Refactored flag system and introduced specialized flags

Redesigned `Flag` as an abstract class and removed `ProtectionFlag`. Added specialized flag implementations such as `BooleanFlag`, `NumberFlag`, and its derivatives including `IntegerFlag`, `DoubleFlag`, and others for enhanced modularity.

Author: NonSwag

api/src/main/java/net/thenextlvl/protect/flag/Flag.java

@@ -1,34 +1,56 @@
 package net.thenextlvl.protect.flag;
 
+import com.google.common.base.Preconditions;
 import net.kyori.adventure.key.Key;
+import net.kyori.adventure.key.Keyed;
 import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
 
-/**
- * Represents a flag with a specific value type.
- *
- * @param <T> The type of the flag value.
- */
-public interface Flag<T> extends Comparable<@NonNull Flag<?>> {
-    /**
-     * Retrieves the {@link Key} associated with this flag.
-     *
-     * @return the Key of the flag
-     */
-    @NonNull
-    Key key();
-
-    /**
-     * Retrieves the type of the flag value.
-     *
-     * @return the type of the flag value
-     */
-    @NonNull
-    Class<? extends T> type();
-
-    /**
-     * Retrieves the default value for a flag.
-     *
-     * @return The default value for the flag.
-     */
-    T defaultValue();
+public abstract class Flag<T> implements Keyed, Comparable<@NonNull Flag<?>> {
+    private final @NonNull Key key;
+    private final T defaultValue;
+    private final T protectedValue;
+    private final boolean nullable;
+
+    protected Flag(@NonNull Key key, @Nullable T defaultValue, @Nullable T protectedValue, boolean nullable) {
+        Preconditions.checkArgument(nullable || defaultValue != null, "Default value must be non-null if flag is not nullable");
+        this.key = key;
+        this.defaultValue = defaultValue;
+        this.protectedValue = protectedValue;
+        this.nullable = nullable;
+    }
+
+    protected Flag(@NonNull Key key, @NonNull T defaultValue, @Nullable T protectedValue) {
+        this(key, defaultValue, protectedValue, false);
+    }
+
+    protected Flag(@NonNull Key key, @Nullable T defaultValue, boolean nullable) {
+        this(key, defaultValue, null, nullable);
+    }
+
+    protected Flag(@NonNull Key key) {
+        this(key, null, false);
+    }
+
+    @Override
+    public @NonNull Key key() {
+        return key;
+    }
+
+    public T getDefaultValue() {
+        return defaultValue;
+    }
+
+    public T getProtectedValue() {
+        return protectedValue;
+    }
+
+    public boolean isNullable() {
+        return nullable;
+    }
+
+    @Override
+    public int compareTo(@NonNull Flag<?> flag) {
+        return key.compareTo(flag.key());
+    }
 }

api/src/main/java/net/thenextlvl/protect/flag/ListFlag.java

@@ -0,0 +1,9 @@
+package net.thenextlvl.protect.flag;
+
+import org.jspecify.annotations.NonNull;
+
+import java.util.List;
+
+public interface ListFlag<T> extends Flag<@NonNull List<T>> {
+    
+}

api/src/main/java/net/thenextlvl/protect/flag/ProtectionFlag.java

@@ -0,0 +1,19 @@
+package net.thenextlvl.protect.flag.number;
+
+import net.kyori.adventure.key.Key;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public final class ByteFlag extends NumberFlag<Byte> {
+    public ByteFlag(@NonNull Key key, @Nullable Byte defaultValue, boolean nullable) {
+        super(key, defaultValue, nullable);
+    }
+
+    public ByteFlag(@NonNull Key key, @NonNull Byte defaultValue) {
+        super(key, defaultValue);
+    }
+
+    public ByteFlag(@NonNull Key key) {
+        super(key);
+    }
+}

api/src/main/java/net/thenextlvl/protect/flag/number/ByteFlag.java

@@ -0,0 +1,19 @@
+package net.thenextlvl.protect.flag.number;
+
+import net.kyori.adventure.key.Key;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public final class DoubleFlag extends NumberFlag<Double> {
+    public DoubleFlag(@NonNull Key key, @Nullable Double defaultValue, boolean nullable) {
+        super(key, defaultValue, nullable);
+    }
+
+    public DoubleFlag(@NonNull Key key, @NonNull Double defaultValue) {
+        super(key, defaultValue);
+    }
+
+    public DoubleFlag(@NonNull Key key) {
+        super(key);
+    }
+}

api/src/main/java/net/thenextlvl/protect/flag/number/DoubleFlag.java

@@ -0,0 +1,19 @@
+package net.thenextlvl.protect.flag.number;
+
+import net.kyori.adventure.key.Key;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public final class FloatFlag extends NumberFlag<Float> {
+    public FloatFlag(@NonNull Key key, @Nullable Float defaultValue, boolean nullable) {
+        super(key, defaultValue, nullable);
+    }
+
+    public FloatFlag(@NonNull Key key, @NonNull Float defaultValue) {
+        super(key, defaultValue);
+    }
+
+    public FloatFlag(@NonNull Key key) {
+        super(key);
+    }
+}

api/src/main/java/net/thenextlvl/protect/flag/number/FloatFlag.java

@@ -0,0 +1,19 @@
+package net.thenextlvl.protect.flag.number;
+
+import net.kyori.adventure.key.Key;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public final class IntegerFlag extends NumberFlag<Integer> {
+    public IntegerFlag(@NonNull Key key, @Nullable Integer defaultValue, boolean nullable) {
+        super(key, defaultValue, nullable);
+    }
+
+    public IntegerFlag(@NonNull Key key, @NonNull Integer defaultValue) {
+        super(key, defaultValue);
+    }
+
+    public IntegerFlag(@NonNull Key key) {
+        super(key);
+    }
+}

api/src/main/java/net/thenextlvl/protect/flag/number/IntegerFlag.java

@@ -0,0 +1,19 @@
+package net.thenextlvl.protect.flag.number;
+
+import net.kyori.adventure.key.Key;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public final class LongFlag extends NumberFlag<Long> {
+    public LongFlag(@NonNull Key key, @Nullable Long defaultValue, boolean nullable) {
+        super(key, defaultValue, nullable);
+    }
+
+    public LongFlag(@NonNull Key key, @NonNull Long defaultValue) {
+        super(key, defaultValue);
+    }
+
+    public LongFlag(@NonNull Key key) {
+        super(key);
+    }
+}

api/src/main/java/net/thenextlvl/protect/flag/number/LongFlag.java

@@ -0,0 +1,20 @@
+package net.thenextlvl.protect.flag.number;
+
+import net.kyori.adventure.key.Key;
+import net.thenextlvl.protect.flag.Flag;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public abstract class NumberFlag<T extends Number> extends Flag<T> {
+    protected NumberFlag(@NonNull Key key, @Nullable T defaultValue, boolean nullable) {
+        super(key, defaultValue, nullable);
+    }
+
+    protected NumberFlag(@NonNull Key key, @NonNull T defaultValue) {
+        super(key, defaultValue);
+    }
+
+    protected NumberFlag(@NonNull Key key) {
+        super(key);
+    }
+}

api/src/main/java/net/thenextlvl/protect/flag/number/NumberFlag.java

@@ -0,0 +1,19 @@
+package net.thenextlvl.protect.flag.number;
+
+import net.kyori.adventure.key.Key;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public final class ShortFlag extends NumberFlag<Short> {
+    public ShortFlag(@NonNull Key key, @Nullable Short defaultValue, boolean nullable) {
+        super(key, defaultValue, nullable);
+    }
+
+    public ShortFlag(@NonNull Key key, @NonNull Short defaultValue) {
+        super(key, defaultValue);
+    }
+
+    public ShortFlag(@NonNull Key key) {
+        super(key);
+    }
+}