/*
 * MIT License
 *
 * Copyright 2017-2018 Sabre GLBL Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.sabre.oss.conf4j.internal.utils.spring;

import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Objects;
import java.util.Set;

abstract class ClassUtils {

    static Class<?>[] getAllInterfacesForClass(Class<?> clazz) {
        return getAllInterfacesForClass(clazz, null);
    }

    private static Class<?>[] getAllInterfacesForClass(Class<?> clazz, ClassLoader classLoader) {
        Set<Class<?>> ifcs = getAllInterfacesForClassAsSet(clazz, classLoader);
        return ifcs.toArray(new Class[ifcs.size()]);
    }

    private static Set<Class<?>> getAllInterfacesForClassAsSet(Class<?> clazz, ClassLoader classLoader) {
        Objects.requireNonNull(clazz, "Class must not be null");
        if (clazz.isInterface() && isVisible(clazz, classLoader)) {
            return Collections.singleton(clazz);
        }
        Set<Class<?>> interfaces = new LinkedHashSet<>();
        Class<?> currentClass = clazz;
        while (currentClass != null) {
            Class<?>[] ifcs = currentClass.getInterfaces();
            for (Class<?> ifc : ifcs) {
                interfaces.addAll(getAllInterfacesForClassAsSet(ifc, classLoader));
            }
            currentClass = currentClass.getSuperclass();
        }
        return interfaces;
    }

    private static boolean isVisible(Class<?> clazz, ClassLoader classLoader) {
        if (classLoader == null) {
            return true;
        }
        try {
            Class<?> actualClass = classLoader.loadClass(clazz.getName());
            return (clazz == actualClass);
            // Else: different interface class found...
        } catch (ClassNotFoundException ex) {
            // No interface class found...
            return false;
        }
    }

}
