Adds support for villager trading (#1316)

* adds villager trading support
Adds handler for tradeList packet and selectTrade packet
* added extra line at end
* removed tab; removed size and hasSecondItem
removed a mistakenly added tab instead of 4 spaces. SelectTrade was already added in 1.13. Removed unnecessary size and hasSecondItem from trade dataType.
* Added VillagerInfo class and capitalized vars in Trade class
* Update VillagerInfo.cs
* Small formatting/naming adjustments
Co-authored-by: ORelio <ORelio@users.noreply.github.com>

MinecraftClient/ChatBot.cs

@@ -220,7 +220,15 @@ namespace MinecraftClient
         /// <param name="locked"></param>
         /// <param name="iconcount"></param>
         public virtual void OnMapData(int mapid, byte scale, bool trackingposition, bool locked, int iconcount) { }
-        
+
+        /// <summary>
+        /// Called when tradeList is received from server
+        /// </summary>
+        /// <param name="windowID">Window ID</param>
+        /// <param name="trades">List of trades.</param>
+        /// <param name="villagerInfo">Contains Level, Experience, IsRegularVillager and CanRestock .</param>
+        public virtual void OnTradeList(int windowID, List<VillagerTrade> trades, VillagerInfo villagerInfo) { }
+
         /// <summary>
         /// Called when received a title from the server
         /// <param name="action"> 0 = set title, 1 = set subtitle, 3 = set action bar, 4 = set times and display, 4 = hide, 5 = reset</param>
@@ -1225,6 +1233,15 @@ namespace MinecraftClient
         {
             return Handler.UpdateSign(location, line1, line2, line3, line4);
         }
+
+        /// <summary>
+        /// Selects villager trade
+        /// </summary>
+        /// <param name="selectedSlot">Trade slot to select, starts at 0.</param>
+        protected bool SelectTrade(int selectedSlot)
+        {
+            return Handler.SelectTrade(selectedSlot);
+        }
         
         /// <summary>
         /// Update command block

MinecraftClient/Inventory/VillagerInfo.cs

@@ -0,0 +1,13 @@
+namespace MinecraftClient.Mapping
+{
+    /// <summary>
+    /// Properties of a villager
+    /// </summary>
+    public class VillagerInfo
+    {
+        public int Level { get; set; }
+        public int Experience { get; set; }
+        public bool IsRegularVillager { get; set; }
+        public bool CanRestock { get; set; }
+    }
+}

MinecraftClient/Inventory/VillagerTrade.cs

@@ -0,0 +1,33 @@
+namespace MinecraftClient.Inventory
+{
+    /// <summary>
+    /// Represents a trade of a villager
+    /// </summary>
+    public class VillagerTrade
+    {
+        public Item InputItem1;
+        public Item OutputItem;
+        public Item InputItem2;
+        public bool TradeDisabled;
+        public int NumberOfTradeUses;
+        public int MaximumNumberOfTradeUses;
+        public int Xp;
+        public int SpecialPrice;
+        public float PriceMultiplier;
+        public int Demand;
+
+        public VillagerTrade(Item inputItem1, Item outputItem, Item inputItem2, bool tradeDisabled, int numberOfTradeUses, int maximumNumberOfTradeUses, int xp, int specialPrice, float priceMultiplier, int demand)
+        {
+            this.InputItem1 = inputItem1;
+            this.OutputItem = outputItem;
+            this.InputItem2 = inputItem2;
+            this.TradeDisabled = tradeDisabled;
+            this.NumberOfTradeUses = numberOfTradeUses;
+            this.MaximumNumberOfTradeUses = maximumNumberOfTradeUses;
+            this.Xp = xp;
+            this.SpecialPrice = specialPrice;
+            this.PriceMultiplier = priceMultiplier;
+            this.Demand = demand;
+        }
+    }
+}

MinecraftClient/Mapping/VillagerInfo.cs

@@ -0,0 +1,13 @@
+namespace MinecraftClient
+{
+    /// <summary>
+    /// Information of a villager
+    /// </summary>
+    public class VillagerInfo
+    {
+        public int Level { get; set; }
+        public int Experience { get; set; }
+        public bool IsRegularVillager { get; set; }
+        public bool CanRestock { get; set; }
+    }
+}

MinecraftClient/McClient.cs

@@ -1449,6 +1449,15 @@ namespace MinecraftClient
             // TODO Open sign editor first https://wiki.vg/Protocol#Open_Sign_Editor
             return handler.SendUpdateSign(location, line1, line2, line3, line4);
         }
+
+        /// <summary>
+        /// Select villager trade
+        /// </summary>
+        /// <param name="selectedSlot">The slot of the trade, starts at 0.</param>
+        public bool SelectTrade(int selectedSlot)
+        {
+            return handler.SelectTrade(selectedSlot);
+        }
         
         /// <summary>
         /// Update command block
@@ -2246,6 +2255,18 @@ namespace MinecraftClient
                 DispatchBotEvent(bot => bot.OnEntityMetadata(entity, metadata));
             }
         }
+
+        /// <summary>
+        /// Called when tradeList is recieved after interacting with villager
+        /// </summary>
+        /// <param name="windowID">Window ID</param>
+        /// <param name="trades">List of trades.</param>
+        /// <param name="villagerInfo">Contains Level, Experience, IsRegularVillager and CanRestock .</param>
+        public void OnTradeList(int windowID, List<VillagerTrade> trades, VillagerInfo villagerInfo)
+        {
+            DispatchBotEvent(bot => bot.OnTradeList(windowID, trades, villagerInfo));
+        }
+
         #endregion
     }
 }

MinecraftClient/MinecraftClient.csproj

@@ -212,8 +212,10 @@
     <Compile Include="Protocol\Handlers\SocketWrapper.cs" />
     <Compile Include="Protocol\DataTypeGenerator.cs" />
     <Compile Include="FileMonitor.cs" />
+    <Compile Include="Inventory\VillagerTrade.cs" />
     <Compile Include="Protocol\ReplayHandler.cs" />
     <Compile Include="Translations.cs" />
+    <Compile Include="Inventory\VillagerInfo.cs" />
     <Compile Include="WinAPI\ConsoleIcon.cs" />
     <Compile Include="ConsoleIO.cs" />
     <Compile Include="Crypto\Streams\BouncyAes\AesFastEngine.cs" />

MinecraftClient/Protocol/Handlers/DataTypes.cs

@@ -610,6 +610,29 @@ namespace MinecraftClient.Protocol.Handlers
             return data;
         }
 
+        /// <summary>
+        /// Read a single villager trade from a cache of bytes and remove it from the cache
+        /// </summary>
+        /// <returns>The item that was read or NULL for an empty slot</returns>
+        public VillagerTrade ReadNextTrade(Queue<byte> cache, ItemPalette itemPalette)
+        {
+            Item inputItem1 = ReadNextItemSlot(cache, itemPalette);
+            Item outputItem = ReadNextItemSlot(cache, itemPalette);
+            Item inputItem2 = null;
+            if (ReadNextBool(cache)) //check if villager has second item
+            {
+                inputItem2 = ReadNextItemSlot(cache, itemPalette);
+            }
+            bool tradeDisabled = ReadNextBool(cache);
+            int numberOfTradeUses = ReadNextInt(cache);
+            int maximumNumberOfTradeUses = ReadNextInt(cache);
+            int xp = ReadNextInt(cache);
+            int specialPrice = ReadNextInt(cache);
+            float priceMultiplier = ReadNextFloat(cache);
+            int demand = ReadNextInt(cache);
+            return new VillagerTrade(inputItem1, outputItem, inputItem2, tradeDisabled, numberOfTradeUses, maximumNumberOfTradeUses, xp, specialPrice, priceMultiplier, demand);
+        }
+
         /// <summary>
         /// Build an uncompressed Named Binary Tag blob for sending over the network
         /// </summary>

MinecraftClient/Protocol/Handlers/Protocol16.cs

@@ -845,5 +845,10 @@ namespace MinecraftClient.Protocol.Handlers
             }
             catch { return false; }
         }
+
+        public bool SelectTrade(int selectedSlot)
+        {
+            return false; //MC 1.13+
+        }
     }
 }

MinecraftClient/Protocol/Handlers/Protocol18.cs

@@ -432,6 +432,28 @@ namespace MinecraftClient.Protocol.Handlers
                         int iconcount = dataTypes.ReadNextVarInt(packetData);
                         handler.OnMapData(mapid, scale, trackingposition, locked, iconcount);
                         break;
+                    case PacketTypesIn.TradeList:
+                        if ((protocolversion >= MC114Version) && (handler.GetInventoryEnabled()))
+                        {
+                            // MC 1.14 or greater
+                            int windowID = dataTypes.ReadNextVarInt(packetData);
+                            int size = dataTypes.ReadNextByte(packetData);
+                            List<VillagerTrade> trades = new List<VillagerTrade>();
+                            for (int tradeId = 0; tradeId < size; tradeId++)
+                            {
+                                VillagerTrade trade = dataTypes.ReadNextTrade(packetData, itemPalette);
+                                    trades.Add(trade);
+                            }
+                            VillagerInfo villagerInfo = new VillagerInfo()
+                            {
+                                Level = dataTypes.ReadNextVarInt(packetData),
+                                Experience = dataTypes.ReadNextVarInt(packetData),
+                                IsRegularVillager = dataTypes.ReadNextBool(packetData),
+                                CanRestock = dataTypes.ReadNextBool(packetData)
+                            };
+                            handler.OnTradeList(windowID, trades, villagerInfo);
+                        }
+                        break;
                     case PacketTypesIn.Title:
                         if (protocolversion >= MC18Version)
                         {
@@ -1889,5 +1911,24 @@ namespace MinecraftClient.Protocol.Handlers
             catch (System.IO.IOException) { return false; }
             catch (ObjectDisposedException) { return false; }
         }
+
+        public bool SelectTrade(int selectedSlot)
+        {
+            // MC 1.13 or greater
+            if (protocolversion >= MC113Version)
+            {
+                try
+                {
+                    List<byte> packet = new List<byte>();
+                    packet.AddRange(dataTypes.GetVarInt(selectedSlot));
+                    SendPacket(PacketTypesOut.SelectTrade, packet);
+                    return true;
+                }
+                catch (SocketException) { return false; }
+                catch (System.IO.IOException) { return false; }
+                catch (ObjectDisposedException) { return false; }
+            }
+            else { return false; }
+        }
     }
 }

MinecraftClient/Protocol/IMinecraftCom.cs

@@ -229,5 +229,11 @@ namespace MinecraftClient.Protocol
         /// <param name="mode">command block mode</param>
         /// <param name="flags">command block flags</param>
         bool UpdateCommandBlock(Location location, string command, CommandBlockMode mode, CommandBlockFlags flags);
+
+        /// <summary>
+        /// Select villager trade
+        /// </summary>
+        /// <param name="selectedSlot">The slot of the trade, starts at 0.</param>
+        bool SelectTrade(int selectedSlot);
     }
 }

MinecraftClient/Protocol/IMinecraftComHandler.cs

@@ -330,5 +330,16 @@ namespace MinecraftClient.Protocol
         /// <param name="objectivename">The name of the objective the score belongs to</param>
         /// <param name="value">he score to be displayed next to the entry. Only sent when Action does not equal 1.</param>
         void OnUpdateScore(string entityname, byte action, string objectivename, int value);
+
+        /// <summary>
+        /// Called when tradeList is received from server
+        /// </summary>
+        /// <param name="windowID">Window ID</param>
+        /// <param name="trades">List of trades.</param>
+        /// <param name="villagerLevel">The level the villager is.</param>
+        /// <param name="experience">The amount of experience the villager has.</param>
+        /// <param name="isRegularVillager">True if regular villagers and false if the wandering trader.</param>
+        /// <param name="canRestock">If the villager can restock his trades at a workstation, True for regular villagers and false for the wandering trader.</param>
+        void OnTradeList(int windowID, List<VillagerTrade> trades, VillagerInfo villagerInfo);
     }
 }