/*
 * 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.flink.runtime.security.modules;

import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.CoreOptions;
import org.apache.flink.runtime.security.SecurityConfiguration;

import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

import static org.apache.flink.runtime.security.modules.JaasModule.JAVA_SECURITY_AUTH_LOGIN_CONFIG;
import static org.hamcrest.core.StringStartsWith.startsWith;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;

/** Test for {@link JaasModule}. */
public class JaasModuleTest {
    @Rule public TemporaryFolder folder = new TemporaryFolder();

    @Before
    public void setUp() throws IOException {
        // clear the property
        System.getProperties().remove(JAVA_SECURITY_AUTH_LOGIN_CONFIG);
        folder.create();
    }

    @Test
    public void testJaasModuleFilePathIfWorkingDirPresent() throws IOException {
        File file = folder.newFolder();
        testJaasModuleFilePath(file.toPath().toString());
    }

    @Test
    public void testJaasModuleFilePathIfWorkingDirNotPresent() throws IOException {
        File file = folder.newFolder();
        testJaasModuleFilePath(file.toPath().toString() + "/tmp");
    }

    @Test
    public void testJaasModuleFilePathIfWorkingDirIsSymLink() throws IOException {
        Path symlink = createSymLinkFolderStructure();
        testJaasModuleFilePath(symlink.toString());
    }

    @Test
    public void testJaasModuleFilePathIfWorkingDirNoPresentAndPathContainsSymLink()
            throws IOException {
        Path symlink = createSymLinkFolderStructure();
        testJaasModuleFilePath(symlink.toString() + "/tmp");
    }

    private Path createSymLinkFolderStructure() throws IOException {
        File baseFolder = folder.newFolder();
        File actualFolder = new File(baseFolder, "actual_folder");
        assertTrue(actualFolder.mkdirs());

        Path symlink = new File(baseFolder, "symlink").toPath();
        Files.createSymbolicLink(symlink, actualFolder.toPath());

        return symlink;
    }

    /** Test that the jaas config file is created in the working directory. */
    private void testJaasModuleFilePath(String workingDir) throws IOException {
        Configuration configuration = new Configuration();
        // set the string for CoreOptions.TMP_DIRS to mock the working directory.
        configuration.setString(CoreOptions.TMP_DIRS, workingDir);
        SecurityConfiguration sc = new SecurityConfiguration(configuration);
        JaasModule module = new JaasModule(sc);

        module.install();

        assertJaasFileLocateInRightDirectory(workingDir);
    }

    /**
     * Test that the jaas file will be created in the directory specified by {@link
     * CoreOptions#TMP_DIRS}'s default value if we do not manually specify it.
     */
    @Test
    public void testCreateJaasModuleFileInTemporary() throws IOException {
        Configuration configuration = new Configuration();
        SecurityConfiguration sc = new SecurityConfiguration(configuration);
        JaasModule module = new JaasModule(sc);

        module.install();

        assertJaasFileLocateInRightDirectory(CoreOptions.TMP_DIRS.defaultValue());
    }

    private void assertJaasFileLocateInRightDirectory(String directory) throws IOException {
        String resolvedExpectedPath = new File(directory).toPath().toRealPath().toString();
        String resolvedActualPathWithFile =
                new File(System.getProperty(JAVA_SECURITY_AUTH_LOGIN_CONFIG))
                        .toPath()
                        .toRealPath()
                        .toString();
        assertThat(
                "The resolved configured directory does not match the expected resolved one.",
                resolvedActualPathWithFile,
                startsWith(resolvedExpectedPath));

        assertThat(
                "The configured directory does not match the expected one.",
                System.getProperty(JAVA_SECURITY_AUTH_LOGIN_CONFIG),
                startsWith(directory));
    }
}
