = entry.count;
+  const int count = entry.count;
+
+  if (!MpApiDropItem(baseId, count)) {
+    spdlog::info("MpActor::DropItem {:x} - blocked by MpApiDropItem "
+                 "(baseId={:x}, count={})",
+                 GetFormId(), baseId, count);
+    return;
+  }
 
   auto worldState = GetParent();
 
@@ -1586,22 +1619,17 @@ void MpActor::ApplyMagicEffect(espm::Effects::Effect& effect, bool hasSweetpie,
 
   if (isValue) { // other types are unsupported
     if (hasSweetpie) {
-      if (CanActorValueBeRestored(av)) {
-        // this coefficient (workaround) has been added for sake of game
-        // balance and because of disability to restrict players use potions
-        // often on client side
-        constexpr float kMagnitudeCoeff = 100.f;
-        RestoreActorValuePatched(this, av, effect.magnitude * kMagnitudeCoeff);
-      }
+      // this coefficient (workaround) has been added for sake of game
+      // balance and because of disability to restrict players use potions
+      // often on client side
+      constexpr float kMagnitudeCoeff = 100.f;
+      RestoreActorValuePatched(this, av, effect.magnitude * kMagnitudeCoeff);
     } else {
       RestoreActorValuePatched(this, av, effect.magnitude);
     }
   }
 
   if (isRate || isMult) {
-    if (hasSweetpie && !CanActorValueBeRestored(av)) {
-      return;
-    }
     MpChangeForm changeForm = GetChangeForm();
     BaseActorValues baseValues = GetBaseActorValues(
       GetParent(), GetBaseId(), GetRaceId(), changeForm.templateChain);

skymp5-server/cpp/server_guest_lib/MpActor.h

@@ -143,6 +143,8 @@ class MpActor : public MpObjectReference
 
   bool MpApiCraft(uint32_t craftedItemBaseId, uint32_t count,
                   uint32_t recipeId);
+  bool MpApiDropItem(uint32_t baseId, uint32_t count);
+  bool MpApiEatItem(uint32_t baseId);
 
   void AddSpell(uint32_t spellId);
   void RemoveSpell(uint32_t spellId);
@@ -165,13 +167,6 @@ class MpActor : public MpObjectReference
 
   void ModifyActorValuePercentage(espm::ActorValue av, float percentageDelta);
 
-  std::chrono::steady_clock::time_point GetLastRestorationTime(
-    espm::ActorValue av) const noexcept;
-
-  void SetLastRestorationTime(espm::ActorValue av,
-                              std::chrono::steady_clock::time_point timePoint);
-  bool CanActorValueBeRestored(espm::ActorValue av);
-
   void EnsureTemplateChainEvaluated(
     espm::Loader& loader,
     ChangeFormGuard::Mode mode = ChangeFormGuard::Mode::RequestSave);

skymp5-server/cpp/server_guest_lib/script_classes/PapyrusClassesFactory.cpp

@@ -12,6 +12,7 @@
 #include "PapyrusMessage.h"
 #include "PapyrusNetImmerse.h"
 #include "PapyrusObjectReference.h"
+#include "PapyrusPotion.h"
 #include "PapyrusSkymp.h"
 #include "PapyrusSound.h"
 #include "PapyrusUtility.h"
@@ -39,6 +40,7 @@ PapyrusClassesFactory::CreateAndRegister(
   result.emplace_back(std::make_unique<PapyrusCell>());
   result.emplace_back(std::make_unique<PapyrusSound>());
   result.emplace_back(std::make_unique<PapyrusNetImmerse>());
+  result.emplace_back(std::make_unique<PapyrusPotion>());
   result.emplace_back(std::make_unique<PapyrusVisualEffect>());
 
   for (auto& papyrusClass : result) {

skymp5-server/cpp/server_guest_lib/script_classes/PapyrusPotion.cpp

@@ -0,0 +1,28 @@
+#include "PapyrusPotion.h"
+#include "script_objects/EspmGameObject.h"
+
+VarValue PapyrusPotion::IsFood(VarValue self,
+                               const std::vector<VarValue>& arguments)
+{
+  const auto& item = GetRecordPtr(self);
+
+  if (!item.rec) {
+    return VarValue(false);
+  }
+
+  auto alch = espm::Convert<espm::ALCH>(item.rec);
+
+  if (!alch) {
+    return VarValue(false);
+  }
+
+  espm::CompressedFieldsCache cache;
+  espm::ALCH::Data data = alch->GetData(cache);
+  return VarValue(data.isFood);
+}
+
+void PapyrusPotion::Register(
+  VirtualMachine& vm, std::shared_ptr<IPapyrusCompatibilityPolicy> policy)
+{
+  AddMethod(vm, "IsFood", &PapyrusPotion::IsFood);
+}

skymp5-server/cpp/server_guest_lib/script_classes/PapyrusPotion.h

@@ -0,0 +1,16 @@
+#pragma once
+#include "IPapyrusClass.h"
+#include "SpSnippetFunctionGen.h"
+
+class PapyrusPotion final : public IPapyrusClass<PapyrusPotion>
+{
+public:
+  const char* GetName() override { return "potion"; }
+
+  VarValue IsFood(VarValue self, const std::vector<VarValue>& arguments);
+
+  void Register(VirtualMachine& vm,
+                std::shared_ptr<IPapyrusCompatibilityPolicy> policy) override;
+
+  std::shared_ptr<IPapyrusCompatibilityPolicy> compatibilityPolicy;
+};

unit/EspmTest.cpp

@@ -615,3 +615,19 @@ TEST_CASE("MGEF parsing", "[espm]")
   auto data = espm::GetData<espm::MGEF>(0x51B15, &provider);
   REQUIRE(data.data.primaryAV == espm::ActorValue::DamageResist);
 }
+
+TEST_CASE("isFood flag is not set for heal potion", "[espm]")
+{
+  MyEspmProvider provider;
+  auto data = espm::GetData<espm::ALCH>(0x0003eade, &provider);
+  REQUIRE(data.isFood == false);
+  REQUIRE(data.isPoison == false);
+}
+
+TEST_CASE("isFood flag is set for sweet roll", "[espm]")
+{
+  MyEspmProvider provider;
+  auto data = espm::GetData<espm::ALCH>(0x00064B3D, &provider);
+  REQUIRE(data.isFood == true);
+  REQUIRE(data.isPoison == false);
+}