/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.apache.causeway.testing.unittestsupport.applib.matchers;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;

/**
 * Hamcrest {@link Matcher} implementations for {@link Class}es.
 *
 * @since 2.0 {@index}
 */
public final class ClassMatchers {

    private ClassMatchers() { }

    public static <T> Matcher<T> anInstanceOf(final Class<T> expected) {
        return new TypeSafeMatcher<>() {
            @Override
            public boolean matchesSafely(final T actual) {
                return expected.isAssignableFrom(actual.getClass());
            }

            @Override
            public void describeTo(final Description description) {
                description.appendText("an instance of ").appendValue(expected);
            }
        };
    }

    public static Matcher<Class<?>> classEqualTo(final Class<?> operand) {

        class ClassEqualsMatcher extends TypeSafeMatcher<Class<?>> {
            private final Class<?> clazz;

            public ClassEqualsMatcher(final Class<?> clazz) {
                this.clazz = clazz;
            }

            @Override
            public boolean matchesSafely(final Class<?> arg) {
                return clazz == arg;
            }

            @Override
            public void describeTo(final Description description) {
                description.appendValue(clazz);
            }
        }

        return new ClassEqualsMatcher(operand);
    }

    public static <X> Matcher<Class<X>> anySubclassOf(final Class<X> cls) {
        return new TypeSafeMatcher<>() {

            @Override
            public void describeTo(final Description arg0) {
                arg0.appendText("is subclass of ").appendText(cls.getName());
            }

            @Override
            public boolean matchesSafely(final Class<X> item) {
                return cls.isAssignableFrom(item);
            }
        };
    }

}
