/*
    * 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
    *
   *   https://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.commons.exec.environment;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  import static org.junit.jupiter.api.Assertions.assertNull;
  
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import org.apache.commons.exec.OS;
  import org.apache.commons.lang3.StringUtils;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link EnvironmentUtils}.
   */
  class EnvironmentUtilsTest {
  
      /**
       * Accessing environment variables is case-sensitive or not depending on the operating system but the values of the environment variable are always
       * case-sensitive. So make sure that this assumption holds on all operating systems.
       *
       * @throws Exception the test failed
       */
      @Test
      void testCaseInsensitiveVariableLookup() throws Exception {
          final Map<String, String> procEnvironment = EnvironmentUtils.getProcEnvironment();
          // Check that case is preserved for values
          EnvironmentUtils.addVariableToEnvironment(procEnvironment, "foo=bAr");
          assertEquals("bAr", procEnvironment.get("foo"));
      }
  
      /**
       * Test to access the environment variables of the current process. Please note that this test does not run on java-gjc.
       *
       * @throws IOException the test failed
       */
      @Test
      void testGetProcEnvironment() throws IOException {
          final Map<String, String> procEnvironment = EnvironmentUtils.getProcEnvironment();
          // we assume that there is at least one environment variable
          // for this process, i.e. $JAVA_HOME
          assertFalse(procEnvironment.isEmpty(), "Expecting non-zero environment size");
          final String[] envArgs = EnvironmentUtils.toStrings(procEnvironment);
          for (int i = 0; i < envArgs.length; i++) {
              assertNotNull(envArgs[i], "Entry " + i + " should not be null");
              assertFalse(envArgs[i].isEmpty(), "Entry " + i + " should not be empty");
              // System.out.println(envArgs[i]);
          }
      }
  
      /**
       * On Windows platforms test that accessing environment variables can be done in a case-insensitive way, e.g. "PATH", "Path" and "path" would reference the
       * same environment variable.
       *
       * @throws IOException the test failed
       */
      @Test
      void testGetProcEnvironmentCaseInsensitiveLookup() throws IOException {
          // run tests only on windows platforms
          if (!OS.isFamilyWindows()) {
              return;
          }
  
          // ensure that we have the same value for upper and lowercase keys
          final Map<String, String> procEnvironment = EnvironmentUtils.getProcEnvironment();
          for (final Entry<String, String> entry : procEnvironment.entrySet()) {
              final String key = entry.getKey();
              final String value = entry.getValue();
              assertEquals(value, procEnvironment.get(StringUtils.toRootLowerCase(key)));
              assertEquals(value, procEnvironment.get(StringUtils.toRootUpperCase(key)));
          }
  
          // add an environment variable and check access
          EnvironmentUtils.addVariableToEnvironment(procEnvironment, "foo=bar");
         assertEquals("bar", procEnvironment.get("FOO"));
         assertEquals("bar", procEnvironment.get("Foo"));
         assertEquals("bar", procEnvironment.get("foo"));
     }
 
     /**
      * Tests the behavior of the EnvironmentUtils.toStrings() when using a {@code null} environment.
      */
     @Test
     void testToStrings() {
         // check for a non-existing environment when passing null
         assertNull(EnvironmentUtils.toStrings(null));
         // check for an environment when filling in two variables
         final Map<String, String> env = new HashMap<>();
         assertArrayEquals(new String[0], EnvironmentUtils.toStrings(env));
         env.put("foo2", "bar2");
         env.put("foo", "bar");
         final String[] envStrings = EnvironmentUtils.toStrings(env);
         final String[] expected = { "foo2=bar2", "foo=bar" };
         // ensure the result does not depend on the hash ordering
         Arrays.sort(expected);
         Arrays.sort(envStrings);
         assertArrayEquals(expected, envStrings);
     }
 
     /**
      * Tests the behavior of the EnvironmentUtils.toStrings() when using a {@code null} key given to the map.
      */
     @Test
     void testToStringWithNullKey() {
         final Map<String, String> env = new HashMap<>();
         env.put(null, "TheNullKey");
         final String[] strings = EnvironmentUtils.toStrings(env);
         assertEquals(1, strings.length);
         assertEquals("=TheNullKey", strings[0]);
     }
 
     /**
      * Tests the behavior of the EnvironmentUtils.toStrings() when using a {@code null} value given to the map.
      */
     @Test
     void testToStringWithNullValue() {
         final Map<String, String> env = new HashMap<>();
         env.put("key", null);
         final String[] strings = EnvironmentUtils.toStrings(env);
         assertEquals(1, strings.length);
         assertEquals("key=", strings[0]);
     }
 
 }