Fix WrapperPlayServerStatistics read on 1.13+ servers

api/src/main/java/com/github/retrooper/packetevents/wrapper/play/server/WrapperPlayServerStatistics.java

@@ -1,14 +1,32 @@
 package com.github.retrooper.packetevents.wrapper.play.server;
 
 import com.github.retrooper.packetevents.event.PacketSendEvent;
+import com.github.retrooper.packetevents.manager.server.ServerVersion;
 import com.github.retrooper.packetevents.protocol.packettype.PacketType;
 import com.github.retrooper.packetevents.wrapper.PacketWrapper;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
+/**
+ * Mojang name: ClientboundAwardStatsPacket
+ */
 public class WrapperPlayServerStatistics extends PacketWrapper<WrapperPlayServerStatistics> {
-    // All statistic names, reference links: https://gist.github.com/thinkofname/a1842c21a0cf2e1fb5e0
-    // key is the statistic name, value is the statistic value or achievement progress
+
+    /**
+     * Some (outdated) statistic names: <a href="https://gist.github.com/thinkofname/a1842c21a0cf2e1fb5e0">https://gist.github.com/thinkofname/a1842c21a0cf2e1fb5e0</a>;
+     * key is the statistic name, value is the statistic value or achievement progress
+     *
+     * @versions -1.12.2
+     */
     private Map<String, Integer> statistics;
+    /**
+     * @versions 1.13+
+     */
+    private List<StatisticEntry> statisticEntries;
 
     public WrapperPlayServerStatistics(PacketSendEvent event) {
         super(event);
@@ -19,26 +37,113 @@ public WrapperPlayServerStatistics(Map<String, Integer> statistics) {
         this.statistics = statistics;
     }
 
+    public WrapperPlayServerStatistics(List<StatisticEntry> statisticEntries) {
+        super(PacketType.Play.Server.STATISTICS);
+        this.statisticEntries = statisticEntries;
+    }
+
     @Override
     public void read() {
-        statistics = readMap(PacketWrapper::readString, PacketWrapper::readVarInt);
+        if (this.serverVersion.isNewerThanOrEquals(ServerVersion.V_1_13)) {
+            this.statisticEntries = this.readList(StatisticEntry::read);
+        } else {
+            this.statistics = this.readMap(PacketWrapper::readString, PacketWrapper::readVarInt);
+        }
     }
 
     @Override
     public void write() {
-        writeMap(statistics, PacketWrapper::writeString, PacketWrapper::writeVarInt);
+        if (this.serverVersion.isNewerThanOrEquals(ServerVersion.V_1_13)) {
+            this.writeList(this.getStatisticEntries(), StatisticEntry::write);
+        } else {
+            this.writeMap(this.getStatistics(), PacketWrapper::writeString, PacketWrapper::writeVarInt);
+        }
     }
 
     @Override
     public void copy(WrapperPlayServerStatistics wrapper) {
         this.statistics = wrapper.statistics;
+        this.statisticEntries = wrapper.statisticEntries;
     }
 
     public Map<String, Integer> getStatistics() {
-        return statistics;
+        if (this.statistics == null) {
+            this.statistics = new HashMap<>();
+        }
+        return this.statistics;
     }
 
     public void setStatistics(Map<String, Integer> statistics) {
         this.statistics = statistics;
+        this.statisticEntries = null;
+    }
+
+    public List<StatisticEntry> getStatisticEntries() {
+        if (this.statisticEntries == null) {
+            this.statisticEntries = new ArrayList<>();
+        }
+        return this.statisticEntries;
+    }
+
+    public void setStatisticEntries(List<StatisticEntry> statisticEntries) {
+        this.statisticEntries = statisticEntries;
+        this.statistics = null;
+    }
+
+    /**
+     * This is marked as experimental, as this just provides access to raw data values - these
+     * are version-specific, and we currently don't provide any API for accessing statistics without relying on IDs.
+     *
+     * @versions 1.13+
+     */
+    @ApiStatus.Experimental
+    public static class StatisticEntry {
+
+        private int categoryId;
+        private int statisticId;
+        private int value;
+
+        public StatisticEntry(int categoryId, int statisticId, int value) {
+            this.categoryId = categoryId;
+            this.statisticId = statisticId;
+            this.value = value;
+        }
+
+        public static StatisticEntry read(PacketWrapper<?> wrapper) {
+            int categoryId = wrapper.readVarInt();
+            int statisticId = wrapper.readVarInt();
+            int value = wrapper.readVarInt();
+            return new StatisticEntry(categoryId, statisticId, value);
+        }
+
+        public static void write(PacketWrapper<?> wrapper, StatisticEntry entry) {
+            wrapper.writeVarInt(entry.categoryId);
+            wrapper.writeVarInt(entry.statisticId);
+            wrapper.writeVarInt(entry.value);
+        }
+
+        public int getCategoryId() {
+            return categoryId;
+        }
+
+        public void setCategoryId(int categoryId) {
+            this.categoryId = categoryId;
+        }
+
+        public int getStatisticId() {
+            return statisticId;
+        }
+
+        public void setStatisticId(int statisticId) {
+            this.statisticId = statisticId;
+        }
+
+        public int getValue() {
+            return value;
+        }
+
+        public void setValue(int value) {
+            this.value = value;
+        }
     }
 }