Merge branch 'bfa'

6 files changed, 139 insertions, 86 deletions

diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index e0f03a7717e..fde7d49a943 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -77,68 +77,67 @@ VendorItem const* VendorItemData::FindItemCostPair(uint32 item_id, uint32 extend
     return nullptr;
 }
 
-uint32 CreatureTemplate::GetRandomValidModelId() const
-{
-    uint8 c = 0;
-    uint32 modelIDs[4];
-
-    if (Modelid1) modelIDs[c++] = Modelid1;
-    if (Modelid2) modelIDs[c++] = Modelid2;
-    if (Modelid3) modelIDs[c++] = Modelid3;
-    if (Modelid4) modelIDs[c++] = Modelid4;
-
-    return ((c>0) ? modelIDs[urand(0, c-1)] : 0);
-}
+CreatureModel const CreatureModel::DefaultInvisibleModel(11686, 1.0f, 1.0f);
+CreatureModel const CreatureModel::DefaultVisibleModel(17519, 1.0f, 1.0f);
 
-uint32 CreatureTemplate::GetFirstValidModelId() const
+CreatureModel const* CreatureTemplate::GetModelByIdx(uint32 idx) const
 {
-    if (Modelid1) return Modelid1;
-    if (Modelid2) return Modelid2;
-    if (Modelid3) return Modelid3;
-    if (Modelid4) return Modelid4;
-    return 0;
+    return idx < Models.size() ? &Models[idx] : nullptr;
 }
 
-uint32 CreatureTemplate::GetFirstInvisibleModel() const
+CreatureModel const* CreatureTemplate::GetRandomValidModel() const
 {
-    CreatureModelInfo const* modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid1);
-    if (modelInfo && modelInfo->is_trigger)
-        return Modelid1;
+    if (!Models.size())
+        return nullptr;
 
-    modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid2);
-    if (modelInfo && modelInfo->is_trigger)
-        return Modelid2;
+    // If only one element, ignore the Probability (even if 0)
+    if (Models.size() == 1)
+        return &Models[0];
 
-    modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid3);
-    if (modelInfo && modelInfo->is_trigger)
-        return Modelid3;
+    auto selectedItr = Trinity::Containers::SelectRandomWeightedContainerElement(Models, [](CreatureModel const& model)
+    {
+        return model.Probability;
+    });
 
-    modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid4);
-    if (modelInfo && modelInfo->is_trigger)
-        return Modelid4;
+    return &(*selectedItr);
+}
 
-    return 11686;
+CreatureModel const* CreatureTemplate::GetFirstValidModel() const
+{
+    for (CreatureModel const& model : Models)
+        if (model.CreatureDisplayID)
+            return &model;
+
+    return nullptr;
 }
 
-uint32 CreatureTemplate::GetFirstVisibleModel() const
+CreatureModel const* CreatureTemplate::GetModelWithDisplayId(uint32 displayId) const
 {
-    CreatureModelInfo const* modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid1);
-    if (modelInfo && !modelInfo->is_trigger)
-        return Modelid1;
+    for (CreatureModel const& model : Models)
+        if (displayId == model.CreatureDisplayID)
+            return &model;
 
-    modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid2);
-    if (modelInfo && !modelInfo->is_trigger)
-        return Modelid2;
+    return nullptr;
+}
 
-    modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid3);
-    if (modelInfo && !modelInfo->is_trigger)
-        return Modelid3;
+CreatureModel const* CreatureTemplate::GetFirstInvisibleModel() const
+{
+    for (CreatureModel const& model : Models)
+        if (CreatureModelInfo const* modelInfo = sObjectMgr->GetCreatureModelInfo(model.CreatureDisplayID))
+            if (modelInfo && modelInfo->is_trigger)
+                return &model;
+
+    return &CreatureModel::DefaultInvisibleModel;
+}
 
-    modelInfo = sObjectMgr->GetCreatureModelInfo(Modelid4);
-    if (modelInfo && !modelInfo->is_trigger)
-        return Modelid4;
+CreatureModel const* CreatureTemplate::GetFirstVisibleModel() const
+{
+    for (CreatureModel const& model : Models)
+        if (CreatureModelInfo const* modelInfo = sObjectMgr->GetCreatureModelInfo(model.CreatureDisplayID))
+            if (modelInfo && !modelInfo->is_trigger)
+                return &model;
 
-    return 17519;
+    return &CreatureModel::DefaultVisibleModel;
 }
 
 bool AssistDelayEvent::Execute(uint64 /*e_time*/, uint32 /*p_time*/)
@@ -347,22 +346,22 @@ bool Creature::InitEntry(uint32 entry, CreatureData const* data /*= nullptr*/)
     SetByteValue(UNIT_FIELD_BYTES_0, UNIT_BYTES_0_OFFSET_CLASS, uint8(cinfo->unit_class));
 
     // Cancel load if no model defined
-    if (!(cinfo->GetFirstValidModelId()))
+    if (!(cinfo->GetFirstValidModel()))
     {
         TC_LOG_ERROR("sql.sql", "Creature (Entry: %u) has no model defined in table `creature_template`, can't load. ", entry);
         return false;
     }
 
-    uint32 displayID = ObjectMgr::ChooseDisplayId(GetCreatureTemplate(), data);
-    CreatureModelInfo const* minfo = sObjectMgr->GetCreatureModelRandomGender(&displayID);
+    CreatureModel model = *ObjectMgr::ChooseDisplayId(cinfo, data);
+    CreatureModelInfo const* minfo = sObjectMgr->GetCreatureModelRandomGender(&model, cinfo);
     if (!minfo)                                             // Cancel load if no model defined
     {
-        TC_LOG_ERROR("sql.sql", "Creature (Entry: %u) has invalid model %u defined in table `creature_template`, can't load.", entry, displayID);
+        TC_LOG_ERROR("sql.sql", "Creature (Entry: %u) has invalid model %u defined in table `creature_template`, can't load.", entry, model.CreatureDisplayID);
         return false;
     }
 
-    SetDisplayId(displayID);
-    SetNativeDisplayId(displayID);
+    SetDisplayId(model.CreatureDisplayID, model.DisplayScale);
+    SetNativeDisplayId(model.CreatureDisplayID, model.DisplayScale);
     SetByteValue(UNIT_FIELD_BYTES_0, UNIT_BYTES_0_OFFSET_GENDER, minfo->gender);
 
     // Load creature equipment
@@ -388,7 +387,7 @@ bool Creature::InitEntry(uint32 entry, CreatureData const* data /*= nullptr*/)
     SetSpeedRate(MOVE_SWIM,   1.0f); // using 1.0 rate
     SetSpeedRate(MOVE_FLIGHT, 1.0f); // using 1.0 rate
 
-    // Will set UNIT_FIELD_BOUNDINGRADIUS and UNIT_FIELD_COMBATREACH
+    // Will set UNIT_FIELD_BOUNDINGRADIUS, UNIT_FIELD_COMBATREACH and UNIT_FIELD_DISPLAYSCALE
     SetObjectScale(cinfo->scale);
 
     SetFloatValue(UNIT_FIELD_HOVERHEIGHT, cinfo->HoverHeight);
@@ -434,6 +433,8 @@ bool Creature::UpdateEntry(uint32 entry, CreatureData const* data /*= nullptr*/,
 
     SetUInt32Value(OBJECT_DYNAMIC_FLAGS, dynamicFlags);
 
+    SetUInt32Value(UNIT_FIELD_STATE_ANIM_ID, sAnimationDataStore.GetNumRows());
+
     RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IN_COMBAT);
 
     SetBaseAttackTime(BASE_ATTACK,   cInfo->BaseAttackTime);
@@ -894,7 +895,8 @@ bool Creature::Create(ObjectGuid::LowType guidlow, Map* map, uint32 entry, float
     if (!CreateFromProto(guidlow, entry, data, vehId))
         return false;
 
-    switch (GetCreatureTemplate()->rank)
+    cinfo = GetCreatureTemplate(); // might be different than initially requested
+    switch (cinfo->rank)
     {
         case CREATURE_ELITE_RARE:
             m_corpseDelay = sWorld->getIntConfig(CONFIG_CORPSE_DECAY_RARE);
@@ -924,12 +926,12 @@ bool Creature::Create(ObjectGuid::LowType guidlow, Map* map, uint32 entry, float
         Relocate(x, y, z, ang);
     }
 
-    uint32 displayID = GetNativeDisplayId();
-    CreatureModelInfo const* minfo = sObjectMgr->GetCreatureModelRandomGender(&displayID);
+    CreatureModel display(GetNativeDisplayId(), GetNativeDisplayScale(), 1.0f);
+    CreatureModelInfo const* minfo = sObjectMgr->GetCreatureModelRandomGender(&display, cinfo);
     if (minfo && !IsTotem())                               // Cancel load if no model defined or if totem
     {
-        SetDisplayId(displayID);
-        SetNativeDisplayId(displayID);
+        SetDisplayId(display.CreatureDisplayID, display.DisplayScale);
+        SetNativeDisplayId(display.CreatureDisplayID, display.DisplayScale);
         SetByteValue(UNIT_FIELD_BYTES_0, UNIT_BYTES_0_OFFSET_GENDER, minfo->gender);
     }
 
@@ -942,10 +944,10 @@ bool Creature::Create(ObjectGuid::LowType guidlow, Map* map, uint32 entry, float
         m_serverSideVisibilityDetect.SetValue(SERVERSIDE_VISIBILITY_GHOST, GHOST_VISIBILITY_GHOST);
     }
 
-    if (GetCreatureTemplate()->flags_extra & CREATURE_FLAG_EXTRA_IGNORE_PATHFINDING)
+    if (cinfo->flags_extra & CREATURE_FLAG_EXTRA_IGNORE_PATHFINDING)
         AddUnitState(UNIT_STATE_IGNORE_PATHFINDING);
 
-    if (GetCreatureTemplate()->flags_extra & CREATURE_FLAG_EXTRA_IMMUNITY_KNOCKBACK)
+    if (cinfo->flags_extra & CREATURE_FLAG_EXTRA_IMMUNITY_KNOCKBACK)
     {
         ApplySpellImmune(0, IMMUNITY_EFFECT, SPELL_EFFECT_KNOCK_BACK, true);
         ApplySpellImmune(0, IMMUNITY_EFFECT, SPELL_EFFECT_KNOCK_BACK_DEST, true);
@@ -1129,9 +1131,9 @@ void Creature::SaveToDB(uint32 mapid, std::vector<Difficulty> const& spawnDiffic
     CreatureTemplate const* cinfo = GetCreatureTemplate();
     if (cinfo)
     {
-        if (displayId == cinfo->Modelid1 || displayId == cinfo->Modelid2 ||
-            displayId == cinfo->Modelid3 || displayId == cinfo->Modelid4)
-            displayId = 0;
+        for (CreatureModel model : cinfo->Models)
+            if (displayId && displayId == model.CreatureDisplayID)
+                displayId = 0;
 
         if (npcflag == cinfo->npcflag)
             npcflag = 0;
@@ -1844,12 +1846,12 @@ void Creature::Respawn(bool force)
 
         setDeathState(JUST_RESPAWNED);
 
-        uint32 displayID = GetNativeDisplayId();
-        CreatureModelInfo const* minfo = sObjectMgr->GetCreatureModelRandomGender(&displayID);
+        CreatureModel display(GetNativeDisplayId(), GetNativeDisplayScale(), 1.0f);
+        CreatureModelInfo const* minfo = sObjectMgr->GetCreatureModelRandomGender(&display, GetCreatureTemplate());
         if (minfo)                                             // Cancel load if no model defined
         {
-            SetDisplayId(displayID);
-            SetNativeDisplayId(displayID);
+            SetDisplayId(display.CreatureDisplayID, display.DisplayScale);
+            SetNativeDisplayId(display.CreatureDisplayID, display.DisplayScale);
             SetByteValue(UNIT_FIELD_BYTES_0, UNIT_BYTES_0_OFFSET_GENDER, minfo->gender);
         }
 
@@ -2575,7 +2577,7 @@ uint8 Creature::GetLevelForTarget(WorldObject const* target) const
             uint8 targetLevelWithDelta = unitTarget->getLevel() + GetInt32Value(UNIT_FIELD_SCALING_LEVEL_DELTA);
 
             if (target->IsPlayer())
-                targetLevelWithDelta += target->GetUInt32Value(PLAYER_FIELD_SCALING_PLAYER_LEVEL_DELTA);
+                targetLevelWithDelta += target->GetUInt32Value(ACTIVE_PLAYER_FIELD_SCALING_PLAYER_LEVEL_DELTA);
 
             return RoundToInterval<uint8>(targetLevelWithDelta, GetUInt32Value(UNIT_FIELD_SCALING_LEVEL_MIN), GetUInt32Value(UNIT_FIELD_SCALING_LEVEL_MAX));
         }
@@ -2853,9 +2855,9 @@ void Creature::SetObjectScale(float scale)
     }
 }
 
-void Creature::SetDisplayId(uint32 modelId)
+void Creature::SetDisplayId(uint32 modelId, float displayScale /*= 1.f*/)
 {
-    Unit::SetDisplayId(modelId);
+    Unit::SetDisplayId(modelId, displayScale);
 
     if (CreatureModelInfo const* minfo = sObjectMgr->GetCreatureModelInfo(modelId))
     {
@@ -2864,6 +2866,12 @@ void Creature::SetDisplayId(uint32 modelId)
     }
 }
 
+void Creature::SetDisplayFromModel(uint32 modelIdx)
+{
+    if (CreatureModel const* model = GetCreatureTemplate()->GetModelByIdx(modelIdx))
+        SetDisplayId(model->CreatureDisplayID, model->DisplayScale);
+}
+
 void Creature::SetTarget(ObjectGuid const& guid)
 {
     if (IsFocusing(nullptr, true))
diff --git a/src/server/game/Entities/Creature/Creature.h b/src/server/game/Entities/Creature/Creature.h
index d87db9be2ca..b56fe8c9137 100644
--- a/src/server/game/Entities/Creature/Creature.h
+++ b/src/server/game/Entities/Creature/Creature.h
@@ -69,7 +69,8 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         void RemoveFromWorld() override;
 
         void SetObjectScale(float scale) override;
-        void SetDisplayId(uint32 modelId) override;
+        void SetDisplayId(uint32 displayId, float displayScale = 1.f) override;
+        void SetDisplayFromModel(uint32 modelIdx);
 
         void DisappearAndDie();
 
@@ -149,7 +150,6 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
 
         bool UpdateStats(Stats stat) override;
         bool UpdateAllStats() override;
-        void UpdateResistances(uint32 school) override;
         void UpdateArmor() override;
         void UpdateMaxHealth() override;
         void UpdateMaxPower(Powers power) override;
diff --git a/src/server/game/Entities/Creature/CreatureData.h b/src/server/game/Entities/Creature/CreatureData.h
index d0d29d842e7..02fdcfbff16 100644
--- a/src/server/game/Entities/Creature/CreatureData.h
+++ b/src/server/game/Entities/Creature/CreatureData.h
@@ -301,16 +301,29 @@ struct CreatureLevelScaling
     int16 DeltaLevelMax;
 };
 
+struct CreatureModel
+{
+    static CreatureModel const DefaultInvisibleModel;
+    static CreatureModel const DefaultVisibleModel;
+
+    CreatureModel() :
+        CreatureDisplayID(0), DisplayScale(0.0f), Probability(0.0f) { }
+
+    CreatureModel(uint32 creatureDisplayID, float displayScale, float probability) :
+        CreatureDisplayID(creatureDisplayID), DisplayScale(displayScale), Probability(probability) { }
+
+    uint32 CreatureDisplayID;
+    float DisplayScale;
+    float Probability;
+};
+
 // from `creature_template` table
 struct TC_GAME_API CreatureTemplate
 {
     uint32  Entry;
     uint32  DifficultyEntry[MAX_CREATURE_DIFFICULTIES];
     uint32  KillCredit[MAX_KILL_CREDIT];
-    uint32  Modelid1;
-    uint32  Modelid2;
-    uint32  Modelid3;
-    uint32  Modelid4;
+    std::vector<CreatureModel> Models;
     std::string  Name;
     std::string FemaleName;
     std::string  SubName;
@@ -369,10 +382,12 @@ struct TC_GAME_API CreatureTemplate
     uint32  MechanicImmuneMask;
     uint32  flags_extra;
     uint32  ScriptID;
-    uint32  GetRandomValidModelId() const;
-    uint32  GetFirstValidModelId() const;
-    uint32  GetFirstInvisibleModel() const;
-    uint32  GetFirstVisibleModel() const;
+    CreatureModel const* GetModelByIdx(uint32 idx) const;
+    CreatureModel const* GetRandomValidModel() const;
+    CreatureModel const* GetFirstValidModel() const;
+    CreatureModel const* GetModelWithDisplayId(uint32 displayId) const;
+    CreatureModel const* GetFirstInvisibleModel() const;
+    CreatureModel const* GetFirstVisibleModel() const;
 
     // helpers
     SkillType GetRequiredLootSkill() const
diff --git a/src/server/game/Entities/Creature/GossipDef.cpp b/src/server/game/Entities/Creature/GossipDef.cpp
index 98a253fe870..9f5b461ef8d 100644
--- a/src/server/game/Entities/Creature/GossipDef.cpp
+++ b/src/server/game/Entities/Creature/GossipDef.cpp
@@ -286,6 +286,7 @@ void PlayerMenu::SendPointOfInterest(uint32 id) const
     }
 
     WorldPackets::NPC::GossipPOI packet;
+    packet.ID = pointOfInterest->ID;
     packet.Name = pointOfInterest->Name;
 
     LocaleConstant localeConstant = _session->GetSessionDbLocaleIndex();
@@ -438,6 +439,7 @@ void PlayerMenu::SendQuestGiverQuestDetails(Quest const* quest, ObjectGuid npcGU
     packet.InformUnit = _session->GetPlayer()->GetDivider();
     packet.QuestID = quest->GetQuestId();
     packet.PortraitGiver = quest->GetQuestGiverPortrait();
+    packet.PortraitGiverMount = quest->GetQuestGiverPortraitMount();
     packet.PortraitTurnIn = quest->GetQuestTurnInPortrait();
     packet.AutoLaunched = autoLaunched;
     packet.DisplayPopup = displayPopup;
@@ -512,6 +514,7 @@ void PlayerMenu::SendQuestQueryResponse(Quest const* quest) const
     packet.Info.QuestID = quest->GetQuestId();
     packet.Info.QuestType = quest->GetQuestType();
     packet.Info.QuestLevel = quest->GetQuestLevel();
+    packet.Info.QuestScalingFactionGroup = quest->GetQuestScalingFactionGroup();
     packet.Info.QuestMaxScalingLevel = quest->GetQuestMaxScalingLevel();
     packet.Info.QuestPackageID = quest->GetQuestPackageID();
     packet.Info.QuestMinLevel = quest->GetMinLevel();
@@ -543,12 +546,14 @@ void PlayerMenu::SendQuestQueryResponse(Quest const* quest) const
     packet.Info.StartItem = quest->GetSrcItemId();
     packet.Info.Flags = quest->GetFlags();
     packet.Info.FlagsEx = quest->GetFlagsEx();
+    packet.Info.FlagsEx2 = quest->GetFlagsEx2();
     packet.Info.RewardTitle = quest->GetRewTitle();
     packet.Info.RewardArenaPoints = quest->GetRewArenaPoints();
     packet.Info.RewardSkillLineID = quest->GetRewardSkillId();
     packet.Info.RewardNumSkillUps = quest->GetRewardSkillPoints();
     packet.Info.RewardFactionFlags = quest->GetRewardReputationMask();
     packet.Info.PortraitGiver = quest->GetQuestGiverPortrait();
+    packet.Info.PortraitGiverMount = quest->GetQuestGiverPortraitMount();
     packet.Info.PortraitTurnIn = quest->GetQuestTurnInPortrait();
 
     for (uint8 i = 0; i < QUEST_ITEM_DROP_COUNT; ++i)
@@ -585,7 +590,7 @@ void PlayerMenu::SendQuestQueryResponse(Quest const* quest) const
     packet.Info.POIPriority = quest->GetPOIPriority();
 
     packet.Info.AllowableRaces = quest->GetAllowableRaces();
-    packet.Info.QuestRewardID = quest->GetRewardId();
+    packet.Info.TreasurePickerID = quest->GetTreasurePickerId();
     packet.Info.Expansion = quest->GetExpansion();
 
     for (QuestObjective const& questObjective : quest->GetObjectives())
@@ -666,6 +671,7 @@ void PlayerMenu::SendQuestGiverOfferReward(Quest const* quest, ObjectGuid npcGUI
 
     packet.PortraitTurnIn = quest->GetQuestTurnInPortrait();
     packet.PortraitGiver = quest->GetQuestGiverPortrait();
+    packet.PortraitGiverMount = quest->GetQuestGiverPortraitMount();
     packet.QuestPackageID = quest->GetQuestPackageID();
 
     _session->SendPacket(packet.Write());
diff --git a/src/server/game/Entities/Creature/Trainer.cpp b/src/server/game/Entities/Creature/Trainer.cpp
index fb9f0af7f19..af59acb7496 100644
--- a/src/server/game/Entities/Creature/Trainer.cpp
+++ b/src/server/game/Entities/Creature/Trainer.cpp
@@ -24,6 +24,10 @@
 
 namespace Trainer
 {
+    bool Spell::IsCastable() const
+    {
+        return sSpellMgr->AssertSpellInfo(SpellId)->HasEffect(SPELL_EFFECT_LEARN_SPELL);
+    }
 
     Trainer::Trainer(uint32 id, Type type, std::string greeting, std::vector<Spell> spells) : _id(id), _type(type), _spells(std::move(spells))
     {
@@ -136,9 +140,30 @@ namespace Trainer
             return SpellState::Unavailable;
 
         // check ranks
-        if (uint32 previousRankSpellId = sSpellMgr->GetPrevSpellInChain(trainerSpell->LearnedSpellId))
-            if (!player->HasSpell(previousRankSpellId))
-                return SpellState::Unavailable;
+        bool hasLearnSpellEffect = false;
+        bool knowsAllLearnedSpells = true;
+        for (SpellEffectInfo const* spellEffect : sSpellMgr->AssertSpellInfo(trainerSpell->SpellId)->GetEffectsForDifficulty(DIFFICULTY_NONE))
+        {
+            if (!spellEffect || !spellEffect->IsEffect(SPELL_EFFECT_LEARN_SPELL))
+                continue;
+
+            hasLearnSpellEffect = true;
+            if (!player->HasSpell(spellEffect->TriggerSpell))
+                knowsAllLearnedSpells = false;
+
+            if (uint32 previousRankSpellId = sSpellMgr->GetPrevSpellInChain(spellEffect->TriggerSpell))
+                if (!player->HasSpell(previousRankSpellId))
+                    return SpellState::Unavailable;
+        }
+
+        if (!hasLearnSpellEffect)
+        {
+            if (uint32 previousRankSpellId = sSpellMgr->GetPrevSpellInChain(trainerSpell->SpellId))
+                if (!player->HasSpell(previousRankSpellId))
+                    return SpellState::Unavailable;
+        }
+        else if (knowsAllLearnedSpells)
+            return SpellState::Known;
 
         // check additional spell requirement
         for (auto const& requirePair : sSpellMgr->GetSpellsRequiredForSpellBounds(trainerSpell->SpellId))
diff --git a/src/server/game/Entities/Creature/Trainer.h b/src/server/game/Entities/Creature/Trainer.h
index f7e9c51dba1..20ee7deb3f5 100644
--- a/src/server/game/Entities/Creature/Trainer.h
+++ b/src/server/game/Entities/Creature/Trainer.h
@@ -59,8 +59,7 @@ namespace Trainer
         std::array<uint32, 3> ReqAbility = { };
         uint8 ReqLevel = 0;
 
-        uint32 LearnedSpellId = 0;
-        bool IsCastable() const { return LearnedSpellId != SpellId; }
+        bool IsCastable() const;
     };
 
     class Trainer