add /prestige

src/main/java/sh/okx/rankup/RankList.java

@@ -0,0 +1,71 @@
+package sh.okx.rankup;
+
+import lombok.Getter;
+import org.bukkit.configuration.ConfigurationSection;
+import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.entity.Player;
+import sh.okx.rankup.ranks.Rank;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+
+public class RankList<T extends Rank> {
+  @Getter
+  protected final FileConfiguration config;
+  protected final Set<T> ranks = new HashSet<>();
+
+  public RankList(Rankup plugin, FileConfiguration config, Function<ConfigurationSection, T> deserializer) {
+    this.config = config;
+    for (Map.Entry<String, Object> entry : config.getValues(false).entrySet()) {
+      ConfigurationSection rankSection = (ConfigurationSection) entry.getValue();
+      ranks.add(deserializer.apply(rankSection));
+    }
+  }
+
+  public T getFirst() {
+    OUTER:
+    for (T rank : ranks) {
+      // see if anything ranks up to this
+      for (T rank0 : ranks) {
+        if (!rank0.isLast() && rank0.getNext().equals(rank.getName())) {
+          continue OUTER;
+        }
+      }
+      // nothing ranks up to this
+      return rank;
+    }
+    return null;
+  }
+
+  public T getByName(String name) {
+    for (T rank : ranks) {
+      if (rank.getName().equalsIgnoreCase(name)) {
+        return rank;
+      }
+    }
+    return null;
+  }
+
+  public T getByPlayer(Player player) {
+    return ranks.stream()
+        .filter(rank -> rank.isIn(player))
+        .findFirst()
+        .orElse(null);
+  }
+
+  public T next(T rank) {
+    if (rank.isLast()) {
+      return null;
+    }
+
+    for (T nextRank : ranks) {
+      if (rank.getNext().equalsIgnoreCase(nextRank.getName())) {
+        return nextRank;
+      }
+    }
+    // this shouldn't happen but whatever
+    return null;
+  }
+}