package net.abhinavsarkar.spelhelper;

import java.util.LinkedHashSet;
import java.util.Set;

final class InheritenceUtil {

	public static Set<Class<?>> getInheritance(final Class<?> in) {
		LinkedHashSet<Class<?>> result = new LinkedHashSet<Class<?>>();
		result.add(in);
		getInheritance(in, result);
		return result;
	}

	/**
	 * Get inheritance of type.
	 * 
	 * @param in
	 * @param result
	 */
	private static void getInheritance(final Class<?> in, final Set<Class<?>> result) {
		Class<?> superclass = getSuperclass(in);

		if (superclass != null) {
			result.add(superclass);
			getInheritance(superclass, result);
		}

		getInterfaceInheritance(in, result);
	}

	/**
	 * Get interfaces that the type inherits from.
	 * 
	 * @param in
	 * @param result
	 */
	private static void getInterfaceInheritance(final Class<?> in,
			final Set<Class<?>> result) {
		for (Class<?> c : in.getInterfaces()) {
			result.add(c);
			getInterfaceInheritance(c, result);
		}
	}

	/**
	 * Get superclass of class.
	 * 
	 * @param in
	 * @return
	 */
	private static Class<?> getSuperclass(final Class<?> in) {
		if (in == null) {
			return null;
		}
		if (in.isArray() && in != Object[].class) {
			Class<?> type = in.getComponentType();
			while (type.isArray()) {
				type = type.getComponentType();
			}
			return type;
		}
		return in.getSuperclass();
	}

}