VillagerTrading

25 files changed, 838 insertions, 74 deletions

diff --git a/Server/Plugins/APIDump/APIDesc.lua b/Server/Plugins/APIDump/APIDesc.lua
index 9a0b7a36e..c0569c5b1 100644
--- a/Server/Plugins/APIDump/APIDesc.lua
+++ b/Server/Plugins/APIDump/APIDesc.lua
@@ -12859,7 +12859,7 @@ end
 				{
 					Notes = "An inventory window",
 				},
-				wtNPCTrade =
+				wtVillagerTrade =
 				{
 					Notes = "A villager trade window",
 				},
diff --git a/src/ClientHandle.cpp b/src/ClientHandle.cpp
index 6923c9855..13c22de52 100644
--- a/src/ClientHandle.cpp
+++ b/src/ClientHandle.cpp
@@ -17,6 +17,7 @@
 #include "UI/AnvilWindow.h"
 #include "UI/BeaconWindow.h"
 #include "UI/EnchantingWindow.h"
+#include "UI/VillagerTradeWindow.h"
 #include "Item.h"
 #include "Mobs/Monster.h"
 #include "ChatColor.h"
@@ -670,8 +671,14 @@ void cClientHandle::RemoveFromAllChunks()
 
 void cClientHandle::HandleNPCTrade(int a_SlotNum)
 {
-	// TODO
-	LOGWARNING("%s: Not implemented yet", __FUNCTION__);
+	auto CurrentWindow = GetPlayer()->GetWindow();
+	if ((CurrentWindow == nullptr) || CurrentWindow->GetWindowType() != cWindow::WindowType::wtVillagerTrade)
+	{
+		Kick("Received trade selection when no trade in progress - hacked client?");
+		return;
+	}
+
+	static_cast<cVillagerTradeWindow *>(CurrentWindow)->PlayerChangedTradeOffer(*GetPlayer(), static_cast<unsigned>(a_SlotNum));
 }
 
 
@@ -3111,6 +3118,11 @@ void cClientHandle::SendUseBed(const cEntity & a_Entity, int a_BlockX, int a_Blo
 	m_Protocol->SendUseBed(a_Entity, a_BlockX, a_BlockY, a_BlockZ);
 }
 
+void cClientHandle::SendVillagerTradeList(const cWindow & TradeWindow, const std::vector<VillagerTradeOffer> & TradeOffers)
+{
+	m_Protocol->SendVillagerTradeList(TradeWindow, TradeOffers);
+}
+
 
 
 
diff --git a/src/ClientHandle.h b/src/ClientHandle.h
index 4a4898179..f790aa7f6 100644
--- a/src/ClientHandle.h
+++ b/src/ClientHandle.h
@@ -36,6 +36,7 @@ class cFallingBlock;
 class cCompositeChat;
 class cStatManager;
 class cMap;
+struct VillagerTradeOffer;
 class cClientHandle;
 typedef std::shared_ptr<cClientHandle> cClientHandlePtr;
 
@@ -221,6 +222,7 @@ public:  // tolua_export
 	void SendUpdateBlockEntity          (cBlockEntity & a_BlockEntity);
 	void SendUpdateSign                 (int a_BlockX, int a_BlockY, int a_BlockZ, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4);
 	void SendUseBed                     (const cEntity & a_Entity, int a_BlockX, int a_BlockY, int a_BlockZ);
+	void SendVillagerTradeList          (const cWindow &, const std::vector<VillagerTradeOffer> &);
 	void SendWeather                    (eWeather a_Weather);
 	void SendWholeInventory             (const cWindow & a_Window);
 	void SendWindowClose                (const cWindow & a_Window);
diff --git a/src/Entities/Entity.cpp b/src/Entities/Entity.cpp
index 836e69961..13d8a8733 100644
--- a/src/Entities/Entity.cpp
+++ b/src/Entities/Entity.cpp
@@ -666,7 +666,7 @@ bool cEntity::ArmorCoversAgainst(eDamageType a_DamageType)
 
 int cEntity::GetEnchantmentCoverAgainst(const cEntity * a_Attacker, eDamageType a_DamageType, int a_Damage)
 {
-	int TotalEPF = 0.0;
+	int TotalEPF = 0;
 
 	const cItem ArmorItems[] = { GetEquippedHelmet(), GetEquippedChestplate(), GetEquippedLeggings(), GetEquippedBoots() };
 	for (size_t i = 0; i < ARRAYCOUNT(ArmorItems); i++)
diff --git a/src/Mobs/Monster.cpp b/src/Mobs/Monster.cpp
index 0d433d861..86060583c 100644
--- a/src/Mobs/Monster.cpp
+++ b/src/Mobs/Monster.cpp
@@ -1135,14 +1135,14 @@ std::unique_ptr<cMonster> cMonster::NewMonsterFromType(eMonsterType a_MobType)
 		}
 		case mtVillager:
 		{
-			int VillagerType = Random.RandInt(6);
-			if (VillagerType == 6)
+			int VillagerType = Random.RandInt(13);
+			if (VillagerType == 13)
 			{
 				// Give farmers a better chance of spawning
 				VillagerType = 0;
 			}
 
-			return cpp14::make_unique<cVillager>(static_cast<cVillager::eVillagerType>(VillagerType));
+			return cpp14::make_unique<cVillager>(static_cast<cVillager::VillagerCareer>(VillagerType), 1U);
 		}
 		case mtHorse:
 		{
diff --git a/src/Mobs/Villager.cpp b/src/Mobs/Villager.cpp
index 26462ba31..36b3d75f9 100644
--- a/src/Mobs/Villager.cpp
+++ b/src/Mobs/Villager.cpp
@@ -2,21 +2,53 @@
 #include "Globals.h"  // NOTE: MSVC stupidness requires this to be the same across all modules
 
 #include "Villager.h"
+#include "../UI/VillagerTradeWindow.h"
+#include "../Entities/Player.h"
 #include "../World.h"
 #include "../BlockArea.h"
 #include "../Blocks/BlockHandler.h"
 #include "../BlockInServerPluginInterface.h"
+#include "../ClientHandle.h"
 
 
 
 
 
-cVillager::cVillager(eVillagerType VillagerType) :
+cVillager::cVillager(VillagerCareer Career, unsigned TradeTier) :
 	super("Villager", mtVillager, "entity.villager.hurt", "entity.villager.death", 0.6, 1.8),
+	cEntityWindowOwner(this),
 	m_ActionCountDown(-1),
-	m_Type(VillagerType),
+	m_Career(Career),
+	m_TradeTier(TradeTier),
 	m_VillagerAction(false)
 {
+	UpdateTradeTier(m_TradeTier);
+}
+
+
+
+
+
+cVillager::VillagerProfession cVillager::VillagerCareerToProfession(VillagerCareer Career)
+{
+	switch (Career)
+	{
+		case VillagerCareer::Farmer:
+		case VillagerCareer::Fisherman:
+		case VillagerCareer::Shepherd:
+		case VillagerCareer::Fletcher: return cVillager::VillagerProfession::Farmer;
+		case VillagerCareer::Librarian:
+		case VillagerCareer::Cartographer: return cVillager::VillagerProfession::Librarian;
+		case VillagerCareer::Cleric:  return cVillager::VillagerProfession::Priest;
+		case VillagerCareer::Armorer:
+		case VillagerCareer::WeaponSmith:
+		case VillagerCareer::ToolSmith: return cVillager::VillagerProfession::Blacksmith;
+		case VillagerCareer::Butcher:
+		case VillagerCareer::Leatherworker: return cVillager::VillagerProfession::Butcher;
+		case VillagerCareer::Nitwit: return cVillager::VillagerProfession::Nitwit;
+	}
+
+	throw std::runtime_error("Unhandled career");
 }
 
 
@@ -32,10 +64,7 @@ bool cVillager::DoTakeDamage(TakeDamageInfo & a_TDI)
 
 	if ((a_TDI.Attacker != nullptr) && a_TDI.Attacker->IsPlayer())
 	{
-		if (GetRandomProvider().RandBool(1.0 / 6.0))
-		{
-			m_World->BroadcastEntityStatus(*this, esVillagerAngry);
-		}
+		m_World->BroadcastEntityStatus(*this, esVillagerAngry);
 	}
 
 	if (a_TDI.DamageType == dtLightning)
@@ -63,27 +92,18 @@ void cVillager::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	if (m_ActionCountDown > -1)
 	{
 		m_ActionCountDown--;
-		if (m_ActionCountDown == 0)
+		if ((m_ActionCountDown == 0) && (m_Career == VillagerCareer::Farmer))
 		{
-			switch (m_Type)
-			{
-				case vtFarmer:
-				{
-					HandleFarmerPlaceCrops();
-				}
-			}
+			HandleFarmerPlaceCrops();
 		}
 		return;
 	}
 
 	if (m_VillagerAction)
 	{
-		switch (m_Type)
+		if (m_Career == VillagerCareer::Farmer)
 		{
-			case vtFarmer:
-			{
-				HandleFarmerTryHarvestCrops();
-			}
+			HandleFarmerTryHarvestCrops();
 		}
 		m_VillagerAction = false;
 		return;
@@ -95,11 +115,169 @@ void cVillager::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 		return;
 	}
 
-	switch (m_Type)
+	if (m_Career == VillagerCareer::Farmer)
+	{
+		HandleFarmerPrepareFarmCrops();
+	}
+}
+
+
+
+
+
+void cVillager::OnRightClicked(cPlayer & InteractingPlayer)
+{
+	if (m_TradeOffers.empty())
+	{
+		// Client handles this ok, but the contract of GetTradeOffer says it must return something
+		return;
+	}
+
+	// If the window is not created, open it anew:
+	if (GetWindow() == nullptr)
+	{
+		OpenWindow(new cVillagerTradeWindow(*this));
+	}
+
+	InteractingPlayer.OpenWindow(*GetWindow());
+	InteractingPlayer.GetClientHandle()->SendVillagerTradeList(*GetWindow(), m_TradeOffers);
+	GetWorld()->BroadcastSoundEffect("entity.villager.trading", GetPosX(), GetPosY(), GetPosZ(), 1, 1);
+}
+
+
+
+
+
+VillagerTradeOffer & cVillager::GetTradeOffer(unsigned PlayerOfferIndex, const cItem & PrimarySlot, const cItem & SecondarySlot)
+{
+	if ((PlayerOfferIndex != 0) || GetTransactionMultiplier(m_TradeOffers[PlayerOfferIndex], PrimarySlot, SecondarySlot) != 0)
+	{
+		return m_TradeOffers[PlayerOfferIndex];
+	}
+
+	for (auto & Offer : m_TradeOffers)
+	{
+		if (GetTransactionMultiplier(Offer, PrimarySlot, SecondarySlot) != 0)
+		{
+			return Offer;
+		}
+	}
+
+	return m_TradeOffers[PlayerOfferIndex];
+}
+
+
+
+
+
+unsigned cVillager::GetTransactionMultiplier(const VillagerTradeOffer & Trade, const cItem & PrimarySlot, const cItem & SecondarySlot)
+{
+	if (Trade.IsTradeExhausted())
+	{
+		return 0;
+	}
+
+	if (
+		PrimarySlot.IsEqual(Trade.PrimaryDesire) &&
+		(PrimarySlot.m_ItemCount >= Trade.PrimaryDesire.m_ItemCount) &&
+		SecondarySlot.IsEqual(Trade.SecondaryDesire) &&
+		(SecondarySlot.m_ItemCount >= Trade.SecondaryDesire.m_ItemCount)
+	)
+	{
+		// Slots matched normally: find common denominator of transaction multiplier
+		return std::min(
+			{
+				static_cast<unsigned>(PrimarySlot.m_ItemCount / Trade.PrimaryDesire.m_ItemCount),
+				Trade.SecondaryDesire.IsEmpty() ? std::numeric_limits<unsigned>::max() : static_cast<unsigned>(SecondarySlot.m_ItemCount / Trade.SecondaryDesire.m_ItemCount),
+				static_cast<unsigned>(Trade.Recompense.GetMaxStackSize() / Trade.Recompense.m_ItemCount)
+			}
+		);
+	}
+	else if (
+		Trade.SecondaryDesire.IsEmpty() &&
+		PrimarySlot.IsEmpty() &&
+		SecondarySlot.IsEqual(Trade.PrimaryDesire) &&
+		(SecondarySlot.m_ItemCount >= Trade.PrimaryDesire.m_ItemCount)
+	)
+	{
+		// Slots crossed - primary desire in secondary slot: swap comparison accordingly
+		return std::min(
+			static_cast<unsigned>(SecondarySlot.m_ItemCount / Trade.PrimaryDesire.m_ItemCount),
+			static_cast<unsigned>(Trade.Recompense.GetMaxStackSize() / Trade.Recompense.m_ItemCount)
+		);
+	}
+
+	return 0;
+}
+
+
+
+
+
+void cVillager::HandleTradeAvailable() const
+{
+	GetWorld()->BroadcastSoundEffect("entity.villager.yes", GetPosX(), GetPosY(), GetPosZ(), 1, 1);
+}
+
+
+
+
+
+void cVillager::HandleTradeInProgress() const
+{
+	GetWorld()->BroadcastSoundEffect("entity.villager.trading", GetPosX(), GetPosY(), GetPosZ(), 1, 1);
+}
+
+
+
+
+
+void cVillager::HandleTradeUnavailable() const
+{
+	GetWorld()->BroadcastSoundEffect("entity.villager.no", GetPosX(), GetPosY(), GetPosZ(), 1, 1);
+}
+
+
+
+
+
+void cVillager::HandleTransaction(VillagerTradeOffer & Trade, unsigned TransactionMultiplier)
+{
+	GetWorld()->BroadcastSoundEffect("entity.villager.yes", GetPosX(), GetPosY(), GetPosZ(), 1, 1);
+	Trade.Transactions += TransactionMultiplier;
+
+	for (unsigned Try = 0; Try != TransactionMultiplier; Try++)
 	{
-		case vtFarmer:
+		// One singular transaction has a 10% chance of upgrading the villager's trading tier
+
+		if (GetRandomProvider().RandBool(0.1))
 		{
-			HandleFarmerPrepareFarmCrops();
+			UpdateTradeTier(m_TradeTier + 1);
+
+			class SendNewTradesCallback : public cItemCallback<cClientHandle>
+			{
+			public:
+				SendNewTradesCallback(const cWindow & VillagerTradeWindow, const std::vector<VillagerTradeOffer> & VillagerTradeOffers) :
+					TradeWindow(VillagerTradeWindow),
+					TradeOffers(VillagerTradeOffers)
+				{
+				}
+
+				bool Item(cClientHandle * Handle)
+				{
+					Handle->SendVillagerTradeList(TradeWindow, TradeOffers);
+					return false;
+				}
+
+			private:
+				const cWindow & TradeWindow;
+				const std::vector<VillagerTradeOffer> & TradeOffers;
+
+			} SNTC(*GetWindow(), m_TradeOffers);
+			GetWindow()->ForEachClient(SNTC);
+
+			m_World->BroadcastEntityStatus(*this, esVillagerHappy);
+			break;
 		}
 	}
 }
@@ -107,6 +285,7 @@ void cVillager::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 
 
 
+
 ////////////////////////////////////////////////////////////////////////////////
 // Farmer functions:
 
@@ -195,6 +374,101 @@ void cVillager::HandleFarmerPlaceCrops()
 
 
 
+void cVillager::UpdateTradeTier(size_t DesiredTier)
+{
+	struct CareerHash
+	{
+		size_t operator()(const VillagerCareer & Career) const
+		{
+			return static_cast<size_t>(Career);
+		}
+	};
+	using Offer = VillagerTradeOffer;
+
+	static const std::unordered_map<
+		VillagerCareer,
+		std::vector<
+			// Element index: trading tier (0-based)
+			std::vector<Offer>  // Trade offer
+		>,
+		CareerHash  // TODO for C++14: unneeded
+	> TradeMatrix =
+	{
+		{
+			VillagerCareer::Farmer,
+			{
+				{  // Tier 1 (equivalent)
+					Offer(cItem(E_ITEM_WHEAT, 18), cItem(E_ITEM_EMERALD)),
+					Offer(cItem(E_ITEM_POTATO, 15), cItem(E_ITEM_EMERALD)),
+					Offer(cItem(E_ITEM_CARROT, 15), cItem(E_ITEM_EMERALD))
+				},
+				{  // Tier 2
+					Offer(cItem(E_BLOCK_PUMPKIN, 8), cItem(E_ITEM_EMERALD)),
+					Offer(cItem(E_ITEM_EMERALD), cItem(E_ITEM_PUMPKIN_PIE, 2))
+				},
+				{  // Tier 3
+					Offer(cItem(E_BLOCK_MELON, 7), cItem(E_ITEM_EMERALD)),
+					Offer(cItem(E_ITEM_EMERALD), cItem(E_ITEM_RED_APPLE, 5))
+				},
+				{  // Tier 4
+					Offer(cItem(E_ITEM_EMERALD), cItem(E_ITEM_COOKIE, 6)),
+					Offer(cItem(E_ITEM_EMERALD), cItem(E_ITEM_CAKE))
+				}
+			}
+		},
+		{
+			VillagerCareer::Fisherman, {}
+		},
+		{
+			VillagerCareer::Shepherd, {}
+		},
+		{
+			VillagerCareer::Fletcher, {}
+		},
+		{
+			VillagerCareer::Librarian, {}
+		},
+		{
+			VillagerCareer::Cartographer, {}
+		},
+		{
+			VillagerCareer::Cleric, {}
+		},
+		{
+			VillagerCareer::Armorer, {}
+		},
+		{
+			VillagerCareer::WeaponSmith, {}
+		},
+		{
+			VillagerCareer::ToolSmith, {}
+		},
+		{
+			VillagerCareer::Butcher, {}
+		},
+		{
+			VillagerCareer::Leatherworker, {}
+		},
+		{
+			VillagerCareer::Nitwit, {}
+		}
+	};
+
+	auto Tiers = TradeMatrix.find(m_Career)->second;
+
+	m_TradeTier = std::min(Tiers.size(), DesiredTier);
+	m_TradeOffers.clear();
+
+	for (unsigned Tier = 0; Tier < m_TradeTier; Tier++)
+	{
+		m_TradeOffers.insert(m_TradeOffers.end(), Tiers[Tier].cbegin(), Tiers[Tier].cend());
+	}
+}
+
+
+
+
+
 bool cVillager::IsBlockFarmable(BLOCKTYPE a_BlockType)
 {
 	switch (a_BlockType)
diff --git a/src/Mobs/Villager.h b/src/Mobs/Villager.h
index 6f3e7b4e8..0d8672c46 100644
--- a/src/Mobs/Villager.h
+++ b/src/Mobs/Villager.h
@@ -3,37 +3,123 @@
 
 #include "PassiveMonster.h"
 #include "Blocks/ChunkInterface.h"
+#include "../UI/WindowOwner.h"
+
+
+
+
+
+struct VillagerTradeOffer
+{
+	VillagerTradeOffer(const cItem & PrimaryTradeDesire, const cItem & TradeRecompense) :
+		PrimaryDesire(PrimaryTradeDesire),
+		Recompense(TradeRecompense),
+		Transactions(0),
+		MaximumTransactions(10)
+	{
+	}
+
+	VillagerTradeOffer(const cItem & PrimaryTradeDesire, const cItem & SecondaryTradeDesire, const cItem & TradeRecompense) :
+		PrimaryDesire(PrimaryTradeDesire),
+		SecondaryDesire(SecondaryTradeDesire),
+		Recompense(TradeRecompense),
+		Transactions(0),
+		MaximumTransactions(10)
+	{
+	}
+
+	cItem PrimaryDesire;
+	cItem SecondaryDesire;
+	cItem Recompense;
+
+	bool IsTradeExhausted() const
+	{
+		return Transactions == MaximumTransactions;
+	}
+
+	unsigned Transactions;
+	unsigned MaximumTransactions;
+};
+
 
 
 
 
 class cVillager :
-	public cPassiveMonster
+	public cPassiveMonster,
+	public cEntityWindowOwner
 {
 	typedef cPassiveMonster super;
 
 public:
 
-	enum eVillagerType
+	enum class VillagerProfession
+	{
+		Farmer = 0,
+		Librarian = 1,
+		Priest = 2,
+		Blacksmith = 3,
+		Butcher = 4,
+		Nitwit = 5
+	};
+
+	enum class VillagerCareer
 	{
-		vtFarmer     = 0,
-		vtLibrarian  = 1,
-		vtPriest     = 2,
-		vtBlacksmith = 3,
-		vtButcher    = 4,
-		vtGeneric    = 5,
-		vtMax
-	} ;
+		Farmer,
+		Fisherman,
+		Shepherd,
+		Fletcher,
+		Librarian,
+		Cartographer,
+		Cleric,
+		Armorer,
+		WeaponSmith,
+		ToolSmith,
+		Butcher,
+		Leatherworker,
+		Nitwit
+	};
+
+	cVillager(VillagerCareer, unsigned);
+	CLASS_PROTODEF(cVillager)
 
-	cVillager(eVillagerType VillagerType);
+	/** Converts internal career to equivalent Vanilla profession.
+	Returns an enumeration with Vanilla-compatible values. */
+	static VillagerProfession VillagerCareerToProfession(VillagerCareer);
 
-	CLASS_PROTODEF(cVillager)
+	/** Returns the career of the villager. */
+	VillagerCareer GetCareer() const { return m_Career; }
+
+	/** Returns a trading offer of the villager subject to criteria.
+	If the player has selected the first trade offer, the first available trade offer matching the input is returned, or the first trade offer if nothing was found.
+	For any other offer selection, the selected offer is returned. */
+	VillagerTradeOffer & GetTradeOffer(unsigned, const cItem &, const cItem &);
+
+	/** Returns number of transactions of a single trade can be completed, given input and output items. */
+	static unsigned GetTransactionMultiplier(const VillagerTradeOffer &, const cItem &, const cItem &);
+
+	/** Handles events where players interact with an available trade.
+	This includes adding a desired item to fulfil or exceed the offer, or otherwise interacting with a trade when it can be performed. */
+	void HandleTradeAvailable() const;
+
+	/** Handles events where players interact with the trading window.
+	This event does not include interactions with the currently presented trade itself. */
+	void HandleTradeInProgress() const;
+
+	/** Handles events where players interact with an unavailable trade.
+	This includes adding a desired item to fulfil or exceed the offer, or otherwise interacting with a trade when it can be performed. */
+	void HandleTradeUnavailable() const;
+
+	/** Convenience function for setting correct item counts and upgrading trade tiers if necessary. */
+	void HandleTransaction(VillagerTradeOffer &, unsigned TransactionMultiplier);
 
 	// cEntity overrides
 	virtual bool DoTakeDamage(TakeDamageInfo & a_TDI) override;
-	virtual void Tick        (std::chrono::milliseconds a_Dt, cChunk & a_Chunk) override;
+	virtual void Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk) override;
+	virtual void OnRightClicked(cPlayer &) override;
+
+private:
 
-	// cVillager functions
 	/** return true if the given blocktype are: crops, potatoes or carrots. */
 	bool IsBlockFarmable(BLOCKTYPE a_BlockType);
 
@@ -48,19 +134,18 @@ public:
 	void HandleFarmerPlaceCrops();
 
 	// Get and set functions.
-	int      GetVilType(void)              const { return m_Type; }
-	Vector3i GetCropsPos(void)             const { return m_CropsPos; }
-	bool     DoesHaveActionActivated(void) const { return m_VillagerAction; }
+	Vector3i GetCropsPos(void) const { return m_CropsPos; }
+	bool DoesHaveActionActivated(void) const { return m_VillagerAction; }
 
-private:
+	/** Levels-up the villager to the given tier, if not already at maximum for their career.
+	Levelling-up unlocks additional trades available at that level, and re-enables all previously exhausted trade offers. */
+	void UpdateTradeTier(size_t);
 
 	int m_ActionCountDown;
-	int m_Type;
+	VillagerCareer m_Career;
+	size_t m_TradeTier;
+	std::vector<VillagerTradeOffer> m_TradeOffers;
 	bool m_VillagerAction;
 	Vector3i m_CropsPos;
 
-} ;
-
-
-
-
+};
diff --git a/src/Protocol/Protocol.h b/src/Protocol/Protocol.h
index 54c5b7223..ad6e00c04 100644
--- a/src/Protocol/Protocol.h
+++ b/src/Protocol/Protocol.h
@@ -33,6 +33,7 @@ class cFallingBlock;
 class cCompositeChat;
 class cStatManager;
 class cPacketizer;
+struct VillagerTradeOffer;
 
 
 
@@ -140,6 +141,7 @@ public:
 	virtual void SendUpdateBlockEntity          (cBlockEntity & a_BlockEntity) = 0;
 	virtual void SendUpdateSign                 (int a_BlockX, int a_BlockY, int a_BlockZ, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4) = 0;
 	virtual void SendUseBed                     (const cEntity & a_Entity, int a_BlockX, int a_BlockY, int a_BlockZ) = 0;
+	virtual void SendVillagerTradeList          (const cWindow &, const std::vector<VillagerTradeOffer> &) = 0;
 	virtual void SendWeather                    (eWeather a_Weather) = 0;
 	virtual void SendWholeInventory             (const cWindow    & a_Window) = 0;
 	virtual void SendWindowClose                (const cWindow    & a_Window) = 0;
diff --git a/src/Protocol/ProtocolRecognizer.cpp b/src/Protocol/ProtocolRecognizer.cpp
index cb2a4fc9d..e28b8ae5c 100644
--- a/src/Protocol/ProtocolRecognizer.cpp
+++ b/src/Protocol/ProtocolRecognizer.cpp
@@ -957,6 +957,16 @@ void cProtocolRecognizer::SendUseBed(const cEntity & a_Entity, int a_BlockX, int
 
 
 
+void cProtocolRecognizer::SendVillagerTradeList(const cWindow & TradeWindow, const std::vector<VillagerTradeOffer> & TradeOffers)
+{
+	ASSERT(m_Protocol != nullptr);
+	m_Protocol->SendVillagerTradeList(TradeWindow, TradeOffers);
+}
+
+
+
+
+
 void cProtocolRecognizer::SendWeather(eWeather a_Weather)
 {
 	ASSERT(m_Protocol != nullptr);
diff --git a/src/Protocol/ProtocolRecognizer.h b/src/Protocol/ProtocolRecognizer.h
index 295c6db16..17347d4a9 100644
--- a/src/Protocol/ProtocolRecognizer.h
+++ b/src/Protocol/ProtocolRecognizer.h
@@ -136,6 +136,7 @@ public:
 	virtual void SendUpdateBlockEntity          (cBlockEntity & a_BlockEntity) override;
 	virtual void SendUpdateSign                 (int a_BlockX, int a_BlockY, int a_BlockZ, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4) override;
 	virtual void SendUseBed                     (const cEntity & a_Entity, int a_BlockX, int a_BlockY, int a_BlockZ) override;
+	virtual void SendVillagerTradeList          (const cWindow &, const std::vector<VillagerTradeOffer> &) override;
 	virtual void SendWeather                    (eWeather a_Weather) override;
 	virtual void SendWholeInventory             (const cWindow & a_Window) override;
 	virtual void SendWindowClose                (const cWindow & a_Window) override;
diff --git a/src/Protocol/Protocol_1_10.cpp b/src/Protocol/Protocol_1_10.cpp
index 7f86d4bdc..2cb9d415b 100644
--- a/src/Protocol/Protocol_1_10.cpp
+++ b/src/Protocol/Protocol_1_10.cpp
@@ -916,7 +916,7 @@ void cProtocol_1_10_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_
 
 			a_Pkt.WriteBEUInt8(VILLAGER_PROFESSION);
 			a_Pkt.WriteBEUInt8(METADATA_TYPE_VARINT);
-			a_Pkt.WriteVarInt32(static_cast<UInt32>(Villager.GetVilType()));
+			a_Pkt.WriteVarInt32(static_cast<UInt32>(cVillager::VillagerCareerToProfession(Villager.GetCareer())));
 			break;
 		}  // case mtVillager
 
diff --git a/src/Protocol/Protocol_1_11.cpp b/src/Protocol/Protocol_1_11.cpp
index b9b6e9ac3..e1d512d0b 100644
--- a/src/Protocol/Protocol_1_11.cpp
+++ b/src/Protocol/Protocol_1_11.cpp
@@ -1076,7 +1076,7 @@ void cProtocol_1_11_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_
 
 			a_Pkt.WriteBEUInt8(VILLAGER_PROFESSION);
 			a_Pkt.WriteBEUInt8(METADATA_TYPE_VARINT);
-			a_Pkt.WriteVarInt32(static_cast<UInt32>(Villager.GetVilType()));
+			a_Pkt.WriteVarInt32(static_cast<UInt32>(cVillager::VillagerCareerToProfession(Villager.GetCareer())));
 			break;
 		}  // case mtVillager
 
diff --git a/src/Protocol/Protocol_1_12.cpp b/src/Protocol/Protocol_1_12.cpp
index a8e38a4e0..6e2ef5daa 100644
--- a/src/Protocol/Protocol_1_12.cpp
+++ b/src/Protocol/Protocol_1_12.cpp
@@ -889,7 +889,7 @@ void cProtocol_1_12::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_Mo
 
 			a_Pkt.WriteBEUInt8(VILLAGER_PROFESSION);
 			a_Pkt.WriteBEUInt8(METADATA_TYPE_VARINT);
-			a_Pkt.WriteVarInt32(static_cast<UInt32>(Villager.GetVilType()));
+			a_Pkt.WriteVarInt32(static_cast<UInt32>(cVillager::VillagerCareerToProfession(Villager.GetCareer())));
 			break;
 		}  // case mtVillager
 
diff --git a/src/Protocol/Protocol_1_8.cpp b/src/Protocol/Protocol_1_8.cpp
index b6e5b5a38..0a0073b21 100644
--- a/src/Protocol/Protocol_1_8.cpp
+++ b/src/Protocol/Protocol_1_8.cpp
@@ -1597,6 +1597,15 @@ void cProtocol_1_8_0::SendUseBed(const cEntity & a_Entity, int a_BlockX, int a_B
 
 
 
+void cProtocol_1_8_0::SendVillagerTradeList(const cWindow &, const std::vector<VillagerTradeOffer> &)
+{
+	// Unimplemented
+}
+
+
+
+
+
 void cProtocol_1_8_0::SendWeather(eWeather a_Weather)
 {
 	ASSERT(m_State == 3);  // In game mode?
@@ -3577,7 +3586,7 @@ void cProtocol_1_8_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_M
 		{
 			auto & Villager = reinterpret_cast<const cVillager &>(a_Mob);
 			a_Pkt.WriteBEUInt8(0x50);
-			a_Pkt.WriteBEInt32(Villager.GetVilType());
+			a_Pkt.WriteBEInt32(static_cast<Int32>(cVillager::VillagerCareerToProfession(Villager.GetCareer())));
 			a_Pkt.WriteBEUInt8(0x0c);
 			a_Pkt.WriteBEInt8(Villager.IsBaby() ? -1 : 0);
 			break;
diff --git a/src/Protocol/Protocol_1_8.h b/src/Protocol/Protocol_1_8.h
index d3d0daf0a..47a7549d3 100644
--- a/src/Protocol/Protocol_1_8.h
+++ b/src/Protocol/Protocol_1_8.h
@@ -129,6 +129,7 @@ public:
 	virtual void SendUpdateBlockEntity          (cBlockEntity & a_BlockEntity) override;
 	virtual void SendUpdateSign                 (int a_BlockX, int a_BlockY, int a_BlockZ, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4) override;
 	virtual void SendUseBed                     (const cEntity & a_Entity, int a_BlockX, int a_BlockY, int a_BlockZ) override;
+	virtual void SendVillagerTradeList          (const cWindow &, const std::vector<VillagerTradeOffer> &) override;
 	virtual void SendWeather                    (eWeather a_Weather) override;
 	virtual void SendWholeInventory             (const cWindow & a_Window) override;
 	virtual void SendWindowClose                (const cWindow & a_Window) override;
diff --git a/src/Protocol/Protocol_1_9.cpp b/src/Protocol/Protocol_1_9.cpp
index 475047417..08f883102 100644
--- a/src/Protocol/Protocol_1_9.cpp
+++ b/src/Protocol/Protocol_1_9.cpp
@@ -1642,6 +1642,40 @@ void cProtocol_1_9_0::SendUseBed(const cEntity & a_Entity, int a_BlockX, int a_B
 
 
 
+void cProtocol_1_9_0::SendVillagerTradeList(const cWindow & TradeWindow, const std::vector<VillagerTradeOffer> & TradeOffers)
+{
+	ASSERT(m_State == 3);  // In game mode?
+
+	cPacketizer Pkt(*this, 0x18);  // Plugin message
+	Pkt.WriteString("MC|TrList");
+	Pkt.WriteBEInt32(static_cast<Int32>(TradeWindow.GetWindowID()));
+	Pkt.WriteBEUInt8(static_cast<UInt8>(TradeOffers.size()));
+
+	for (const auto & Trade : TradeOffers)
+	{
+		WriteItem(Pkt, Trade.PrimaryDesire);
+		WriteItem(Pkt, Trade.Recompense);
+
+		if (Trade.SecondaryDesire.IsEmpty())
+		{
+			Pkt.WriteBool(false);
+		}
+		else
+		{
+			Pkt.WriteBool(true);
+			WriteItem(Pkt, Trade.SecondaryDesire);
+		}
+
+		Pkt.WriteBool(Trade.IsTradeExhausted());
+		Pkt.WriteBEInt32(static_cast<Int32>(Trade.Transactions));
+		Pkt.WriteBEInt32(static_cast<Int32>(Trade.MaximumTransactions));
+	}
+}
+
+
+
+
+
 void cProtocol_1_9_0::SendWeather(eWeather a_Weather)
 {
 	ASSERT(m_State == 3);  // In game mode?
@@ -4044,7 +4078,7 @@ void cProtocol_1_9_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_M
 
 			a_Pkt.WriteBEUInt8(12);  // Index 12: Type
 			a_Pkt.WriteBEUInt8(METADATA_TYPE_VARINT);
-			a_Pkt.WriteVarInt32(static_cast<UInt32>(Villager.GetVilType()));
+			a_Pkt.WriteVarInt32(static_cast<UInt32>(cVillager::VillagerCareerToProfession(Villager.GetCareer())));
 			break;
 		}  // case mtVillager
 
diff --git a/src/Protocol/Protocol_1_9.h b/src/Protocol/Protocol_1_9.h
index 3fbbe86da..aae77fec8 100644
--- a/src/Protocol/Protocol_1_9.h
+++ b/src/Protocol/Protocol_1_9.h
@@ -135,6 +135,7 @@ public:
 	virtual void SendUpdateBlockEntity          (cBlockEntity & a_BlockEntity) override;
 	virtual void SendUpdateSign                 (int a_BlockX, int a_BlockY, int a_BlockZ, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4) override;
 	virtual void SendUseBed                     (const cEntity & a_Entity, int a_BlockX, int a_BlockY, int a_BlockZ) override;
+	virtual void SendVillagerTradeList          (const cWindow &, const std::vector<VillagerTradeOffer> &) override;
 	virtual void SendWeather                    (eWeather a_Weather) override;
 	virtual void SendWholeInventory             (const cWindow & a_Window) override;
 	virtual void SendWindowClose                (const cWindow & a_Window) override;
diff --git a/src/UI/CMakeLists.txt b/src/UI/CMakeLists.txt
index d71e08ade..8d7848756 100644
--- a/src/UI/CMakeLists.txt
+++ b/src/UI/CMakeLists.txt
@@ -32,6 +32,7 @@ SET (HDRS
 	HopperWindow.h
 	InventoryWindow.h
 	MinecartWithChestWindow.h
+	VillagerTradeWindow.h
 	WindowOwner.h)
 
 if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
diff --git a/src/UI/SlotArea.cpp b/src/UI/SlotArea.cpp
index 94fd958d5..94b059fb9 100644
--- a/src/UI/SlotArea.cpp
+++ b/src/UI/SlotArea.cpp
@@ -6,6 +6,7 @@
 #include "Globals.h"
 #include "SlotArea.h"
 #include "../Entities/Player.h"
+#include "../Mobs/Villager.h"
 #include "../BlockEntities/BeaconEntity.h"
 #include "../BlockEntities/BrewingstandEntity.h"
 #include "../BlockEntities/ChestEntity.h"
@@ -15,6 +16,7 @@
 #include "../Entities/Minecart.h"
 #include "../Items/ItemHandler.h"
 #include "AnvilWindow.h"
+#include "VillagerTradeWindow.h"
 #include "../CraftingRecipes.h"
 #include "../Root.h"
 #include "../FastRandom.h"
@@ -235,16 +237,11 @@ void cSlotArea::ShiftClicked(cPlayer & a_Player, int a_SlotNum, const cItem & a_
 
 void cSlotArea::DblClicked(cPlayer & a_Player, int a_SlotNum)
 {
+	// Assume single-click was sent first
+
 	cItem & Dragging = a_Player.GetDraggingItem();
 	if (Dragging.IsEmpty())
 	{
-		// Move the item in the dblclicked slot into hand:
-		Dragging = *GetSlot(a_SlotNum, a_Player);
-		cItem EmptyItem;
-		SetSlot(a_SlotNum, a_Player, EmptyItem);
-	}
-	if (Dragging.IsEmpty())
-	{
 		LOGD("%s DblClicked with an empty hand over empty slot, ignoring", a_Player.GetName().c_str());
 		return;
 	}
@@ -2217,6 +2214,216 @@ void cSlotAreaMinecartWithChest::SetSlot(int a_SlotNum, cPlayer & a_Player, cons
 
 
 ////////////////////////////////////////////////////////////////////////////////
+// cSlotAreaVillagerTrade:
+
+cSlotAreaVillagerTrade::cSlotAreaVillagerTrade(cVillager & Villager, cWindow & ParentWindow) :
+	cSlotAreaTemporary(3, ParentWindow),
+	m_Villager(Villager)
+{
+}
+
+
+
+
+
+void cSlotAreaVillagerTrade::UpdateTrade(const cPlayer & TradingPlayer)
+{
+	const auto & Contents = GetPlayerSlots(TradingPlayer);
+	const auto & Trade = m_Villager.GetTradeOffer(
+		static_cast<cVillagerTradeWindow *>(&m_ParentWindow)->GetPlayerTradeOfferIndex(TradingPlayer),
+		Contents[SlotIndices::PrimaryDesire],
+		Contents[SlotIndices::SecondaryDesire]
+	);
+	const auto TransactionMultiplier = cVillager::GetTransactionMultiplier(Trade, Contents[SlotIndices::PrimaryDesire], Contents[SlotIndices::SecondaryDesire]);
+
+	if (TransactionMultiplier != 0)
+	{
+		cItem Recompense(Trade.Recompense);
+		Recompense.m_ItemCount *= TransactionMultiplier;
+		Contents[SlotIndices::Recompense] = Recompense;
+	}
+	else
+	{
+		Contents[SlotIndices::Recompense].Empty();
+	}
+}
+
+
+
+
+
+void cSlotAreaVillagerTrade::SetSlot(int ActionIndex, cPlayer & TradingPlayer, const cItem & Item)
+{
+	const auto & Contents = GetPlayerSlots(TradingPlayer);
+	const auto & RecompenseSlot = Contents[SlotIndices::Recompense];
+
+	if ((ActionIndex == SlotIndices::Recompense) && !RecompenseSlot.IsEmpty())
+	{
+		// Player clicked recompense slot. Slot was populated, meaning the trade can go ahead.
+		// Note that parameter Item holds the new remaining count of compensation items (if any)
+
+		auto & Trade = m_Villager.GetTradeOffer(
+			static_cast<cVillagerTradeWindow *>(&m_ParentWindow)->GetPlayerTradeOfferIndex(TradingPlayer),
+			Contents[SlotIndices::PrimaryDesire],
+			Contents[SlotIndices::SecondaryDesire]
+		);
+		const auto ActualTransactionMultiplier = static_cast<unsigned>((RecompenseSlot.m_ItemCount - Item.m_ItemCount) / Trade.Recompense.m_ItemCount);
+
+		if (ActualTransactionMultiplier == 0)
+		{
+			// Not strictly needed in terms of preserving item count integrity but nothing will change so exit early
+			// Prevents associated villager from responding to a "trade" with no items exchanged
+			return;
+		}
+
+		if (Contents[SlotIndices::PrimaryDesire].IsEmpty())
+		{
+			// (Given that a trade can be made), player must have placed primary desire into secondary slot
+
+			ASSERT(Trade.SecondaryDesire.IsEmpty());
+			Contents[SlotIndices::SecondaryDesire].m_ItemCount -= Trade.PrimaryDesire.m_ItemCount * static_cast<char>(ActualTransactionMultiplier);
+		}
+		else
+		{
+			// Primary\secondary desire\offer slots match up respectively
+
+			Contents[SlotIndices::PrimaryDesire].m_ItemCount -= Trade.PrimaryDesire.m_ItemCount * static_cast<char>(ActualTransactionMultiplier);
+			Contents[SlotIndices::SecondaryDesire].m_ItemCount -= Trade.SecondaryDesire.m_ItemCount * static_cast<char>(ActualTransactionMultiplier);
+		}
+
+		m_Villager.HandleTransaction(Trade, ActualTransactionMultiplier);
+	}
+
+	super::SetSlot(ActionIndex, TradingPlayer, Item);
+}
+
+
+
+
+
+void cSlotAreaVillagerTrade::OnPlayerRemoved(cPlayer & Player)
+{
+	TossItems(Player, SlotIndices::PrimaryDesire, SlotIndices::SecondaryDesire);
+	super::OnPlayerRemoved(Player);
+}
+
+
+
+
+
+void cSlotAreaVillagerTrade::Clicked(cPlayer & Player, int SlotNumber, eClickAction ClickAction, const cItem & ClickedItem)
+{
+	auto & DraggingItem = Player.GetDraggingItem();
+	if (
+		(SlotNumber == SlotIndices::Recompense) &&
+		((ClickAction == eClickAction::caLeftClick) || (ClickAction == eClickAction::caRightClick))
+	)
+	{
+		cItem RecompenseSlot = *GetSlot(SlotIndices::Recompense, Player);
+		if (RecompenseSlot.IsEmpty())
+		{
+			// No trade possible right now
+			return;
+		}
+
+		// Single clicking on recompense slot should transfer one transaction's worth of items to the hand
+		// As long as there is no dragging item or the dragging item is of the same type as the compensation
+
+		const auto MoveCount = m_Villager.GetTradeOffer(
+			static_cast<cVillagerTradeWindow *>(&m_ParentWindow)->GetPlayerTradeOfferIndex(Player),
+			*GetSlot(SlotIndices::PrimaryDesire, Player),
+			*GetSlot(SlotIndices::SecondaryDesire, Player)
+		).Recompense.m_ItemCount;
+		if (DraggingItem.IsEmpty())
+		{
+			DraggingItem = RecompenseSlot;
+			DraggingItem.m_ItemCount = MoveCount;
+			RecompenseSlot.m_ItemCount -= MoveCount;
+			SetSlot(SlotIndices::Recompense, Player, RecompenseSlot);  // Perform transaction
+		}
+		else if (DraggingItem.IsEqual(RecompenseSlot))
+		{
+			if (DraggingItem.GetMaxStackSize() < (DraggingItem.m_ItemCount + MoveCount))
+			{
+				return;
+			}
+
+			DraggingItem.m_ItemCount += MoveCount;
+			RecompenseSlot.m_ItemCount -= MoveCount;
+			SetSlot(SlotIndices::Recompense, Player, RecompenseSlot);  // Perform transaction
+		}
+
+		return;
+	}
+
+	super::Clicked(Player, SlotNumber, ClickAction, ClickedItem);
+	UpdateTrade(Player);
+
+	if (GetSlot(SlotIndices::Recompense, Player)->IsEmpty())
+	{
+		m_Villager.HandleTradeUnavailable();
+	}
+	else
+	{
+		m_Villager.HandleTradeAvailable();
+	}
+}
+
+
+
+
+
+void cSlotAreaVillagerTrade::NumberClicked(cPlayer & Player, int SlotNumber, eClickAction ClickAction)
+{
+	if (SlotNumber != SlotIndices::Recompense)
+	{
+		super::NumberClicked(Player, SlotNumber, ClickAction);
+		return;
+	}
+
+	int HotbarSlotIndex = static_cast<int>(ClickAction - caNumber1);
+	cItem HotbarSlot(Player.GetInventory().GetHotbarSlot(HotbarSlotIndex));
+	cItem RecompenseSlot(*GetSlot(SlotNumber, Player));
+
+	if (!HotbarSlot.IsEmpty())
+	{
+		// Prevent items being inserted into trade compensation slot
+		return;
+	}
+
+	const auto MoveCount = m_Villager.GetTradeOffer(
+		static_cast<cVillagerTradeWindow *>(&m_ParentWindow)->GetPlayerTradeOfferIndex(Player),
+		*GetSlot(SlotIndices::PrimaryDesire, Player),
+		*GetSlot(SlotIndices::SecondaryDesire, Player)
+	).Recompense.m_ItemCount;
+
+	HotbarSlot = RecompenseSlot;
+	HotbarSlot.m_ItemCount = MoveCount;
+	RecompenseSlot.m_ItemCount -= MoveCount;
+
+	Player.GetInventory().SetHotbarSlot(HotbarSlotIndex, HotbarSlot);
+	SetSlot(SlotNumber, Player, RecompenseSlot);
+}
+
+
+
+
+
+void cSlotAreaVillagerTrade::DblClicked(cPlayer & Player, int SlotNumber)
+{
+	if (SlotNumber == SlotIndices::Recompense)
+	{
+		return;
+	}
+
+	super::DblClicked(Player, SlotNumber);
+}
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
 // cSlotAreaInventoryBase:
 
 cSlotAreaInventoryBase::cSlotAreaInventoryBase(int a_NumSlots, int a_SlotOffset, cWindow & a_ParentWindow) :
@@ -2579,7 +2786,7 @@ void cSlotAreaTemporary::TossItems(cPlayer & a_Player, int a_Begin, int a_End)
 
 
 
-cItem * cSlotAreaTemporary::GetPlayerSlots(cPlayer & a_Player)
+cItem * cSlotAreaTemporary::GetPlayerSlots(const cPlayer & a_Player)
 {
 	cItemMap::iterator itr = m_Items.find(a_Player.GetUniqueID());
 	if (itr == m_Items.end())
diff --git a/src/UI/SlotArea.h b/src/UI/SlotArea.h
index be21cdada..99075aad7 100644
--- a/src/UI/SlotArea.h
+++ b/src/UI/SlotArea.h
@@ -22,6 +22,7 @@ class cChestEntity;
 class cEnderChestEntity;
 class cFurnaceEntity;
 class cMinecartWithChest;
+class cVillager;
 class cCraftingRecipe;
 class cWorld;
 
@@ -238,7 +239,7 @@ protected:
 	cItemMap m_Items;
 
 	/** Returns the pointer to the slot array for the player specified. */
-	cItem * GetPlayerSlots(cPlayer & a_Player);
+	cItem * GetPlayerSlots(const cPlayer & a_Player);
 } ;
 
 
@@ -498,7 +499,7 @@ protected:
 
 	/** Called after an item has been brewed to handle statistics etc. */
 	void HandleBrewedItem(cPlayer & a_Player, const cItem & a_ClickedItem);
-} ;
+};
 
 
 
@@ -520,3 +521,48 @@ protected:
 
 
 
+
+class cSlotAreaVillagerTrade :
+	public cSlotAreaTemporary
+{
+	typedef cSlotAreaTemporary super;
+
+public:
+	cSlotAreaVillagerTrade(cVillager & Villager, cWindow & a_ParentWindow);
+
+	/** Handles player interaction with a given trade.
+	Sets appropriate item counts based on input counts and output types. */
+	void UpdateTrade(const cPlayer &);
+
+protected:
+
+	enum SlotIndices : unsigned
+	{
+		PrimaryDesire = 0,
+		SecondaryDesire = 1,
+		Recompense = 2
+	};
+
+	/** Override to respond to attempted trades.
+	Updates primary and secondary desire counts, assuming that they are correctly set for the given trade.
+	Informs the associated villager of the transaction. */
+	virtual void SetSlot(int, cPlayer &, const cItem &) override;
+
+	/** Override to toss all items in the trading window on player exit. */
+	virtual void OnPlayerRemoved(cPlayer &) override;
+
+	/** Override to update the trade items and inform the associated villager of the trading status. */
+	virtual void Clicked(cPlayer &, int, eClickAction, const cItem &) override;
+
+	/** Override to disable transferral of the compensation item to an already populated hotbar slot.
+	Default behaviour when destination hotbar slot is populated is to swap the source and destination, but this is not possible since the compensation slot cannot be backfilled. */
+	virtual void NumberClicked(cPlayer &, int, eClickAction) override;
+
+	/** Override to disable double-click behaviour for the compensation slot. */
+	virtual void DblClicked(cPlayer &, int) override;
+
+	/** Override to prevent distribution of items into the trading window. */
+	virtual void DistributeStack(cItem &, cPlayer &, bool, bool, bool) override {}
+
+	cVillager & m_Villager;
+};
diff --git a/src/UI/VillagerTradeWindow.h b/src/UI/VillagerTradeWindow.h
new file mode 100644
index 000000000..ec5ea26e7
--- /dev/null
+++ b/src/UI/VillagerTradeWindow.h
@@ -0,0 +1,74 @@
+
+#pragma once
+
+#include "Window.h"
+#include "SlotArea.h"
+#include "../Mobs/Villager.h"
+
+
+
+
+
+class cVillagerTradeWindow :
+	public cWindow
+{
+	typedef cWindow super;
+
+public:
+	cVillagerTradeWindow(cVillager & Villager) :
+		cWindow(wtVillagerTrade, Printf("Villager № %i", Villager.GetUniqueID())),
+		m_Villager(Villager)
+	{
+		m_SlotAreas.push_back(new cSlotAreaVillagerTrade(m_Villager, *this));
+		m_SlotAreas.push_back(new cSlotAreaInventory(*this));
+		m_SlotAreas.push_back(new cSlotAreaHotBar(*this));
+	}
+
+	virtual void DistributeStack(cItem & a_ItemStack, int a_Slot, cPlayer & a_Player, cSlotArea * a_ClickedArea, bool a_ShouldApply) override
+	{
+		cSlotAreas AreasInOrder;
+
+		if (a_ClickedArea == m_SlotAreas[0])
+		{
+			// Trading Area
+			AreasInOrder.push_back(m_SlotAreas[1]);  /* Inventory */
+			AreasInOrder.push_back(m_SlotAreas[2]);  /* Hotbar */
+			super::DistributeStackToAreas(a_ItemStack, a_Player, AreasInOrder, a_ShouldApply, true);
+		}
+		else if (a_ClickedArea == m_SlotAreas[1])
+		{
+			// Inventory
+			AreasInOrder.push_back(m_SlotAreas[2]);  /* Hotbar */
+			super::DistributeStackToAreas(a_ItemStack, a_Player, AreasInOrder, a_ShouldApply, true);
+		}
+		else
+		{
+			// Hotbar
+			AreasInOrder.push_back(m_SlotAreas[1]);  /* Inventory */
+			super::DistributeStackToAreas(a_ItemStack, a_Player, AreasInOrder, a_ShouldApply, true);
+		}
+	}
+
+	virtual void OpenedByPlayer(cPlayer & Player) override
+	{
+		super::OpenedByPlayer(Player);
+		m_TradeIndexOpenedByPlayer[&Player] = 0;
+		m_Villager.HandleTradeInProgress();
+	}
+
+	void PlayerChangedTradeOffer(const cPlayer & Player, unsigned NewIndex)
+	{
+		m_TradeIndexOpenedByPlayer[&Player] = NewIndex;
+		static_cast<cSlotAreaVillagerTrade *>(m_SlotAreas[0])->UpdateTrade(Player);
+		m_Villager.HandleTradeInProgress();
+	}
+
+	unsigned GetPlayerTradeOfferIndex(const cPlayer & Player)
+	{
+		return m_TradeIndexOpenedByPlayer[&Player];
+	}
+
+private:
+	cVillager & m_Villager;
+	std::unordered_map<const cPlayer *, unsigned> m_TradeIndexOpenedByPlayer;
+};
diff --git a/src/UI/Window.cpp b/src/UI/Window.cpp
index 8bbc4f482..52364b287 100644
--- a/src/UI/Window.cpp
+++ b/src/UI/Window.cpp
@@ -71,7 +71,7 @@ const AString cWindow::GetWindowTypeName(void) const
 		case wtDropSpenser: return "minecraft:dispenser";
 		case wtEnchantment: return "minecraft:enchanting_table";
 		case wtBrewery:     return "minecraft:brewing_stand";
-		case wtNPCTrade:    return "minecraft:villager";
+		case wtVillagerTrade: return "minecraft:villager";
 		case wtBeacon:      return "minecraft:beacon";
 		case wtAnvil:       return "minecraft:anvil";
 		case wtHopper:      return "minecraft:hopper";
diff --git a/src/UI/Window.h b/src/UI/Window.h
index d7a29dc47..c834eb0ed 100644
--- a/src/UI/Window.h
+++ b/src/UI/Window.h
@@ -60,7 +60,7 @@ public:
 		wtDropSpenser = 3,  // Dropper or Dispenser
 		wtEnchantment = 4,
 		wtBrewery     = 5,
-		wtNPCTrade    = 6,
+		wtVillagerTrade = 6,
 		wtBeacon      = 7,
 		wtAnvil       = 8,
 		wtHopper      = 9,
diff --git a/src/WorldStorage/NBTChunkSerializer.cpp b/src/WorldStorage/NBTChunkSerializer.cpp
index 1e8543648..5011075f1 100644
--- a/src/WorldStorage/NBTChunkSerializer.cpp
+++ b/src/WorldStorage/NBTChunkSerializer.cpp
@@ -664,8 +664,9 @@ void cNBTChunkSerializer::AddMonsterEntity(cMonster * a_Monster)
 			case mtVillager:
 			{
 				const cVillager *Villager = reinterpret_cast<const cVillager *>(a_Monster);
-				m_Writer.AddInt("Profession", Villager->GetVilType());
-				m_Writer.AddInt("Age",        Villager->GetAge());
+				m_Writer.AddInt("Profession", static_cast<Int32>(cVillager::VillagerCareerToProfession(Villager->GetCareer())));
+				m_Writer.AddInt("Career", static_cast<Int32>(Villager->GetCareer()));
+				m_Writer.AddInt("Age", Villager->GetAge());
 				break;
 			}
 			case mtWither:
diff --git a/src/WorldStorage/WSSAnvil.cpp b/src/WorldStorage/WSSAnvil.cpp
index a3251481f..774699b8f 100755
--- a/src/WorldStorage/WSSAnvil.cpp
+++ b/src/WorldStorage/WSSAnvil.cpp
@@ -2837,9 +2837,13 @@ void cWSSAnvil::LoadVillagerFromNBT(cEntityList & a_Entities, const cParsedNBT &
 		return;
 	}
 
-	int Type = a_NBT.GetInt(TypeIdx);
+	int CareerIdx = a_NBT.FindChildByName(a_TagIdx, "Career");
+	if (CareerIdx < 0)
+	{
+		return;
+	}
 
-	std::unique_ptr<cVillager> Monster = cpp14::make_unique<cVillager>(cVillager::eVillagerType(Type));
+	std::unique_ptr<cVillager> Monster = cpp14::make_unique<cVillager>(cVillager::VillagerCareer(a_NBT.GetInt(TypeIdx)), 1U);
 	if (!LoadEntityBaseFromNBT(*Monster.get(), a_NBT, a_TagIdx))
 	{
 		return;