/*
    * 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.configuration2;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertIterableEquals;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Test class for {@code ConfigurationLookup}.
   */
  public class TestConfigurationLookup {
  
      /** Constant for a test variable name. */
      private static final String VAR = "testVariable";
  
      /** Constant for the value of the test variable. */
      private static final Object VALUE = "SomeTestValue";
  
      /**
       * Tries to create an instance without a configuration.
       */
      @Test
      void testInitNoConfig() {
          assertThrows(IllegalArgumentException.class, () -> new ConfigurationLookup(null));
      }
  
      /**
       * Tests lookup() for a complex property value.
       */
      @Test
      void testLookupComplex() {
          final int count = 5;
          final Configuration conf = new BaseConfiguration();
          for (int i = 0; i < count; i++) {
              conf.addProperty(VAR, String.valueOf(VALUE) + i);
          }
          final ConfigurationLookup lookup = new ConfigurationLookup(conf);
          final Collection<?> col = (Collection<?>) lookup.lookup(VAR);
  
          final List<String> expected = new ArrayList<>();
          for (int i = 0; i < count; i++) {
              expected.add(String.valueOf(VALUE) + i);
          }
          assertIterableEquals(expected, col);
      }
  
      /**
       * Tests lookup() if the variable cannot be resolved.
       */
      @Test
      void testLookupNotFound() {
          final Configuration conf = new BaseConfiguration();
          final ConfigurationLookup lookup = new ConfigurationLookup(conf);
          assertNull(lookup.lookup(VAR));
      }
  
      /**
       * Tests lookup() if the variable cannot be resolved, and the configuration throws an exception.
       */
      @Test
      void testLookupNotFoundEx() {
          final BaseConfiguration conf = new BaseConfiguration();
          conf.setThrowExceptionOnMissing(true);
          final ConfigurationLookup lookup = new ConfigurationLookup(conf);
          assertNull(lookup.lookup(VAR));
      }
  
      /**
       * Tests whether an existing variable can be resolved.
       */
      @Test
      void testLookupSuccess() {
          final Configuration conf = new BaseConfiguration();
          conf.addProperty(VAR, VALUE);
          final ConfigurationLookup lookup = new ConfigurationLookup(conf);
          assertEquals(VALUE, lookup.lookup(VAR));
      }
 }