Add FabricPingRetriever to calculate player ping metrics

Author: renvins

fabric/src/main/java/it/renvins/serverpulse/fabric/metrics/FabricPingRetriever.java

@@ -0,0 +1,50 @@
+package it.renvins.serverpulse.fabric.metrics;
+
+import it.renvins.serverpulse.api.metrics.IPingRetriever;
+import it.renvins.serverpulse.fabric.ServerPulseFabric;
+import lombok.RequiredArgsConstructor;
+import net.fabricmc.fabric.api.networking.v1.PlayerLookup;
+import net.minecraft.server.network.ServerPlayerEntity;
+
+@RequiredArgsConstructor
+public class FabricPingRetriever implements IPingRetriever {
+
+    private final ServerPulseFabric mod;
+
+    @Override
+    public int getMinPing() {
+        int minPing = Integer.MAX_VALUE;
+        if (PlayerLookup.all(mod.getServer()).isEmpty()) {
+            return 0;
+        }
+        for (ServerPlayerEntity player : PlayerLookup.all(mod.getServer())) {
+            minPing = Math.toIntExact(Math.min(minPing, player.networkHandler.getLatency()));
+        }
+        return minPing;
+    }
+
+    @Override
+    public int getMaxPing() {
+        int maxPing = 0;
+        if (PlayerLookup.all(mod.getServer()).isEmpty()) {
+            return 0;
+        }
+        for (ServerPlayerEntity player : PlayerLookup.all(mod.getServer())) {
+            maxPing = Math.toIntExact(Math.max(maxPing, player.networkHandler.getLatency()));
+        }
+        return maxPing;
+    }
+
+    @Override
+    public int getAveragePing() {
+        int totalPing = 0;
+        int playerCount = PlayerLookup.all(mod.getServer()).size();
+        if (playerCount == 0) {
+            return 0;
+        }
+        for (ServerPlayerEntity player : PlayerLookup.all(mod.getServer())) {
+            totalPing += player.networkHandler.getLatency();
+        }
+        return totalPing / playerCount;
+    }
+}