added null value check for material

craftattack/src/main/java/eu/mhsl/craftattack/spawn/craftattack/appliances/tooling/statistics/Statistics.java

@@ -0,0 +1,50 @@
+package eu.mhsl.craftattack.spawn.craftattack.appliances.tooling.statistics;
+
+import eu.mhsl.craftattack.spawn.core.Main;
+import eu.mhsl.craftattack.spawn.core.api.server.HttpServer;
+import eu.mhsl.craftattack.spawn.core.appliance.Appliance;
+import org.bukkit.Bukkit;
+import org.bukkit.Material;
+import org.bukkit.Statistic;
+
+import java.util.*;
+
+public class Statistics extends Appliance {
+    record StatisticsResponse(List<PlayerStatistics> playerStatistics) {
+        record PlayerStatistics(String player, List<MaterialStatistic> statistics) {
+        }
+    }
+
+    record MaterialStatistic(String name, String material, int value) {
+    }
+
+    record StatisticsRequest(List<MaterialStatistic> categories) {
+    }
+
+    @Override
+    public void httpApi(HttpServer.ApiBuilder apiBuilder) {
+        apiBuilder.post(
+            "getStatistics",
+            StatisticsRequest.class,
+            (statistics, request) -> {
+                Main.instance().getLogger().info("API requested statistics");
+                List<StatisticsResponse.PlayerStatistics> statisticsList = Arrays.stream(Bukkit.getOfflinePlayers())
+                    .parallel()
+                    .map(player -> new StatisticsResponse.PlayerStatistics(
+                        player.getUniqueId().toString(),
+                        statistics.categories().stream()
+                            .map(category -> {
+                                String material = (category.material() == null || category.material().isBlank()) ? null : category.material();
+                                return new MaterialStatistic(category.name(), material, material == null
+                                    ? player.getStatistic(Statistic.valueOf(category.name()))
+                                    : player.getStatistic(Statistic.valueOf(category.name()), Material.valueOf(material))
+                                );
+                            })
+                            .toList()
+                    ))
+                    .toList();
+                return new StatisticsResponse(statisticsList);
+            }
+        );
+    }
+}