Added Achievement and Statistics

By: Dinnerbone <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/Statistic.java

@@ -0,0 +1,84 @@
+
+package org.bukkit;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Represents a countable statistic, which is collected by the client
+ */
+public enum Statistic {
+    DAMAGE_DEALT(2020),
+    DAMAGE_TAKEN(2021),
+    DEATHS(2022),
+    MOB_KILLS(2023),
+    PLAYER_KILLS(2024),
+    FISH_CAUGHT(2025),
+    MINE_BLOCK(16777216, true),
+    USE_ITEM(6908288, false),
+    BREAK_ITEM(16973824, true);
+
+    private final static Map<Integer, Statistic> statistics = new HashMap<Integer, Statistic>();
+    private final int id;
+    private final boolean isSubstat;
+    private final boolean isBlock;
+
+    private Statistic(int id) {
+       this(id, false, false);
+    }
+    
+    private Statistic(int id, boolean isBlock) {
+        this(id, true, isBlock);
+    }
+
+    private Statistic(int id, boolean isSubstat, boolean isBlock) {
+        this.id = id;
+        this.isSubstat = isSubstat;
+        this.isBlock = isBlock;
+    }
+
+    /**
+     * Gets the ID for this statistic.
+     *
+     * @return ID of this statistic
+     */
+    public int getId() {
+        return id;
+    }
+
+    /**
+     * Checks if this is a substatistic.
+     *
+     * A substatistic exists in mass for each block or item, depending on {@link #isBlock()}
+     *
+     * @return true if this is a substatistic
+     */
+    public boolean isSubstatistic() {
+        return isSubstat;
+    }
+
+    /**
+     * Checks if this is a substatistic dealing with blocks (As opposed to items)
+     *
+     * @return true if this deals with blocks, false if with items
+     */
+    public boolean isBlock() {
+        return isSubstat && isBlock;
+    }
+
+    /**
+     * Gets the statistic associated with the given ID.
+     *
+     * @param id ID of the statistic to return
+     * @return statistic with the given ID
+     */
+    public static Statistic getStatistic(int id) {
+        return statistics.get(id);
+    }
+
+    static {
+        for (Statistic stat : values()) {
+            statistics.put(stat.getId(), stat);
+        }
+    }
+}