/*
 * 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.sshd.common;

import java.util.Collection;
import java.util.EnumSet;
import java.util.List;
import java.util.Set;

import org.apache.sshd.common.cipher.BuiltinCiphers;
import org.apache.sshd.common.cipher.Cipher;
import org.apache.sshd.common.kex.BuiltinDHFactories;
import org.apache.sshd.common.mac.BuiltinMacs;
import org.apache.sshd.common.signature.BuiltinSignatures;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.util.test.BaseTestSupport;
import org.junit.FixMethodOrder;
import org.junit.Test;
import org.junit.runners.MethodSorters;

/**
 * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
 */
@FixMethodOrder(MethodSorters.NAME_ASCENDING)
public class SshBuilderTest extends BaseTestSupport {
    public SshBuilderTest() {
        super();
    }

    /**
     * Make sure that all values in {@link BuiltinCiphers} are
     * listed in {@link BaseBuilder#DEFAULT_CIPHERS_PREFERENCE}
     */
    @Test
    public void testAllBuiltinCiphersListed() {
        Set<BuiltinCiphers> all = EnumSet.allOf(BuiltinCiphers.class);
        // The 'none' cipher is not listed as preferred - it is implied
        assertTrue("Missing " + BuiltinCiphers.Constants.NONE + " cipher in all values", all.remove(BuiltinCiphers.none));
        testAllInstancesListed(all, BaseBuilder.DEFAULT_CIPHERS_PREFERENCE);
    }

    /**
     * Make sure that all values in {@link BuiltinMacs} are
     * listed in {@link BaseBuilder#DEFAULT_MAC_PREFERENCE}
     */
    @Test
    public void testAllBuiltinMacsListed() {
        testAllInstancesListed(BuiltinMacs.VALUES, BaseBuilder.DEFAULT_MAC_PREFERENCE);
    }

    /**
     * Make sure that all values in {@link BuiltinSignatures} are
     * listed in {@link BaseBuilder#DEFAULT_SIGNATURE_PREFERENCE}
     */
    @Test
    public void testAllBuiltinSignaturesListed() {
        testAllInstancesListed(BuiltinSignatures.VALUES, BaseBuilder.DEFAULT_SIGNATURE_PREFERENCE);
    }

    /**
     * Make sure that all values in {@link BuiltinDHFactories} are
     * listed in {@link BaseBuilder#DEFAULT_KEX_PREFERENCE}
     */
    @Test
    public void testAllBuiltinDHFactoriesListed() {
        testAllInstancesListed(BuiltinDHFactories.VALUES, BaseBuilder.DEFAULT_KEX_PREFERENCE);
    }

    private static <E extends Enum<E>> void testAllInstancesListed(Set<? extends E> expValues, Collection<? extends E> actValues) {
        assertEquals("Mismatched actual values size", expValues.size(), actValues.size());
        for (E expected : expValues) {
            assertTrue(expected.name() + " not found in actual values", actValues.contains(expected));
        }
    }

    /**
     * Make sure that {@link BaseBuilder#setUpDefaultCiphers(boolean)} returns
     * the correct result - i.e., according to the {@code ingoreUnsupported}
     * parameter and in the defined preference order
     */
    @Test
    public void testSetUpDefaultCiphers() {
        for (boolean ignoreUnsupported : new boolean[]{true, false}) {
            List<NamedFactory<Cipher>> ciphers = BaseBuilder.setUpDefaultCiphers(ignoreUnsupported);
            int numCiphers = GenericUtils.size(ciphers);
            // make sure returned list size matches expected count
            if (ignoreUnsupported) {
                assertEquals("Incomplete full ciphers size", BaseBuilder.DEFAULT_CIPHERS_PREFERENCE.size(), numCiphers);
            } else {
                int expectedCount = 0;
                for (BuiltinCiphers c : BaseBuilder.DEFAULT_CIPHERS_PREFERENCE) {
                    if (c.isSupported()) {
                        expectedCount++;
                    }
                }
                assertEquals("Incomplete supported ciphers size", expectedCount, numCiphers);
            }

            // make sure order is according to the default preference list
            List<String> cipherNames = NamedResource.getNameList(ciphers);
            int nameIndex = 0;
            for (BuiltinCiphers c : BaseBuilder.DEFAULT_CIPHERS_PREFERENCE) {
                if ((!c.isSupported()) && (!ignoreUnsupported)) {
                    continue;
                }

                String expectedName = c.getName();
                assertTrue("Out of actual ciphers for expected=" + expectedName, nameIndex < numCiphers);

                String actualName = cipherNames.get(nameIndex);
                assertEquals("Mismatched cipher at position " + nameIndex + " for ignoreUnsupported=" + ignoreUnsupported, expectedName, actualName);
                nameIndex++;
            }
        }
    }
}